diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/CMakeLists.txt b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/CMakeLists.txt
new file mode 100644
index 00000000..9e834b72
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/CMakeLists.txt
@@ -0,0 +1,99 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package ( MPI )
+
+message ( STATUS  "MPI_FOUND=${MPI_FOUND}" )
+message ( STATUS  "MPI_CXX_INCLUDE_DIRS=${MPI_CXX_INCLUDE_DIRS}" )
+message ( STATUS  "MPI_LIBRARIES=${MPI_LIBRARIES}" )
+if ( MPI_FOUND )
+	list ( APPEND PRJ_INCLUDE_DIRS ${MPI_CXX_INCLUDE_DIRS} )
+	list ( APPEND PRJ_LIBRARIES ${MPI_LIBRARIES} )
+endif ()
+
+#get_directory_property( my_import_targets DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} IMPORTED_TARGETS )
+#message( STATUS "my_import_targets=${my_import_targets}" )
+
+list ( APPEND PRJ_LIBRARIES MPI::MPI_C )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+list ( APPEND PRJ_COMPILE_DEFINITIONS HX_PARALLEL )
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	LogFile.h LogFile.cpp
+	Parallel.h Parallel.cpp
+	Solver.h Solver.cpp
+	ZoneState.h ZoneState.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/CgnsGrid.cpp b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/CgnsGrid.cpp
new file mode 100644
index 00000000..825442a2
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/CgnsGrid.cpp
@@ -0,0 +1,850 @@
+#include "CgnsGrid.h"
+#include "Parallel.h"
+#include "cgnslib.h"
+#include "global.h"
+#include "ZoneState.h"
+#include <iostream>
+#include <vector>
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "fileId = " << fileId << "\n";
+    }
+    
+    int nbases = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_nbases( fileId, &nbases );
+    }
+    HXBcastData( &nbases, 1, Parallel::serverid );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "nbases = " << nbases << "\n";
+    
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        }
+
+        HXBcastData( &icelldim, 1, Parallel::serverid );
+        HXBcastData( &iphysdim, 1, Parallel::serverid );
+
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+
+        int nzones = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_nzones( fileId, baseId, &nzones );
+        }
+
+        HXBcastData( &nzones, 1, Parallel::serverid );
+
+        ZoneState::nZones = nzones;
+        ZoneState::pids.resize( nzones );
+        ZoneState::g2lzoneids.resize( nzones );
+        std::vector<int> pcount( Parallel::nProc, 0 );
+
+        for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+        {
+            int zone_pid = iZone % Parallel::nProc;
+            ZoneState::pids[ iZone ] = zone_pid;
+            ZoneState::g2lzoneids[ iZone ] = pcount[ zone_pid ];
+            pcount[ zone_pid ] ++;
+        }
+
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nzones = " << nzones << "\n";
+
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "iZone = " << iZone << "\n";
+
+            int index_dim = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            }
+            HXBcastData( &index_dim, 1, Parallel::serverid );
+
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            if ( Parallel::IsServer() )
+            {
+                cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            }
+
+            HXBcastData( zonename, 33, Parallel::serverid );
+            HXBcastData( isize.data(), isize.size(), Parallel::serverid);
+
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "zonename = " << zonename << "\n";
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+
+    if ( Parallel::IsServer() )
+    {
+        cg_close( fileId );
+    }
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+        std::cout << "fileId = " << fileId << "\n";
+    }
+    
+    int nbases = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_nbases( fileId, &nbases );
+    }
+    MPI_Bcast( &nbases, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        }
+
+        HXBcastData( &icelldim, 1, Parallel::serverid );
+        HXBcastData( &iphysdim, 1, Parallel::serverid );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+
+        int nzones = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_nzones( fileId, baseId, &nzones );
+        }
+        HXBcastData( &nzones, 1, Parallel::serverid );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nzones = " << nzones << "\n";
+
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            }
+            HXSendRecvData( &index_dim, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "index_dim = " << index_dim << "\n";
+            }
+
+            std::vector<cgsize_t> isize;
+            char zonename[ 33 ];
+            if ( Parallel::IsServer() )
+            {
+                isize.resize( index_dim * 3 );
+                cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            }
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                isize.resize( index_dim * 3 );
+            }
+
+            HXSendRecvData( zonename, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+            HXSendRecvData( isize.data(), index_dim * 3, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "zonename = " << zonename << "\n";
+
+                for ( int i = 0; i < isize.size(); ++ i )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+                }
+            }
+
+            std::vector<cgsize_t> irmin;
+            std::vector<cgsize_t> irmax;
+            int nNodes = 1;
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                irmin.resize( index_dim );
+                irmax.resize( index_dim );
+                for ( int m = 0; m < index_dim; ++ m )
+                {
+                    /* lower range index */
+                    irmin[ m ] = 1;
+                    /* upper range index of vertices */
+                    irmax[ m ] = isize[ m ];
+                    nNodes *= irmax[ m ];
+                }
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "nNodes = " << nNodes << "\n";
+            }
+
+            ZoneType_t zoneType;
+            if ( Parallel::IsServer() )
+            {
+                cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            }
+            HXSendRecvData( &zoneType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            }
+
+            Zone * zone = nullptr;
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                zone = new Zone();
+                Global::zones.push_back( zone );
+                LocalZone::global_zoneids.push_back( iZone );
+                LocalZone::nZones = LocalZone::global_zoneids.size();
+                for ( int m = 0; m < index_dim; ++ m )
+                {
+                    zone->nijk.push_back( isize[ m ] );
+                }
+            }
+
+            Grid * grid = nullptr;
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                grid = new Grid();
+                Global::grids.push_back( grid );
+            }
+
+            BaseZone baseZone;
+
+            int gZoneId = -1;
+            if ( Parallel::IsServer() )
+            {
+                baseZone.zone_name = zonename;
+                gZoneId = Global::zone_names.FindBaseZone( baseZone );
+            }
+
+            HXSendRecvData( &gZoneId, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "gZoneId = " << gZoneId << "\n";
+            }
+
+            int ncoords = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            }
+            HXSendRecvData( &ncoords, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "ncoords = " << ncoords << "\n";
+            }
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                if ( Parallel::IsServer() )
+                {
+                    cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                }
+                HXSendRecvData( coordname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &dataType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "coordname = " << coordname << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                }
+
+                std::vector<char> coord;
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    coord.resize( nNodes * sizeof( double ) );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coord.data() );
+                }
+
+                HXSendRecvData( coord.data(), coord.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                Coor * coor = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    coor = new Coor();
+                    zone->coors.push_back( coor );
+                    coor->coorname = coordname;
+                    coor->nNodes = nNodes;
+                    coor->coord = coord;
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    coor->DumpCoor();
+
+                    if ( icoord == 0 )
+                    {
+                        grid->x.resize( nNodes );
+                        coor->DumpCoorX( grid->x );
+                    }
+                }
+            }
+
+            int nbocos = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            }
+            HXSendRecvData( &nbocos, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "nbocos = " << nbocos << "\n";
+            }
+
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                if ( Parallel::IsServer() )
+                {
+                    cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                }
+                HXSendRecvData( &location, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+                }
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                //std::vector<int> normalIndex( index_dim, -1 );
+                std::vector<int> normalIndex;
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+                if ( Parallel::IsServer() )
+                {
+                    normalIndex.resize( index_dim );
+                    cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                        &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                }
+
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    normalIndex.resize( index_dim );
+                }
+                
+                HXSendRecvData( boconame, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &bocotype, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &ptset_type, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &npnts, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &normalDataType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &normalListSize, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( normalIndex.data(), index_dim, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &ndataset, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "npnts = " << npnts << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalListSize = " << normalListSize << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalIndex = ";
+                    for ( int i = 0; i < index_dim; ++ i )
+                    {
+                        std::cout << normalIndex[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "ndataset = " << ndataset << "\n";
+                }
+
+                std::vector<char> normalList;
+                std::vector<cgsize_t> pnts;
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    if ( normalDataType == DataTypeNull )
+                    {
+                        normalList.resize( sizeof( int ) );
+                    }
+                    else
+                    {
+                        int nSize = nNodes * index_dim * sizeof( double );
+                        normalList.resize( nSize );
+                    }
+                    pnts.resize( npnts * index_dim );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                }
+
+                HXSendRecvData( pnts.data(), npnts * index_dim, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "pnts = ";
+                    for ( int i = 0; i < pnts.size(); ++ i )
+                    {
+                        std::cout << pnts[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                }
+                HXSendRecvData( normalList.data(), normalList.size(), Parallel::serverid, ZoneState::GetProcID(iZone));
+
+                ZoneBc * zonebc = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    zonebc = new ZoneBc();
+                    zone->bccos.push_back( zonebc );
+                    zonebc->bcType = bocotype;
+                    for ( int i = 0; i < pnts.size(); ++ i )
+                    {
+                        zonebc->pnts.push_back( pnts[ i ] );
+                    }
+                }
+            }
+            int n1to1 = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            }
+
+            HXSendRecvData( &n1to1, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "n1to1 = " << n1to1 << "\n";
+            }
+
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range;
+                std::vector<cgsize_t> donor_range;
+                std::vector<int> transform;
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    range.resize( npnts * index_dim );
+                    donor_range.resize( npnts * index_dim );
+                    transform.resize( index_dim );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                }
+
+                HXSendRecvData( connectname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( donorname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( range.data(), range.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( donor_range.data(), donor_range.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( transform.data(), transform.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "connectname = " << connectname << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "donorname = " << donorname << "\n";
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "range = ";
+                    for ( int i = 0; i < range.size(); ++ i )
+                    {
+                        std::cout << range[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "donor_range = ";
+                    for ( int i = 0; i < donor_range.size(); ++ i )
+                    {
+                        std::cout << donor_range[ i ] << " ";
+                    }
+                    std::cout << "\n";
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "transform = ";
+                    for ( int i = 0; i < transform.size(); ++ i )
+                    {
+                        std::cout << transform[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                }
+
+                int gDonorZoneId = -1;
+                if ( Parallel::IsServer() )
+                {
+                    BaseZone baseZoneDonor;
+                    baseZoneDonor.zone_name = donorname;
+
+                    gDonorZoneId = Global::zone_names.FindBaseZone( baseZoneDonor );
+                }
+
+                HXSendRecvData( &gDonorZoneId, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                ZoneBc1To1 * zonebc_1to1 = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    zonebc_1to1 = new ZoneBc1To1();
+                    zone->bc1to1s.push_back( zonebc_1to1 );
+                    zonebc_1to1->zoneid = gZoneId;
+                    zonebc_1to1->transform = transform;
+                    zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                    for ( int i = 0; i < range.size(); ++ i )
+                    {
+                        zonebc_1to1->pnts.push_back( range[ i ] );
+                        zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                    }
+                }
+            }
+        }
+    }
+
+    {
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "Global::zones.size() = " << Global::zones.size() << "\n";
+    }
+
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/CgnsGrid.h b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/CgnsGrid.h
new file mode 100644
index 00000000..fddf1db6
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/CgnsGrid.h
@@ -0,0 +1,103 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    int zoneIndex;
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/Field.cpp b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/Field.cpp
new file mode 100644
index 00000000..659432f8
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/Field.cpp
@@ -0,0 +1,177 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+
+    std::vector<double> & x = grid->x;
+    this->dx = std::abs( x[ 1 ] - x[ 0 ] );
+    this->dt = dx / 10.0;
+    this->t = 1.0;
+    this->nt = std::round( t / dt );
+
+    double total_time = nt * dt;
+
+    std::cout << "this->dt   = " << this->dt << "\n";
+    std::cout << "this->t    = " << this->t << "\n";
+    std::cout << "this->nt   = " << this->nt << "\n";
+    std::cout << "this->ni   = " << this->ni << "\n";
+    std::cout << "total_time = " << total_time << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+    r.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        u_e[ i ] = - std::exp( -total_time ) * std::sin( std::numbers::pi * xm ); //theory solution
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+    int kkk = 1;
+}
+
+void Field::Solve( Zone * zone )
+{
+    //this->FTCS( zone );
+    this->RungeKutta3( zone );
+}
+
+void Field::FTCS( Zone * zone )
+{
+    int ist = 1;
+    int ied = ni;
+
+    this->Rhs( this->un, this->r );
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + dt * r[ i ];
+    }
+}
+
+void Field::RungeKutta3( Zone * zone )
+{
+    int ist = 1;
+    int ied = ni;
+
+    this->Rhs( this->un, this->r );
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + dt * r[ i ];
+    }
+}
+
+void Field::Rhs( std::vector<double> & u, std::vector<double> & r )
+{
+    int ist = 1;
+    int ied = ni;
+
+    double coef = this->alpha / ( dx * dx );
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        r[ i ] = coef * ( u[ i + 1 ] - 2.0 * u[ i ] + u[ i - 1 ] );
+    }
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        //std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        //region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+        int kkk = 1;
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
+
+void Field::UpdateOldField()
+{
+    for ( int i = 0; i < this->u.size(); ++ i )
+    {
+        this->un[ i ] = this->u[ i ];
+    }
+}
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/Field.h b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/Field.h
new file mode 100644
index 00000000..965bb327
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/Field.h
@@ -0,0 +1,41 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> r;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid );
+    void Solve( Zone * zone );
+public:
+    void FTCS( Zone * zone );
+    void RungeKutta3( Zone * zone );
+    void Rhs( std::vector<double> & u, std::vector<double> & r );
+
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void UpdateOldField();
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/LogFile.cpp b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/LogFile.cpp
new file mode 100644
index 00000000..08ccd453
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/LogFile.cpp
@@ -0,0 +1,138 @@
+#include "LogFile.h"
+#include "Parallel.h"
+#include <sstream>
+#include <iostream>
+
+#ifdef _WINDOWS
+#include <windows.h>
+#include <direct.h>
+#include <io.h>
+#else
+#include <sys/stat.h>
+#include <unistd.h>
+#endif
+
+LogFile logFile;
+
+class OStream : public std::ostringstream
+{
+public:
+    OStream() {}
+    ~OStream() {}
+public:
+    void ClearAll()
+    {
+        this->clear();
+        this->str("");
+    }
+};
+
+OStream StrIO;
+std::string GetPrjDirName( const std::string & fileName );
+bool DirExist( const std::string & dirName );
+void MakeDir( const std::string & dirName );
+
+std::string GetPrjDirName( const std::string & fileName )
+{
+    size_t pos = fileName.find_last_of("\\/");
+    if ( std::string::npos == pos )
+    {
+        return "";
+    }
+    else
+    {
+        return fileName.substr( 0, pos );
+    }
+}
+
+bool DirExist( const std::string & dirName )
+{
+#ifdef _WINDOWS
+    bool flag = ( _access( dirName.c_str(), 0 ) == 0 );
+    return flag;
+#else
+    bool flag = ( access( dirName.c_str(), 0 ) == 0 );
+    return flag;
+#endif
+}
+
+void MakeDir( const std::string & dirName )
+{
+    int flag;
+#ifdef _WINDOWS
+    flag = _mkdir( dirName.c_str() );
+#else
+    flag = mkdir( dirName.c_str(), S_IRWXU );
+#endif
+    if ( flag == 0 )
+    {
+        std::cout << dirName << " directory has been created successfully !\n";
+    }
+}
+
+void CreateDirIfNeeded( std::string & prjFileName )
+{
+    std::string prj_dir = GetPrjDirName( prjFileName );
+
+    if ( ! DirExist( prj_dir ) )
+    {
+        MakeDir( prj_dir );
+    }
+}
+
+
+void OpenLogFile( int logFileIndex, std::fstream & file )
+{
+    static int ifReWrite = 0;
+
+    StrIO.ClearAll();
+    StrIO << "log/log" << logFileIndex << ".log";
+    std::string fileName = StrIO.str();
+
+    std::ios_base::openmode openMode;
+
+    if ( ifReWrite == 0 )
+    {
+        CreateDirIfNeeded( fileName );
+
+        openMode = std::ios_base::out | std::ios_base::trunc;
+
+        ifReWrite = 1;
+    }
+    else
+    {
+        openMode = std::ios_base::out | std::ios_base::app;
+    }
+
+    file.open( fileName.c_str(), openMode );
+    if ( ! file )
+    {
+        std::cout << "could not open " << fileName << std::endl;
+        exit( 0 );
+    }
+}
+
+void CloseLogFile( std::fstream & file )
+{
+    file.close();
+    file.clear();
+}
+
+LogFile::LogFile()
+{
+}
+
+LogFile::~LogFile()
+{
+}
+
+void LogFile::Open()
+{
+    int pid = Parallel::pid;
+    OpenLogFile( pid, this->my_fstream );
+}
+
+void LogFile::Close()
+{
+    CloseLogFile( this->my_fstream );
+}
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/LogFile.h b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/LogFile.h
new file mode 100644
index 00000000..00e775ab
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/LogFile.h
@@ -0,0 +1,27 @@
+#pragma once
+#include <fstream>
+
+void OpenLogFile( int logFileIndex, std::fstream & file );
+void CloseLogFile( std::fstream & file );
+class LogFile;
+extern LogFile logFile;
+
+class LogFile
+{
+public:
+    LogFile();
+    ~LogFile();
+    std::fstream my_fstream;
+public:
+    void Open();
+    void Close();
+};
+
+template< typename T >
+LogFile & operator << ( LogFile & f, const T & value )
+{
+    f.Open();
+    f.my_fstream << value;
+    f.Close();
+    return f;
+}
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/Parallel.cpp b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/Parallel.cpp
new file mode 100644
index 00000000..0bce1a60
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/Parallel.cpp
@@ -0,0 +1,54 @@
+#include "Parallel.h"
+#include <iostream>
+
+int Parallel::pid = 0;
+int Parallel::nProc = 1;
+int Parallel::serverid = 0;
+int Parallel::tag = 0;
+
+void Parallel::Init()
+{
+#ifdef HX_PARALLEL
+    int argc     = 0;
+    char ** argv = 0;
+    MPI_Init( &argc, &argv );
+    MPI_Comm_rank( MPI_COMM_WORLD, &Parallel::pid );
+    MPI_Comm_size( MPI_COMM_WORLD, &Parallel::nProc );
+    int len = -1;
+    char version[ MPI_MAX_LIBRARY_VERSION_STRING ];
+    MPI_Get_library_version( version, &len );
+    std::cout << "Hello, world!  I am " << Parallel::pid << " of " << Parallel::nProc
+        << "(" << version << ", " << len << ")" << std::endl;
+#endif
+}
+
+void Parallel::Finalize()
+{
+#ifdef HX_PARALLEL
+    MPI_Finalize();
+#endif
+}
+
+bool Parallel::IsServer()
+{
+    return Parallel::pid == Parallel::serverid;
+}
+
+void HXSendChar( void * data, int size, int pid, int tag )
+{
+#ifdef HX_PARALLEL
+    if ( size <= 0 ) return;
+    MPI_Send( data, size, MPI_CHAR, pid, tag, MPI_COMM_WORLD );
+#endif
+}
+
+void HXRecvChar( void * data, int size, int pid, int tag )
+{
+#ifdef HX_PARALLEL
+    if ( size <= 0 ) return;
+
+    MPI_Status status;
+    MPI_Recv( data, size, MPI_CHAR, pid, tag, MPI_COMM_WORLD, & status );
+#endif
+}
+
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/Parallel.h b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/Parallel.h
new file mode 100644
index 00000000..880a71cb
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/Parallel.h
@@ -0,0 +1,78 @@
+#pragma once
+#ifdef HX_PARALLEL
+#include "mpi.h"
+#endif
+#include <vector>
+#include "LogFile.h"
+
+class Parallel
+{
+public:
+    static int pid;
+    static int nProc;
+    static int serverid;
+    static int tag;
+public:
+    static void Init();
+    static void Finalize();
+public:
+    static bool IsServer();
+};
+
+void HXSendChar( void * data, int size, int pid, int tag );
+void HXRecvChar( void * data, int size, int pid, int tag );
+
+template< typename T >
+void HXSendData( T * field, int nElement, int recv_pid, int tag  );
+
+template< typename T >
+void HXRecvData( T * field, int nElement, int send_pid, int tag );
+
+template< typename T >
+void HXSendData( T * field, int nElement, int recv_pid, int tag = 0 )
+{
+    if ( nElement <= 0 ) return;
+
+    int buffer_size = nElement * sizeof( T );
+
+    HXSendChar( field, buffer_size, recv_pid, tag );
+}
+
+template< typename T >
+void HXRecvData( T * field, int nElement, int send_pid, int tag = 0 )
+{
+    if ( nElement <= 0 ) return;
+
+    int buffer_size = nElement * sizeof( T );
+
+    HXRecvChar( field, buffer_size, send_pid, tag );
+}
+
+template< typename T >
+void HXSendRecvData( T * field, int nElement, int send_pid, int recv_pid, int tag = 0 )
+{
+    if ( send_pid == recv_pid ) return;
+
+    if ( nElement <= 0 ) return;
+
+    int buffer_size = nElement * sizeof( T );
+
+    if ( Parallel::pid == send_pid )
+    {
+        HXSendChar( field, buffer_size, recv_pid, tag );
+    }
+    else if ( Parallel::pid == recv_pid )
+    {
+        HXRecvChar( field, buffer_size, send_pid, tag );
+    }
+}
+
+template< typename T >
+void HXBcastData( T * field, int nElement, int send_pid )
+{
+    if ( nElement <= 0 ) return;
+    int buffer_size = nElement * sizeof( T );
+#ifdef HX_PARALLEL
+    MPI_Bcast( field, buffer_size, MPI_CHAR, send_pid, MPI_COMM_WORLD );
+#endif
+}
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/README.txt b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/README.txt
new file mode 100644
index 00000000..5a4410fb
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/README.txt
@@ -0,0 +1,3 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
+
+PS D:\github\OneFLOW\example\1d-heat-equation\ftcs\cpp\multiblock\parallel\8blocks\01\build> mpiexec -n 8 .\Debug\testprj.exe
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/Solver.cpp b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/Solver.cpp
new file mode 100644
index 00000000..25038559
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/Solver.cpp
@@ -0,0 +1,680 @@
+#include "Solver.h"
+#include "Parallel.h"
+#include "ZoneState.h"
+#include "global.h"
+#include <fstream>
+#include <set>
+#include <unordered_map>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+Solver::Solver()
+{
+    Parallel::Init();
+}
+
+Solver::~Solver()
+{
+    Parallel::Finalize();
+}
+
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    this->InitTopo();
+    this->InitFields();
+    this->SolveMultiZones();
+    this->PostProcess();
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d4blocksv1.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    ReadCgnsGrid( fileName );
+}
+
+void Solver::InitTopo()
+{
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "Solver::InitTopo() " << "\n";
+
+    Global::donor_zone_sets.resize( LocalZone::nZones );
+    Global::donor_zones.resize( LocalZone::nZones );
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        int global_zoneid = LocalZone::global_zoneids[ iZone ];
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "iZone = " << iZone << " global_zoneid = " << global_zoneid << "\n";
+
+        Interface * interface = new Interface();
+        interface->zoneid = global_zoneid;
+        Global::interfaces.push_back( interface );
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+        Interface * interface = Global::interfaces[ iZone ];
+
+        int nbc1to1s = zone->bc1to1s.size();
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout <<  "nbc1to1s = " << nbc1to1s << "\n";
+
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "zoneid = " << zoneid << " donor_zoneid = " << donor_zoneid << "\n";
+
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+        int nInterfaces = interface->zoneList.size();
+        interface->data_recv.resize( nInterfaces );
+        interface->data_send.resize( nInterfaces );
+    }
+
+    for ( int iProc = 0; iProc < Parallel::nProc; ++ iProc )
+    {
+        int nSize = -1;
+        if ( iProc == Parallel::pid )
+        {
+            nSize = Global::facePairList.size();
+        }
+        HXBcastData( &nSize, 1, iProc );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nSize = " << nSize << "\n";
+        std::vector<FacePair> tmp;
+        if ( iProc == Parallel::pid )
+        {
+            tmp = Global::facePairList;
+        }
+        else
+        {
+            tmp.resize( nSize );
+        }
+
+        HXBcastData( tmp.data(), tmp.size(), iProc );
+        Global::AddFacePairList( Global::mpi_facePairList, tmp );
+    }
+
+    for ( int i = 0; i < Global::mpi_facePairList.size(); ++ i )
+    {
+        FacePair &facePair = Global::mpi_facePairList[ i ];
+        Global::InsertFacePairMap( facePair );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        facePair.Print();
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterfaces = interface->local_faceids.size();
+        for ( int iInterface = 0; iInterface < nInterfaces; ++ iInterface )
+        {
+            int local_faceid = interface->local_faceids[ iInterface ];
+            int proc_global_faceid = interface->proc_global_faceids[ iInterface ];
+            FacePair & facePair = Global::facePairList[ proc_global_faceid ];
+            int global_faceid = Global::InsertFacePairMap( facePair );
+            interface->global_faceids.push_back( global_faceid );
+            interface->global_local_face_map.insert( std::make_pair( global_faceid, local_faceid ) );
+        }
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        std::set<int> &donor_zoneSet = Global::donor_zone_sets[ iZone ];
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            donor_zoneSet.insert( donor_zoneid );
+        }
+
+        std::vector<int> &donor_zones = Global::donor_zones[ iZone ];
+        for ( std::set<int>::iterator iter = donor_zoneSet.begin(); iter != donor_zoneSet.end(); ++ iter )
+        {
+            donor_zones.push_back( *iter );
+        }
+
+        interface->neighbor_donor_zones = donor_zones;
+
+        std::unordered_map<int, int> donor_zonelocal;
+
+        for ( int idonor = 0; idonor < donor_zones.size(); ++ idonor )
+        {
+            int donor_zone = donor_zones[ idonor ];
+            donor_zonelocal.insert( std::make_pair( donor_zone, idonor ) );
+        }
+        int ndonors = donor_zones.size();
+        std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+        neighbor_donorfaces.resize( ndonors );
+
+        std::vector<std::vector<int>> & sub_local_faceids = interface->sub_local_faceids;
+        sub_local_faceids.resize( ndonors );
+
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ineighbor = donor_zonelocal[ donor_zoneid ];
+            std::vector<int> &donorfaces = neighbor_donorfaces[ ineighbor ];
+            int global_faceid = interface->global_faceids[ iFace ];
+            donorfaces.push_back( global_faceid );
+            int local_faceid = interface->local_faceids[ iFace ];
+
+            std::vector<int> & sub_local_faces = sub_local_faceids[ ineighbor ];
+            sub_local_faces.push_back( local_faceid );
+        }
+    }
+
+    Global::interfaceTopo.InitNeighborInfo();
+    Global::interfaceTopo.SwapNeighborInfo();
+
+    int kkk = 1;
+}
+
+void Solver::InitFields()
+{
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "Solver::InitFields() ZoneState::nZones = " << ZoneState::nZones <<  "\n";
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+    }
+
+    Boundary();
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        //std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        //std::cout << "it = " << it << " nt = " << Global::nt << "\n";
+        for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+        {
+            Field * field = Global::fields[ iZone ];
+            Zone * zone = Global::zones[ iZone ];
+            zone->zoneIndex = iZone;
+            field->Solve( zone );
+        }
+        Boundary();
+    }
+}
+
+void Solver::Boundary()
+{
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+    ExchangeInterfaceField();
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->UpdateOldField();
+    }
+}
+
+void Solver::UploadInterfaceField()
+{
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> & send_to_zones = interface->send_to_zones;
+        int nsend_zones = send_to_zones.size();
+
+        std::vector<std::vector<int>> & donorfaces_for_send = interface->donorfaces_for_send;
+        std::vector<std::vector<int>> & donorijk_for_send = interface->donorijk_for_send;
+        std::vector<std::vector<double>> & donordata_for_send = interface->donordata_for_send;
+
+        Field * field = Global::fields[ iZone ];
+
+        for ( int iSend = 0; iSend < nsend_zones; ++ iSend )
+        {
+            int zone_to_send = send_to_zones[ iSend ];
+            std::vector<int> & donorfaces = donorfaces_for_send[ iSend ];
+            std::vector<int> & donorijks = donorijk_for_send[ iSend ];
+            std::vector<double> & donordatas = donordata_for_send[ iSend ];
+
+            int nface = donorfaces.size();
+            int index_dim = 1;
+            for ( int i = 0; i < nface; ++ i )
+            {
+                int ijkpos = index_dim * i;
+                int i_donor_cell = donorijks[ ijkpos + 0 ];
+                donordatas[ i ] = field->u[ i_donor_cell ];
+            }
+        }
+    }
+}
+
+void Solver::UpdateInterfaceField()
+{
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        int ndonor_zones = Global::interfaceTopo.linkmap[ iZone ].size();
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donor_zone = Global::interfaceTopo.linkmap[ iZone ][ iNei ];
+            int send_pid = ZoneState::pids[ iZone ];
+            int recv_pid = ZoneState::pids[ donor_zone ];
+            int nsend = -1;
+            std::vector<double> donordata;
+            if ( Parallel::pid != send_pid && Parallel::pid != recv_pid ) continue;
+            if ( Parallel::pid == send_pid )
+            {
+                int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+                Interface * interface = Global::interfaces[ local_zoneid ];
+                donordata = interface->donordata_for_send[ iNei ];
+                nsend = donordata.size();
+            }
+            HXSendRecvData( &nsend, 1, send_pid, recv_pid );
+
+            if ( Parallel::pid == recv_pid )
+            {
+                donordata.resize( nsend );
+            }
+            HXSendRecvData( donordata.data(), donordata.size(), send_pid, recv_pid );
+
+            if ( Parallel::pid == recv_pid )
+            {
+                int local_donor_zoneid = ZoneState::g2lzoneids[ donor_zone ];
+                Interface * donor_interface = Global::interfaces[ local_donor_zoneid ];
+                int nSize = donor_interface->neighbor_donor_zones.size();
+                int ipos = -1;
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    int nei_zone = donor_interface->neighbor_donor_zones[ i ];
+                    if ( nei_zone == iZone )
+                    {
+                        ipos = i;
+                        break;
+                    }
+                }
+
+                std::vector<int> & neighbor_donorfaces = donor_interface->neighbor_donorfaces[ ipos ];
+                std::vector<int> & sub_local_faceids = donor_interface->sub_local_faceids[ ipos ];
+                for ( int i = 0; i < neighbor_donorfaces.size(); ++ i )
+                {
+                    int local_faceid = sub_local_faceids[ i ];
+                    double donor_value = donordata[ i ];
+                    donor_interface->data_recv[ local_faceid ] = donor_value;
+                }
+            }
+        }
+    }
+}
+
+void Solver::DownloadInterfaceField()
+{
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+        Field * field = Global::fields[ iZone ];
+
+        int nInterFaces = interface->data_recv.size();
+
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+
+            double donor_value = interface->data_recv[ iFace ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    this->UploadInterfaceField();
+    this->UpdateInterfaceField();
+    this->DownloadInterfaceField();
+}
+
+void Solver::PostProcess()
+{
+    Post post;
+    post.Process();
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        if ( !ZoneState::IsValid( iZone ) && !Parallel::IsServer() ) continue;
+
+        double xmin = 0.0;
+        double xmax = 0.0;
+
+        if ( ZoneState::IsValid( iZone ) )
+        {
+            int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+            Grid * grid = Global::grids[ local_zoneid ];
+            int ni = grid->x.size();
+            xmin = grid->x[ 0 ];
+            xmax = grid->x[ 0 ];
+            int imin = 0;
+            int imax = 0;
+            for ( int i = 0; i < ni; ++ i )
+            {
+                if ( xmin > grid->x[ i ] )
+                {
+                    xmin = grid->x[ i ];
+                    imin = i;
+                }
+                if ( xmax < grid->x[ i ] )
+                {
+                    xmax = grid->x[ i ];
+                    imax = i;
+                }
+            }
+        }
+
+        HXSendRecvData( &xmin, 1, ZoneState::pids[ iZone ], Parallel::serverid );
+        HXSendRecvData( &xmax, 1, ZoneState::pids[ iZone ], Parallel::serverid );
+
+        //if ( Parallel::IsServer() )
+        //{
+        //    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        //    std::cout << "xmin = " << xmin << "\n";
+        //    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        //    std::cout << "xmax = " << xmax << "\n";
+        //}
+
+        if ( Parallel::IsServer() )
+        {
+            xmin_list.push_back( xmin );
+            xmax_list.push_back( xmax );
+        }
+    }
+
+    //if ( Parallel::IsServer() )
+    //{
+    //    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    //    for ( int i = 0; i < xmin_list.size(); ++ i )
+    //    {
+    //        std::cout << "(" << xmin_list[ i ] << "," << xmax_list[ i ] << ") ";
+    //    }
+    //    std::cout << "\n";
+    //}
+
+    if ( Parallel::IsServer() )
+    {
+        std::vector<std::pair<double, int>> pairs;
+        int nSize = xmin_list.size();
+        for ( int i = 0; i < nSize; ++ i )
+        {
+            pairs.push_back( std::make_pair( xmin_list[ i ], i ) );
+        }
+
+        std::sort( pairs.begin(), pairs.end() );
+
+        for ( int i = 0; i < nSize; ++ i )
+        {
+            this->zoneids.push_back( pairs[ i ].second );
+        }
+    }
+
+    int kkk = 1;
+}
+
+bool IsLastZone( int iZone );
+bool IsLastZone( int iZone )
+{
+    return iZone == ZoneState::nZones - 1;
+}
+
+void Post::AddVector( std::vector<double> & a, std::vector<double> & b )
+{
+    for ( int i = 0; i < b.size(); ++ i )
+    {
+        a.push_back( b[ i ] );
+    }
+}
+
+void Post::GatherField()
+{
+    this->zoneids.resize( ZoneState::nZones );
+    HXBcastData( this->zoneids.data(), this->zoneids.size(), Parallel::serverid );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "Post::GatherField() this->zoneids = \n";
+    for ( int i = 0; i < this->zoneids.size(); ++ i )
+    {
+        std::cout << this->zoneids[ i ] << " ";
+    }
+    std::cout << "\n";
+
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+
+        if ( !ZoneState::IsValid( zoneid ) && !Parallel::IsServer() ) continue;
+
+        int nSize = -1;
+        std::vector<double> local_x;
+        std::vector<double> local_u_e;
+        std::vector<double> local_un;
+        std::vector<double> local_u;
+
+        if ( Parallel::pid == ZoneState::pids[ zoneid ] )
+        {
+            int local_zoneid = ZoneState::g2lzoneids[ zoneid ];
+            Grid * grid = Global::grids[ local_zoneid ];
+            Field * field = Global::fields[ local_zoneid ];
+            int ni = grid->x.size();
+
+            int ist = 1;
+            int ied = ni;
+
+            int dir = 1;
+            if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+            if ( dir == 1 )
+            {
+                if ( IsLastZone( iZone ) )
+                {
+                    for ( int i = ist; i <= ied; ++ i )
+                    {
+                        double xm = grid->x[ i - ist ];
+                        local_x.push_back( xm );
+                        local_u_e.push_back( field->u_e[ i ] );
+                        local_un.push_back( field->un[ i ] );
+                        local_u.push_back( field->u[ i ] );
+                    }
+                }
+                else
+                {
+                    for ( int i = ist; i <= ied - 1; ++ i )
+                    {
+                        double xm = grid->x[ i - ist ];
+                        local_x.push_back( xm );
+                        local_u_e.push_back( field->u_e[ i ] );
+                        local_un.push_back( field->un[ i ] );
+                        local_u.push_back( field->u[ i ] );
+                    }
+                }
+            }
+            else
+            {
+                if ( IsLastZone( iZone ) )
+                {
+                    for ( int i = ied; i >= ist; -- i )
+                    {
+                        double xm = grid->x[ i - ist ];
+                        local_x.push_back( xm );
+                        local_u_e.push_back( field->u_e[ i ] );
+                        local_un.push_back( field->un[ i ] );
+                        local_u.push_back( field->u[ i ] );
+                    }
+                }
+                else
+                {
+                    for ( int i = ied; i >= ist + 1; -- i )
+                    {
+                        double xm = grid->x[ i - ist ];
+                        local_x.push_back( xm );
+                        local_u_e.push_back( field->u_e[ i ] );
+                        local_un.push_back( field->un[ i ] );
+                        local_u.push_back( field->u[ i ] );
+                    }
+                }
+            }
+            nSize = local_x.size();
+        }
+
+        int send_pid = ZoneState::pids[ zoneid ];
+
+        HXSendRecvData( &nSize, 1, send_pid, Parallel::serverid );
+
+        if ( Parallel::IsServer() )
+        {
+            local_x.resize( nSize );
+            local_u_e.resize( nSize );
+            local_un.resize( nSize );
+            local_u.resize( nSize );
+        }
+
+        HXSendRecvData( local_x.data(), local_x.size(), send_pid, Parallel::serverid );
+        HXSendRecvData( local_u_e.data(), local_u_e.size(), send_pid, Parallel::serverid );
+        HXSendRecvData( local_un.data(), local_un.size(), send_pid, Parallel::serverid );
+        HXSendRecvData( local_u.data(), local_u.size(), send_pid, Parallel::serverid );
+
+        if ( Parallel::IsServer() )
+        {
+            this->AddVector( this->x, local_x );
+            this->AddVector( this->u_e, local_u_e );
+            this->AddVector( this->un, local_un );
+            this->AddVector( this->u, local_u );
+        }
+    }
+}
+
+void Post::DumpField()
+{
+    if ( !Parallel::IsServer() ) return;
+    int ni_total = this->x.size();
+    std::cout << " DumpField x.size() = " << x.size() << "\n";
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    this->DumpErrorDetails( u_error );
+
+    std::string csvname = "field_final.csv";
+    this->DumpCsvFile( csvname, x, u_e, un, u_error );
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.20f} {:.20f} {:.20f} {:.20f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/Solver.h b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/Solver.h
new file mode 100644
index 00000000..9914c1d7
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/Solver.h
@@ -0,0 +1,49 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+
+class Solver
+{
+public:
+    Solver();
+    ~Solver();
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveMultiZones();
+public:
+    void Boundary();
+    void UploadInterfaceField();
+    void UpdateInterfaceField();
+    void DownloadInterfaceField();
+    void ExchangeInterfaceField();
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcess();
+};
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+    std::vector<double> u;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+public:
+    void AddVector( std::vector<double> & a, std::vector<double> & b );
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/ZoneState.cpp b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/ZoneState.cpp
new file mode 100644
index 00000000..ff810849
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/ZoneState.cpp
@@ -0,0 +1,20 @@
+#include "ZoneState.h"
+#include "Parallel.h"
+
+int ZoneState::nZones = 0;
+std::vector<int> ZoneState::pids;
+std::vector<int> ZoneState::g2lzoneids;
+
+bool ZoneState::IsValid( int zoneid )
+{
+    return ZoneState::pids[ zoneid ] == Parallel::pid;
+}
+
+int ZoneState::GetProcID( int zoneid )
+{
+    return ZoneState::pids[ zoneid ];
+}
+
+int LocalZone::nZones = 0;
+std::vector<int> LocalZone::global_zoneids;
+
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/ZoneState.h b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/ZoneState.h
new file mode 100644
index 00000000..1096d632
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/ZoneState.h
@@ -0,0 +1,21 @@
+#pragma once
+#include <vector>
+
+class ZoneState
+{
+public:
+    static int nZones;
+    static int zone_id;
+    static std::vector<int> pids;
+    static std::vector<int> g2lzoneids; //global zone id to local zone id
+public:
+    static bool IsValid( int zoneid );
+    static int GetProcID( int zoneid );
+};
+
+class LocalZone
+{
+public:
+    static int nZones;
+    static std::vector<int> global_zoneids;
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/global.cpp b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/global.cpp
new file mode 100644
index 00000000..df1e6bae
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/global.cpp
@@ -0,0 +1,300 @@
+#include "global.h"
+#include "CgnsGrid.h"
+#include "ZoneState.h"
+#include "Parallel.h"
+#include <iostream>
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *> Global::interfaces;
+
+std::map<Face, int> Global::faceMap;
+std::map<FacePair, int> Global::facePairMap;
+std::vector<FacePair> Global::facePairList;
+std::vector<FacePair> Global::mpi_facePairList;
+
+std::vector<std::set<int>> Global::donor_zone_sets;
+std::vector<std::vector<int>> Global::donor_zones;
+
+InterfaceTopo Global::interfaceTopo;
+
+bool Face::operator < ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return this->zone < rhs.zone;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return this->i < rhs.i;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return this->j < rhs.j;
+    }
+
+    return this->k < rhs.k;
+}
+
+bool Face::operator == ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return false;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return false;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return false;
+    }
+
+    return this->k == rhs.k;
+}
+
+void Face::Print()
+{
+    std::cout << "(" << this->zone << "," << this->i << ")";
+}
+
+void FacePair::AddPair( const Face & face1, const Face & face2 )
+{
+    if ( face1 < face2 )
+    {
+        this->left = face1;
+        this->right = face2;
+    }
+    else
+    {
+        this->left = face2;
+        this->right = face1;
+    }
+}
+
+bool FacePair::operator < ( const FacePair & rhs ) const
+{
+    if ( this->left == rhs.left || this->left == rhs.right )
+    {
+        return false;
+    }
+
+    return this->left < rhs.left;
+}
+
+void FacePair::Print()
+{
+    this->left.Print();
+    std::cout << " ";
+    this->right.Print();
+    std::cout << "\n";
+}
+
+void InterfaceTopo::InitNeighborInfo()
+{
+    this->linkmap.resize( ZoneState::nZones );
+
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        if ( ! ZoneState::IsValid( iZone ) ) continue;
+
+        int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+
+        Interface * interface = Global::interfaces[ local_zoneid ];
+
+        std::vector<int> & t = this->linkmap[ iZone ];
+        t = interface->neighbor_donor_zones;
+    }
+}
+
+void InterfaceTopo::SwapNeighborInfo()
+{
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        int pid = ZoneState::pids[ iZone ];
+
+        std::vector<int> & donor_zones = this->linkmap[ iZone ];
+        int nNeighbor = donor_zones.size();
+
+        HXBcastData( &nNeighbor, 1, pid );
+
+        donor_zones.resize( nNeighbor );
+
+        HXBcastData( donor_zones.data(), donor_zones.size(), pid );
+    }
+
+    this->SwapNeighborDonorfaces();
+}
+
+void InterfaceTopo::SwapNeighborDonorfaces()
+{
+    int gl = 0;
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        int send_pid = ZoneState::pids[ iZone ];
+
+        std::vector<int> & donor_zones = this->linkmap[ iZone ];
+        int ndonor_zones = donor_zones.size();
+
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donor_zone = donor_zones[ iNei ];
+            int recv_pid = ZoneState::pids[ donor_zone ];
+            int nInterFaces = 0;
+            std::vector<int> donorfaces;
+
+            if ( Parallel::pid == send_pid )
+            {
+                int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+
+                Interface * interface = Global::interfaces[ local_zoneid ];
+
+                std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+
+                std::vector<int> & neighbor_donorface = neighbor_donorfaces[ iNei ];
+
+                nInterFaces = neighbor_donorface.size();
+
+                donorfaces = neighbor_donorface;
+            }
+
+            HXSendRecvData( &nInterFaces, 1, send_pid, recv_pid );
+
+            if ( Parallel::pid == recv_pid && send_pid != recv_pid )
+            {
+                donorfaces.resize( nInterFaces );
+            }
+
+            HXSendRecvData( donorfaces.data(), donorfaces.size(), send_pid, recv_pid );
+
+            if ( Parallel::pid == recv_pid )
+            {
+                int local_donor_zoneid = ZoneState::g2lzoneids[ donor_zone ];
+                Interface * interface_recv = Global::interfaces[ local_donor_zoneid ];
+                interface_recv->SendGeom( iZone, donorfaces );
+            }
+        }
+    }
+}
+
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->local_faceids.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        Face face;
+        face.zone = zoneid;
+        face.i = i;
+
+        int i_donor = index2[ 0 ];
+
+        Face face_donor;
+        face_donor.zone = donor_zoneid;
+        face_donor.i = i_donor;
+
+        FacePair facePair;
+        facePair.AddPair( face, face_donor );
+
+        Global::facePairList.push_back( facePair );
+        int nSize = Global::facePairList.size();
+        this->proc_global_faceids.push_back( nSize - 1 );
+
+        int i_ghost_cell = i + 1;
+        int i_local_donor_cell = i - 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+            i_local_donor_cell = i + 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+        ijk_donors.push_back( i_local_donor_cell );
+
+        icount ++;
+    }
+}
+
+void Interface::SendGeom( int zone, std::vector<int> & donorfaces )
+{
+    Interface * interface = this;
+
+    std::vector<int> & send_to_zones = interface->send_to_zones;
+
+    send_to_zones.push_back( zone );
+    interface->donorfaces_for_send.push_back( donorfaces );
+
+    int nface = donorfaces.size();
+    std::vector<int> sub_donorijk;
+    int index_dim = 1;
+    for ( int i = 0; i < nface; ++ i )
+    {
+        int global_faceid = donorfaces[ i ];
+        int local_faceid = interface->global_local_face_map[ global_faceid ];
+        int ijkpos = index_dim * local_faceid;
+        int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+        sub_donorijk.push_back( i_donor_cell );
+        int kkk = 1;
+    }
+
+    interface->donorijk_for_send.push_back( sub_donorijk );
+
+    std::vector<double> sub_donordata( sub_donorijk.size() );
+    interface->donordata_for_send.push_back( sub_donordata );
+}
+
+void Global::InsertFaceMap( const Face & face )
+{
+    std::map<Face, int>::iterator iter;
+    iter = Global::faceMap.find( face );
+    if ( iter == Global::faceMap.end() )
+    {
+        int faceid = Global::faceMap.size();
+        Global::faceMap.insert( std::make_pair( face, faceid ) );
+    }
+}
+
+int Global::InsertFacePairMap( const FacePair & facePair )
+{
+    std::map<FacePair, int>::iterator iter;
+    iter = Global::facePairMap.find( facePair );
+    if ( iter == Global::facePairMap.end() )
+    {
+        int facePairId = Global::facePairMap.size();
+        Global::facePairMap.insert( std::make_pair( facePair, facePairId ) );
+        return facePairId;
+    }
+    return iter->second;
+}
+
+void Global::AddFacePairList( std::vector<FacePair> & a, std::vector<FacePair> & b )
+{
+    for ( int i = 0; i < b.size(); ++ i )
+    {
+        a.push_back( b[ i ] );
+    }
+}
+
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/global.h b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/global.h
new file mode 100644
index 00000000..933cec05
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/global.h
@@ -0,0 +1,157 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <unordered_map>
+#include <set>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class Face
+{
+public:
+    int zone = 0;
+    int i = 0;
+    int j = 1;
+    int k = 1;
+public:
+    bool operator < ( const Face & rhs ) const;
+    bool operator == ( const Face & rhs ) const;
+public:
+    void Print();
+};
+
+class FacePair
+{
+public:
+    Face left;
+    Face right;
+public:
+    bool operator < ( const FacePair & rhs ) const;
+    void AddPair( const Face &face1, const Face &face2);
+public:
+    void Print();
+};
+
+class Transform;
+
+class InterfaceTopo
+{
+public:
+    std::vector<std::vector<int>> linkmap;
+public:
+    void InitNeighborInfo();
+    void SwapNeighborInfo();
+    void SwapNeighborDonorfaces();
+};
+
+
+class Interface
+{
+public:
+    int zoneid;
+    std::vector<int> zoneList;
+    std::vector<int> global_faceids;
+    std::vector<int> mpi_global_faceids;
+    std::vector<int> proc_global_faceids;
+    std::vector<int> local_faceids;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+    std::vector<double> data_recv;
+    std::vector<double> data_send;
+    std::unordered_map<int, int> global_local_face_map;
+public:
+    std::vector<int> neighbor_donor_zones;
+    std::vector<std::vector<int>> neighbor_donorfaces;
+    std::vector<std::vector<int>> sub_local_faceids;
+    std::vector<int> send_to_zones;
+    std::vector<std::vector<int>> donorfaces_for_send;
+    std::vector<std::vector<int>> donorijk_for_send;
+    std::vector<std::vector<double>> donordata_for_send;
+public:
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+    void SendGeom( int zone, std::vector<int> & donorfaces );
+};
+
+class Field;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+public:
+    static std::map<Face, int> faceMap;
+    static std::map<FacePair, int> facePairMap;
+    static std::vector<FacePair> facePairList;
+    static std::vector<FacePair> mpi_facePairList;
+    static std::vector<std::set<int>> donor_zone_sets;
+    static std::vector<std::vector<int>> donor_zones;
+    static InterfaceTopo interfaceTopo;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+public:
+    static void InsertFaceMap( const Face & face );
+    static int InsertFacePairMap( const FacePair & facePair );
+    static void AddFacePairList( std::vector<FacePair> & a, std::vector<FacePair> & b );
+};
+
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/heat1d4blocksv1.cgns b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/heat1d4blocksv1.cgns
new file mode 100644
index 00000000..df5ffc5f
Binary files /dev/null and b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/heat1d4blocksv1.cgns differ
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/main.cpp b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/main.cpp
new file mode 100644
index 00000000..df63b7da
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/main.cpp
@@ -0,0 +1,9 @@
+#include "Solver.h"
+#include "Parallel.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/plot.py b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/plotting2.jl b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/CMakeLists.txt b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/CMakeLists.txt
new file mode 100644
index 00000000..9e834b72
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/CMakeLists.txt
@@ -0,0 +1,99 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package ( MPI )
+
+message ( STATUS  "MPI_FOUND=${MPI_FOUND}" )
+message ( STATUS  "MPI_CXX_INCLUDE_DIRS=${MPI_CXX_INCLUDE_DIRS}" )
+message ( STATUS  "MPI_LIBRARIES=${MPI_LIBRARIES}" )
+if ( MPI_FOUND )
+	list ( APPEND PRJ_INCLUDE_DIRS ${MPI_CXX_INCLUDE_DIRS} )
+	list ( APPEND PRJ_LIBRARIES ${MPI_LIBRARIES} )
+endif ()
+
+#get_directory_property( my_import_targets DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} IMPORTED_TARGETS )
+#message( STATUS "my_import_targets=${my_import_targets}" )
+
+list ( APPEND PRJ_LIBRARIES MPI::MPI_C )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+list ( APPEND PRJ_COMPILE_DEFINITIONS HX_PARALLEL )
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	LogFile.h LogFile.cpp
+	Parallel.h Parallel.cpp
+	Solver.h Solver.cpp
+	ZoneState.h ZoneState.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/CgnsGrid.cpp b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/CgnsGrid.cpp
new file mode 100644
index 00000000..825442a2
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/CgnsGrid.cpp
@@ -0,0 +1,850 @@
+#include "CgnsGrid.h"
+#include "Parallel.h"
+#include "cgnslib.h"
+#include "global.h"
+#include "ZoneState.h"
+#include <iostream>
+#include <vector>
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "fileId = " << fileId << "\n";
+    }
+    
+    int nbases = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_nbases( fileId, &nbases );
+    }
+    HXBcastData( &nbases, 1, Parallel::serverid );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "nbases = " << nbases << "\n";
+    
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        }
+
+        HXBcastData( &icelldim, 1, Parallel::serverid );
+        HXBcastData( &iphysdim, 1, Parallel::serverid );
+
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+
+        int nzones = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_nzones( fileId, baseId, &nzones );
+        }
+
+        HXBcastData( &nzones, 1, Parallel::serverid );
+
+        ZoneState::nZones = nzones;
+        ZoneState::pids.resize( nzones );
+        ZoneState::g2lzoneids.resize( nzones );
+        std::vector<int> pcount( Parallel::nProc, 0 );
+
+        for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+        {
+            int zone_pid = iZone % Parallel::nProc;
+            ZoneState::pids[ iZone ] = zone_pid;
+            ZoneState::g2lzoneids[ iZone ] = pcount[ zone_pid ];
+            pcount[ zone_pid ] ++;
+        }
+
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nzones = " << nzones << "\n";
+
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "iZone = " << iZone << "\n";
+
+            int index_dim = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            }
+            HXBcastData( &index_dim, 1, Parallel::serverid );
+
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            if ( Parallel::IsServer() )
+            {
+                cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            }
+
+            HXBcastData( zonename, 33, Parallel::serverid );
+            HXBcastData( isize.data(), isize.size(), Parallel::serverid);
+
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "zonename = " << zonename << "\n";
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+
+    if ( Parallel::IsServer() )
+    {
+        cg_close( fileId );
+    }
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+        std::cout << "fileId = " << fileId << "\n";
+    }
+    
+    int nbases = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_nbases( fileId, &nbases );
+    }
+    MPI_Bcast( &nbases, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        }
+
+        HXBcastData( &icelldim, 1, Parallel::serverid );
+        HXBcastData( &iphysdim, 1, Parallel::serverid );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+
+        int nzones = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_nzones( fileId, baseId, &nzones );
+        }
+        HXBcastData( &nzones, 1, Parallel::serverid );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nzones = " << nzones << "\n";
+
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            }
+            HXSendRecvData( &index_dim, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "index_dim = " << index_dim << "\n";
+            }
+
+            std::vector<cgsize_t> isize;
+            char zonename[ 33 ];
+            if ( Parallel::IsServer() )
+            {
+                isize.resize( index_dim * 3 );
+                cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            }
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                isize.resize( index_dim * 3 );
+            }
+
+            HXSendRecvData( zonename, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+            HXSendRecvData( isize.data(), index_dim * 3, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "zonename = " << zonename << "\n";
+
+                for ( int i = 0; i < isize.size(); ++ i )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+                }
+            }
+
+            std::vector<cgsize_t> irmin;
+            std::vector<cgsize_t> irmax;
+            int nNodes = 1;
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                irmin.resize( index_dim );
+                irmax.resize( index_dim );
+                for ( int m = 0; m < index_dim; ++ m )
+                {
+                    /* lower range index */
+                    irmin[ m ] = 1;
+                    /* upper range index of vertices */
+                    irmax[ m ] = isize[ m ];
+                    nNodes *= irmax[ m ];
+                }
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "nNodes = " << nNodes << "\n";
+            }
+
+            ZoneType_t zoneType;
+            if ( Parallel::IsServer() )
+            {
+                cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            }
+            HXSendRecvData( &zoneType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            }
+
+            Zone * zone = nullptr;
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                zone = new Zone();
+                Global::zones.push_back( zone );
+                LocalZone::global_zoneids.push_back( iZone );
+                LocalZone::nZones = LocalZone::global_zoneids.size();
+                for ( int m = 0; m < index_dim; ++ m )
+                {
+                    zone->nijk.push_back( isize[ m ] );
+                }
+            }
+
+            Grid * grid = nullptr;
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                grid = new Grid();
+                Global::grids.push_back( grid );
+            }
+
+            BaseZone baseZone;
+
+            int gZoneId = -1;
+            if ( Parallel::IsServer() )
+            {
+                baseZone.zone_name = zonename;
+                gZoneId = Global::zone_names.FindBaseZone( baseZone );
+            }
+
+            HXSendRecvData( &gZoneId, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "gZoneId = " << gZoneId << "\n";
+            }
+
+            int ncoords = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            }
+            HXSendRecvData( &ncoords, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "ncoords = " << ncoords << "\n";
+            }
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                if ( Parallel::IsServer() )
+                {
+                    cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                }
+                HXSendRecvData( coordname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &dataType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "coordname = " << coordname << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                }
+
+                std::vector<char> coord;
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    coord.resize( nNodes * sizeof( double ) );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coord.data() );
+                }
+
+                HXSendRecvData( coord.data(), coord.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                Coor * coor = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    coor = new Coor();
+                    zone->coors.push_back( coor );
+                    coor->coorname = coordname;
+                    coor->nNodes = nNodes;
+                    coor->coord = coord;
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    coor->DumpCoor();
+
+                    if ( icoord == 0 )
+                    {
+                        grid->x.resize( nNodes );
+                        coor->DumpCoorX( grid->x );
+                    }
+                }
+            }
+
+            int nbocos = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            }
+            HXSendRecvData( &nbocos, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "nbocos = " << nbocos << "\n";
+            }
+
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                if ( Parallel::IsServer() )
+                {
+                    cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                }
+                HXSendRecvData( &location, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+                }
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                //std::vector<int> normalIndex( index_dim, -1 );
+                std::vector<int> normalIndex;
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+                if ( Parallel::IsServer() )
+                {
+                    normalIndex.resize( index_dim );
+                    cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                        &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                }
+
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    normalIndex.resize( index_dim );
+                }
+                
+                HXSendRecvData( boconame, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &bocotype, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &ptset_type, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &npnts, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &normalDataType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &normalListSize, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( normalIndex.data(), index_dim, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &ndataset, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "npnts = " << npnts << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalListSize = " << normalListSize << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalIndex = ";
+                    for ( int i = 0; i < index_dim; ++ i )
+                    {
+                        std::cout << normalIndex[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "ndataset = " << ndataset << "\n";
+                }
+
+                std::vector<char> normalList;
+                std::vector<cgsize_t> pnts;
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    if ( normalDataType == DataTypeNull )
+                    {
+                        normalList.resize( sizeof( int ) );
+                    }
+                    else
+                    {
+                        int nSize = nNodes * index_dim * sizeof( double );
+                        normalList.resize( nSize );
+                    }
+                    pnts.resize( npnts * index_dim );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                }
+
+                HXSendRecvData( pnts.data(), npnts * index_dim, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "pnts = ";
+                    for ( int i = 0; i < pnts.size(); ++ i )
+                    {
+                        std::cout << pnts[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                }
+                HXSendRecvData( normalList.data(), normalList.size(), Parallel::serverid, ZoneState::GetProcID(iZone));
+
+                ZoneBc * zonebc = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    zonebc = new ZoneBc();
+                    zone->bccos.push_back( zonebc );
+                    zonebc->bcType = bocotype;
+                    for ( int i = 0; i < pnts.size(); ++ i )
+                    {
+                        zonebc->pnts.push_back( pnts[ i ] );
+                    }
+                }
+            }
+            int n1to1 = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            }
+
+            HXSendRecvData( &n1to1, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "n1to1 = " << n1to1 << "\n";
+            }
+
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range;
+                std::vector<cgsize_t> donor_range;
+                std::vector<int> transform;
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    range.resize( npnts * index_dim );
+                    donor_range.resize( npnts * index_dim );
+                    transform.resize( index_dim );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                }
+
+                HXSendRecvData( connectname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( donorname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( range.data(), range.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( donor_range.data(), donor_range.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( transform.data(), transform.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "connectname = " << connectname << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "donorname = " << donorname << "\n";
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "range = ";
+                    for ( int i = 0; i < range.size(); ++ i )
+                    {
+                        std::cout << range[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "donor_range = ";
+                    for ( int i = 0; i < donor_range.size(); ++ i )
+                    {
+                        std::cout << donor_range[ i ] << " ";
+                    }
+                    std::cout << "\n";
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "transform = ";
+                    for ( int i = 0; i < transform.size(); ++ i )
+                    {
+                        std::cout << transform[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                }
+
+                int gDonorZoneId = -1;
+                if ( Parallel::IsServer() )
+                {
+                    BaseZone baseZoneDonor;
+                    baseZoneDonor.zone_name = donorname;
+
+                    gDonorZoneId = Global::zone_names.FindBaseZone( baseZoneDonor );
+                }
+
+                HXSendRecvData( &gDonorZoneId, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                ZoneBc1To1 * zonebc_1to1 = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    zonebc_1to1 = new ZoneBc1To1();
+                    zone->bc1to1s.push_back( zonebc_1to1 );
+                    zonebc_1to1->zoneid = gZoneId;
+                    zonebc_1to1->transform = transform;
+                    zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                    for ( int i = 0; i < range.size(); ++ i )
+                    {
+                        zonebc_1to1->pnts.push_back( range[ i ] );
+                        zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                    }
+                }
+            }
+        }
+    }
+
+    {
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "Global::zones.size() = " << Global::zones.size() << "\n";
+    }
+
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/CgnsGrid.h b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/CgnsGrid.h
new file mode 100644
index 00000000..fddf1db6
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/CgnsGrid.h
@@ -0,0 +1,103 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    int zoneIndex;
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/Field.cpp b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/Field.cpp
new file mode 100644
index 00000000..9afbf451
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/Field.cpp
@@ -0,0 +1,197 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+
+    std::vector<double> & x = grid->x;
+    this->dx = std::abs( x[ 1 ] - x[ 0 ] );
+    this->dt = dx / 10.0;
+    this->t = 1.0;
+    this->nt = std::round( t / dt );
+
+    double total_time = nt * dt;
+
+    std::cout << "this->dt   = " << this->dt << "\n";
+    std::cout << "this->t    = " << this->t << "\n";
+    std::cout << "this->nt   = " << this->nt << "\n";
+    std::cout << "this->ni   = " << this->ni << "\n";
+    std::cout << "total_time = " << total_time << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+    u1.resize( ni_total );
+    r.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        u_e[ i ] = - std::exp( -total_time ) * std::sin( std::numbers::pi * xm ); //theory solution
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+    int kkk = 1;
+}
+
+void Field::Solve( Zone * zone )
+{
+    //this->FTCS( zone );
+    this->RungeKutta3( zone );
+}
+
+void Field::FTCS( Zone * zone )
+{
+    int ist = 1;
+    int ied = ni;
+
+    this->Rhs( this->un, this->r );
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + dt * r[ i ];
+    }
+}
+
+void Field::RungeKutta3( Zone * zone )
+{
+    int ist = 1;
+    int ied = ni;
+
+    this->Rhs( this->un, this->r );
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u1[ i ] = un[ i ] + dt * r[ i ];
+    }
+
+    this->Rhs( this->u1, this->r );
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = 0.75 * un[ i ] + 0.25 * u1[ i ] + 0.25 * dt * r[ i ];
+    }
+
+    this->Rhs( this->u, this->r );
+
+    double c1 = 1.0 / 3.0;
+    double c2 = 2.0 / 3.0;
+    double c3 = 2.0 / 3.0;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = c1 * un[ i ] + c2 * u[ i ] + c3 * dt * r[ i ];
+    }
+
+}
+
+void Field::Rhs( std::vector<double> & u, std::vector<double> & r )
+{
+    int ist = 1;
+    int ied = ni;
+
+    double coef = this->alpha / ( dx * dx );
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        r[ i ] = coef * ( u[ i + 1 ] - 2.0 * u[ i ] + u[ i - 1 ] );
+    }
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        //std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        //region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+        int kkk = 1;
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
+
+void Field::UpdateOldField()
+{
+    for ( int i = 0; i < this->u.size(); ++ i )
+    {
+        this->un[ i ] = this->u[ i ];
+    }
+}
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/Field.h b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/Field.h
new file mode 100644
index 00000000..f6e78a8b
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/Field.h
@@ -0,0 +1,41 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un, u1;
+    std::vector<double> r;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid );
+    void Solve( Zone * zone );
+public:
+    void FTCS( Zone * zone );
+    void RungeKutta3( Zone * zone );
+    void Rhs( std::vector<double> & u, std::vector<double> & r );
+
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void UpdateOldField();
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/LogFile.cpp b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/LogFile.cpp
new file mode 100644
index 00000000..08ccd453
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/LogFile.cpp
@@ -0,0 +1,138 @@
+#include "LogFile.h"
+#include "Parallel.h"
+#include <sstream>
+#include <iostream>
+
+#ifdef _WINDOWS
+#include <windows.h>
+#include <direct.h>
+#include <io.h>
+#else
+#include <sys/stat.h>
+#include <unistd.h>
+#endif
+
+LogFile logFile;
+
+class OStream : public std::ostringstream
+{
+public:
+    OStream() {}
+    ~OStream() {}
+public:
+    void ClearAll()
+    {
+        this->clear();
+        this->str("");
+    }
+};
+
+OStream StrIO;
+std::string GetPrjDirName( const std::string & fileName );
+bool DirExist( const std::string & dirName );
+void MakeDir( const std::string & dirName );
+
+std::string GetPrjDirName( const std::string & fileName )
+{
+    size_t pos = fileName.find_last_of("\\/");
+    if ( std::string::npos == pos )
+    {
+        return "";
+    }
+    else
+    {
+        return fileName.substr( 0, pos );
+    }
+}
+
+bool DirExist( const std::string & dirName )
+{
+#ifdef _WINDOWS
+    bool flag = ( _access( dirName.c_str(), 0 ) == 0 );
+    return flag;
+#else
+    bool flag = ( access( dirName.c_str(), 0 ) == 0 );
+    return flag;
+#endif
+}
+
+void MakeDir( const std::string & dirName )
+{
+    int flag;
+#ifdef _WINDOWS
+    flag = _mkdir( dirName.c_str() );
+#else
+    flag = mkdir( dirName.c_str(), S_IRWXU );
+#endif
+    if ( flag == 0 )
+    {
+        std::cout << dirName << " directory has been created successfully !\n";
+    }
+}
+
+void CreateDirIfNeeded( std::string & prjFileName )
+{
+    std::string prj_dir = GetPrjDirName( prjFileName );
+
+    if ( ! DirExist( prj_dir ) )
+    {
+        MakeDir( prj_dir );
+    }
+}
+
+
+void OpenLogFile( int logFileIndex, std::fstream & file )
+{
+    static int ifReWrite = 0;
+
+    StrIO.ClearAll();
+    StrIO << "log/log" << logFileIndex << ".log";
+    std::string fileName = StrIO.str();
+
+    std::ios_base::openmode openMode;
+
+    if ( ifReWrite == 0 )
+    {
+        CreateDirIfNeeded( fileName );
+
+        openMode = std::ios_base::out | std::ios_base::trunc;
+
+        ifReWrite = 1;
+    }
+    else
+    {
+        openMode = std::ios_base::out | std::ios_base::app;
+    }
+
+    file.open( fileName.c_str(), openMode );
+    if ( ! file )
+    {
+        std::cout << "could not open " << fileName << std::endl;
+        exit( 0 );
+    }
+}
+
+void CloseLogFile( std::fstream & file )
+{
+    file.close();
+    file.clear();
+}
+
+LogFile::LogFile()
+{
+}
+
+LogFile::~LogFile()
+{
+}
+
+void LogFile::Open()
+{
+    int pid = Parallel::pid;
+    OpenLogFile( pid, this->my_fstream );
+}
+
+void LogFile::Close()
+{
+    CloseLogFile( this->my_fstream );
+}
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/LogFile.h b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/LogFile.h
new file mode 100644
index 00000000..00e775ab
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/LogFile.h
@@ -0,0 +1,27 @@
+#pragma once
+#include <fstream>
+
+void OpenLogFile( int logFileIndex, std::fstream & file );
+void CloseLogFile( std::fstream & file );
+class LogFile;
+extern LogFile logFile;
+
+class LogFile
+{
+public:
+    LogFile();
+    ~LogFile();
+    std::fstream my_fstream;
+public:
+    void Open();
+    void Close();
+};
+
+template< typename T >
+LogFile & operator << ( LogFile & f, const T & value )
+{
+    f.Open();
+    f.my_fstream << value;
+    f.Close();
+    return f;
+}
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/Parallel.cpp b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/Parallel.cpp
new file mode 100644
index 00000000..0bce1a60
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/Parallel.cpp
@@ -0,0 +1,54 @@
+#include "Parallel.h"
+#include <iostream>
+
+int Parallel::pid = 0;
+int Parallel::nProc = 1;
+int Parallel::serverid = 0;
+int Parallel::tag = 0;
+
+void Parallel::Init()
+{
+#ifdef HX_PARALLEL
+    int argc     = 0;
+    char ** argv = 0;
+    MPI_Init( &argc, &argv );
+    MPI_Comm_rank( MPI_COMM_WORLD, &Parallel::pid );
+    MPI_Comm_size( MPI_COMM_WORLD, &Parallel::nProc );
+    int len = -1;
+    char version[ MPI_MAX_LIBRARY_VERSION_STRING ];
+    MPI_Get_library_version( version, &len );
+    std::cout << "Hello, world!  I am " << Parallel::pid << " of " << Parallel::nProc
+        << "(" << version << ", " << len << ")" << std::endl;
+#endif
+}
+
+void Parallel::Finalize()
+{
+#ifdef HX_PARALLEL
+    MPI_Finalize();
+#endif
+}
+
+bool Parallel::IsServer()
+{
+    return Parallel::pid == Parallel::serverid;
+}
+
+void HXSendChar( void * data, int size, int pid, int tag )
+{
+#ifdef HX_PARALLEL
+    if ( size <= 0 ) return;
+    MPI_Send( data, size, MPI_CHAR, pid, tag, MPI_COMM_WORLD );
+#endif
+}
+
+void HXRecvChar( void * data, int size, int pid, int tag )
+{
+#ifdef HX_PARALLEL
+    if ( size <= 0 ) return;
+
+    MPI_Status status;
+    MPI_Recv( data, size, MPI_CHAR, pid, tag, MPI_COMM_WORLD, & status );
+#endif
+}
+
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/Parallel.h b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/Parallel.h
new file mode 100644
index 00000000..880a71cb
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/Parallel.h
@@ -0,0 +1,78 @@
+#pragma once
+#ifdef HX_PARALLEL
+#include "mpi.h"
+#endif
+#include <vector>
+#include "LogFile.h"
+
+class Parallel
+{
+public:
+    static int pid;
+    static int nProc;
+    static int serverid;
+    static int tag;
+public:
+    static void Init();
+    static void Finalize();
+public:
+    static bool IsServer();
+};
+
+void HXSendChar( void * data, int size, int pid, int tag );
+void HXRecvChar( void * data, int size, int pid, int tag );
+
+template< typename T >
+void HXSendData( T * field, int nElement, int recv_pid, int tag  );
+
+template< typename T >
+void HXRecvData( T * field, int nElement, int send_pid, int tag );
+
+template< typename T >
+void HXSendData( T * field, int nElement, int recv_pid, int tag = 0 )
+{
+    if ( nElement <= 0 ) return;
+
+    int buffer_size = nElement * sizeof( T );
+
+    HXSendChar( field, buffer_size, recv_pid, tag );
+}
+
+template< typename T >
+void HXRecvData( T * field, int nElement, int send_pid, int tag = 0 )
+{
+    if ( nElement <= 0 ) return;
+
+    int buffer_size = nElement * sizeof( T );
+
+    HXRecvChar( field, buffer_size, send_pid, tag );
+}
+
+template< typename T >
+void HXSendRecvData( T * field, int nElement, int send_pid, int recv_pid, int tag = 0 )
+{
+    if ( send_pid == recv_pid ) return;
+
+    if ( nElement <= 0 ) return;
+
+    int buffer_size = nElement * sizeof( T );
+
+    if ( Parallel::pid == send_pid )
+    {
+        HXSendChar( field, buffer_size, recv_pid, tag );
+    }
+    else if ( Parallel::pid == recv_pid )
+    {
+        HXRecvChar( field, buffer_size, send_pid, tag );
+    }
+}
+
+template< typename T >
+void HXBcastData( T * field, int nElement, int send_pid )
+{
+    if ( nElement <= 0 ) return;
+    int buffer_size = nElement * sizeof( T );
+#ifdef HX_PARALLEL
+    MPI_Bcast( field, buffer_size, MPI_CHAR, send_pid, MPI_COMM_WORLD );
+#endif
+}
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/README.txt b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/README.txt
new file mode 100644
index 00000000..5a4410fb
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/README.txt
@@ -0,0 +1,3 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
+
+PS D:\github\OneFLOW\example\1d-heat-equation\ftcs\cpp\multiblock\parallel\8blocks\01\build> mpiexec -n 8 .\Debug\testprj.exe
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/Solver.cpp b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/Solver.cpp
new file mode 100644
index 00000000..25038559
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/Solver.cpp
@@ -0,0 +1,680 @@
+#include "Solver.h"
+#include "Parallel.h"
+#include "ZoneState.h"
+#include "global.h"
+#include <fstream>
+#include <set>
+#include <unordered_map>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+Solver::Solver()
+{
+    Parallel::Init();
+}
+
+Solver::~Solver()
+{
+    Parallel::Finalize();
+}
+
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    this->InitTopo();
+    this->InitFields();
+    this->SolveMultiZones();
+    this->PostProcess();
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d4blocksv1.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    ReadCgnsGrid( fileName );
+}
+
+void Solver::InitTopo()
+{
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "Solver::InitTopo() " << "\n";
+
+    Global::donor_zone_sets.resize( LocalZone::nZones );
+    Global::donor_zones.resize( LocalZone::nZones );
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        int global_zoneid = LocalZone::global_zoneids[ iZone ];
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "iZone = " << iZone << " global_zoneid = " << global_zoneid << "\n";
+
+        Interface * interface = new Interface();
+        interface->zoneid = global_zoneid;
+        Global::interfaces.push_back( interface );
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+        Interface * interface = Global::interfaces[ iZone ];
+
+        int nbc1to1s = zone->bc1to1s.size();
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout <<  "nbc1to1s = " << nbc1to1s << "\n";
+
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "zoneid = " << zoneid << " donor_zoneid = " << donor_zoneid << "\n";
+
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+        int nInterfaces = interface->zoneList.size();
+        interface->data_recv.resize( nInterfaces );
+        interface->data_send.resize( nInterfaces );
+    }
+
+    for ( int iProc = 0; iProc < Parallel::nProc; ++ iProc )
+    {
+        int nSize = -1;
+        if ( iProc == Parallel::pid )
+        {
+            nSize = Global::facePairList.size();
+        }
+        HXBcastData( &nSize, 1, iProc );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nSize = " << nSize << "\n";
+        std::vector<FacePair> tmp;
+        if ( iProc == Parallel::pid )
+        {
+            tmp = Global::facePairList;
+        }
+        else
+        {
+            tmp.resize( nSize );
+        }
+
+        HXBcastData( tmp.data(), tmp.size(), iProc );
+        Global::AddFacePairList( Global::mpi_facePairList, tmp );
+    }
+
+    for ( int i = 0; i < Global::mpi_facePairList.size(); ++ i )
+    {
+        FacePair &facePair = Global::mpi_facePairList[ i ];
+        Global::InsertFacePairMap( facePair );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        facePair.Print();
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterfaces = interface->local_faceids.size();
+        for ( int iInterface = 0; iInterface < nInterfaces; ++ iInterface )
+        {
+            int local_faceid = interface->local_faceids[ iInterface ];
+            int proc_global_faceid = interface->proc_global_faceids[ iInterface ];
+            FacePair & facePair = Global::facePairList[ proc_global_faceid ];
+            int global_faceid = Global::InsertFacePairMap( facePair );
+            interface->global_faceids.push_back( global_faceid );
+            interface->global_local_face_map.insert( std::make_pair( global_faceid, local_faceid ) );
+        }
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        std::set<int> &donor_zoneSet = Global::donor_zone_sets[ iZone ];
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            donor_zoneSet.insert( donor_zoneid );
+        }
+
+        std::vector<int> &donor_zones = Global::donor_zones[ iZone ];
+        for ( std::set<int>::iterator iter = donor_zoneSet.begin(); iter != donor_zoneSet.end(); ++ iter )
+        {
+            donor_zones.push_back( *iter );
+        }
+
+        interface->neighbor_donor_zones = donor_zones;
+
+        std::unordered_map<int, int> donor_zonelocal;
+
+        for ( int idonor = 0; idonor < donor_zones.size(); ++ idonor )
+        {
+            int donor_zone = donor_zones[ idonor ];
+            donor_zonelocal.insert( std::make_pair( donor_zone, idonor ) );
+        }
+        int ndonors = donor_zones.size();
+        std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+        neighbor_donorfaces.resize( ndonors );
+
+        std::vector<std::vector<int>> & sub_local_faceids = interface->sub_local_faceids;
+        sub_local_faceids.resize( ndonors );
+
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ineighbor = donor_zonelocal[ donor_zoneid ];
+            std::vector<int> &donorfaces = neighbor_donorfaces[ ineighbor ];
+            int global_faceid = interface->global_faceids[ iFace ];
+            donorfaces.push_back( global_faceid );
+            int local_faceid = interface->local_faceids[ iFace ];
+
+            std::vector<int> & sub_local_faces = sub_local_faceids[ ineighbor ];
+            sub_local_faces.push_back( local_faceid );
+        }
+    }
+
+    Global::interfaceTopo.InitNeighborInfo();
+    Global::interfaceTopo.SwapNeighborInfo();
+
+    int kkk = 1;
+}
+
+void Solver::InitFields()
+{
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "Solver::InitFields() ZoneState::nZones = " << ZoneState::nZones <<  "\n";
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+    }
+
+    Boundary();
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        //std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        //std::cout << "it = " << it << " nt = " << Global::nt << "\n";
+        for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+        {
+            Field * field = Global::fields[ iZone ];
+            Zone * zone = Global::zones[ iZone ];
+            zone->zoneIndex = iZone;
+            field->Solve( zone );
+        }
+        Boundary();
+    }
+}
+
+void Solver::Boundary()
+{
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+    ExchangeInterfaceField();
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->UpdateOldField();
+    }
+}
+
+void Solver::UploadInterfaceField()
+{
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> & send_to_zones = interface->send_to_zones;
+        int nsend_zones = send_to_zones.size();
+
+        std::vector<std::vector<int>> & donorfaces_for_send = interface->donorfaces_for_send;
+        std::vector<std::vector<int>> & donorijk_for_send = interface->donorijk_for_send;
+        std::vector<std::vector<double>> & donordata_for_send = interface->donordata_for_send;
+
+        Field * field = Global::fields[ iZone ];
+
+        for ( int iSend = 0; iSend < nsend_zones; ++ iSend )
+        {
+            int zone_to_send = send_to_zones[ iSend ];
+            std::vector<int> & donorfaces = donorfaces_for_send[ iSend ];
+            std::vector<int> & donorijks = donorijk_for_send[ iSend ];
+            std::vector<double> & donordatas = donordata_for_send[ iSend ];
+
+            int nface = donorfaces.size();
+            int index_dim = 1;
+            for ( int i = 0; i < nface; ++ i )
+            {
+                int ijkpos = index_dim * i;
+                int i_donor_cell = donorijks[ ijkpos + 0 ];
+                donordatas[ i ] = field->u[ i_donor_cell ];
+            }
+        }
+    }
+}
+
+void Solver::UpdateInterfaceField()
+{
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        int ndonor_zones = Global::interfaceTopo.linkmap[ iZone ].size();
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donor_zone = Global::interfaceTopo.linkmap[ iZone ][ iNei ];
+            int send_pid = ZoneState::pids[ iZone ];
+            int recv_pid = ZoneState::pids[ donor_zone ];
+            int nsend = -1;
+            std::vector<double> donordata;
+            if ( Parallel::pid != send_pid && Parallel::pid != recv_pid ) continue;
+            if ( Parallel::pid == send_pid )
+            {
+                int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+                Interface * interface = Global::interfaces[ local_zoneid ];
+                donordata = interface->donordata_for_send[ iNei ];
+                nsend = donordata.size();
+            }
+            HXSendRecvData( &nsend, 1, send_pid, recv_pid );
+
+            if ( Parallel::pid == recv_pid )
+            {
+                donordata.resize( nsend );
+            }
+            HXSendRecvData( donordata.data(), donordata.size(), send_pid, recv_pid );
+
+            if ( Parallel::pid == recv_pid )
+            {
+                int local_donor_zoneid = ZoneState::g2lzoneids[ donor_zone ];
+                Interface * donor_interface = Global::interfaces[ local_donor_zoneid ];
+                int nSize = donor_interface->neighbor_donor_zones.size();
+                int ipos = -1;
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    int nei_zone = donor_interface->neighbor_donor_zones[ i ];
+                    if ( nei_zone == iZone )
+                    {
+                        ipos = i;
+                        break;
+                    }
+                }
+
+                std::vector<int> & neighbor_donorfaces = donor_interface->neighbor_donorfaces[ ipos ];
+                std::vector<int> & sub_local_faceids = donor_interface->sub_local_faceids[ ipos ];
+                for ( int i = 0; i < neighbor_donorfaces.size(); ++ i )
+                {
+                    int local_faceid = sub_local_faceids[ i ];
+                    double donor_value = donordata[ i ];
+                    donor_interface->data_recv[ local_faceid ] = donor_value;
+                }
+            }
+        }
+    }
+}
+
+void Solver::DownloadInterfaceField()
+{
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+        Field * field = Global::fields[ iZone ];
+
+        int nInterFaces = interface->data_recv.size();
+
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+
+            double donor_value = interface->data_recv[ iFace ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    this->UploadInterfaceField();
+    this->UpdateInterfaceField();
+    this->DownloadInterfaceField();
+}
+
+void Solver::PostProcess()
+{
+    Post post;
+    post.Process();
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        if ( !ZoneState::IsValid( iZone ) && !Parallel::IsServer() ) continue;
+
+        double xmin = 0.0;
+        double xmax = 0.0;
+
+        if ( ZoneState::IsValid( iZone ) )
+        {
+            int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+            Grid * grid = Global::grids[ local_zoneid ];
+            int ni = grid->x.size();
+            xmin = grid->x[ 0 ];
+            xmax = grid->x[ 0 ];
+            int imin = 0;
+            int imax = 0;
+            for ( int i = 0; i < ni; ++ i )
+            {
+                if ( xmin > grid->x[ i ] )
+                {
+                    xmin = grid->x[ i ];
+                    imin = i;
+                }
+                if ( xmax < grid->x[ i ] )
+                {
+                    xmax = grid->x[ i ];
+                    imax = i;
+                }
+            }
+        }
+
+        HXSendRecvData( &xmin, 1, ZoneState::pids[ iZone ], Parallel::serverid );
+        HXSendRecvData( &xmax, 1, ZoneState::pids[ iZone ], Parallel::serverid );
+
+        //if ( Parallel::IsServer() )
+        //{
+        //    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        //    std::cout << "xmin = " << xmin << "\n";
+        //    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        //    std::cout << "xmax = " << xmax << "\n";
+        //}
+
+        if ( Parallel::IsServer() )
+        {
+            xmin_list.push_back( xmin );
+            xmax_list.push_back( xmax );
+        }
+    }
+
+    //if ( Parallel::IsServer() )
+    //{
+    //    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    //    for ( int i = 0; i < xmin_list.size(); ++ i )
+    //    {
+    //        std::cout << "(" << xmin_list[ i ] << "," << xmax_list[ i ] << ") ";
+    //    }
+    //    std::cout << "\n";
+    //}
+
+    if ( Parallel::IsServer() )
+    {
+        std::vector<std::pair<double, int>> pairs;
+        int nSize = xmin_list.size();
+        for ( int i = 0; i < nSize; ++ i )
+        {
+            pairs.push_back( std::make_pair( xmin_list[ i ], i ) );
+        }
+
+        std::sort( pairs.begin(), pairs.end() );
+
+        for ( int i = 0; i < nSize; ++ i )
+        {
+            this->zoneids.push_back( pairs[ i ].second );
+        }
+    }
+
+    int kkk = 1;
+}
+
+bool IsLastZone( int iZone );
+bool IsLastZone( int iZone )
+{
+    return iZone == ZoneState::nZones - 1;
+}
+
+void Post::AddVector( std::vector<double> & a, std::vector<double> & b )
+{
+    for ( int i = 0; i < b.size(); ++ i )
+    {
+        a.push_back( b[ i ] );
+    }
+}
+
+void Post::GatherField()
+{
+    this->zoneids.resize( ZoneState::nZones );
+    HXBcastData( this->zoneids.data(), this->zoneids.size(), Parallel::serverid );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "Post::GatherField() this->zoneids = \n";
+    for ( int i = 0; i < this->zoneids.size(); ++ i )
+    {
+        std::cout << this->zoneids[ i ] << " ";
+    }
+    std::cout << "\n";
+
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+
+        if ( !ZoneState::IsValid( zoneid ) && !Parallel::IsServer() ) continue;
+
+        int nSize = -1;
+        std::vector<double> local_x;
+        std::vector<double> local_u_e;
+        std::vector<double> local_un;
+        std::vector<double> local_u;
+
+        if ( Parallel::pid == ZoneState::pids[ zoneid ] )
+        {
+            int local_zoneid = ZoneState::g2lzoneids[ zoneid ];
+            Grid * grid = Global::grids[ local_zoneid ];
+            Field * field = Global::fields[ local_zoneid ];
+            int ni = grid->x.size();
+
+            int ist = 1;
+            int ied = ni;
+
+            int dir = 1;
+            if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+            if ( dir == 1 )
+            {
+                if ( IsLastZone( iZone ) )
+                {
+                    for ( int i = ist; i <= ied; ++ i )
+                    {
+                        double xm = grid->x[ i - ist ];
+                        local_x.push_back( xm );
+                        local_u_e.push_back( field->u_e[ i ] );
+                        local_un.push_back( field->un[ i ] );
+                        local_u.push_back( field->u[ i ] );
+                    }
+                }
+                else
+                {
+                    for ( int i = ist; i <= ied - 1; ++ i )
+                    {
+                        double xm = grid->x[ i - ist ];
+                        local_x.push_back( xm );
+                        local_u_e.push_back( field->u_e[ i ] );
+                        local_un.push_back( field->un[ i ] );
+                        local_u.push_back( field->u[ i ] );
+                    }
+                }
+            }
+            else
+            {
+                if ( IsLastZone( iZone ) )
+                {
+                    for ( int i = ied; i >= ist; -- i )
+                    {
+                        double xm = grid->x[ i - ist ];
+                        local_x.push_back( xm );
+                        local_u_e.push_back( field->u_e[ i ] );
+                        local_un.push_back( field->un[ i ] );
+                        local_u.push_back( field->u[ i ] );
+                    }
+                }
+                else
+                {
+                    for ( int i = ied; i >= ist + 1; -- i )
+                    {
+                        double xm = grid->x[ i - ist ];
+                        local_x.push_back( xm );
+                        local_u_e.push_back( field->u_e[ i ] );
+                        local_un.push_back( field->un[ i ] );
+                        local_u.push_back( field->u[ i ] );
+                    }
+                }
+            }
+            nSize = local_x.size();
+        }
+
+        int send_pid = ZoneState::pids[ zoneid ];
+
+        HXSendRecvData( &nSize, 1, send_pid, Parallel::serverid );
+
+        if ( Parallel::IsServer() )
+        {
+            local_x.resize( nSize );
+            local_u_e.resize( nSize );
+            local_un.resize( nSize );
+            local_u.resize( nSize );
+        }
+
+        HXSendRecvData( local_x.data(), local_x.size(), send_pid, Parallel::serverid );
+        HXSendRecvData( local_u_e.data(), local_u_e.size(), send_pid, Parallel::serverid );
+        HXSendRecvData( local_un.data(), local_un.size(), send_pid, Parallel::serverid );
+        HXSendRecvData( local_u.data(), local_u.size(), send_pid, Parallel::serverid );
+
+        if ( Parallel::IsServer() )
+        {
+            this->AddVector( this->x, local_x );
+            this->AddVector( this->u_e, local_u_e );
+            this->AddVector( this->un, local_un );
+            this->AddVector( this->u, local_u );
+        }
+    }
+}
+
+void Post::DumpField()
+{
+    if ( !Parallel::IsServer() ) return;
+    int ni_total = this->x.size();
+    std::cout << " DumpField x.size() = " << x.size() << "\n";
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    this->DumpErrorDetails( u_error );
+
+    std::string csvname = "field_final.csv";
+    this->DumpCsvFile( csvname, x, u_e, un, u_error );
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.20f} {:.20f} {:.20f} {:.20f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/Solver.h b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/Solver.h
new file mode 100644
index 00000000..9914c1d7
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/Solver.h
@@ -0,0 +1,49 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+
+class Solver
+{
+public:
+    Solver();
+    ~Solver();
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveMultiZones();
+public:
+    void Boundary();
+    void UploadInterfaceField();
+    void UpdateInterfaceField();
+    void DownloadInterfaceField();
+    void ExchangeInterfaceField();
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcess();
+};
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+    std::vector<double> u;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+public:
+    void AddVector( std::vector<double> & a, std::vector<double> & b );
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/ZoneState.cpp b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/ZoneState.cpp
new file mode 100644
index 00000000..ff810849
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/ZoneState.cpp
@@ -0,0 +1,20 @@
+#include "ZoneState.h"
+#include "Parallel.h"
+
+int ZoneState::nZones = 0;
+std::vector<int> ZoneState::pids;
+std::vector<int> ZoneState::g2lzoneids;
+
+bool ZoneState::IsValid( int zoneid )
+{
+    return ZoneState::pids[ zoneid ] == Parallel::pid;
+}
+
+int ZoneState::GetProcID( int zoneid )
+{
+    return ZoneState::pids[ zoneid ];
+}
+
+int LocalZone::nZones = 0;
+std::vector<int> LocalZone::global_zoneids;
+
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/ZoneState.h b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/ZoneState.h
new file mode 100644
index 00000000..1096d632
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/ZoneState.h
@@ -0,0 +1,21 @@
+#pragma once
+#include <vector>
+
+class ZoneState
+{
+public:
+    static int nZones;
+    static int zone_id;
+    static std::vector<int> pids;
+    static std::vector<int> g2lzoneids; //global zone id to local zone id
+public:
+    static bool IsValid( int zoneid );
+    static int GetProcID( int zoneid );
+};
+
+class LocalZone
+{
+public:
+    static int nZones;
+    static std::vector<int> global_zoneids;
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/global.cpp b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/global.cpp
new file mode 100644
index 00000000..df1e6bae
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/global.cpp
@@ -0,0 +1,300 @@
+#include "global.h"
+#include "CgnsGrid.h"
+#include "ZoneState.h"
+#include "Parallel.h"
+#include <iostream>
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *> Global::interfaces;
+
+std::map<Face, int> Global::faceMap;
+std::map<FacePair, int> Global::facePairMap;
+std::vector<FacePair> Global::facePairList;
+std::vector<FacePair> Global::mpi_facePairList;
+
+std::vector<std::set<int>> Global::donor_zone_sets;
+std::vector<std::vector<int>> Global::donor_zones;
+
+InterfaceTopo Global::interfaceTopo;
+
+bool Face::operator < ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return this->zone < rhs.zone;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return this->i < rhs.i;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return this->j < rhs.j;
+    }
+
+    return this->k < rhs.k;
+}
+
+bool Face::operator == ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return false;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return false;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return false;
+    }
+
+    return this->k == rhs.k;
+}
+
+void Face::Print()
+{
+    std::cout << "(" << this->zone << "," << this->i << ")";
+}
+
+void FacePair::AddPair( const Face & face1, const Face & face2 )
+{
+    if ( face1 < face2 )
+    {
+        this->left = face1;
+        this->right = face2;
+    }
+    else
+    {
+        this->left = face2;
+        this->right = face1;
+    }
+}
+
+bool FacePair::operator < ( const FacePair & rhs ) const
+{
+    if ( this->left == rhs.left || this->left == rhs.right )
+    {
+        return false;
+    }
+
+    return this->left < rhs.left;
+}
+
+void FacePair::Print()
+{
+    this->left.Print();
+    std::cout << " ";
+    this->right.Print();
+    std::cout << "\n";
+}
+
+void InterfaceTopo::InitNeighborInfo()
+{
+    this->linkmap.resize( ZoneState::nZones );
+
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        if ( ! ZoneState::IsValid( iZone ) ) continue;
+
+        int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+
+        Interface * interface = Global::interfaces[ local_zoneid ];
+
+        std::vector<int> & t = this->linkmap[ iZone ];
+        t = interface->neighbor_donor_zones;
+    }
+}
+
+void InterfaceTopo::SwapNeighborInfo()
+{
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        int pid = ZoneState::pids[ iZone ];
+
+        std::vector<int> & donor_zones = this->linkmap[ iZone ];
+        int nNeighbor = donor_zones.size();
+
+        HXBcastData( &nNeighbor, 1, pid );
+
+        donor_zones.resize( nNeighbor );
+
+        HXBcastData( donor_zones.data(), donor_zones.size(), pid );
+    }
+
+    this->SwapNeighborDonorfaces();
+}
+
+void InterfaceTopo::SwapNeighborDonorfaces()
+{
+    int gl = 0;
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        int send_pid = ZoneState::pids[ iZone ];
+
+        std::vector<int> & donor_zones = this->linkmap[ iZone ];
+        int ndonor_zones = donor_zones.size();
+
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donor_zone = donor_zones[ iNei ];
+            int recv_pid = ZoneState::pids[ donor_zone ];
+            int nInterFaces = 0;
+            std::vector<int> donorfaces;
+
+            if ( Parallel::pid == send_pid )
+            {
+                int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+
+                Interface * interface = Global::interfaces[ local_zoneid ];
+
+                std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+
+                std::vector<int> & neighbor_donorface = neighbor_donorfaces[ iNei ];
+
+                nInterFaces = neighbor_donorface.size();
+
+                donorfaces = neighbor_donorface;
+            }
+
+            HXSendRecvData( &nInterFaces, 1, send_pid, recv_pid );
+
+            if ( Parallel::pid == recv_pid && send_pid != recv_pid )
+            {
+                donorfaces.resize( nInterFaces );
+            }
+
+            HXSendRecvData( donorfaces.data(), donorfaces.size(), send_pid, recv_pid );
+
+            if ( Parallel::pid == recv_pid )
+            {
+                int local_donor_zoneid = ZoneState::g2lzoneids[ donor_zone ];
+                Interface * interface_recv = Global::interfaces[ local_donor_zoneid ];
+                interface_recv->SendGeom( iZone, donorfaces );
+            }
+        }
+    }
+}
+
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->local_faceids.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        Face face;
+        face.zone = zoneid;
+        face.i = i;
+
+        int i_donor = index2[ 0 ];
+
+        Face face_donor;
+        face_donor.zone = donor_zoneid;
+        face_donor.i = i_donor;
+
+        FacePair facePair;
+        facePair.AddPair( face, face_donor );
+
+        Global::facePairList.push_back( facePair );
+        int nSize = Global::facePairList.size();
+        this->proc_global_faceids.push_back( nSize - 1 );
+
+        int i_ghost_cell = i + 1;
+        int i_local_donor_cell = i - 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+            i_local_donor_cell = i + 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+        ijk_donors.push_back( i_local_donor_cell );
+
+        icount ++;
+    }
+}
+
+void Interface::SendGeom( int zone, std::vector<int> & donorfaces )
+{
+    Interface * interface = this;
+
+    std::vector<int> & send_to_zones = interface->send_to_zones;
+
+    send_to_zones.push_back( zone );
+    interface->donorfaces_for_send.push_back( donorfaces );
+
+    int nface = donorfaces.size();
+    std::vector<int> sub_donorijk;
+    int index_dim = 1;
+    for ( int i = 0; i < nface; ++ i )
+    {
+        int global_faceid = donorfaces[ i ];
+        int local_faceid = interface->global_local_face_map[ global_faceid ];
+        int ijkpos = index_dim * local_faceid;
+        int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+        sub_donorijk.push_back( i_donor_cell );
+        int kkk = 1;
+    }
+
+    interface->donorijk_for_send.push_back( sub_donorijk );
+
+    std::vector<double> sub_donordata( sub_donorijk.size() );
+    interface->donordata_for_send.push_back( sub_donordata );
+}
+
+void Global::InsertFaceMap( const Face & face )
+{
+    std::map<Face, int>::iterator iter;
+    iter = Global::faceMap.find( face );
+    if ( iter == Global::faceMap.end() )
+    {
+        int faceid = Global::faceMap.size();
+        Global::faceMap.insert( std::make_pair( face, faceid ) );
+    }
+}
+
+int Global::InsertFacePairMap( const FacePair & facePair )
+{
+    std::map<FacePair, int>::iterator iter;
+    iter = Global::facePairMap.find( facePair );
+    if ( iter == Global::facePairMap.end() )
+    {
+        int facePairId = Global::facePairMap.size();
+        Global::facePairMap.insert( std::make_pair( facePair, facePairId ) );
+        return facePairId;
+    }
+    return iter->second;
+}
+
+void Global::AddFacePairList( std::vector<FacePair> & a, std::vector<FacePair> & b )
+{
+    for ( int i = 0; i < b.size(); ++ i )
+    {
+        a.push_back( b[ i ] );
+    }
+}
+
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/global.h b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/global.h
new file mode 100644
index 00000000..933cec05
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/global.h
@@ -0,0 +1,157 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <unordered_map>
+#include <set>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class Face
+{
+public:
+    int zone = 0;
+    int i = 0;
+    int j = 1;
+    int k = 1;
+public:
+    bool operator < ( const Face & rhs ) const;
+    bool operator == ( const Face & rhs ) const;
+public:
+    void Print();
+};
+
+class FacePair
+{
+public:
+    Face left;
+    Face right;
+public:
+    bool operator < ( const FacePair & rhs ) const;
+    void AddPair( const Face &face1, const Face &face2);
+public:
+    void Print();
+};
+
+class Transform;
+
+class InterfaceTopo
+{
+public:
+    std::vector<std::vector<int>> linkmap;
+public:
+    void InitNeighborInfo();
+    void SwapNeighborInfo();
+    void SwapNeighborDonorfaces();
+};
+
+
+class Interface
+{
+public:
+    int zoneid;
+    std::vector<int> zoneList;
+    std::vector<int> global_faceids;
+    std::vector<int> mpi_global_faceids;
+    std::vector<int> proc_global_faceids;
+    std::vector<int> local_faceids;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+    std::vector<double> data_recv;
+    std::vector<double> data_send;
+    std::unordered_map<int, int> global_local_face_map;
+public:
+    std::vector<int> neighbor_donor_zones;
+    std::vector<std::vector<int>> neighbor_donorfaces;
+    std::vector<std::vector<int>> sub_local_faceids;
+    std::vector<int> send_to_zones;
+    std::vector<std::vector<int>> donorfaces_for_send;
+    std::vector<std::vector<int>> donorijk_for_send;
+    std::vector<std::vector<double>> donordata_for_send;
+public:
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+    void SendGeom( int zone, std::vector<int> & donorfaces );
+};
+
+class Field;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+public:
+    static std::map<Face, int> faceMap;
+    static std::map<FacePair, int> facePairMap;
+    static std::vector<FacePair> facePairList;
+    static std::vector<FacePair> mpi_facePairList;
+    static std::vector<std::set<int>> donor_zone_sets;
+    static std::vector<std::vector<int>> donor_zones;
+    static InterfaceTopo interfaceTopo;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+public:
+    static void InsertFaceMap( const Face & face );
+    static int InsertFacePairMap( const FacePair & facePair );
+    static void AddFacePairList( std::vector<FacePair> & a, std::vector<FacePair> & b );
+};
+
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/heat1d4blocksv1.cgns b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/heat1d4blocksv1.cgns
new file mode 100644
index 00000000..df5ffc5f
Binary files /dev/null and b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/heat1d4blocksv1.cgns differ
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/main.cpp b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/main.cpp
new file mode 100644
index 00000000..df63b7da
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/main.cpp
@@ -0,0 +1,9 @@
+#include "Solver.h"
+#include "Parallel.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/plot.py b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/plotting2.jl b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01a/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/CMakeLists.txt b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/CMakeLists.txt
new file mode 100644
index 00000000..9e834b72
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/CMakeLists.txt
@@ -0,0 +1,99 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package ( MPI )
+
+message ( STATUS  "MPI_FOUND=${MPI_FOUND}" )
+message ( STATUS  "MPI_CXX_INCLUDE_DIRS=${MPI_CXX_INCLUDE_DIRS}" )
+message ( STATUS  "MPI_LIBRARIES=${MPI_LIBRARIES}" )
+if ( MPI_FOUND )
+	list ( APPEND PRJ_INCLUDE_DIRS ${MPI_CXX_INCLUDE_DIRS} )
+	list ( APPEND PRJ_LIBRARIES ${MPI_LIBRARIES} )
+endif ()
+
+#get_directory_property( my_import_targets DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} IMPORTED_TARGETS )
+#message( STATUS "my_import_targets=${my_import_targets}" )
+
+list ( APPEND PRJ_LIBRARIES MPI::MPI_C )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+list ( APPEND PRJ_COMPILE_DEFINITIONS HX_PARALLEL )
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	LogFile.h LogFile.cpp
+	Parallel.h Parallel.cpp
+	Solver.h Solver.cpp
+	ZoneState.h ZoneState.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/CgnsGrid.cpp b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/CgnsGrid.cpp
new file mode 100644
index 00000000..825442a2
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/CgnsGrid.cpp
@@ -0,0 +1,850 @@
+#include "CgnsGrid.h"
+#include "Parallel.h"
+#include "cgnslib.h"
+#include "global.h"
+#include "ZoneState.h"
+#include <iostream>
+#include <vector>
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "fileId = " << fileId << "\n";
+    }
+    
+    int nbases = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_nbases( fileId, &nbases );
+    }
+    HXBcastData( &nbases, 1, Parallel::serverid );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "nbases = " << nbases << "\n";
+    
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        }
+
+        HXBcastData( &icelldim, 1, Parallel::serverid );
+        HXBcastData( &iphysdim, 1, Parallel::serverid );
+
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+
+        int nzones = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_nzones( fileId, baseId, &nzones );
+        }
+
+        HXBcastData( &nzones, 1, Parallel::serverid );
+
+        ZoneState::nZones = nzones;
+        ZoneState::pids.resize( nzones );
+        ZoneState::g2lzoneids.resize( nzones );
+        std::vector<int> pcount( Parallel::nProc, 0 );
+
+        for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+        {
+            int zone_pid = iZone % Parallel::nProc;
+            ZoneState::pids[ iZone ] = zone_pid;
+            ZoneState::g2lzoneids[ iZone ] = pcount[ zone_pid ];
+            pcount[ zone_pid ] ++;
+        }
+
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nzones = " << nzones << "\n";
+
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "iZone = " << iZone << "\n";
+
+            int index_dim = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            }
+            HXBcastData( &index_dim, 1, Parallel::serverid );
+
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            if ( Parallel::IsServer() )
+            {
+                cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            }
+
+            HXBcastData( zonename, 33, Parallel::serverid );
+            HXBcastData( isize.data(), isize.size(), Parallel::serverid);
+
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "zonename = " << zonename << "\n";
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+
+    if ( Parallel::IsServer() )
+    {
+        cg_close( fileId );
+    }
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+        std::cout << "fileId = " << fileId << "\n";
+    }
+    
+    int nbases = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_nbases( fileId, &nbases );
+    }
+    MPI_Bcast( &nbases, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        }
+
+        HXBcastData( &icelldim, 1, Parallel::serverid );
+        HXBcastData( &iphysdim, 1, Parallel::serverid );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+
+        int nzones = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_nzones( fileId, baseId, &nzones );
+        }
+        HXBcastData( &nzones, 1, Parallel::serverid );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nzones = " << nzones << "\n";
+
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            }
+            HXSendRecvData( &index_dim, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "index_dim = " << index_dim << "\n";
+            }
+
+            std::vector<cgsize_t> isize;
+            char zonename[ 33 ];
+            if ( Parallel::IsServer() )
+            {
+                isize.resize( index_dim * 3 );
+                cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            }
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                isize.resize( index_dim * 3 );
+            }
+
+            HXSendRecvData( zonename, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+            HXSendRecvData( isize.data(), index_dim * 3, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "zonename = " << zonename << "\n";
+
+                for ( int i = 0; i < isize.size(); ++ i )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+                }
+            }
+
+            std::vector<cgsize_t> irmin;
+            std::vector<cgsize_t> irmax;
+            int nNodes = 1;
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                irmin.resize( index_dim );
+                irmax.resize( index_dim );
+                for ( int m = 0; m < index_dim; ++ m )
+                {
+                    /* lower range index */
+                    irmin[ m ] = 1;
+                    /* upper range index of vertices */
+                    irmax[ m ] = isize[ m ];
+                    nNodes *= irmax[ m ];
+                }
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "nNodes = " << nNodes << "\n";
+            }
+
+            ZoneType_t zoneType;
+            if ( Parallel::IsServer() )
+            {
+                cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            }
+            HXSendRecvData( &zoneType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            }
+
+            Zone * zone = nullptr;
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                zone = new Zone();
+                Global::zones.push_back( zone );
+                LocalZone::global_zoneids.push_back( iZone );
+                LocalZone::nZones = LocalZone::global_zoneids.size();
+                for ( int m = 0; m < index_dim; ++ m )
+                {
+                    zone->nijk.push_back( isize[ m ] );
+                }
+            }
+
+            Grid * grid = nullptr;
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                grid = new Grid();
+                Global::grids.push_back( grid );
+            }
+
+            BaseZone baseZone;
+
+            int gZoneId = -1;
+            if ( Parallel::IsServer() )
+            {
+                baseZone.zone_name = zonename;
+                gZoneId = Global::zone_names.FindBaseZone( baseZone );
+            }
+
+            HXSendRecvData( &gZoneId, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "gZoneId = " << gZoneId << "\n";
+            }
+
+            int ncoords = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            }
+            HXSendRecvData( &ncoords, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "ncoords = " << ncoords << "\n";
+            }
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                if ( Parallel::IsServer() )
+                {
+                    cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                }
+                HXSendRecvData( coordname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &dataType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "coordname = " << coordname << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                }
+
+                std::vector<char> coord;
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    coord.resize( nNodes * sizeof( double ) );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coord.data() );
+                }
+
+                HXSendRecvData( coord.data(), coord.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                Coor * coor = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    coor = new Coor();
+                    zone->coors.push_back( coor );
+                    coor->coorname = coordname;
+                    coor->nNodes = nNodes;
+                    coor->coord = coord;
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    coor->DumpCoor();
+
+                    if ( icoord == 0 )
+                    {
+                        grid->x.resize( nNodes );
+                        coor->DumpCoorX( grid->x );
+                    }
+                }
+            }
+
+            int nbocos = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            }
+            HXSendRecvData( &nbocos, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "nbocos = " << nbocos << "\n";
+            }
+
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                if ( Parallel::IsServer() )
+                {
+                    cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                }
+                HXSendRecvData( &location, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+                }
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                //std::vector<int> normalIndex( index_dim, -1 );
+                std::vector<int> normalIndex;
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+                if ( Parallel::IsServer() )
+                {
+                    normalIndex.resize( index_dim );
+                    cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                        &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                }
+
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    normalIndex.resize( index_dim );
+                }
+                
+                HXSendRecvData( boconame, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &bocotype, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &ptset_type, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &npnts, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &normalDataType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &normalListSize, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( normalIndex.data(), index_dim, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &ndataset, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "npnts = " << npnts << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalListSize = " << normalListSize << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalIndex = ";
+                    for ( int i = 0; i < index_dim; ++ i )
+                    {
+                        std::cout << normalIndex[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "ndataset = " << ndataset << "\n";
+                }
+
+                std::vector<char> normalList;
+                std::vector<cgsize_t> pnts;
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    if ( normalDataType == DataTypeNull )
+                    {
+                        normalList.resize( sizeof( int ) );
+                    }
+                    else
+                    {
+                        int nSize = nNodes * index_dim * sizeof( double );
+                        normalList.resize( nSize );
+                    }
+                    pnts.resize( npnts * index_dim );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                }
+
+                HXSendRecvData( pnts.data(), npnts * index_dim, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "pnts = ";
+                    for ( int i = 0; i < pnts.size(); ++ i )
+                    {
+                        std::cout << pnts[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                }
+                HXSendRecvData( normalList.data(), normalList.size(), Parallel::serverid, ZoneState::GetProcID(iZone));
+
+                ZoneBc * zonebc = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    zonebc = new ZoneBc();
+                    zone->bccos.push_back( zonebc );
+                    zonebc->bcType = bocotype;
+                    for ( int i = 0; i < pnts.size(); ++ i )
+                    {
+                        zonebc->pnts.push_back( pnts[ i ] );
+                    }
+                }
+            }
+            int n1to1 = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            }
+
+            HXSendRecvData( &n1to1, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "n1to1 = " << n1to1 << "\n";
+            }
+
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range;
+                std::vector<cgsize_t> donor_range;
+                std::vector<int> transform;
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    range.resize( npnts * index_dim );
+                    donor_range.resize( npnts * index_dim );
+                    transform.resize( index_dim );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                }
+
+                HXSendRecvData( connectname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( donorname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( range.data(), range.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( donor_range.data(), donor_range.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( transform.data(), transform.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "connectname = " << connectname << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "donorname = " << donorname << "\n";
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "range = ";
+                    for ( int i = 0; i < range.size(); ++ i )
+                    {
+                        std::cout << range[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "donor_range = ";
+                    for ( int i = 0; i < donor_range.size(); ++ i )
+                    {
+                        std::cout << donor_range[ i ] << " ";
+                    }
+                    std::cout << "\n";
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "transform = ";
+                    for ( int i = 0; i < transform.size(); ++ i )
+                    {
+                        std::cout << transform[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                }
+
+                int gDonorZoneId = -1;
+                if ( Parallel::IsServer() )
+                {
+                    BaseZone baseZoneDonor;
+                    baseZoneDonor.zone_name = donorname;
+
+                    gDonorZoneId = Global::zone_names.FindBaseZone( baseZoneDonor );
+                }
+
+                HXSendRecvData( &gDonorZoneId, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                ZoneBc1To1 * zonebc_1to1 = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    zonebc_1to1 = new ZoneBc1To1();
+                    zone->bc1to1s.push_back( zonebc_1to1 );
+                    zonebc_1to1->zoneid = gZoneId;
+                    zonebc_1to1->transform = transform;
+                    zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                    for ( int i = 0; i < range.size(); ++ i )
+                    {
+                        zonebc_1to1->pnts.push_back( range[ i ] );
+                        zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                    }
+                }
+            }
+        }
+    }
+
+    {
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "Global::zones.size() = " << Global::zones.size() << "\n";
+    }
+
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/CgnsGrid.h b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/CgnsGrid.h
new file mode 100644
index 00000000..fddf1db6
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/CgnsGrid.h
@@ -0,0 +1,103 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    int zoneIndex;
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/Field.cpp b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/Field.cpp
new file mode 100644
index 00000000..ead20d0f
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/Field.cpp
@@ -0,0 +1,250 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+
+    std::vector<double> & x = grid->x;
+    this->dx = std::abs( x[ 1 ] - x[ 0 ] );
+    this->dt = dx / 10.0;
+    this->t = 1.0;
+    this->nt = std::round( t / dt );
+
+    double total_time = nt * dt;
+
+    std::cout << "this->dt   = " << this->dt << "\n";
+    std::cout << "this->t    = " << this->t << "\n";
+    std::cout << "this->nt   = " << this->nt << "\n";
+    std::cout << "this->ni   = " << this->ni << "\n";
+    std::cout << "total_time = " << total_time << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+    u1.resize( ni_total );
+    r.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        u_e[ i ] = - std::exp( -total_time ) * std::sin( std::numbers::pi * xm ); //theory solution
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+    int kkk = 1;
+}
+
+void Field::FTCS( Zone * zone )
+{
+    int ist = 1;
+    int ied = ni;
+
+    this->Rhs( this->un, this->r );
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + dt * r[ i ];
+    }
+}
+
+void Field::RungeKutta( Zone * zone, int istage )
+{
+    if ( istage == 0 )
+    {
+        this->RungeKutta3Stage0( zone );
+        return;
+    }
+
+    if ( istage == 1 )
+    {
+        this->RungeKutta3Stage1( zone );
+        return;
+    }
+
+    if ( istage == 2 )
+    {
+        this->RungeKutta3Stage2( zone );
+        return;
+    }
+}
+
+void Field::RungeKutta3Stage0( Zone * zone )
+{
+    int ist = 1;
+    int ied = ni;
+
+    this->Rhs( this->un, this->r );
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + dt * r[ i ];
+    }
+}
+
+void Field::UpdateOldField()
+{
+    for ( int i = 0; i < this->u.size(); ++ i )
+    {
+        this->un[ i ] = this->u[ i ];
+    }
+}
+
+void Field::UpdateRungeKuttaOldField( int istage )
+{
+    if ( istage == 0 )
+    {
+        for ( int i = 0; i < this->u.size(); ++ i )
+        {
+            this->u1[ i ] = this->u[ i ];
+        }
+        return;
+    }
+
+    if ( istage == 1 )
+    {
+        return;
+    }
+
+    if ( istage == 2 )
+    {
+        for ( int i = 0; i < this->u.size(); ++ i )
+        {
+            this->un[ i ] = this->u[ i ];
+        }
+        return;
+    }
+}
+
+void Field::RungeKutta3Stage1( Zone * zone )
+{
+    int ist = 1;
+    int ied = ni;
+
+    this->Rhs( this->u1, this->r );
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = 0.75 * un[ i ] + 0.25 * u1[ i ] + 0.25 * dt * r[ i ];
+    }
+}
+
+void Field::RungeKutta3Stage2( Zone * zone )
+{
+    int ist = 1;
+    int ied = ni;
+
+    this->Rhs( this->u, this->r );
+
+    double c1 = 1.0 / 3.0;
+    double c2 = 2.0 / 3.0;
+    double c3 = 2.0 / 3.0;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = c1 * un[ i ] + c2 * u[ i ] + c3 * dt * r[ i ];
+    }
+}
+
+
+void Field::Rhs( std::vector<double> & u, std::vector<double> & r )
+{
+    int ist = 1;
+    int ied = ni;
+
+    double coef = this->alpha / ( dx * dx );
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        r[ i ] = coef * ( u[ i + 1 ] - 2.0 * u[ i ] + u[ i - 1 ] );
+    }
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        //std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        //region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate || bcType == BCOutflow )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+        int kkk = 1;
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/Field.h b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/Field.h
new file mode 100644
index 00000000..d2ed4c1c
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/Field.h
@@ -0,0 +1,45 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un, u1;
+    std::vector<double> r;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid );
+public:
+    void FTCS( Zone * zone );
+    void Rhs( std::vector<double> & u, std::vector<double> & r );
+
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void UpdateOldField();
+    void UpdateRungeKuttaOldField( int istage = 0 );
+public:
+    void RungeKutta( Zone * zone, int istage );
+    void RungeKutta3Stage0( Zone * zone );
+    void RungeKutta3Stage1( Zone * zone );
+    void RungeKutta3Stage2( Zone * zone );
+};
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/LogFile.cpp b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/LogFile.cpp
new file mode 100644
index 00000000..08ccd453
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/LogFile.cpp
@@ -0,0 +1,138 @@
+#include "LogFile.h"
+#include "Parallel.h"
+#include <sstream>
+#include <iostream>
+
+#ifdef _WINDOWS
+#include <windows.h>
+#include <direct.h>
+#include <io.h>
+#else
+#include <sys/stat.h>
+#include <unistd.h>
+#endif
+
+LogFile logFile;
+
+class OStream : public std::ostringstream
+{
+public:
+    OStream() {}
+    ~OStream() {}
+public:
+    void ClearAll()
+    {
+        this->clear();
+        this->str("");
+    }
+};
+
+OStream StrIO;
+std::string GetPrjDirName( const std::string & fileName );
+bool DirExist( const std::string & dirName );
+void MakeDir( const std::string & dirName );
+
+std::string GetPrjDirName( const std::string & fileName )
+{
+    size_t pos = fileName.find_last_of("\\/");
+    if ( std::string::npos == pos )
+    {
+        return "";
+    }
+    else
+    {
+        return fileName.substr( 0, pos );
+    }
+}
+
+bool DirExist( const std::string & dirName )
+{
+#ifdef _WINDOWS
+    bool flag = ( _access( dirName.c_str(), 0 ) == 0 );
+    return flag;
+#else
+    bool flag = ( access( dirName.c_str(), 0 ) == 0 );
+    return flag;
+#endif
+}
+
+void MakeDir( const std::string & dirName )
+{
+    int flag;
+#ifdef _WINDOWS
+    flag = _mkdir( dirName.c_str() );
+#else
+    flag = mkdir( dirName.c_str(), S_IRWXU );
+#endif
+    if ( flag == 0 )
+    {
+        std::cout << dirName << " directory has been created successfully !\n";
+    }
+}
+
+void CreateDirIfNeeded( std::string & prjFileName )
+{
+    std::string prj_dir = GetPrjDirName( prjFileName );
+
+    if ( ! DirExist( prj_dir ) )
+    {
+        MakeDir( prj_dir );
+    }
+}
+
+
+void OpenLogFile( int logFileIndex, std::fstream & file )
+{
+    static int ifReWrite = 0;
+
+    StrIO.ClearAll();
+    StrIO << "log/log" << logFileIndex << ".log";
+    std::string fileName = StrIO.str();
+
+    std::ios_base::openmode openMode;
+
+    if ( ifReWrite == 0 )
+    {
+        CreateDirIfNeeded( fileName );
+
+        openMode = std::ios_base::out | std::ios_base::trunc;
+
+        ifReWrite = 1;
+    }
+    else
+    {
+        openMode = std::ios_base::out | std::ios_base::app;
+    }
+
+    file.open( fileName.c_str(), openMode );
+    if ( ! file )
+    {
+        std::cout << "could not open " << fileName << std::endl;
+        exit( 0 );
+    }
+}
+
+void CloseLogFile( std::fstream & file )
+{
+    file.close();
+    file.clear();
+}
+
+LogFile::LogFile()
+{
+}
+
+LogFile::~LogFile()
+{
+}
+
+void LogFile::Open()
+{
+    int pid = Parallel::pid;
+    OpenLogFile( pid, this->my_fstream );
+}
+
+void LogFile::Close()
+{
+    CloseLogFile( this->my_fstream );
+}
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/LogFile.h b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/LogFile.h
new file mode 100644
index 00000000..00e775ab
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/LogFile.h
@@ -0,0 +1,27 @@
+#pragma once
+#include <fstream>
+
+void OpenLogFile( int logFileIndex, std::fstream & file );
+void CloseLogFile( std::fstream & file );
+class LogFile;
+extern LogFile logFile;
+
+class LogFile
+{
+public:
+    LogFile();
+    ~LogFile();
+    std::fstream my_fstream;
+public:
+    void Open();
+    void Close();
+};
+
+template< typename T >
+LogFile & operator << ( LogFile & f, const T & value )
+{
+    f.Open();
+    f.my_fstream << value;
+    f.Close();
+    return f;
+}
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/Parallel.cpp b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/Parallel.cpp
new file mode 100644
index 00000000..0bce1a60
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/Parallel.cpp
@@ -0,0 +1,54 @@
+#include "Parallel.h"
+#include <iostream>
+
+int Parallel::pid = 0;
+int Parallel::nProc = 1;
+int Parallel::serverid = 0;
+int Parallel::tag = 0;
+
+void Parallel::Init()
+{
+#ifdef HX_PARALLEL
+    int argc     = 0;
+    char ** argv = 0;
+    MPI_Init( &argc, &argv );
+    MPI_Comm_rank( MPI_COMM_WORLD, &Parallel::pid );
+    MPI_Comm_size( MPI_COMM_WORLD, &Parallel::nProc );
+    int len = -1;
+    char version[ MPI_MAX_LIBRARY_VERSION_STRING ];
+    MPI_Get_library_version( version, &len );
+    std::cout << "Hello, world!  I am " << Parallel::pid << " of " << Parallel::nProc
+        << "(" << version << ", " << len << ")" << std::endl;
+#endif
+}
+
+void Parallel::Finalize()
+{
+#ifdef HX_PARALLEL
+    MPI_Finalize();
+#endif
+}
+
+bool Parallel::IsServer()
+{
+    return Parallel::pid == Parallel::serverid;
+}
+
+void HXSendChar( void * data, int size, int pid, int tag )
+{
+#ifdef HX_PARALLEL
+    if ( size <= 0 ) return;
+    MPI_Send( data, size, MPI_CHAR, pid, tag, MPI_COMM_WORLD );
+#endif
+}
+
+void HXRecvChar( void * data, int size, int pid, int tag )
+{
+#ifdef HX_PARALLEL
+    if ( size <= 0 ) return;
+
+    MPI_Status status;
+    MPI_Recv( data, size, MPI_CHAR, pid, tag, MPI_COMM_WORLD, & status );
+#endif
+}
+
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/Parallel.h b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/Parallel.h
new file mode 100644
index 00000000..880a71cb
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/Parallel.h
@@ -0,0 +1,78 @@
+#pragma once
+#ifdef HX_PARALLEL
+#include "mpi.h"
+#endif
+#include <vector>
+#include "LogFile.h"
+
+class Parallel
+{
+public:
+    static int pid;
+    static int nProc;
+    static int serverid;
+    static int tag;
+public:
+    static void Init();
+    static void Finalize();
+public:
+    static bool IsServer();
+};
+
+void HXSendChar( void * data, int size, int pid, int tag );
+void HXRecvChar( void * data, int size, int pid, int tag );
+
+template< typename T >
+void HXSendData( T * field, int nElement, int recv_pid, int tag  );
+
+template< typename T >
+void HXRecvData( T * field, int nElement, int send_pid, int tag );
+
+template< typename T >
+void HXSendData( T * field, int nElement, int recv_pid, int tag = 0 )
+{
+    if ( nElement <= 0 ) return;
+
+    int buffer_size = nElement * sizeof( T );
+
+    HXSendChar( field, buffer_size, recv_pid, tag );
+}
+
+template< typename T >
+void HXRecvData( T * field, int nElement, int send_pid, int tag = 0 )
+{
+    if ( nElement <= 0 ) return;
+
+    int buffer_size = nElement * sizeof( T );
+
+    HXRecvChar( field, buffer_size, send_pid, tag );
+}
+
+template< typename T >
+void HXSendRecvData( T * field, int nElement, int send_pid, int recv_pid, int tag = 0 )
+{
+    if ( send_pid == recv_pid ) return;
+
+    if ( nElement <= 0 ) return;
+
+    int buffer_size = nElement * sizeof( T );
+
+    if ( Parallel::pid == send_pid )
+    {
+        HXSendChar( field, buffer_size, recv_pid, tag );
+    }
+    else if ( Parallel::pid == recv_pid )
+    {
+        HXRecvChar( field, buffer_size, send_pid, tag );
+    }
+}
+
+template< typename T >
+void HXBcastData( T * field, int nElement, int send_pid )
+{
+    if ( nElement <= 0 ) return;
+    int buffer_size = nElement * sizeof( T );
+#ifdef HX_PARALLEL
+    MPI_Bcast( field, buffer_size, MPI_CHAR, send_pid, MPI_COMM_WORLD );
+#endif
+}
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/README.txt b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/README.txt
new file mode 100644
index 00000000..5a4410fb
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/README.txt
@@ -0,0 +1,3 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
+
+PS D:\github\OneFLOW\example\1d-heat-equation\ftcs\cpp\multiblock\parallel\8blocks\01\build> mpiexec -n 8 .\Debug\testprj.exe
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/Solver.cpp b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/Solver.cpp
new file mode 100644
index 00000000..b3830397
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/Solver.cpp
@@ -0,0 +1,713 @@
+#include "Solver.h"
+#include "Parallel.h"
+#include "ZoneState.h"
+#include "global.h"
+#include <fstream>
+#include <set>
+#include <unordered_map>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+Solver::Solver()
+{
+    Parallel::Init();
+    //this->scheme = Scheme::FTCS;
+    this->scheme = Scheme::RungeKutta;
+}
+
+Solver::~Solver()
+{
+    Parallel::Finalize();
+}
+
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    this->InitTopo();
+    this->InitFields();
+    this->SolveFields();
+    this->PostProcess();
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d4blocksv1.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    ReadCgnsGrid( fileName );
+}
+
+void Solver::InitTopo()
+{
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "Solver::InitTopo() " << "\n";
+
+    Global::donor_zone_sets.resize( LocalZone::nZones );
+    Global::donor_zones.resize( LocalZone::nZones );
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        int global_zoneid = LocalZone::global_zoneids[ iZone ];
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "iZone = " << iZone << " global_zoneid = " << global_zoneid << "\n";
+
+        Interface * interface = new Interface();
+        interface->zoneid = global_zoneid;
+        Global::interfaces.push_back( interface );
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+        Interface * interface = Global::interfaces[ iZone ];
+
+        int nbc1to1s = zone->bc1to1s.size();
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout <<  "nbc1to1s = " << nbc1to1s << "\n";
+
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "zoneid = " << zoneid << " donor_zoneid = " << donor_zoneid << "\n";
+
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+        int nInterfaces = interface->zoneList.size();
+        interface->data_recv.resize( nInterfaces );
+        interface->data_send.resize( nInterfaces );
+    }
+
+    for ( int iProc = 0; iProc < Parallel::nProc; ++ iProc )
+    {
+        int nSize = -1;
+        if ( iProc == Parallel::pid )
+        {
+            nSize = Global::facePairList.size();
+        }
+        HXBcastData( &nSize, 1, iProc );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nSize = " << nSize << "\n";
+        std::vector<FacePair> tmp;
+        if ( iProc == Parallel::pid )
+        {
+            tmp = Global::facePairList;
+        }
+        else
+        {
+            tmp.resize( nSize );
+        }
+
+        HXBcastData( tmp.data(), tmp.size(), iProc );
+        Global::AddFacePairList( Global::mpi_facePairList, tmp );
+    }
+
+    for ( int i = 0; i < Global::mpi_facePairList.size(); ++ i )
+    {
+        FacePair &facePair = Global::mpi_facePairList[ i ];
+        Global::InsertFacePairMap( facePair );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        facePair.Print();
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterfaces = interface->local_faceids.size();
+        for ( int iInterface = 0; iInterface < nInterfaces; ++ iInterface )
+        {
+            int local_faceid = interface->local_faceids[ iInterface ];
+            int proc_global_faceid = interface->proc_global_faceids[ iInterface ];
+            FacePair & facePair = Global::facePairList[ proc_global_faceid ];
+            int global_faceid = Global::InsertFacePairMap( facePair );
+            interface->global_faceids.push_back( global_faceid );
+            interface->global_local_face_map.insert( std::make_pair( global_faceid, local_faceid ) );
+        }
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        std::set<int> &donor_zoneSet = Global::donor_zone_sets[ iZone ];
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            donor_zoneSet.insert( donor_zoneid );
+        }
+
+        std::vector<int> &donor_zones = Global::donor_zones[ iZone ];
+        for ( std::set<int>::iterator iter = donor_zoneSet.begin(); iter != donor_zoneSet.end(); ++ iter )
+        {
+            donor_zones.push_back( *iter );
+        }
+
+        interface->neighbor_donor_zones = donor_zones;
+
+        std::unordered_map<int, int> donor_zonelocal;
+
+        for ( int idonor = 0; idonor < donor_zones.size(); ++ idonor )
+        {
+            int donor_zone = donor_zones[ idonor ];
+            donor_zonelocal.insert( std::make_pair( donor_zone, idonor ) );
+        }
+        int ndonors = donor_zones.size();
+        std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+        neighbor_donorfaces.resize( ndonors );
+
+        std::vector<std::vector<int>> & sub_local_faceids = interface->sub_local_faceids;
+        sub_local_faceids.resize( ndonors );
+
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ineighbor = donor_zonelocal[ donor_zoneid ];
+            std::vector<int> &donorfaces = neighbor_donorfaces[ ineighbor ];
+            int global_faceid = interface->global_faceids[ iFace ];
+            donorfaces.push_back( global_faceid );
+            int local_faceid = interface->local_faceids[ iFace ];
+
+            std::vector<int> & sub_local_faces = sub_local_faceids[ ineighbor ];
+            sub_local_faces.push_back( local_faceid );
+        }
+    }
+
+    Global::interfaceTopo.InitNeighborInfo();
+    Global::interfaceTopo.SwapNeighborInfo();
+
+    int kkk = 1;
+}
+
+void Solver::InitFields()
+{
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "Solver::InitFields() ZoneState::nZones = " << ZoneState::nZones <<  "\n";
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+    }
+
+    this->Boundary();
+    this->UpdateOldField();
+}
+
+void Solver::SolveFields()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        switch (scheme) {  
+        case Scheme::FTCS:
+            this->FTCS();
+            break;  
+        case Scheme::RungeKutta:  
+            this->RungeKutta();
+            break;  
+        default:
+            this->FTCS();
+        }  
+    }
+}
+
+void Solver::FTCS()
+{
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        zone->zoneIndex = iZone;
+        field->FTCS( zone );
+    }
+    this->Boundary();
+    this->UpdateOldField();
+}
+
+void Solver::RungeKutta()
+{
+    for ( int istage = 0; istage < 3; ++ istage )
+    {
+        this->RungeKutta( istage );
+    }
+}
+
+void Solver::RungeKutta( int istage )
+{
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        zone->zoneIndex = iZone;
+        field->RungeKutta( zone, istage );
+    }
+    this->Boundary();
+    this->UpdateRungeKuttaOldField( istage );
+}
+
+void Solver::Boundary()
+{
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+    ExchangeInterfaceField();
+}
+
+void Solver::UpdateOldField()
+{
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->UpdateOldField();
+    }
+}
+
+void Solver::UpdateRungeKuttaOldField( int istage )
+{
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->UpdateRungeKuttaOldField( istage );
+    }
+}
+
+void Solver::UploadInterfaceField()
+{
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> & send_to_zones = interface->send_to_zones;
+        int nsend_zones = send_to_zones.size();
+
+        std::vector<std::vector<int>> & donorfaces_for_send = interface->donorfaces_for_send;
+        std::vector<std::vector<int>> & donorijk_for_send = interface->donorijk_for_send;
+        std::vector<std::vector<double>> & donordata_for_send = interface->donordata_for_send;
+
+        Field * field = Global::fields[ iZone ];
+
+        for ( int iSend = 0; iSend < nsend_zones; ++ iSend )
+        {
+            int zone_to_send = send_to_zones[ iSend ];
+            std::vector<int> & donorfaces = donorfaces_for_send[ iSend ];
+            std::vector<int> & donorijks = donorijk_for_send[ iSend ];
+            std::vector<double> & donordatas = donordata_for_send[ iSend ];
+
+            int nface = donorfaces.size();
+            int index_dim = 1;
+            for ( int i = 0; i < nface; ++ i )
+            {
+                int ijkpos = index_dim * i;
+                int i_donor_cell = donorijks[ ijkpos + 0 ];
+                donordatas[ i ] = field->u[ i_donor_cell ];
+            }
+        }
+    }
+}
+
+void Solver::UpdateInterfaceField()
+{
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        int ndonor_zones = Global::interfaceTopo.linkmap[ iZone ].size();
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donor_zone = Global::interfaceTopo.linkmap[ iZone ][ iNei ];
+            int send_pid = ZoneState::pids[ iZone ];
+            int recv_pid = ZoneState::pids[ donor_zone ];
+            int nsend = -1;
+            std::vector<double> donordata;
+            if ( Parallel::pid != send_pid && Parallel::pid != recv_pid ) continue;
+            if ( Parallel::pid == send_pid )
+            {
+                int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+                Interface * interface = Global::interfaces[ local_zoneid ];
+                donordata = interface->donordata_for_send[ iNei ];
+                nsend = donordata.size();
+            }
+            HXSendRecvData( &nsend, 1, send_pid, recv_pid );
+
+            if ( Parallel::pid == recv_pid )
+            {
+                donordata.resize( nsend );
+            }
+            HXSendRecvData( donordata.data(), donordata.size(), send_pid, recv_pid );
+
+            if ( Parallel::pid == recv_pid )
+            {
+                int local_donor_zoneid = ZoneState::g2lzoneids[ donor_zone ];
+                Interface * donor_interface = Global::interfaces[ local_donor_zoneid ];
+                int nSize = donor_interface->neighbor_donor_zones.size();
+                int ipos = -1;
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    int nei_zone = donor_interface->neighbor_donor_zones[ i ];
+                    if ( nei_zone == iZone )
+                    {
+                        ipos = i;
+                        break;
+                    }
+                }
+
+                std::vector<int> & neighbor_donorfaces = donor_interface->neighbor_donorfaces[ ipos ];
+                std::vector<int> & sub_local_faceids = donor_interface->sub_local_faceids[ ipos ];
+                for ( int i = 0; i < neighbor_donorfaces.size(); ++ i )
+                {
+                    int local_faceid = sub_local_faceids[ i ];
+                    double donor_value = donordata[ i ];
+                    donor_interface->data_recv[ local_faceid ] = donor_value;
+                }
+            }
+        }
+    }
+}
+
+void Solver::DownloadInterfaceField()
+{
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+        Field * field = Global::fields[ iZone ];
+
+        int nInterFaces = interface->data_recv.size();
+
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+
+            double donor_value = interface->data_recv[ iFace ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    this->UploadInterfaceField();
+    this->UpdateInterfaceField();
+    this->DownloadInterfaceField();
+}
+
+void Solver::PostProcess()
+{
+    Post post;
+    post.Process();
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        if ( !ZoneState::IsValid( iZone ) && !Parallel::IsServer() ) continue;
+
+        double xmin = 0.0;
+        double xmax = 0.0;
+
+        if ( ZoneState::IsValid( iZone ) )
+        {
+            int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+            Grid * grid = Global::grids[ local_zoneid ];
+            int ni = grid->x.size();
+            xmin = grid->x[ 0 ];
+            xmax = grid->x[ 0 ];
+            int imin = 0;
+            int imax = 0;
+            for ( int i = 0; i < ni; ++ i )
+            {
+                if ( xmin > grid->x[ i ] )
+                {
+                    xmin = grid->x[ i ];
+                    imin = i;
+                }
+                if ( xmax < grid->x[ i ] )
+                {
+                    xmax = grid->x[ i ];
+                    imax = i;
+                }
+            }
+        }
+
+        HXSendRecvData( &xmin, 1, ZoneState::pids[ iZone ], Parallel::serverid );
+        HXSendRecvData( &xmax, 1, ZoneState::pids[ iZone ], Parallel::serverid );
+
+        if ( Parallel::IsServer() )
+        {
+            xmin_list.push_back( xmin );
+            xmax_list.push_back( xmax );
+        }
+    }
+
+    if ( Parallel::IsServer() )
+    {
+        std::vector<std::pair<double, int>> pairs;
+        int nSize = xmin_list.size();
+        for ( int i = 0; i < nSize; ++ i )
+        {
+            pairs.push_back( std::make_pair( xmin_list[ i ], i ) );
+        }
+
+        std::sort( pairs.begin(), pairs.end() );
+
+        for ( int i = 0; i < nSize; ++ i )
+        {
+            this->zoneids.push_back( pairs[ i ].second );
+        }
+    }
+
+    int kkk = 1;
+}
+
+bool IsLastZone( int iZone );
+bool IsLastZone( int iZone )
+{
+    return iZone == ZoneState::nZones - 1;
+}
+
+void Post::AddVector( std::vector<double> & a, std::vector<double> & b )
+{
+    for ( int i = 0; i < b.size(); ++ i )
+    {
+        a.push_back( b[ i ] );
+    }
+}
+
+void Post::GatherField()
+{
+    this->zoneids.resize( ZoneState::nZones );
+    HXBcastData( this->zoneids.data(), this->zoneids.size(), Parallel::serverid );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "Post::GatherField() this->zoneids = \n";
+    for ( int i = 0; i < this->zoneids.size(); ++ i )
+    {
+        std::cout << this->zoneids[ i ] << " ";
+    }
+    std::cout << "\n";
+
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+
+        if ( !ZoneState::IsValid( zoneid ) && !Parallel::IsServer() ) continue;
+
+        int nSize = -1;
+        std::vector<double> local_x;
+        std::vector<double> local_u_e;
+        std::vector<double> local_un;
+        std::vector<double> local_u;
+
+        if ( Parallel::pid == ZoneState::pids[ zoneid ] )
+        {
+            int local_zoneid = ZoneState::g2lzoneids[ zoneid ];
+            Grid * grid = Global::grids[ local_zoneid ];
+            Field * field = Global::fields[ local_zoneid ];
+            int ni = grid->x.size();
+
+            int ist = 1;
+            int ied = ni;
+
+            int dir = 1;
+            if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+            if ( dir == 1 )
+            {
+                if ( IsLastZone( iZone ) )
+                {
+                    for ( int i = ist; i <= ied; ++ i )
+                    {
+                        double xm = grid->x[ i - ist ];
+                        local_x.push_back( xm );
+                        local_u_e.push_back( field->u_e[ i ] );
+                        local_un.push_back( field->un[ i ] );
+                        local_u.push_back( field->u[ i ] );
+                    }
+                }
+                else
+                {
+                    for ( int i = ist; i <= ied - 1; ++ i )
+                    {
+                        double xm = grid->x[ i - ist ];
+                        local_x.push_back( xm );
+                        local_u_e.push_back( field->u_e[ i ] );
+                        local_un.push_back( field->un[ i ] );
+                        local_u.push_back( field->u[ i ] );
+                    }
+                }
+            }
+            else
+            {
+                if ( IsLastZone( iZone ) )
+                {
+                    for ( int i = ied; i >= ist; -- i )
+                    {
+                        double xm = grid->x[ i - ist ];
+                        local_x.push_back( xm );
+                        local_u_e.push_back( field->u_e[ i ] );
+                        local_un.push_back( field->un[ i ] );
+                        local_u.push_back( field->u[ i ] );
+                    }
+                }
+                else
+                {
+                    for ( int i = ied; i >= ist + 1; -- i )
+                    {
+                        double xm = grid->x[ i - ist ];
+                        local_x.push_back( xm );
+                        local_u_e.push_back( field->u_e[ i ] );
+                        local_un.push_back( field->un[ i ] );
+                        local_u.push_back( field->u[ i ] );
+                    }
+                }
+            }
+            nSize = local_x.size();
+        }
+
+        int send_pid = ZoneState::pids[ zoneid ];
+
+        HXSendRecvData( &nSize, 1, send_pid, Parallel::serverid );
+
+        if ( Parallel::IsServer() )
+        {
+            local_x.resize( nSize );
+            local_u_e.resize( nSize );
+            local_un.resize( nSize );
+            local_u.resize( nSize );
+        }
+
+        HXSendRecvData( local_x.data(), local_x.size(), send_pid, Parallel::serverid );
+        HXSendRecvData( local_u_e.data(), local_u_e.size(), send_pid, Parallel::serverid );
+        HXSendRecvData( local_un.data(), local_un.size(), send_pid, Parallel::serverid );
+        HXSendRecvData( local_u.data(), local_u.size(), send_pid, Parallel::serverid );
+
+        if ( Parallel::IsServer() )
+        {
+            this->AddVector( this->x, local_x );
+            this->AddVector( this->u_e, local_u_e );
+            this->AddVector( this->un, local_un );
+            this->AddVector( this->u, local_u );
+        }
+    }
+}
+
+void Post::DumpField()
+{
+    if ( !Parallel::IsServer() ) return;
+    int ni_total = this->x.size();
+    std::cout << " DumpField x.size() = " << x.size() << "\n";
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    this->DumpErrorDetails( u_error );
+
+    std::string csvname = "field_final.csv";
+    this->DumpCsvFile( csvname, x, u_e, un, u_error );
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.20f} {:.20f} {:.20f} {:.20f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/Solver.h b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/Solver.h
new file mode 100644
index 00000000..59838940
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/Solver.h
@@ -0,0 +1,63 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+
+enum class Scheme
+{
+    FTCS = 0,
+    RungeKutta
+};
+
+class Solver
+{
+public:
+    Solver();
+    ~Solver();
+public:
+    Scheme scheme;
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveFields();
+public:
+    void Boundary();
+    void UpdateOldField();
+    void UpdateRungeKuttaOldField( int istage );
+    void UploadInterfaceField();
+    void UpdateInterfaceField();
+    void DownloadInterfaceField();
+    void ExchangeInterfaceField();
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcess();
+public:
+    void FTCS();
+    void RungeKutta();
+    void RungeKutta( int istage );
+};
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+    std::vector<double> u;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+public:
+    void AddVector( std::vector<double> & a, std::vector<double> & b );
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/ZoneState.cpp b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/ZoneState.cpp
new file mode 100644
index 00000000..ff810849
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/ZoneState.cpp
@@ -0,0 +1,20 @@
+#include "ZoneState.h"
+#include "Parallel.h"
+
+int ZoneState::nZones = 0;
+std::vector<int> ZoneState::pids;
+std::vector<int> ZoneState::g2lzoneids;
+
+bool ZoneState::IsValid( int zoneid )
+{
+    return ZoneState::pids[ zoneid ] == Parallel::pid;
+}
+
+int ZoneState::GetProcID( int zoneid )
+{
+    return ZoneState::pids[ zoneid ];
+}
+
+int LocalZone::nZones = 0;
+std::vector<int> LocalZone::global_zoneids;
+
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/ZoneState.h b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/ZoneState.h
new file mode 100644
index 00000000..1096d632
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/ZoneState.h
@@ -0,0 +1,21 @@
+#pragma once
+#include <vector>
+
+class ZoneState
+{
+public:
+    static int nZones;
+    static int zone_id;
+    static std::vector<int> pids;
+    static std::vector<int> g2lzoneids; //global zone id to local zone id
+public:
+    static bool IsValid( int zoneid );
+    static int GetProcID( int zoneid );
+};
+
+class LocalZone
+{
+public:
+    static int nZones;
+    static std::vector<int> global_zoneids;
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/global.cpp b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/global.cpp
new file mode 100644
index 00000000..df1e6bae
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/global.cpp
@@ -0,0 +1,300 @@
+#include "global.h"
+#include "CgnsGrid.h"
+#include "ZoneState.h"
+#include "Parallel.h"
+#include <iostream>
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *> Global::interfaces;
+
+std::map<Face, int> Global::faceMap;
+std::map<FacePair, int> Global::facePairMap;
+std::vector<FacePair> Global::facePairList;
+std::vector<FacePair> Global::mpi_facePairList;
+
+std::vector<std::set<int>> Global::donor_zone_sets;
+std::vector<std::vector<int>> Global::donor_zones;
+
+InterfaceTopo Global::interfaceTopo;
+
+bool Face::operator < ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return this->zone < rhs.zone;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return this->i < rhs.i;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return this->j < rhs.j;
+    }
+
+    return this->k < rhs.k;
+}
+
+bool Face::operator == ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return false;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return false;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return false;
+    }
+
+    return this->k == rhs.k;
+}
+
+void Face::Print()
+{
+    std::cout << "(" << this->zone << "," << this->i << ")";
+}
+
+void FacePair::AddPair( const Face & face1, const Face & face2 )
+{
+    if ( face1 < face2 )
+    {
+        this->left = face1;
+        this->right = face2;
+    }
+    else
+    {
+        this->left = face2;
+        this->right = face1;
+    }
+}
+
+bool FacePair::operator < ( const FacePair & rhs ) const
+{
+    if ( this->left == rhs.left || this->left == rhs.right )
+    {
+        return false;
+    }
+
+    return this->left < rhs.left;
+}
+
+void FacePair::Print()
+{
+    this->left.Print();
+    std::cout << " ";
+    this->right.Print();
+    std::cout << "\n";
+}
+
+void InterfaceTopo::InitNeighborInfo()
+{
+    this->linkmap.resize( ZoneState::nZones );
+
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        if ( ! ZoneState::IsValid( iZone ) ) continue;
+
+        int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+
+        Interface * interface = Global::interfaces[ local_zoneid ];
+
+        std::vector<int> & t = this->linkmap[ iZone ];
+        t = interface->neighbor_donor_zones;
+    }
+}
+
+void InterfaceTopo::SwapNeighborInfo()
+{
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        int pid = ZoneState::pids[ iZone ];
+
+        std::vector<int> & donor_zones = this->linkmap[ iZone ];
+        int nNeighbor = donor_zones.size();
+
+        HXBcastData( &nNeighbor, 1, pid );
+
+        donor_zones.resize( nNeighbor );
+
+        HXBcastData( donor_zones.data(), donor_zones.size(), pid );
+    }
+
+    this->SwapNeighborDonorfaces();
+}
+
+void InterfaceTopo::SwapNeighborDonorfaces()
+{
+    int gl = 0;
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        int send_pid = ZoneState::pids[ iZone ];
+
+        std::vector<int> & donor_zones = this->linkmap[ iZone ];
+        int ndonor_zones = donor_zones.size();
+
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donor_zone = donor_zones[ iNei ];
+            int recv_pid = ZoneState::pids[ donor_zone ];
+            int nInterFaces = 0;
+            std::vector<int> donorfaces;
+
+            if ( Parallel::pid == send_pid )
+            {
+                int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+
+                Interface * interface = Global::interfaces[ local_zoneid ];
+
+                std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+
+                std::vector<int> & neighbor_donorface = neighbor_donorfaces[ iNei ];
+
+                nInterFaces = neighbor_donorface.size();
+
+                donorfaces = neighbor_donorface;
+            }
+
+            HXSendRecvData( &nInterFaces, 1, send_pid, recv_pid );
+
+            if ( Parallel::pid == recv_pid && send_pid != recv_pid )
+            {
+                donorfaces.resize( nInterFaces );
+            }
+
+            HXSendRecvData( donorfaces.data(), donorfaces.size(), send_pid, recv_pid );
+
+            if ( Parallel::pid == recv_pid )
+            {
+                int local_donor_zoneid = ZoneState::g2lzoneids[ donor_zone ];
+                Interface * interface_recv = Global::interfaces[ local_donor_zoneid ];
+                interface_recv->SendGeom( iZone, donorfaces );
+            }
+        }
+    }
+}
+
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->local_faceids.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        Face face;
+        face.zone = zoneid;
+        face.i = i;
+
+        int i_donor = index2[ 0 ];
+
+        Face face_donor;
+        face_donor.zone = donor_zoneid;
+        face_donor.i = i_donor;
+
+        FacePair facePair;
+        facePair.AddPair( face, face_donor );
+
+        Global::facePairList.push_back( facePair );
+        int nSize = Global::facePairList.size();
+        this->proc_global_faceids.push_back( nSize - 1 );
+
+        int i_ghost_cell = i + 1;
+        int i_local_donor_cell = i - 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+            i_local_donor_cell = i + 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+        ijk_donors.push_back( i_local_donor_cell );
+
+        icount ++;
+    }
+}
+
+void Interface::SendGeom( int zone, std::vector<int> & donorfaces )
+{
+    Interface * interface = this;
+
+    std::vector<int> & send_to_zones = interface->send_to_zones;
+
+    send_to_zones.push_back( zone );
+    interface->donorfaces_for_send.push_back( donorfaces );
+
+    int nface = donorfaces.size();
+    std::vector<int> sub_donorijk;
+    int index_dim = 1;
+    for ( int i = 0; i < nface; ++ i )
+    {
+        int global_faceid = donorfaces[ i ];
+        int local_faceid = interface->global_local_face_map[ global_faceid ];
+        int ijkpos = index_dim * local_faceid;
+        int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+        sub_donorijk.push_back( i_donor_cell );
+        int kkk = 1;
+    }
+
+    interface->donorijk_for_send.push_back( sub_donorijk );
+
+    std::vector<double> sub_donordata( sub_donorijk.size() );
+    interface->donordata_for_send.push_back( sub_donordata );
+}
+
+void Global::InsertFaceMap( const Face & face )
+{
+    std::map<Face, int>::iterator iter;
+    iter = Global::faceMap.find( face );
+    if ( iter == Global::faceMap.end() )
+    {
+        int faceid = Global::faceMap.size();
+        Global::faceMap.insert( std::make_pair( face, faceid ) );
+    }
+}
+
+int Global::InsertFacePairMap( const FacePair & facePair )
+{
+    std::map<FacePair, int>::iterator iter;
+    iter = Global::facePairMap.find( facePair );
+    if ( iter == Global::facePairMap.end() )
+    {
+        int facePairId = Global::facePairMap.size();
+        Global::facePairMap.insert( std::make_pair( facePair, facePairId ) );
+        return facePairId;
+    }
+    return iter->second;
+}
+
+void Global::AddFacePairList( std::vector<FacePair> & a, std::vector<FacePair> & b )
+{
+    for ( int i = 0; i < b.size(); ++ i )
+    {
+        a.push_back( b[ i ] );
+    }
+}
+
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/global.h b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/global.h
new file mode 100644
index 00000000..933cec05
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/global.h
@@ -0,0 +1,157 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <unordered_map>
+#include <set>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class Face
+{
+public:
+    int zone = 0;
+    int i = 0;
+    int j = 1;
+    int k = 1;
+public:
+    bool operator < ( const Face & rhs ) const;
+    bool operator == ( const Face & rhs ) const;
+public:
+    void Print();
+};
+
+class FacePair
+{
+public:
+    Face left;
+    Face right;
+public:
+    bool operator < ( const FacePair & rhs ) const;
+    void AddPair( const Face &face1, const Face &face2);
+public:
+    void Print();
+};
+
+class Transform;
+
+class InterfaceTopo
+{
+public:
+    std::vector<std::vector<int>> linkmap;
+public:
+    void InitNeighborInfo();
+    void SwapNeighborInfo();
+    void SwapNeighborDonorfaces();
+};
+
+
+class Interface
+{
+public:
+    int zoneid;
+    std::vector<int> zoneList;
+    std::vector<int> global_faceids;
+    std::vector<int> mpi_global_faceids;
+    std::vector<int> proc_global_faceids;
+    std::vector<int> local_faceids;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+    std::vector<double> data_recv;
+    std::vector<double> data_send;
+    std::unordered_map<int, int> global_local_face_map;
+public:
+    std::vector<int> neighbor_donor_zones;
+    std::vector<std::vector<int>> neighbor_donorfaces;
+    std::vector<std::vector<int>> sub_local_faceids;
+    std::vector<int> send_to_zones;
+    std::vector<std::vector<int>> donorfaces_for_send;
+    std::vector<std::vector<int>> donorijk_for_send;
+    std::vector<std::vector<double>> donordata_for_send;
+public:
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+    void SendGeom( int zone, std::vector<int> & donorfaces );
+};
+
+class Field;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+public:
+    static std::map<Face, int> faceMap;
+    static std::map<FacePair, int> facePairMap;
+    static std::vector<FacePair> facePairList;
+    static std::vector<FacePair> mpi_facePairList;
+    static std::vector<std::set<int>> donor_zone_sets;
+    static std::vector<std::vector<int>> donor_zones;
+    static InterfaceTopo interfaceTopo;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+public:
+    static void InsertFaceMap( const Face & face );
+    static int InsertFacePairMap( const FacePair & facePair );
+    static void AddFacePairList( std::vector<FacePair> & a, std::vector<FacePair> & b );
+};
+
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/heat1d1block.cgns b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/heat1d1block.cgns
new file mode 100644
index 00000000..b7d4954a
Binary files /dev/null and b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/heat1d1block.cgns differ
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/heat1d4blocksv1.cgns b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/heat1d4blocksv1.cgns
new file mode 100644
index 00000000..df5ffc5f
Binary files /dev/null and b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/heat1d4blocksv1.cgns differ
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/main.cpp b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/main.cpp
new file mode 100644
index 00000000..df63b7da
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/main.cpp
@@ -0,0 +1,9 @@
+#include "Solver.h"
+#include "Parallel.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/plot.py b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/plotting2.jl b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/multiblock/parallel/4blocks/01b/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/RK3/cpp/singleblock/01/CMakeLists.txt b/example/1d-heat-equation/RK3/cpp/singleblock/01/CMakeLists.txt
new file mode 100644
index 00000000..9e834b72
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/singleblock/01/CMakeLists.txt
@@ -0,0 +1,99 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package ( MPI )
+
+message ( STATUS  "MPI_FOUND=${MPI_FOUND}" )
+message ( STATUS  "MPI_CXX_INCLUDE_DIRS=${MPI_CXX_INCLUDE_DIRS}" )
+message ( STATUS  "MPI_LIBRARIES=${MPI_LIBRARIES}" )
+if ( MPI_FOUND )
+	list ( APPEND PRJ_INCLUDE_DIRS ${MPI_CXX_INCLUDE_DIRS} )
+	list ( APPEND PRJ_LIBRARIES ${MPI_LIBRARIES} )
+endif ()
+
+#get_directory_property( my_import_targets DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} IMPORTED_TARGETS )
+#message( STATUS "my_import_targets=${my_import_targets}" )
+
+list ( APPEND PRJ_LIBRARIES MPI::MPI_C )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+list ( APPEND PRJ_COMPILE_DEFINITIONS HX_PARALLEL )
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	LogFile.h LogFile.cpp
+	Parallel.h Parallel.cpp
+	Solver.h Solver.cpp
+	ZoneState.h ZoneState.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/RK3/cpp/singleblock/01/CgnsGrid.cpp b/example/1d-heat-equation/RK3/cpp/singleblock/01/CgnsGrid.cpp
new file mode 100644
index 00000000..825442a2
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/singleblock/01/CgnsGrid.cpp
@@ -0,0 +1,850 @@
+#include "CgnsGrid.h"
+#include "Parallel.h"
+#include "cgnslib.h"
+#include "global.h"
+#include "ZoneState.h"
+#include <iostream>
+#include <vector>
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "fileId = " << fileId << "\n";
+    }
+    
+    int nbases = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_nbases( fileId, &nbases );
+    }
+    HXBcastData( &nbases, 1, Parallel::serverid );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "nbases = " << nbases << "\n";
+    
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        }
+
+        HXBcastData( &icelldim, 1, Parallel::serverid );
+        HXBcastData( &iphysdim, 1, Parallel::serverid );
+
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+
+        int nzones = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_nzones( fileId, baseId, &nzones );
+        }
+
+        HXBcastData( &nzones, 1, Parallel::serverid );
+
+        ZoneState::nZones = nzones;
+        ZoneState::pids.resize( nzones );
+        ZoneState::g2lzoneids.resize( nzones );
+        std::vector<int> pcount( Parallel::nProc, 0 );
+
+        for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+        {
+            int zone_pid = iZone % Parallel::nProc;
+            ZoneState::pids[ iZone ] = zone_pid;
+            ZoneState::g2lzoneids[ iZone ] = pcount[ zone_pid ];
+            pcount[ zone_pid ] ++;
+        }
+
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nzones = " << nzones << "\n";
+
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "iZone = " << iZone << "\n";
+
+            int index_dim = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            }
+            HXBcastData( &index_dim, 1, Parallel::serverid );
+
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            if ( Parallel::IsServer() )
+            {
+                cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            }
+
+            HXBcastData( zonename, 33, Parallel::serverid );
+            HXBcastData( isize.data(), isize.size(), Parallel::serverid);
+
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "zonename = " << zonename << "\n";
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+
+    if ( Parallel::IsServer() )
+    {
+        cg_close( fileId );
+    }
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+        std::cout << "fileId = " << fileId << "\n";
+    }
+    
+    int nbases = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_nbases( fileId, &nbases );
+    }
+    MPI_Bcast( &nbases, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        }
+
+        HXBcastData( &icelldim, 1, Parallel::serverid );
+        HXBcastData( &iphysdim, 1, Parallel::serverid );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+
+        int nzones = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_nzones( fileId, baseId, &nzones );
+        }
+        HXBcastData( &nzones, 1, Parallel::serverid );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nzones = " << nzones << "\n";
+
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            }
+            HXSendRecvData( &index_dim, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "index_dim = " << index_dim << "\n";
+            }
+
+            std::vector<cgsize_t> isize;
+            char zonename[ 33 ];
+            if ( Parallel::IsServer() )
+            {
+                isize.resize( index_dim * 3 );
+                cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            }
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                isize.resize( index_dim * 3 );
+            }
+
+            HXSendRecvData( zonename, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+            HXSendRecvData( isize.data(), index_dim * 3, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "zonename = " << zonename << "\n";
+
+                for ( int i = 0; i < isize.size(); ++ i )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+                }
+            }
+
+            std::vector<cgsize_t> irmin;
+            std::vector<cgsize_t> irmax;
+            int nNodes = 1;
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                irmin.resize( index_dim );
+                irmax.resize( index_dim );
+                for ( int m = 0; m < index_dim; ++ m )
+                {
+                    /* lower range index */
+                    irmin[ m ] = 1;
+                    /* upper range index of vertices */
+                    irmax[ m ] = isize[ m ];
+                    nNodes *= irmax[ m ];
+                }
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "nNodes = " << nNodes << "\n";
+            }
+
+            ZoneType_t zoneType;
+            if ( Parallel::IsServer() )
+            {
+                cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            }
+            HXSendRecvData( &zoneType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            }
+
+            Zone * zone = nullptr;
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                zone = new Zone();
+                Global::zones.push_back( zone );
+                LocalZone::global_zoneids.push_back( iZone );
+                LocalZone::nZones = LocalZone::global_zoneids.size();
+                for ( int m = 0; m < index_dim; ++ m )
+                {
+                    zone->nijk.push_back( isize[ m ] );
+                }
+            }
+
+            Grid * grid = nullptr;
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                grid = new Grid();
+                Global::grids.push_back( grid );
+            }
+
+            BaseZone baseZone;
+
+            int gZoneId = -1;
+            if ( Parallel::IsServer() )
+            {
+                baseZone.zone_name = zonename;
+                gZoneId = Global::zone_names.FindBaseZone( baseZone );
+            }
+
+            HXSendRecvData( &gZoneId, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "gZoneId = " << gZoneId << "\n";
+            }
+
+            int ncoords = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            }
+            HXSendRecvData( &ncoords, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "ncoords = " << ncoords << "\n";
+            }
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                if ( Parallel::IsServer() )
+                {
+                    cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                }
+                HXSendRecvData( coordname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &dataType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "coordname = " << coordname << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                }
+
+                std::vector<char> coord;
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    coord.resize( nNodes * sizeof( double ) );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coord.data() );
+                }
+
+                HXSendRecvData( coord.data(), coord.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                Coor * coor = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    coor = new Coor();
+                    zone->coors.push_back( coor );
+                    coor->coorname = coordname;
+                    coor->nNodes = nNodes;
+                    coor->coord = coord;
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    coor->DumpCoor();
+
+                    if ( icoord == 0 )
+                    {
+                        grid->x.resize( nNodes );
+                        coor->DumpCoorX( grid->x );
+                    }
+                }
+            }
+
+            int nbocos = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            }
+            HXSendRecvData( &nbocos, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "nbocos = " << nbocos << "\n";
+            }
+
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                if ( Parallel::IsServer() )
+                {
+                    cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                }
+                HXSendRecvData( &location, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+                }
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                //std::vector<int> normalIndex( index_dim, -1 );
+                std::vector<int> normalIndex;
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+                if ( Parallel::IsServer() )
+                {
+                    normalIndex.resize( index_dim );
+                    cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                        &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                }
+
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    normalIndex.resize( index_dim );
+                }
+                
+                HXSendRecvData( boconame, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &bocotype, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &ptset_type, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &npnts, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &normalDataType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &normalListSize, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( normalIndex.data(), index_dim, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &ndataset, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "npnts = " << npnts << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalListSize = " << normalListSize << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalIndex = ";
+                    for ( int i = 0; i < index_dim; ++ i )
+                    {
+                        std::cout << normalIndex[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "ndataset = " << ndataset << "\n";
+                }
+
+                std::vector<char> normalList;
+                std::vector<cgsize_t> pnts;
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    if ( normalDataType == DataTypeNull )
+                    {
+                        normalList.resize( sizeof( int ) );
+                    }
+                    else
+                    {
+                        int nSize = nNodes * index_dim * sizeof( double );
+                        normalList.resize( nSize );
+                    }
+                    pnts.resize( npnts * index_dim );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                }
+
+                HXSendRecvData( pnts.data(), npnts * index_dim, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "pnts = ";
+                    for ( int i = 0; i < pnts.size(); ++ i )
+                    {
+                        std::cout << pnts[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                }
+                HXSendRecvData( normalList.data(), normalList.size(), Parallel::serverid, ZoneState::GetProcID(iZone));
+
+                ZoneBc * zonebc = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    zonebc = new ZoneBc();
+                    zone->bccos.push_back( zonebc );
+                    zonebc->bcType = bocotype;
+                    for ( int i = 0; i < pnts.size(); ++ i )
+                    {
+                        zonebc->pnts.push_back( pnts[ i ] );
+                    }
+                }
+            }
+            int n1to1 = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            }
+
+            HXSendRecvData( &n1to1, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "n1to1 = " << n1to1 << "\n";
+            }
+
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range;
+                std::vector<cgsize_t> donor_range;
+                std::vector<int> transform;
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    range.resize( npnts * index_dim );
+                    donor_range.resize( npnts * index_dim );
+                    transform.resize( index_dim );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                }
+
+                HXSendRecvData( connectname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( donorname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( range.data(), range.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( donor_range.data(), donor_range.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( transform.data(), transform.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "connectname = " << connectname << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "donorname = " << donorname << "\n";
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "range = ";
+                    for ( int i = 0; i < range.size(); ++ i )
+                    {
+                        std::cout << range[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "donor_range = ";
+                    for ( int i = 0; i < donor_range.size(); ++ i )
+                    {
+                        std::cout << donor_range[ i ] << " ";
+                    }
+                    std::cout << "\n";
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "transform = ";
+                    for ( int i = 0; i < transform.size(); ++ i )
+                    {
+                        std::cout << transform[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                }
+
+                int gDonorZoneId = -1;
+                if ( Parallel::IsServer() )
+                {
+                    BaseZone baseZoneDonor;
+                    baseZoneDonor.zone_name = donorname;
+
+                    gDonorZoneId = Global::zone_names.FindBaseZone( baseZoneDonor );
+                }
+
+                HXSendRecvData( &gDonorZoneId, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                ZoneBc1To1 * zonebc_1to1 = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    zonebc_1to1 = new ZoneBc1To1();
+                    zone->bc1to1s.push_back( zonebc_1to1 );
+                    zonebc_1to1->zoneid = gZoneId;
+                    zonebc_1to1->transform = transform;
+                    zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                    for ( int i = 0; i < range.size(); ++ i )
+                    {
+                        zonebc_1to1->pnts.push_back( range[ i ] );
+                        zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                    }
+                }
+            }
+        }
+    }
+
+    {
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "Global::zones.size() = " << Global::zones.size() << "\n";
+    }
+
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/RK3/cpp/singleblock/01/CgnsGrid.h b/example/1d-heat-equation/RK3/cpp/singleblock/01/CgnsGrid.h
new file mode 100644
index 00000000..fddf1db6
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/singleblock/01/CgnsGrid.h
@@ -0,0 +1,103 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    int zoneIndex;
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/RK3/cpp/singleblock/01/Field.cpp b/example/1d-heat-equation/RK3/cpp/singleblock/01/Field.cpp
new file mode 100644
index 00000000..227bd499
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/singleblock/01/Field.cpp
@@ -0,0 +1,288 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+
+    std::vector<double> & x = grid->x;
+    this->dx = std::abs( x[ 1 ] - x[ 0 ] );
+    this->dt = dx / 10.0;
+    this->t = 1.0;
+    this->nt = std::round( t / dt );
+
+    double total_time = nt * dt;
+
+    std::cout << "this->dt   = " << this->dt << "\n";
+    std::cout << "this->t    = " << this->t << "\n";
+    std::cout << "this->nt   = " << this->nt << "\n";
+    std::cout << "this->ni   = " << this->ni << "\n";
+    std::cout << "total_time = " << total_time << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+    u1.resize( ni_total );
+    r.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        u_e[ i ] = - std::exp( -total_time ) * std::sin( std::numbers::pi * xm ); //theory solution
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+    int kkk = 1;
+}
+
+void Field::Solve( Zone * zone )
+{
+    //this->FTCS( zone );
+    this->RungeKutta3( zone );
+}
+
+void Field::FTCS( Zone * zone )
+{
+    int ist = 1;
+    int ied = ni;
+
+    this->Rhs( this->un, this->r );
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + dt * r[ i ];
+    }
+}
+
+void Field::RungeKutta( Zone * zone, int istage )
+{
+    if ( istage == 0 )
+    {
+        this->RungeKutta3Stage0( zone );
+        return;
+    }
+
+    if ( istage == 1 )
+    {
+        this->RungeKutta3Stage1( zone );
+        return;
+    }
+
+    if ( istage == 2 )
+    {
+        this->RungeKutta3Stage2( zone );
+        return;
+    }
+}
+
+void Field::RungeKutta3Stage0( Zone * zone )
+{
+    int ist = 1;
+    int ied = ni;
+
+    this->Rhs( this->un, this->r );
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + dt * r[ i ];
+    }
+}
+
+void Field::UpdateOldField()
+{
+    for ( int i = 0; i < this->u.size(); ++ i )
+    {
+        this->un[ i ] = this->u[ i ];
+    }
+}
+
+void Field::UpdateRungeKuttaOldField( int istage )
+{
+    if ( istage == 0 )
+    {
+        for ( int i = 0; i < this->u.size(); ++ i )
+        {
+            this->u1[ i ] = this->u[ i ];
+        }
+        return;
+    }
+
+    if ( istage == 1 )
+    {
+        return;
+    }
+
+    if ( istage == 2 )
+    {
+        for ( int i = 0; i < this->u.size(); ++ i )
+        {
+            this->un[ i ] = this->u[ i ];
+        }
+        return;
+    }
+}
+
+void Field::RungeKutta3Stage1( Zone * zone )
+{
+    int ist = 1;
+    int ied = ni;
+
+    this->Rhs( this->u1, this->r );
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = 0.75 * un[ i ] + 0.25 * u1[ i ] + 0.25 * dt * r[ i ];
+    }
+}
+
+void Field::RungeKutta3Stage2( Zone * zone )
+{
+    int ist = 1;
+    int ied = ni;
+
+    this->Rhs( this->u, this->r );
+
+    double c1 = 1.0 / 3.0;
+    double c2 = 2.0 / 3.0;
+    double c3 = 2.0 / 3.0;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = c1 * un[ i ] + c2 * u[ i ] + c3 * dt * r[ i ];
+    }
+}
+
+
+void Field::RungeKutta3( Zone * zone )
+{
+    int ist = 1;
+    int ied = ni;
+
+    this->Rhs( this->un, this->r );
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u1[ i ] = un[ i ] + dt * r[ i ];
+    }
+
+    this->Rhs( this->u1, this->r );
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = 0.75 * un[ i ] + 0.25 * u1[ i ] + 0.25 * dt * r[ i ];
+    }
+
+    this->Rhs( this->u, this->r );
+
+    double c1 = 1.0 / 3.0;
+    double c2 = 2.0 / 3.0;
+    double c3 = 2.0 / 3.0;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = c1 * un[ i ] + c2 * u[ i ] + c3 * dt * r[ i ];
+    }
+
+}
+
+void Field::Rhs( std::vector<double> & u, std::vector<double> & r )
+{
+    int ist = 1;
+    int ied = ni;
+
+    double coef = this->alpha / ( dx * dx );
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        r[ i ] = coef * ( u[ i + 1 ] - 2.0 * u[ i ] + u[ i - 1 ] );
+    }
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        //std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        //region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate || bcType == BCOutflow )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+        int kkk = 1;
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
diff --git a/example/1d-heat-equation/RK3/cpp/singleblock/01/Field.h b/example/1d-heat-equation/RK3/cpp/singleblock/01/Field.h
new file mode 100644
index 00000000..122557c3
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/singleblock/01/Field.h
@@ -0,0 +1,47 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un, u1;
+    std::vector<double> r;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid );
+    void Solve( Zone * zone );
+public:
+    void FTCS( Zone * zone );
+    void RungeKutta3( Zone * zone );
+    void Rhs( std::vector<double> & u, std::vector<double> & r );
+
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void UpdateOldField();
+    void UpdateRungeKuttaOldField( int istage = 0 );
+public:
+    void RungeKutta( Zone * zone, int istage );
+    void RungeKutta3Stage0( Zone * zone );
+    void RungeKutta3Stage1( Zone * zone );
+    void RungeKutta3Stage2( Zone * zone );
+};
diff --git a/example/1d-heat-equation/RK3/cpp/singleblock/01/LogFile.cpp b/example/1d-heat-equation/RK3/cpp/singleblock/01/LogFile.cpp
new file mode 100644
index 00000000..08ccd453
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/singleblock/01/LogFile.cpp
@@ -0,0 +1,138 @@
+#include "LogFile.h"
+#include "Parallel.h"
+#include <sstream>
+#include <iostream>
+
+#ifdef _WINDOWS
+#include <windows.h>
+#include <direct.h>
+#include <io.h>
+#else
+#include <sys/stat.h>
+#include <unistd.h>
+#endif
+
+LogFile logFile;
+
+class OStream : public std::ostringstream
+{
+public:
+    OStream() {}
+    ~OStream() {}
+public:
+    void ClearAll()
+    {
+        this->clear();
+        this->str("");
+    }
+};
+
+OStream StrIO;
+std::string GetPrjDirName( const std::string & fileName );
+bool DirExist( const std::string & dirName );
+void MakeDir( const std::string & dirName );
+
+std::string GetPrjDirName( const std::string & fileName )
+{
+    size_t pos = fileName.find_last_of("\\/");
+    if ( std::string::npos == pos )
+    {
+        return "";
+    }
+    else
+    {
+        return fileName.substr( 0, pos );
+    }
+}
+
+bool DirExist( const std::string & dirName )
+{
+#ifdef _WINDOWS
+    bool flag = ( _access( dirName.c_str(), 0 ) == 0 );
+    return flag;
+#else
+    bool flag = ( access( dirName.c_str(), 0 ) == 0 );
+    return flag;
+#endif
+}
+
+void MakeDir( const std::string & dirName )
+{
+    int flag;
+#ifdef _WINDOWS
+    flag = _mkdir( dirName.c_str() );
+#else
+    flag = mkdir( dirName.c_str(), S_IRWXU );
+#endif
+    if ( flag == 0 )
+    {
+        std::cout << dirName << " directory has been created successfully !\n";
+    }
+}
+
+void CreateDirIfNeeded( std::string & prjFileName )
+{
+    std::string prj_dir = GetPrjDirName( prjFileName );
+
+    if ( ! DirExist( prj_dir ) )
+    {
+        MakeDir( prj_dir );
+    }
+}
+
+
+void OpenLogFile( int logFileIndex, std::fstream & file )
+{
+    static int ifReWrite = 0;
+
+    StrIO.ClearAll();
+    StrIO << "log/log" << logFileIndex << ".log";
+    std::string fileName = StrIO.str();
+
+    std::ios_base::openmode openMode;
+
+    if ( ifReWrite == 0 )
+    {
+        CreateDirIfNeeded( fileName );
+
+        openMode = std::ios_base::out | std::ios_base::trunc;
+
+        ifReWrite = 1;
+    }
+    else
+    {
+        openMode = std::ios_base::out | std::ios_base::app;
+    }
+
+    file.open( fileName.c_str(), openMode );
+    if ( ! file )
+    {
+        std::cout << "could not open " << fileName << std::endl;
+        exit( 0 );
+    }
+}
+
+void CloseLogFile( std::fstream & file )
+{
+    file.close();
+    file.clear();
+}
+
+LogFile::LogFile()
+{
+}
+
+LogFile::~LogFile()
+{
+}
+
+void LogFile::Open()
+{
+    int pid = Parallel::pid;
+    OpenLogFile( pid, this->my_fstream );
+}
+
+void LogFile::Close()
+{
+    CloseLogFile( this->my_fstream );
+}
diff --git a/example/1d-heat-equation/RK3/cpp/singleblock/01/LogFile.h b/example/1d-heat-equation/RK3/cpp/singleblock/01/LogFile.h
new file mode 100644
index 00000000..00e775ab
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/singleblock/01/LogFile.h
@@ -0,0 +1,27 @@
+#pragma once
+#include <fstream>
+
+void OpenLogFile( int logFileIndex, std::fstream & file );
+void CloseLogFile( std::fstream & file );
+class LogFile;
+extern LogFile logFile;
+
+class LogFile
+{
+public:
+    LogFile();
+    ~LogFile();
+    std::fstream my_fstream;
+public:
+    void Open();
+    void Close();
+};
+
+template< typename T >
+LogFile & operator << ( LogFile & f, const T & value )
+{
+    f.Open();
+    f.my_fstream << value;
+    f.Close();
+    return f;
+}
diff --git a/example/1d-heat-equation/RK3/cpp/singleblock/01/Parallel.cpp b/example/1d-heat-equation/RK3/cpp/singleblock/01/Parallel.cpp
new file mode 100644
index 00000000..0bce1a60
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/singleblock/01/Parallel.cpp
@@ -0,0 +1,54 @@
+#include "Parallel.h"
+#include <iostream>
+
+int Parallel::pid = 0;
+int Parallel::nProc = 1;
+int Parallel::serverid = 0;
+int Parallel::tag = 0;
+
+void Parallel::Init()
+{
+#ifdef HX_PARALLEL
+    int argc     = 0;
+    char ** argv = 0;
+    MPI_Init( &argc, &argv );
+    MPI_Comm_rank( MPI_COMM_WORLD, &Parallel::pid );
+    MPI_Comm_size( MPI_COMM_WORLD, &Parallel::nProc );
+    int len = -1;
+    char version[ MPI_MAX_LIBRARY_VERSION_STRING ];
+    MPI_Get_library_version( version, &len );
+    std::cout << "Hello, world!  I am " << Parallel::pid << " of " << Parallel::nProc
+        << "(" << version << ", " << len << ")" << std::endl;
+#endif
+}
+
+void Parallel::Finalize()
+{
+#ifdef HX_PARALLEL
+    MPI_Finalize();
+#endif
+}
+
+bool Parallel::IsServer()
+{
+    return Parallel::pid == Parallel::serverid;
+}
+
+void HXSendChar( void * data, int size, int pid, int tag )
+{
+#ifdef HX_PARALLEL
+    if ( size <= 0 ) return;
+    MPI_Send( data, size, MPI_CHAR, pid, tag, MPI_COMM_WORLD );
+#endif
+}
+
+void HXRecvChar( void * data, int size, int pid, int tag )
+{
+#ifdef HX_PARALLEL
+    if ( size <= 0 ) return;
+
+    MPI_Status status;
+    MPI_Recv( data, size, MPI_CHAR, pid, tag, MPI_COMM_WORLD, & status );
+#endif
+}
+
diff --git a/example/1d-heat-equation/RK3/cpp/singleblock/01/Parallel.h b/example/1d-heat-equation/RK3/cpp/singleblock/01/Parallel.h
new file mode 100644
index 00000000..880a71cb
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/singleblock/01/Parallel.h
@@ -0,0 +1,78 @@
+#pragma once
+#ifdef HX_PARALLEL
+#include "mpi.h"
+#endif
+#include <vector>
+#include "LogFile.h"
+
+class Parallel
+{
+public:
+    static int pid;
+    static int nProc;
+    static int serverid;
+    static int tag;
+public:
+    static void Init();
+    static void Finalize();
+public:
+    static bool IsServer();
+};
+
+void HXSendChar( void * data, int size, int pid, int tag );
+void HXRecvChar( void * data, int size, int pid, int tag );
+
+template< typename T >
+void HXSendData( T * field, int nElement, int recv_pid, int tag  );
+
+template< typename T >
+void HXRecvData( T * field, int nElement, int send_pid, int tag );
+
+template< typename T >
+void HXSendData( T * field, int nElement, int recv_pid, int tag = 0 )
+{
+    if ( nElement <= 0 ) return;
+
+    int buffer_size = nElement * sizeof( T );
+
+    HXSendChar( field, buffer_size, recv_pid, tag );
+}
+
+template< typename T >
+void HXRecvData( T * field, int nElement, int send_pid, int tag = 0 )
+{
+    if ( nElement <= 0 ) return;
+
+    int buffer_size = nElement * sizeof( T );
+
+    HXRecvChar( field, buffer_size, send_pid, tag );
+}
+
+template< typename T >
+void HXSendRecvData( T * field, int nElement, int send_pid, int recv_pid, int tag = 0 )
+{
+    if ( send_pid == recv_pid ) return;
+
+    if ( nElement <= 0 ) return;
+
+    int buffer_size = nElement * sizeof( T );
+
+    if ( Parallel::pid == send_pid )
+    {
+        HXSendChar( field, buffer_size, recv_pid, tag );
+    }
+    else if ( Parallel::pid == recv_pid )
+    {
+        HXRecvChar( field, buffer_size, send_pid, tag );
+    }
+}
+
+template< typename T >
+void HXBcastData( T * field, int nElement, int send_pid )
+{
+    if ( nElement <= 0 ) return;
+    int buffer_size = nElement * sizeof( T );
+#ifdef HX_PARALLEL
+    MPI_Bcast( field, buffer_size, MPI_CHAR, send_pid, MPI_COMM_WORLD );
+#endif
+}
diff --git a/example/1d-heat-equation/RK3/cpp/singleblock/01/README.txt b/example/1d-heat-equation/RK3/cpp/singleblock/01/README.txt
new file mode 100644
index 00000000..5a4410fb
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/singleblock/01/README.txt
@@ -0,0 +1,3 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
+
+PS D:\github\OneFLOW\example\1d-heat-equation\ftcs\cpp\multiblock\parallel\8blocks\01\build> mpiexec -n 8 .\Debug\testprj.exe
diff --git a/example/1d-heat-equation/RK3/cpp/singleblock/01/Solver.cpp b/example/1d-heat-equation/RK3/cpp/singleblock/01/Solver.cpp
new file mode 100644
index 00000000..6388d7d5
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/singleblock/01/Solver.cpp
@@ -0,0 +1,720 @@
+#include "Solver.h"
+#include "Parallel.h"
+#include "ZoneState.h"
+#include "global.h"
+#include <fstream>
+#include <set>
+#include <unordered_map>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+Solver::Solver()
+{
+    Parallel::Init();
+}
+
+Solver::~Solver()
+{
+    Parallel::Finalize();
+}
+
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    this->InitTopo();
+    this->InitFields();
+    //this->SolveMultiZones();
+    this->RungeKutta();
+    this->PostProcess();
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d1block.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    ReadCgnsGrid( fileName );
+}
+
+void Solver::InitTopo()
+{
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "Solver::InitTopo() " << "\n";
+
+    Global::donor_zone_sets.resize( LocalZone::nZones );
+    Global::donor_zones.resize( LocalZone::nZones );
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        int global_zoneid = LocalZone::global_zoneids[ iZone ];
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "iZone = " << iZone << " global_zoneid = " << global_zoneid << "\n";
+
+        Interface * interface = new Interface();
+        interface->zoneid = global_zoneid;
+        Global::interfaces.push_back( interface );
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+        Interface * interface = Global::interfaces[ iZone ];
+
+        int nbc1to1s = zone->bc1to1s.size();
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout <<  "nbc1to1s = " << nbc1to1s << "\n";
+
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "zoneid = " << zoneid << " donor_zoneid = " << donor_zoneid << "\n";
+
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+        int nInterfaces = interface->zoneList.size();
+        interface->data_recv.resize( nInterfaces );
+        interface->data_send.resize( nInterfaces );
+    }
+
+    for ( int iProc = 0; iProc < Parallel::nProc; ++ iProc )
+    {
+        int nSize = -1;
+        if ( iProc == Parallel::pid )
+        {
+            nSize = Global::facePairList.size();
+        }
+        HXBcastData( &nSize, 1, iProc );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nSize = " << nSize << "\n";
+        std::vector<FacePair> tmp;
+        if ( iProc == Parallel::pid )
+        {
+            tmp = Global::facePairList;
+        }
+        else
+        {
+            tmp.resize( nSize );
+        }
+
+        HXBcastData( tmp.data(), tmp.size(), iProc );
+        Global::AddFacePairList( Global::mpi_facePairList, tmp );
+    }
+
+    for ( int i = 0; i < Global::mpi_facePairList.size(); ++ i )
+    {
+        FacePair &facePair = Global::mpi_facePairList[ i ];
+        Global::InsertFacePairMap( facePair );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        facePair.Print();
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterfaces = interface->local_faceids.size();
+        for ( int iInterface = 0; iInterface < nInterfaces; ++ iInterface )
+        {
+            int local_faceid = interface->local_faceids[ iInterface ];
+            int proc_global_faceid = interface->proc_global_faceids[ iInterface ];
+            FacePair & facePair = Global::facePairList[ proc_global_faceid ];
+            int global_faceid = Global::InsertFacePairMap( facePair );
+            interface->global_faceids.push_back( global_faceid );
+            interface->global_local_face_map.insert( std::make_pair( global_faceid, local_faceid ) );
+        }
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        std::set<int> &donor_zoneSet = Global::donor_zone_sets[ iZone ];
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            donor_zoneSet.insert( donor_zoneid );
+        }
+
+        std::vector<int> &donor_zones = Global::donor_zones[ iZone ];
+        for ( std::set<int>::iterator iter = donor_zoneSet.begin(); iter != donor_zoneSet.end(); ++ iter )
+        {
+            donor_zones.push_back( *iter );
+        }
+
+        interface->neighbor_donor_zones = donor_zones;
+
+        std::unordered_map<int, int> donor_zonelocal;
+
+        for ( int idonor = 0; idonor < donor_zones.size(); ++ idonor )
+        {
+            int donor_zone = donor_zones[ idonor ];
+            donor_zonelocal.insert( std::make_pair( donor_zone, idonor ) );
+        }
+        int ndonors = donor_zones.size();
+        std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+        neighbor_donorfaces.resize( ndonors );
+
+        std::vector<std::vector<int>> & sub_local_faceids = interface->sub_local_faceids;
+        sub_local_faceids.resize( ndonors );
+
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ineighbor = donor_zonelocal[ donor_zoneid ];
+            std::vector<int> &donorfaces = neighbor_donorfaces[ ineighbor ];
+            int global_faceid = interface->global_faceids[ iFace ];
+            donorfaces.push_back( global_faceid );
+            int local_faceid = interface->local_faceids[ iFace ];
+
+            std::vector<int> & sub_local_faces = sub_local_faceids[ ineighbor ];
+            sub_local_faces.push_back( local_faceid );
+        }
+    }
+
+    Global::interfaceTopo.InitNeighborInfo();
+    Global::interfaceTopo.SwapNeighborInfo();
+
+    int kkk = 1;
+}
+
+void Solver::InitFields()
+{
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "Solver::InitFields() ZoneState::nZones = " << ZoneState::nZones <<  "\n";
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+    }
+
+    this->Boundary();
+    this->UpdateOldField();
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        //std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        //std::cout << "it = " << it << " nt = " << Global::nt << "\n";
+        for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+        {
+            Field * field = Global::fields[ iZone ];
+            Zone * zone = Global::zones[ iZone ];
+            zone->zoneIndex = iZone;
+            field->Solve( zone );
+        }
+        Boundary();
+    }
+}
+
+void Solver::RungeKutta()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        for ( int istage = 0; istage < 3; ++ istage )
+        {
+            this->RungeKutta( istage );
+        }
+    }
+}
+
+void Solver::RungeKutta( int istage )
+{
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        zone->zoneIndex = iZone;
+        field->RungeKutta( zone, istage );
+    }
+    this->Boundary();
+    this->UpdateRungeKuttaOldField( istage );
+}
+
+void Solver::Boundary()
+{
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+    ExchangeInterfaceField();
+}
+
+void Solver::UpdateOldField()
+{
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->UpdateOldField();
+    }
+}
+
+void Solver::UpdateRungeKuttaOldField( int istage )
+{
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->UpdateRungeKuttaOldField( istage );
+    }
+}
+
+void Solver::UploadInterfaceField()
+{
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> & send_to_zones = interface->send_to_zones;
+        int nsend_zones = send_to_zones.size();
+
+        std::vector<std::vector<int>> & donorfaces_for_send = interface->donorfaces_for_send;
+        std::vector<std::vector<int>> & donorijk_for_send = interface->donorijk_for_send;
+        std::vector<std::vector<double>> & donordata_for_send = interface->donordata_for_send;
+
+        Field * field = Global::fields[ iZone ];
+
+        for ( int iSend = 0; iSend < nsend_zones; ++ iSend )
+        {
+            int zone_to_send = send_to_zones[ iSend ];
+            std::vector<int> & donorfaces = donorfaces_for_send[ iSend ];
+            std::vector<int> & donorijks = donorijk_for_send[ iSend ];
+            std::vector<double> & donordatas = donordata_for_send[ iSend ];
+
+            int nface = donorfaces.size();
+            int index_dim = 1;
+            for ( int i = 0; i < nface; ++ i )
+            {
+                int ijkpos = index_dim * i;
+                int i_donor_cell = donorijks[ ijkpos + 0 ];
+                donordatas[ i ] = field->u[ i_donor_cell ];
+            }
+        }
+    }
+}
+
+void Solver::UpdateInterfaceField()
+{
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        int ndonor_zones = Global::interfaceTopo.linkmap[ iZone ].size();
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donor_zone = Global::interfaceTopo.linkmap[ iZone ][ iNei ];
+            int send_pid = ZoneState::pids[ iZone ];
+            int recv_pid = ZoneState::pids[ donor_zone ];
+            int nsend = -1;
+            std::vector<double> donordata;
+            if ( Parallel::pid != send_pid && Parallel::pid != recv_pid ) continue;
+            if ( Parallel::pid == send_pid )
+            {
+                int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+                Interface * interface = Global::interfaces[ local_zoneid ];
+                donordata = interface->donordata_for_send[ iNei ];
+                nsend = donordata.size();
+            }
+            HXSendRecvData( &nsend, 1, send_pid, recv_pid );
+
+            if ( Parallel::pid == recv_pid )
+            {
+                donordata.resize( nsend );
+            }
+            HXSendRecvData( donordata.data(), donordata.size(), send_pid, recv_pid );
+
+            if ( Parallel::pid == recv_pid )
+            {
+                int local_donor_zoneid = ZoneState::g2lzoneids[ donor_zone ];
+                Interface * donor_interface = Global::interfaces[ local_donor_zoneid ];
+                int nSize = donor_interface->neighbor_donor_zones.size();
+                int ipos = -1;
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    int nei_zone = donor_interface->neighbor_donor_zones[ i ];
+                    if ( nei_zone == iZone )
+                    {
+                        ipos = i;
+                        break;
+                    }
+                }
+
+                std::vector<int> & neighbor_donorfaces = donor_interface->neighbor_donorfaces[ ipos ];
+                std::vector<int> & sub_local_faceids = donor_interface->sub_local_faceids[ ipos ];
+                for ( int i = 0; i < neighbor_donorfaces.size(); ++ i )
+                {
+                    int local_faceid = sub_local_faceids[ i ];
+                    double donor_value = donordata[ i ];
+                    donor_interface->data_recv[ local_faceid ] = donor_value;
+                }
+            }
+        }
+    }
+}
+
+void Solver::DownloadInterfaceField()
+{
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+        Field * field = Global::fields[ iZone ];
+
+        int nInterFaces = interface->data_recv.size();
+
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+
+            double donor_value = interface->data_recv[ iFace ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    this->UploadInterfaceField();
+    this->UpdateInterfaceField();
+    this->DownloadInterfaceField();
+}
+
+void Solver::PostProcess()
+{
+    Post post;
+    post.Process();
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        if ( !ZoneState::IsValid( iZone ) && !Parallel::IsServer() ) continue;
+
+        double xmin = 0.0;
+        double xmax = 0.0;
+
+        if ( ZoneState::IsValid( iZone ) )
+        {
+            int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+            Grid * grid = Global::grids[ local_zoneid ];
+            int ni = grid->x.size();
+            xmin = grid->x[ 0 ];
+            xmax = grid->x[ 0 ];
+            int imin = 0;
+            int imax = 0;
+            for ( int i = 0; i < ni; ++ i )
+            {
+                if ( xmin > grid->x[ i ] )
+                {
+                    xmin = grid->x[ i ];
+                    imin = i;
+                }
+                if ( xmax < grid->x[ i ] )
+                {
+                    xmax = grid->x[ i ];
+                    imax = i;
+                }
+            }
+        }
+
+        HXSendRecvData( &xmin, 1, ZoneState::pids[ iZone ], Parallel::serverid );
+        HXSendRecvData( &xmax, 1, ZoneState::pids[ iZone ], Parallel::serverid );
+
+        //if ( Parallel::IsServer() )
+        //{
+        //    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        //    std::cout << "xmin = " << xmin << "\n";
+        //    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        //    std::cout << "xmax = " << xmax << "\n";
+        //}
+
+        if ( Parallel::IsServer() )
+        {
+            xmin_list.push_back( xmin );
+            xmax_list.push_back( xmax );
+        }
+    }
+
+    //if ( Parallel::IsServer() )
+    //{
+    //    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    //    for ( int i = 0; i < xmin_list.size(); ++ i )
+    //    {
+    //        std::cout << "(" << xmin_list[ i ] << "," << xmax_list[ i ] << ") ";
+    //    }
+    //    std::cout << "\n";
+    //}
+
+    if ( Parallel::IsServer() )
+    {
+        std::vector<std::pair<double, int>> pairs;
+        int nSize = xmin_list.size();
+        for ( int i = 0; i < nSize; ++ i )
+        {
+            pairs.push_back( std::make_pair( xmin_list[ i ], i ) );
+        }
+
+        std::sort( pairs.begin(), pairs.end() );
+
+        for ( int i = 0; i < nSize; ++ i )
+        {
+            this->zoneids.push_back( pairs[ i ].second );
+        }
+    }
+
+    int kkk = 1;
+}
+
+bool IsLastZone( int iZone );
+bool IsLastZone( int iZone )
+{
+    return iZone == ZoneState::nZones - 1;
+}
+
+void Post::AddVector( std::vector<double> & a, std::vector<double> & b )
+{
+    for ( int i = 0; i < b.size(); ++ i )
+    {
+        a.push_back( b[ i ] );
+    }
+}
+
+void Post::GatherField()
+{
+    this->zoneids.resize( ZoneState::nZones );
+    HXBcastData( this->zoneids.data(), this->zoneids.size(), Parallel::serverid );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "Post::GatherField() this->zoneids = \n";
+    for ( int i = 0; i < this->zoneids.size(); ++ i )
+    {
+        std::cout << this->zoneids[ i ] << " ";
+    }
+    std::cout << "\n";
+
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+
+        if ( !ZoneState::IsValid( zoneid ) && !Parallel::IsServer() ) continue;
+
+        int nSize = -1;
+        std::vector<double> local_x;
+        std::vector<double> local_u_e;
+        std::vector<double> local_un;
+        std::vector<double> local_u;
+
+        if ( Parallel::pid == ZoneState::pids[ zoneid ] )
+        {
+            int local_zoneid = ZoneState::g2lzoneids[ zoneid ];
+            Grid * grid = Global::grids[ local_zoneid ];
+            Field * field = Global::fields[ local_zoneid ];
+            int ni = grid->x.size();
+
+            int ist = 1;
+            int ied = ni;
+
+            int dir = 1;
+            if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+            if ( dir == 1 )
+            {
+                if ( IsLastZone( iZone ) )
+                {
+                    for ( int i = ist; i <= ied; ++ i )
+                    {
+                        double xm = grid->x[ i - ist ];
+                        local_x.push_back( xm );
+                        local_u_e.push_back( field->u_e[ i ] );
+                        local_un.push_back( field->un[ i ] );
+                        local_u.push_back( field->u[ i ] );
+                    }
+                }
+                else
+                {
+                    for ( int i = ist; i <= ied - 1; ++ i )
+                    {
+                        double xm = grid->x[ i - ist ];
+                        local_x.push_back( xm );
+                        local_u_e.push_back( field->u_e[ i ] );
+                        local_un.push_back( field->un[ i ] );
+                        local_u.push_back( field->u[ i ] );
+                    }
+                }
+            }
+            else
+            {
+                if ( IsLastZone( iZone ) )
+                {
+                    for ( int i = ied; i >= ist; -- i )
+                    {
+                        double xm = grid->x[ i - ist ];
+                        local_x.push_back( xm );
+                        local_u_e.push_back( field->u_e[ i ] );
+                        local_un.push_back( field->un[ i ] );
+                        local_u.push_back( field->u[ i ] );
+                    }
+                }
+                else
+                {
+                    for ( int i = ied; i >= ist + 1; -- i )
+                    {
+                        double xm = grid->x[ i - ist ];
+                        local_x.push_back( xm );
+                        local_u_e.push_back( field->u_e[ i ] );
+                        local_un.push_back( field->un[ i ] );
+                        local_u.push_back( field->u[ i ] );
+                    }
+                }
+            }
+            nSize = local_x.size();
+        }
+
+        int send_pid = ZoneState::pids[ zoneid ];
+
+        HXSendRecvData( &nSize, 1, send_pid, Parallel::serverid );
+
+        if ( Parallel::IsServer() )
+        {
+            local_x.resize( nSize );
+            local_u_e.resize( nSize );
+            local_un.resize( nSize );
+            local_u.resize( nSize );
+        }
+
+        HXSendRecvData( local_x.data(), local_x.size(), send_pid, Parallel::serverid );
+        HXSendRecvData( local_u_e.data(), local_u_e.size(), send_pid, Parallel::serverid );
+        HXSendRecvData( local_un.data(), local_un.size(), send_pid, Parallel::serverid );
+        HXSendRecvData( local_u.data(), local_u.size(), send_pid, Parallel::serverid );
+
+        if ( Parallel::IsServer() )
+        {
+            this->AddVector( this->x, local_x );
+            this->AddVector( this->u_e, local_u_e );
+            this->AddVector( this->un, local_un );
+            this->AddVector( this->u, local_u );
+        }
+    }
+}
+
+void Post::DumpField()
+{
+    if ( !Parallel::IsServer() ) return;
+    int ni_total = this->x.size();
+    std::cout << " DumpField x.size() = " << x.size() << "\n";
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    this->DumpErrorDetails( u_error );
+
+    std::string csvname = "field_final.csv";
+    this->DumpCsvFile( csvname, x, u_e, un, u_error );
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.20f} {:.20f} {:.20f} {:.20f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
diff --git a/example/1d-heat-equation/RK3/cpp/singleblock/01/Solver.h b/example/1d-heat-equation/RK3/cpp/singleblock/01/Solver.h
new file mode 100644
index 00000000..1527dd2b
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/singleblock/01/Solver.h
@@ -0,0 +1,54 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+
+class Solver
+{
+public:
+    Solver();
+    ~Solver();
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveMultiZones();
+public:
+    void Boundary();
+    void UpdateOldField();
+    void UpdateRungeKuttaOldField( int istage );
+    void UploadInterfaceField();
+    void UpdateInterfaceField();
+    void DownloadInterfaceField();
+    void ExchangeInterfaceField();
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcess();
+public:
+    void RungeKutta();
+    void RungeKutta( int istage );
+};
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+    std::vector<double> u;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+public:
+    void AddVector( std::vector<double> & a, std::vector<double> & b );
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/RK3/cpp/singleblock/01/ZoneState.cpp b/example/1d-heat-equation/RK3/cpp/singleblock/01/ZoneState.cpp
new file mode 100644
index 00000000..ff810849
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/singleblock/01/ZoneState.cpp
@@ -0,0 +1,20 @@
+#include "ZoneState.h"
+#include "Parallel.h"
+
+int ZoneState::nZones = 0;
+std::vector<int> ZoneState::pids;
+std::vector<int> ZoneState::g2lzoneids;
+
+bool ZoneState::IsValid( int zoneid )
+{
+    return ZoneState::pids[ zoneid ] == Parallel::pid;
+}
+
+int ZoneState::GetProcID( int zoneid )
+{
+    return ZoneState::pids[ zoneid ];
+}
+
+int LocalZone::nZones = 0;
+std::vector<int> LocalZone::global_zoneids;
+
diff --git a/example/1d-heat-equation/RK3/cpp/singleblock/01/ZoneState.h b/example/1d-heat-equation/RK3/cpp/singleblock/01/ZoneState.h
new file mode 100644
index 00000000..1096d632
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/singleblock/01/ZoneState.h
@@ -0,0 +1,21 @@
+#pragma once
+#include <vector>
+
+class ZoneState
+{
+public:
+    static int nZones;
+    static int zone_id;
+    static std::vector<int> pids;
+    static std::vector<int> g2lzoneids; //global zone id to local zone id
+public:
+    static bool IsValid( int zoneid );
+    static int GetProcID( int zoneid );
+};
+
+class LocalZone
+{
+public:
+    static int nZones;
+    static std::vector<int> global_zoneids;
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/RK3/cpp/singleblock/01/global.cpp b/example/1d-heat-equation/RK3/cpp/singleblock/01/global.cpp
new file mode 100644
index 00000000..df1e6bae
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/singleblock/01/global.cpp
@@ -0,0 +1,300 @@
+#include "global.h"
+#include "CgnsGrid.h"
+#include "ZoneState.h"
+#include "Parallel.h"
+#include <iostream>
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *> Global::interfaces;
+
+std::map<Face, int> Global::faceMap;
+std::map<FacePair, int> Global::facePairMap;
+std::vector<FacePair> Global::facePairList;
+std::vector<FacePair> Global::mpi_facePairList;
+
+std::vector<std::set<int>> Global::donor_zone_sets;
+std::vector<std::vector<int>> Global::donor_zones;
+
+InterfaceTopo Global::interfaceTopo;
+
+bool Face::operator < ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return this->zone < rhs.zone;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return this->i < rhs.i;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return this->j < rhs.j;
+    }
+
+    return this->k < rhs.k;
+}
+
+bool Face::operator == ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return false;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return false;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return false;
+    }
+
+    return this->k == rhs.k;
+}
+
+void Face::Print()
+{
+    std::cout << "(" << this->zone << "," << this->i << ")";
+}
+
+void FacePair::AddPair( const Face & face1, const Face & face2 )
+{
+    if ( face1 < face2 )
+    {
+        this->left = face1;
+        this->right = face2;
+    }
+    else
+    {
+        this->left = face2;
+        this->right = face1;
+    }
+}
+
+bool FacePair::operator < ( const FacePair & rhs ) const
+{
+    if ( this->left == rhs.left || this->left == rhs.right )
+    {
+        return false;
+    }
+
+    return this->left < rhs.left;
+}
+
+void FacePair::Print()
+{
+    this->left.Print();
+    std::cout << " ";
+    this->right.Print();
+    std::cout << "\n";
+}
+
+void InterfaceTopo::InitNeighborInfo()
+{
+    this->linkmap.resize( ZoneState::nZones );
+
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        if ( ! ZoneState::IsValid( iZone ) ) continue;
+
+        int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+
+        Interface * interface = Global::interfaces[ local_zoneid ];
+
+        std::vector<int> & t = this->linkmap[ iZone ];
+        t = interface->neighbor_donor_zones;
+    }
+}
+
+void InterfaceTopo::SwapNeighborInfo()
+{
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        int pid = ZoneState::pids[ iZone ];
+
+        std::vector<int> & donor_zones = this->linkmap[ iZone ];
+        int nNeighbor = donor_zones.size();
+
+        HXBcastData( &nNeighbor, 1, pid );
+
+        donor_zones.resize( nNeighbor );
+
+        HXBcastData( donor_zones.data(), donor_zones.size(), pid );
+    }
+
+    this->SwapNeighborDonorfaces();
+}
+
+void InterfaceTopo::SwapNeighborDonorfaces()
+{
+    int gl = 0;
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        int send_pid = ZoneState::pids[ iZone ];
+
+        std::vector<int> & donor_zones = this->linkmap[ iZone ];
+        int ndonor_zones = donor_zones.size();
+
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donor_zone = donor_zones[ iNei ];
+            int recv_pid = ZoneState::pids[ donor_zone ];
+            int nInterFaces = 0;
+            std::vector<int> donorfaces;
+
+            if ( Parallel::pid == send_pid )
+            {
+                int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+
+                Interface * interface = Global::interfaces[ local_zoneid ];
+
+                std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+
+                std::vector<int> & neighbor_donorface = neighbor_donorfaces[ iNei ];
+
+                nInterFaces = neighbor_donorface.size();
+
+                donorfaces = neighbor_donorface;
+            }
+
+            HXSendRecvData( &nInterFaces, 1, send_pid, recv_pid );
+
+            if ( Parallel::pid == recv_pid && send_pid != recv_pid )
+            {
+                donorfaces.resize( nInterFaces );
+            }
+
+            HXSendRecvData( donorfaces.data(), donorfaces.size(), send_pid, recv_pid );
+
+            if ( Parallel::pid == recv_pid )
+            {
+                int local_donor_zoneid = ZoneState::g2lzoneids[ donor_zone ];
+                Interface * interface_recv = Global::interfaces[ local_donor_zoneid ];
+                interface_recv->SendGeom( iZone, donorfaces );
+            }
+        }
+    }
+}
+
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->local_faceids.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        Face face;
+        face.zone = zoneid;
+        face.i = i;
+
+        int i_donor = index2[ 0 ];
+
+        Face face_donor;
+        face_donor.zone = donor_zoneid;
+        face_donor.i = i_donor;
+
+        FacePair facePair;
+        facePair.AddPair( face, face_donor );
+
+        Global::facePairList.push_back( facePair );
+        int nSize = Global::facePairList.size();
+        this->proc_global_faceids.push_back( nSize - 1 );
+
+        int i_ghost_cell = i + 1;
+        int i_local_donor_cell = i - 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+            i_local_donor_cell = i + 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+        ijk_donors.push_back( i_local_donor_cell );
+
+        icount ++;
+    }
+}
+
+void Interface::SendGeom( int zone, std::vector<int> & donorfaces )
+{
+    Interface * interface = this;
+
+    std::vector<int> & send_to_zones = interface->send_to_zones;
+
+    send_to_zones.push_back( zone );
+    interface->donorfaces_for_send.push_back( donorfaces );
+
+    int nface = donorfaces.size();
+    std::vector<int> sub_donorijk;
+    int index_dim = 1;
+    for ( int i = 0; i < nface; ++ i )
+    {
+        int global_faceid = donorfaces[ i ];
+        int local_faceid = interface->global_local_face_map[ global_faceid ];
+        int ijkpos = index_dim * local_faceid;
+        int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+        sub_donorijk.push_back( i_donor_cell );
+        int kkk = 1;
+    }
+
+    interface->donorijk_for_send.push_back( sub_donorijk );
+
+    std::vector<double> sub_donordata( sub_donorijk.size() );
+    interface->donordata_for_send.push_back( sub_donordata );
+}
+
+void Global::InsertFaceMap( const Face & face )
+{
+    std::map<Face, int>::iterator iter;
+    iter = Global::faceMap.find( face );
+    if ( iter == Global::faceMap.end() )
+    {
+        int faceid = Global::faceMap.size();
+        Global::faceMap.insert( std::make_pair( face, faceid ) );
+    }
+}
+
+int Global::InsertFacePairMap( const FacePair & facePair )
+{
+    std::map<FacePair, int>::iterator iter;
+    iter = Global::facePairMap.find( facePair );
+    if ( iter == Global::facePairMap.end() )
+    {
+        int facePairId = Global::facePairMap.size();
+        Global::facePairMap.insert( std::make_pair( facePair, facePairId ) );
+        return facePairId;
+    }
+    return iter->second;
+}
+
+void Global::AddFacePairList( std::vector<FacePair> & a, std::vector<FacePair> & b )
+{
+    for ( int i = 0; i < b.size(); ++ i )
+    {
+        a.push_back( b[ i ] );
+    }
+}
+
diff --git a/example/1d-heat-equation/RK3/cpp/singleblock/01/global.h b/example/1d-heat-equation/RK3/cpp/singleblock/01/global.h
new file mode 100644
index 00000000..933cec05
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/singleblock/01/global.h
@@ -0,0 +1,157 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <unordered_map>
+#include <set>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class Face
+{
+public:
+    int zone = 0;
+    int i = 0;
+    int j = 1;
+    int k = 1;
+public:
+    bool operator < ( const Face & rhs ) const;
+    bool operator == ( const Face & rhs ) const;
+public:
+    void Print();
+};
+
+class FacePair
+{
+public:
+    Face left;
+    Face right;
+public:
+    bool operator < ( const FacePair & rhs ) const;
+    void AddPair( const Face &face1, const Face &face2);
+public:
+    void Print();
+};
+
+class Transform;
+
+class InterfaceTopo
+{
+public:
+    std::vector<std::vector<int>> linkmap;
+public:
+    void InitNeighborInfo();
+    void SwapNeighborInfo();
+    void SwapNeighborDonorfaces();
+};
+
+
+class Interface
+{
+public:
+    int zoneid;
+    std::vector<int> zoneList;
+    std::vector<int> global_faceids;
+    std::vector<int> mpi_global_faceids;
+    std::vector<int> proc_global_faceids;
+    std::vector<int> local_faceids;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+    std::vector<double> data_recv;
+    std::vector<double> data_send;
+    std::unordered_map<int, int> global_local_face_map;
+public:
+    std::vector<int> neighbor_donor_zones;
+    std::vector<std::vector<int>> neighbor_donorfaces;
+    std::vector<std::vector<int>> sub_local_faceids;
+    std::vector<int> send_to_zones;
+    std::vector<std::vector<int>> donorfaces_for_send;
+    std::vector<std::vector<int>> donorijk_for_send;
+    std::vector<std::vector<double>> donordata_for_send;
+public:
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+    void SendGeom( int zone, std::vector<int> & donorfaces );
+};
+
+class Field;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+public:
+    static std::map<Face, int> faceMap;
+    static std::map<FacePair, int> facePairMap;
+    static std::vector<FacePair> facePairList;
+    static std::vector<FacePair> mpi_facePairList;
+    static std::vector<std::set<int>> donor_zone_sets;
+    static std::vector<std::vector<int>> donor_zones;
+    static InterfaceTopo interfaceTopo;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+public:
+    static void InsertFaceMap( const Face & face );
+    static int InsertFacePairMap( const FacePair & facePair );
+    static void AddFacePairList( std::vector<FacePair> & a, std::vector<FacePair> & b );
+};
+
diff --git a/example/1d-heat-equation/RK3/cpp/singleblock/01/heat1d1block.cgns b/example/1d-heat-equation/RK3/cpp/singleblock/01/heat1d1block.cgns
new file mode 100644
index 00000000..b7d4954a
Binary files /dev/null and b/example/1d-heat-equation/RK3/cpp/singleblock/01/heat1d1block.cgns differ
diff --git a/example/1d-heat-equation/RK3/cpp/singleblock/01/heat1d4blocksv1.cgns b/example/1d-heat-equation/RK3/cpp/singleblock/01/heat1d4blocksv1.cgns
new file mode 100644
index 00000000..df5ffc5f
Binary files /dev/null and b/example/1d-heat-equation/RK3/cpp/singleblock/01/heat1d4blocksv1.cgns differ
diff --git a/example/1d-heat-equation/RK3/cpp/singleblock/01/main.cpp b/example/1d-heat-equation/RK3/cpp/singleblock/01/main.cpp
new file mode 100644
index 00000000..df63b7da
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/singleblock/01/main.cpp
@@ -0,0 +1,9 @@
+#include "Solver.h"
+#include "Parallel.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/RK3/cpp/singleblock/01/plot.py b/example/1d-heat-equation/RK3/cpp/singleblock/01/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/singleblock/01/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/RK3/cpp/singleblock/01/plotting2.jl b/example/1d-heat-equation/RK3/cpp/singleblock/01/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/RK3/cpp/singleblock/01/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/RK3/01/rk3.py b/example/1d-heat-equation/RK3/python/01/rk3.py
similarity index 100%
rename from example/1d-heat-equation/RK3/01/rk3.py
rename to example/1d-heat-equation/RK3/python/01/rk3.py
diff --git a/example/1d-heat-equation/RK3/02/rk3.py b/example/1d-heat-equation/RK3/python/02/rk3.py
similarity index 100%
rename from example/1d-heat-equation/RK3/02/rk3.py
rename to example/1d-heat-equation/RK3/python/02/rk3.py
diff --git a/example/1d-heat-equation/RK3/03/rk3.py b/example/1d-heat-equation/RK3/python/03/rk3.py
similarity index 100%
rename from example/1d-heat-equation/RK3/03/rk3.py
rename to example/1d-heat-equation/RK3/python/03/rk3.py
diff --git a/example/1d-heat-equation/ftcs/cpp/01/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/01/CMakeLists.txt
new file mode 100644
index 00000000..bfdbab14
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/01/CMakeLists.txt
@@ -0,0 +1,75 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/01/README.txt b/example/1d-heat-equation/ftcs/cpp/01/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/01/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/01/heat1dni81.cgns b/example/1d-heat-equation/ftcs/cpp/01/heat1dni81.cgns
new file mode 100644
index 00000000..b7d4954a
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/01/heat1dni81.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/01/main.cpp b/example/1d-heat-equation/ftcs/cpp/01/main.cpp
new file mode 100644
index 00000000..6bfa0a0e
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/01/main.cpp
@@ -0,0 +1,320 @@
+#include "cgnslib.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip> 
+
+class Grid;
+void ReadCgnsGrid( const std::string & filename, Grid * grid );
+
+class Grid
+{
+public:
+    std::vector<double> x;
+};
+
+class Solver
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u,un;
+    std::vector<double> error;
+public:
+    void solve()
+    {
+        std::cout << "solve()\n";
+        Grid grid;
+        //ReadCgnsGrid( "../heat1d.cgns", &grid );
+        ReadCgnsGrid( "../heat1dni81.cgns", &grid );
+        int ni = grid.x.size();
+        std::cout << "ni = " << ni << "\n";
+
+        std::vector<double> & x = grid.x;
+        double dx = x[ 1 ] - x[ 0 ];
+        //double dt = 0.0025;
+        double dt = dx / 10.0;
+        double t = 1.0;
+        int nt = static_cast<int>( t / dt )+1;
+        //int nt = 1;
+
+        std::cout << "nt = " << nt << "\n";
+
+        u_e.resize( ni );
+        u.resize( ni );
+        un.resize( ni );
+
+        for ( int i = 0; i < ni; ++ i )
+        {
+            u_e[ i ] = - std::exp( -t ) * std::sin( std::numbers::pi * x[i] ); //theory solution
+            un[ i ] = - std::sin( std::numbers::pi * x[ i ] ); //initial condition @ t=0
+        }
+        un[ 0 ] = 0.0;
+        un[ ni - 1 ] = 0.0;
+
+        int icount = 0;
+        for ( int i = 0; i < ni; ++ i )
+        {
+            std::cout << std::setprecision(15) << un[ i ] << " ";
+            icount ++;
+            if ( icount % 5 == 0 )
+            {
+                std::cout << "\n";
+            }
+        }
+        std::cout << "\n";
+        std::cout << "\n";
+
+        double alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+        double beta = alpha * dt / ( dx * dx );
+        std::cout << "alpha = " << std::setprecision(15) << alpha << "\n";
+        std::cout << "beta = " << std::setprecision(15) << beta << "\n";
+
+        for ( int it = 0; it < nt; ++ it )
+        {
+            for ( int i = 1; i < ni - 1; ++ i )
+            {
+                u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+            }
+            //boundary
+            u[ 0 ] = 0.0; // boundary condition at x = -1
+            u[ ni - 1 ] = 0.0; // boundary condition at x = 1
+            this->update( un, u );
+        }
+
+        icount = 0;
+        for ( int i = 0; i < ni; ++ i )
+        {
+            std::cout << std::setprecision(15) << un[ i ] << " ";
+            icount ++;
+            if ( icount % 5 == 0 )
+            {
+                std::cout << "\n";
+            }
+        }
+        std::cout << "\n";
+
+        //compute L2 norm of the error
+        std::vector<double> u_error( ni );
+        icount = 0;
+        for ( int i = 0; i < ni; ++ i )
+        {
+            u_error[ i ] = un[ i ] - u_e[ i ];
+            std::cout << std::setprecision(15) << u_error[ i ] << " ";
+            icount ++;
+            if ( icount % 5 == 0 )
+            {
+                std::cout << "\n";
+            }
+        }
+        std::cout << "\n";
+        std::cout << "\n";
+
+        icount = 0;
+        for ( int i = 0; i < ni; ++ i )
+        {
+            std::cout << std::setprecision(15) << u_e[ i ] << " ";
+            icount ++;
+            if ( icount % 5 == 0 )
+            {
+                std::cout << "\n";
+            }
+        }
+        std::cout << "\n";
+
+        double rms_error = compute_l2norm( ni, u_error );
+        double max_error = compute_max_error( ni, u_error );
+        std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+        //create output file for L2-norm
+        std::fstream file;
+        file.open("output.txt", std::fstream::out);
+        std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+        std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+        std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+        file.close();
+        int kkk = 1;
+    }
+
+    void update( std::vector<double> &un, std::vector<double> &u )
+    {
+        for ( int i = 0; i < u.size(); ++ i )
+        {
+            un[ i ] = u[ i ];
+        }
+    }
+
+    double compute_l2norm( int ni, std::vector<double> & r )
+    {
+        double rms = 0.0;
+        for ( int i = 1; i < ni - 1; ++ i )
+        {
+            rms += r[ i ] * r[ i ];
+        }
+        rms = std::sqrt( rms / ( ni - 2 ) );
+        return rms;
+    }
+
+    double compute_max_error( int ni, std::vector<double> & u_error )
+    {
+        double val_max = -1;
+        int ipos = -1;
+        for ( int i = 1; i < ni - 1; ++ i )
+        {
+            //val_max = std::max( val_max, std::abs( u_error[ i ] ) );
+            if ( val_max < std::abs( u_error[ i ] ) )
+            {
+                ipos = i;
+                val_max = std::abs( u_error[ i ] );
+            }
+        }
+        std::cout << " ipos = " << ipos << "\n";
+        return val_max;
+    }
+};
+
+void ReadCgnsGrid( const std::string & filename, Grid * grid )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones(fileId, baseId, &nzones);
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize(index_dim*3);
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[33];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                //std::vector<double> coord( nNodes );
+                std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coord.data() );
+                double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+                for ( int i = 0; i < nNodes; ++ i )
+                {
+                    //std::cout << coord[i] << " ";
+                    std::cout << xd[i] << " ";
+                    grid->x[ i ] = xd[ i ];
+                    if( (i+1)%5 == 0 ) std::cout << "\n";
+                }
+                std::cout << "\n";
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex(index_dim,-1);
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type, 
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset);
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[i] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[normalDataType] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList(nNodes*iphysdim*sizeof(double));
+
+                std::vector<cgsize_t> pnts(npnts*index_dim);
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double*>(const_cast<char *>(normalList.data()));
+
+                //std::cout << "normalList = ";
+                //for ( int i = 0; i < nNodes*iphysdim; ++ i )
+                //{
+                //    std::cout << normal_d[ i ] << " ";
+                //}
+                //std::cout << "\n";
+            }
+        }
+    }
+    cg_close(fileId);
+}
+
+int main(int argc, char **argv)
+{
+    Solver solver;
+    solver.solve();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/01a/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/01a/CMakeLists.txt
new file mode 100644
index 00000000..bfdbab14
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/01a/CMakeLists.txt
@@ -0,0 +1,75 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/01a/README.txt b/example/1d-heat-equation/ftcs/cpp/01a/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/01a/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/01a/heat1dni101.cgns b/example/1d-heat-equation/ftcs/cpp/01a/heat1dni101.cgns
new file mode 100644
index 00000000..851c2c3d
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/01a/heat1dni101.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/01a/main.cpp b/example/1d-heat-equation/ftcs/cpp/01a/main.cpp
new file mode 100644
index 00000000..fdbe5f1b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/01a/main.cpp
@@ -0,0 +1,306 @@
+#include "cgnslib.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip> 
+
+class Grid;
+void ReadCgnsGrid( const std::string & filename, Grid * grid );
+
+class Grid
+{
+public:
+    std::vector<double> x;
+};
+
+class Solver
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u,un;
+    std::vector<double> error;
+public:
+    void solve()
+    {
+        std::cout << "solve()\n";
+        Grid grid;
+        ReadCgnsGrid( "../heat1dni101.cgns", &grid );
+        int ni = grid.x.size();
+        std::cout << "ni = " << ni << "\n";
+
+        std::vector<double> & x = grid.x;
+        double dx = x[ 1 ] - x[ 0 ];
+        double dt = dx / 10.0;
+        double t = 1.0;
+        int nt = static_cast<int>( t / dt )+1;
+        std::cout << "nt = " << nt << "\n";
+
+        u_e.resize( ni );
+        u.resize( ni );
+        un.resize( ni );
+
+        for ( int i = 0; i < ni; ++ i )
+        {
+            u_e[ i ] = - std::exp( -t ) * std::sin( std::numbers::pi * x[i] ); //theory solution
+            un[ i ] = - std::sin( std::numbers::pi * x[ i ] ); //initial condition @ t=0
+        }
+        un[ 0 ] = 0.0;
+        un[ ni - 1 ] = 0.0;
+
+        double alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+        double beta = alpha * dt / ( dx * dx );
+        std::cout << "alpha = " << std::setprecision(15) << alpha << "\n";
+        std::cout << "beta = " << std::setprecision(15) << beta << "\n";
+
+        for ( int it = 0; it < nt; ++ it )
+        {
+            for ( int i = 1; i < ni - 1; ++ i )
+            {
+                u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+            }
+            //boundary
+            u[ 0 ] = 0.0; // boundary condition at x = -1
+            u[ ni - 1 ] = 0.0; // boundary condition at x = 1
+            this->update( un, u );
+        }
+
+        //compute L2 norm of the error
+        std::vector<double> u_error( ni );
+        for ( int i = 0; i < ni; ++ i )
+        {
+            u_error[ i ] = un[ i ] - u_e[ i ];
+        }
+
+        this->DumpErrorDetails(u_error);
+        this->DumpCsvFile("field_final.csv",x,u_e,un,u_error);
+
+        int kkk = 1;
+    }
+
+    void PrintField( std::vector<double> &f )
+    {
+        int icount = 0;
+        for ( int i = 0; i < f.size(); ++ i )
+        {
+            std::cout << std::setprecision(15) << f[ i ] << " ";
+            icount ++;
+            if ( icount % 5 == 0 )
+            {
+                std::cout << "\n";
+            }
+        }
+        std::cout << "\n";
+        std::cout << "\n";
+    }
+
+    void DumpErrorDetails( std::vector<double> &u_error )
+    {
+        int ni = u_error.size();
+        double rms_error = compute_l2norm( ni, u_error );
+        double max_error = compute_max_error( ni, u_error );
+        std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+        //create output file for L2-norm
+        std::fstream file;
+        file.open("output.txt", std::fstream::out);
+        std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+        std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+        std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+        file.close();
+    }
+
+    void DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+    {
+        std::fstream file;
+        file.open(filename.c_str(), std::fstream::out);
+        std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+        for ( int i = 0; i < x.size(); ++ i )
+        {
+            std::format_to(std::ostream_iterator<char>(file), "{:.16f} {:.16f} {:.16f} {:.16f}\n", x[i], ue[i], un[i], uerror[i] );
+        }
+        file.close();
+    }
+
+    void update( std::vector<double> &un, std::vector<double> &u )
+    {
+        for ( int i = 0; i < u.size(); ++ i )
+        {
+            un[ i ] = u[ i ];
+        }
+    }
+
+    double compute_l2norm( int ni, std::vector<double> & r )
+    {
+        double rms = 0.0;
+        for ( int i = 1; i < ni - 1; ++ i )
+        {
+            rms += r[ i ] * r[ i ];
+        }
+        rms = std::sqrt( rms / ( ni - 2 ) );
+        return rms;
+    }
+
+    double compute_max_error( int ni, std::vector<double> & u_error )
+    {
+        double val_max = -1;
+        int ipos = -1;
+        for ( int i = 1; i < ni - 1; ++ i )
+        {
+            //val_max = std::max( val_max, std::abs( u_error[ i ] ) );
+            if ( val_max < std::abs( u_error[ i ] ) )
+            {
+                ipos = i;
+                val_max = std::abs( u_error[ i ] );
+            }
+        }
+        std::cout << " ipos = " << ipos << "\n";
+        return val_max;
+    }
+};
+
+void ReadCgnsGrid( const std::string & filename, Grid * grid )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones(fileId, baseId, &nzones);
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize(index_dim*3);
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[33];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                //std::vector<double> coord( nNodes );
+                std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coord.data() );
+                double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+                for ( int i = 0; i < nNodes; ++ i )
+                {
+                    //std::cout << coord[i] << " ";
+                    std::cout << xd[i] << " ";
+                    grid->x[ i ] = xd[ i ];
+                    if( (i+1)%5 == 0 ) std::cout << "\n";
+                }
+                std::cout << "\n";
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex(index_dim,-1);
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type, 
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset);
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[i] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[normalDataType] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList(nNodes*iphysdim*sizeof(double));
+
+                std::vector<cgsize_t> pnts(npnts*index_dim);
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double*>(const_cast<char *>(normalList.data()));
+
+                //std::cout << "normalList = ";
+                //for ( int i = 0; i < nNodes*iphysdim; ++ i )
+                //{
+                //    std::cout << normal_d[ i ] << " ";
+                //}
+                //std::cout << "\n";
+            }
+        }
+    }
+    cg_close(fileId);
+}
+
+int main(int argc, char **argv)
+{
+    Solver solver;
+    solver.solve();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/01a/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/01a/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/01a/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/01b/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/01b/CMakeLists.txt
new file mode 100644
index 00000000..bfdbab14
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/01b/CMakeLists.txt
@@ -0,0 +1,75 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/01b/README.txt b/example/1d-heat-equation/ftcs/cpp/01b/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/01b/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/01b/heat1dni101.cgns b/example/1d-heat-equation/ftcs/cpp/01b/heat1dni101.cgns
new file mode 100644
index 00000000..851c2c3d
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/01b/heat1dni101.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/01b/main.cpp b/example/1d-heat-equation/ftcs/cpp/01b/main.cpp
new file mode 100644
index 00000000..fdbe5f1b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/01b/main.cpp
@@ -0,0 +1,306 @@
+#include "cgnslib.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip> 
+
+class Grid;
+void ReadCgnsGrid( const std::string & filename, Grid * grid );
+
+class Grid
+{
+public:
+    std::vector<double> x;
+};
+
+class Solver
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u,un;
+    std::vector<double> error;
+public:
+    void solve()
+    {
+        std::cout << "solve()\n";
+        Grid grid;
+        ReadCgnsGrid( "../heat1dni101.cgns", &grid );
+        int ni = grid.x.size();
+        std::cout << "ni = " << ni << "\n";
+
+        std::vector<double> & x = grid.x;
+        double dx = x[ 1 ] - x[ 0 ];
+        double dt = dx / 10.0;
+        double t = 1.0;
+        int nt = static_cast<int>( t / dt )+1;
+        std::cout << "nt = " << nt << "\n";
+
+        u_e.resize( ni );
+        u.resize( ni );
+        un.resize( ni );
+
+        for ( int i = 0; i < ni; ++ i )
+        {
+            u_e[ i ] = - std::exp( -t ) * std::sin( std::numbers::pi * x[i] ); //theory solution
+            un[ i ] = - std::sin( std::numbers::pi * x[ i ] ); //initial condition @ t=0
+        }
+        un[ 0 ] = 0.0;
+        un[ ni - 1 ] = 0.0;
+
+        double alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+        double beta = alpha * dt / ( dx * dx );
+        std::cout << "alpha = " << std::setprecision(15) << alpha << "\n";
+        std::cout << "beta = " << std::setprecision(15) << beta << "\n";
+
+        for ( int it = 0; it < nt; ++ it )
+        {
+            for ( int i = 1; i < ni - 1; ++ i )
+            {
+                u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+            }
+            //boundary
+            u[ 0 ] = 0.0; // boundary condition at x = -1
+            u[ ni - 1 ] = 0.0; // boundary condition at x = 1
+            this->update( un, u );
+        }
+
+        //compute L2 norm of the error
+        std::vector<double> u_error( ni );
+        for ( int i = 0; i < ni; ++ i )
+        {
+            u_error[ i ] = un[ i ] - u_e[ i ];
+        }
+
+        this->DumpErrorDetails(u_error);
+        this->DumpCsvFile("field_final.csv",x,u_e,un,u_error);
+
+        int kkk = 1;
+    }
+
+    void PrintField( std::vector<double> &f )
+    {
+        int icount = 0;
+        for ( int i = 0; i < f.size(); ++ i )
+        {
+            std::cout << std::setprecision(15) << f[ i ] << " ";
+            icount ++;
+            if ( icount % 5 == 0 )
+            {
+                std::cout << "\n";
+            }
+        }
+        std::cout << "\n";
+        std::cout << "\n";
+    }
+
+    void DumpErrorDetails( std::vector<double> &u_error )
+    {
+        int ni = u_error.size();
+        double rms_error = compute_l2norm( ni, u_error );
+        double max_error = compute_max_error( ni, u_error );
+        std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+        //create output file for L2-norm
+        std::fstream file;
+        file.open("output.txt", std::fstream::out);
+        std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+        std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+        std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+        file.close();
+    }
+
+    void DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+    {
+        std::fstream file;
+        file.open(filename.c_str(), std::fstream::out);
+        std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+        for ( int i = 0; i < x.size(); ++ i )
+        {
+            std::format_to(std::ostream_iterator<char>(file), "{:.16f} {:.16f} {:.16f} {:.16f}\n", x[i], ue[i], un[i], uerror[i] );
+        }
+        file.close();
+    }
+
+    void update( std::vector<double> &un, std::vector<double> &u )
+    {
+        for ( int i = 0; i < u.size(); ++ i )
+        {
+            un[ i ] = u[ i ];
+        }
+    }
+
+    double compute_l2norm( int ni, std::vector<double> & r )
+    {
+        double rms = 0.0;
+        for ( int i = 1; i < ni - 1; ++ i )
+        {
+            rms += r[ i ] * r[ i ];
+        }
+        rms = std::sqrt( rms / ( ni - 2 ) );
+        return rms;
+    }
+
+    double compute_max_error( int ni, std::vector<double> & u_error )
+    {
+        double val_max = -1;
+        int ipos = -1;
+        for ( int i = 1; i < ni - 1; ++ i )
+        {
+            //val_max = std::max( val_max, std::abs( u_error[ i ] ) );
+            if ( val_max < std::abs( u_error[ i ] ) )
+            {
+                ipos = i;
+                val_max = std::abs( u_error[ i ] );
+            }
+        }
+        std::cout << " ipos = " << ipos << "\n";
+        return val_max;
+    }
+};
+
+void ReadCgnsGrid( const std::string & filename, Grid * grid )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones(fileId, baseId, &nzones);
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize(index_dim*3);
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[33];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                //std::vector<double> coord( nNodes );
+                std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coord.data() );
+                double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+                for ( int i = 0; i < nNodes; ++ i )
+                {
+                    //std::cout << coord[i] << " ";
+                    std::cout << xd[i] << " ";
+                    grid->x[ i ] = xd[ i ];
+                    if( (i+1)%5 == 0 ) std::cout << "\n";
+                }
+                std::cout << "\n";
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex(index_dim,-1);
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type, 
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset);
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[i] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[normalDataType] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList(nNodes*iphysdim*sizeof(double));
+
+                std::vector<cgsize_t> pnts(npnts*index_dim);
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double*>(const_cast<char *>(normalList.data()));
+
+                //std::cout << "normalList = ";
+                //for ( int i = 0; i < nNodes*iphysdim; ++ i )
+                //{
+                //    std::cout << normal_d[ i ] << " ";
+                //}
+                //std::cout << "\n";
+            }
+        }
+    }
+    cg_close(fileId);
+}
+
+int main(int argc, char **argv)
+{
+    Solver solver;
+    solver.solve();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/01b/plot.py b/example/1d-heat-equation/ftcs/cpp/01b/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/01b/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/01b/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/01b/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/01b/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/01c/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/01c/CMakeLists.txt
new file mode 100644
index 00000000..bfdbab14
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/01c/CMakeLists.txt
@@ -0,0 +1,75 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/01c/README.txt b/example/1d-heat-equation/ftcs/cpp/01c/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/01c/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/01c/heat1d1blocksv1.cgns b/example/1d-heat-equation/ftcs/cpp/01c/heat1d1blocksv1.cgns
new file mode 100644
index 00000000..470808f4
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/01c/heat1d1blocksv1.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/01c/main.cpp b/example/1d-heat-equation/ftcs/cpp/01c/main.cpp
new file mode 100644
index 00000000..951a3daf
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/01c/main.cpp
@@ -0,0 +1,306 @@
+#include "cgnslib.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip> 
+
+class Grid;
+void ReadCgnsGrid( const std::string & filename, Grid * grid );
+
+class Grid
+{
+public:
+    std::vector<double> x;
+};
+
+class Solver
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u,un;
+    std::vector<double> error;
+public:
+    void solve()
+    {
+        std::cout << "solve()\n";
+        Grid grid;
+        ReadCgnsGrid( "../heat1d1blocksv1.cgns", &grid );
+        int ni = grid.x.size();
+        std::cout << "ni = " << ni << "\n";
+
+        std::vector<double> & x = grid.x;
+        double dx = x[ 1 ] - x[ 0 ];
+        double dt = dx / 10.0;
+        double t = 1.0;
+        int nt = static_cast<int>( t / dt )+1;
+        std::cout << "nt = " << nt << "\n";
+
+        u_e.resize( ni );
+        u.resize( ni );
+        un.resize( ni );
+
+        for ( int i = 0; i < ni; ++ i )
+        {
+            u_e[ i ] = - std::exp( -t ) * std::sin( std::numbers::pi * x[i] ); //theory solution
+            un[ i ] = - std::sin( std::numbers::pi * x[ i ] ); //initial condition @ t=0
+        }
+        un[ 0 ] = 0.0;
+        un[ ni - 1 ] = 0.0;
+
+        double alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+        double beta = alpha * dt / ( dx * dx );
+        std::cout << "alpha = " << std::setprecision(15) << alpha << "\n";
+        std::cout << "beta = " << std::setprecision(15) << beta << "\n";
+
+        for ( int it = 0; it < nt; ++ it )
+        {
+            for ( int i = 1; i < ni - 1; ++ i )
+            {
+                u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+            }
+            //boundary
+            u[ 0 ] = 0.0; // boundary condition at x = -1
+            u[ ni - 1 ] = 0.0; // boundary condition at x = 1
+            this->update( un, u );
+        }
+
+        //compute L2 norm of the error
+        std::vector<double> u_error( ni );
+        for ( int i = 0; i < ni; ++ i )
+        {
+            u_error[ i ] = un[ i ] - u_e[ i ];
+        }
+
+        this->DumpErrorDetails(u_error);
+        this->DumpCsvFile("field_final.csv",x,u_e,un,u_error);
+
+        int kkk = 1;
+    }
+
+    void PrintField( std::vector<double> &f )
+    {
+        int icount = 0;
+        for ( int i = 0; i < f.size(); ++ i )
+        {
+            std::cout << std::setprecision(15) << f[ i ] << " ";
+            icount ++;
+            if ( icount % 5 == 0 )
+            {
+                std::cout << "\n";
+            }
+        }
+        std::cout << "\n";
+        std::cout << "\n";
+    }
+
+    void DumpErrorDetails( std::vector<double> &u_error )
+    {
+        int ni = u_error.size();
+        double rms_error = compute_l2norm( ni, u_error );
+        double max_error = compute_max_error( ni, u_error );
+        std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+        //create output file for L2-norm
+        std::fstream file;
+        file.open("output.txt", std::fstream::out);
+        std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+        std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+        std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+        file.close();
+    }
+
+    void DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+    {
+        std::fstream file;
+        file.open(filename.c_str(), std::fstream::out);
+        std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+        for ( int i = 0; i < x.size(); ++ i )
+        {
+            std::format_to(std::ostream_iterator<char>(file), "{:.16f} {:.16f} {:.16f} {:.16f}\n", x[i], ue[i], un[i], uerror[i] );
+        }
+        file.close();
+    }
+
+    void update( std::vector<double> &un, std::vector<double> &u )
+    {
+        for ( int i = 0; i < u.size(); ++ i )
+        {
+            un[ i ] = u[ i ];
+        }
+    }
+
+    double compute_l2norm( int ni, std::vector<double> & r )
+    {
+        double rms = 0.0;
+        for ( int i = 1; i < ni - 1; ++ i )
+        {
+            rms += r[ i ] * r[ i ];
+        }
+        rms = std::sqrt( rms / ( ni - 2 ) );
+        return rms;
+    }
+
+    double compute_max_error( int ni, std::vector<double> & u_error )
+    {
+        double val_max = -1;
+        int ipos = -1;
+        for ( int i = 1; i < ni - 1; ++ i )
+        {
+            //val_max = std::max( val_max, std::abs( u_error[ i ] ) );
+            if ( val_max < std::abs( u_error[ i ] ) )
+            {
+                ipos = i;
+                val_max = std::abs( u_error[ i ] );
+            }
+        }
+        std::cout << " ipos = " << ipos << "\n";
+        return val_max;
+    }
+};
+
+void ReadCgnsGrid( const std::string & filename, Grid * grid )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones(fileId, baseId, &nzones);
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize(index_dim*3);
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[33];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                //std::vector<double> coord( nNodes );
+                std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coord.data() );
+                double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+                for ( int i = 0; i < nNodes; ++ i )
+                {
+                    //std::cout << coord[i] << " ";
+                    std::cout << xd[i] << " ";
+                    grid->x[ i ] = xd[ i ];
+                    if( (i+1)%5 == 0 ) std::cout << "\n";
+                }
+                std::cout << "\n";
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex(index_dim,-1);
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type, 
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset);
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[i] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[normalDataType] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList(nNodes*iphysdim*sizeof(double));
+
+                std::vector<cgsize_t> pnts(npnts*index_dim);
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double*>(const_cast<char *>(normalList.data()));
+
+                //std::cout << "normalList = ";
+                //for ( int i = 0; i < nNodes*iphysdim; ++ i )
+                //{
+                //    std::cout << normal_d[ i ] << " ";
+                //}
+                //std::cout << "\n";
+            }
+        }
+    }
+    cg_close(fileId);
+}
+
+int main(int argc, char **argv)
+{
+    Solver solver;
+    solver.solve();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/01c/plot.py b/example/1d-heat-equation/ftcs/cpp/01c/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/01c/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/01c/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/01c/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/01c/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/01d/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/01d/CMakeLists.txt
new file mode 100644
index 00000000..bfdbab14
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/01d/CMakeLists.txt
@@ -0,0 +1,75 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/01d/README.txt b/example/1d-heat-equation/ftcs/cpp/01d/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/01d/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/01d/heat1d1blocksv2.cgns b/example/1d-heat-equation/ftcs/cpp/01d/heat1d1blocksv2.cgns
new file mode 100644
index 00000000..1901648a
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/01d/heat1d1blocksv2.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/01d/main.cpp b/example/1d-heat-equation/ftcs/cpp/01d/main.cpp
new file mode 100644
index 00000000..c9a2eb81
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/01d/main.cpp
@@ -0,0 +1,299 @@
+#include "cgnslib.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip> 
+
+class Grid;
+void ReadCgnsGrid( const std::string & filename, Grid * grid );
+
+class Grid
+{
+public:
+    std::vector<double> x;
+};
+
+class Solver
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u,un;
+    std::vector<double> error;
+public:
+    void solve()
+    {
+        std::cout << "solve()\n";
+        Grid grid;
+        ReadCgnsGrid( "../heat1d1blocksv2.cgns", &grid );
+        int ni = grid.x.size();
+        std::cout << "ni = " << ni << "\n";
+
+        std::vector<double> & x = grid.x;
+        double dx = std::abs(x[ 1 ] - x[ 0 ]);
+        double dt = dx / 10.0;
+        double t = 1.0;
+        int nt = static_cast<int>( t / dt )+1;
+        std::cout << "nt = " << nt << "\n";
+
+        u_e.resize( ni );
+        u.resize( ni );
+        un.resize( ni );
+
+        for ( int i = 0; i < ni; ++ i )
+        {
+            u_e[ i ] = - std::exp( -t ) * std::sin( std::numbers::pi * x[i] ); //theory solution
+            un[ i ] = - std::sin( std::numbers::pi * x[ i ] ); //initial condition @ t=0
+        }
+        un[ 0 ] = 0.0;
+        un[ ni - 1 ] = 0.0;
+
+        double alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+        double beta = alpha * dt / ( dx * dx );
+        std::cout << "alpha = " << std::setprecision(15) << alpha << "\n";
+        std::cout << "beta = " << std::setprecision(15) << beta << "\n";
+
+        for ( int it = 0; it < nt; ++ it )
+        {
+            for ( int i = 1; i < ni - 1; ++ i )
+            {
+                u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+            }
+            //boundary
+            u[ 0 ] = 0.0; // boundary condition at x = -1
+            u[ ni - 1 ] = 0.0; // boundary condition at x = 1
+            this->update( un, u );
+        }
+
+        //compute L2 norm of the error
+        std::vector<double> u_error( ni );
+        for ( int i = 0; i < ni; ++ i )
+        {
+            u_error[ i ] = un[ i ] - u_e[ i ];
+        }
+
+        this->DumpErrorDetails(u_error);
+        this->DumpCsvFile("field_final.csv",x,u_e,un,u_error);
+
+        int kkk = 1;
+    }
+
+    void PrintField( std::vector<double> &f )
+    {
+        int icount = 0;
+        for ( int i = 0; i < f.size(); ++ i )
+        {
+            std::cout << std::setprecision(15) << f[ i ] << " ";
+            icount ++;
+            if ( icount % 5 == 0 )
+            {
+                std::cout << "\n";
+            }
+        }
+        std::cout << "\n";
+        std::cout << "\n";
+    }
+
+    void DumpErrorDetails( std::vector<double> &u_error )
+    {
+        int ni = u_error.size();
+        double rms_error = compute_l2norm( ni, u_error );
+        double max_error = compute_max_error( ni, u_error );
+        std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+        //create output file for L2-norm
+        std::fstream file;
+        file.open("output.txt", std::fstream::out);
+        std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+        std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+        std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+        file.close();
+    }
+
+    void DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+    {
+        std::fstream file;
+        file.open(filename.c_str(), std::fstream::out);
+        std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+        for ( int i = 0; i < x.size(); ++ i )
+        {
+            std::format_to(std::ostream_iterator<char>(file), "{:.16f} {:.16f} {:.16f} {:.16f}\n", x[i], ue[i], un[i], uerror[i] );
+        }
+        file.close();
+    }
+
+    void update( std::vector<double> &un, std::vector<double> &u )
+    {
+        for ( int i = 0; i < u.size(); ++ i )
+        {
+            un[ i ] = u[ i ];
+        }
+    }
+
+    double compute_l2norm( int ni, std::vector<double> & r )
+    {
+        double rms = 0.0;
+        for ( int i = 1; i < ni - 1; ++ i )
+        {
+            rms += r[ i ] * r[ i ];
+        }
+        rms = std::sqrt( rms / ( ni - 2 ) );
+        return rms;
+    }
+
+    double compute_max_error( int ni, std::vector<double> & u_error )
+    {
+        double val_max = -1;
+        int ipos = -1;
+        for ( int i = 1; i < ni - 1; ++ i )
+        {
+            //val_max = std::max( val_max, std::abs( u_error[ i ] ) );
+            if ( val_max < std::abs( u_error[ i ] ) )
+            {
+                ipos = i;
+                val_max = std::abs( u_error[ i ] );
+            }
+        }
+        std::cout << " ipos = " << ipos << "\n";
+        return val_max;
+    }
+};
+
+void ReadCgnsGrid( const std::string & filename, Grid * grid )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones(fileId, baseId, &nzones);
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize(index_dim*3);
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[33];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                //std::vector<double> coord( nNodes );
+                std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coord.data() );
+                double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+                for ( int i = 0; i < nNodes; ++ i )
+                {
+                    //std::cout << coord[i] << " ";
+                    std::cout << xd[i] << " ";
+                    grid->x[ i ] = xd[ i ];
+                    if( (i+1)%5 == 0 ) std::cout << "\n";
+                }
+                std::cout << "\n";
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex(index_dim,-1);
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type, 
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset);
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[i] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[normalDataType] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList(nNodes*iphysdim*sizeof(double));
+
+                std::vector<cgsize_t> pnts(npnts*index_dim);
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double*>(const_cast<char *>(normalList.data()));
+            }
+        }
+    }
+    cg_close(fileId);
+}
+
+int main(int argc, char **argv)
+{
+    Solver solver;
+    solver.solve();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/01d/plot.py b/example/1d-heat-equation/ftcs/cpp/01d/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/01d/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/01d/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/01d/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/01d/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/01e/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/01e/CMakeLists.txt
new file mode 100644
index 00000000..bfdbab14
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/01e/CMakeLists.txt
@@ -0,0 +1,75 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/01e/README.txt b/example/1d-heat-equation/ftcs/cpp/01e/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/01e/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/01e/heat1d1blocksv3.cgns b/example/1d-heat-equation/ftcs/cpp/01e/heat1d1blocksv3.cgns
new file mode 100644
index 00000000..72a50a8e
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/01e/heat1d1blocksv3.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/01e/main.cpp b/example/1d-heat-equation/ftcs/cpp/01e/main.cpp
new file mode 100644
index 00000000..5e457a4f
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/01e/main.cpp
@@ -0,0 +1,299 @@
+#include "cgnslib.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip> 
+
+class Grid;
+void ReadCgnsGrid( const std::string & filename, Grid * grid );
+
+class Grid
+{
+public:
+    std::vector<double> x;
+};
+
+class Solver
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u,un;
+    std::vector<double> error;
+public:
+    void solve()
+    {
+        std::cout << "solve()\n";
+        Grid grid;
+        ReadCgnsGrid( "../heat1d1blocksv3.cgns", &grid );
+        int ni = grid.x.size();
+        std::cout << "ni = " << ni << "\n";
+
+        std::vector<double> & x = grid.x;
+        double dx = std::abs(x[ 1 ] - x[ 0 ]);
+        double dt = dx / 10.0;
+        double t = 1.0;
+        int nt = static_cast<int>( t / dt )+1;
+        std::cout << "nt = " << nt << "\n";
+
+        u_e.resize( ni );
+        u.resize( ni );
+        un.resize( ni );
+
+        for ( int i = 0; i < ni; ++ i )
+        {
+            u_e[ i ] = - std::exp( -t ) * std::sin( std::numbers::pi * x[i] ); //theory solution
+            un[ i ] = - std::sin( std::numbers::pi * x[ i ] ); //initial condition @ t=0
+        }
+        un[ 0 ] = 0.0;
+        un[ ni - 1 ] = 0.0;
+
+        double alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+        double beta = alpha * dt / ( dx * dx );
+        std::cout << "alpha = " << std::setprecision(15) << alpha << "\n";
+        std::cout << "beta = " << std::setprecision(15) << beta << "\n";
+
+        for ( int it = 0; it < nt; ++ it )
+        {
+            for ( int i = 1; i < ni - 1; ++ i )
+            {
+                u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+            }
+            //boundary
+            u[ 0 ] = 0.0; // boundary condition at x = -1
+            u[ ni - 1 ] = 0.0; // boundary condition at x = 1
+            this->update( un, u );
+        }
+
+        //compute L2 norm of the error
+        std::vector<double> u_error( ni );
+        for ( int i = 0; i < ni; ++ i )
+        {
+            u_error[ i ] = un[ i ] - u_e[ i ];
+        }
+
+        this->DumpErrorDetails(u_error);
+        this->DumpCsvFile("field_final.csv",x,u_e,un,u_error);
+
+        int kkk = 1;
+    }
+
+    void PrintField( std::vector<double> &f )
+    {
+        int icount = 0;
+        for ( int i = 0; i < f.size(); ++ i )
+        {
+            std::cout << std::setprecision(15) << f[ i ] << " ";
+            icount ++;
+            if ( icount % 5 == 0 )
+            {
+                std::cout << "\n";
+            }
+        }
+        std::cout << "\n";
+        std::cout << "\n";
+    }
+
+    void DumpErrorDetails( std::vector<double> &u_error )
+    {
+        int ni = u_error.size();
+        double rms_error = compute_l2norm( ni, u_error );
+        double max_error = compute_max_error( ni, u_error );
+        std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+        //create output file for L2-norm
+        std::fstream file;
+        file.open("output.txt", std::fstream::out);
+        std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+        std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+        std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+        file.close();
+    }
+
+    void DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+    {
+        std::fstream file;
+        file.open(filename.c_str(), std::fstream::out);
+        std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+        for ( int i = 0; i < x.size(); ++ i )
+        {
+            std::format_to(std::ostream_iterator<char>(file), "{:.16f} {:.16f} {:.16f} {:.16f}\n", x[i], ue[i], un[i], uerror[i] );
+        }
+        file.close();
+    }
+
+    void update( std::vector<double> &un, std::vector<double> &u )
+    {
+        for ( int i = 0; i < u.size(); ++ i )
+        {
+            un[ i ] = u[ i ];
+        }
+    }
+
+    double compute_l2norm( int ni, std::vector<double> & r )
+    {
+        double rms = 0.0;
+        for ( int i = 1; i < ni - 1; ++ i )
+        {
+            rms += r[ i ] * r[ i ];
+        }
+        rms = std::sqrt( rms / ( ni - 2 ) );
+        return rms;
+    }
+
+    double compute_max_error( int ni, std::vector<double> & u_error )
+    {
+        double val_max = -1;
+        int ipos = -1;
+        for ( int i = 1; i < ni - 1; ++ i )
+        {
+            //val_max = std::max( val_max, std::abs( u_error[ i ] ) );
+            if ( val_max < std::abs( u_error[ i ] ) )
+            {
+                ipos = i;
+                val_max = std::abs( u_error[ i ] );
+            }
+        }
+        std::cout << " ipos = " << ipos << "\n";
+        return val_max;
+    }
+};
+
+void ReadCgnsGrid( const std::string & filename, Grid * grid )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones(fileId, baseId, &nzones);
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize(index_dim*3);
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[33];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                //std::vector<double> coord( nNodes );
+                std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coord.data() );
+                double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+                for ( int i = 0; i < nNodes; ++ i )
+                {
+                    //std::cout << coord[i] << " ";
+                    std::cout << xd[i] << " ";
+                    grid->x[ i ] = xd[ i ];
+                    if( (i+1)%5 == 0 ) std::cout << "\n";
+                }
+                std::cout << "\n";
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex(index_dim,-1);
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type, 
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset);
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[i] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[normalDataType] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList(nNodes*iphysdim*sizeof(double));
+
+                std::vector<cgsize_t> pnts(npnts*index_dim);
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double*>(const_cast<char *>(normalList.data()));
+            }
+        }
+    }
+    cg_close(fileId);
+}
+
+int main(int argc, char **argv)
+{
+    Solver solver;
+    solver.solve();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/01e/plot.py b/example/1d-heat-equation/ftcs/cpp/01e/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/01e/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/01e/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/01e/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/01e/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/02/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/02/CMakeLists.txt
new file mode 100644
index 00000000..bfdbab14
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/02/CMakeLists.txt
@@ -0,0 +1,75 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/02/README.txt b/example/1d-heat-equation/ftcs/cpp/02/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/02/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/02/heat1d2blocks.cgns b/example/1d-heat-equation/ftcs/cpp/02/heat1d2blocks.cgns
new file mode 100644
index 00000000..4f4441f0
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/02/heat1d2blocks.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/02/main.cpp b/example/1d-heat-equation/ftcs/cpp/02/main.cpp
new file mode 100644
index 00000000..362f000f
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/02/main.cpp
@@ -0,0 +1,392 @@
+#include "cgnslib.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip> 
+#include <string> 
+
+class Grid;
+void ReadCgnsGrid( const std::string & filename );
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid )
+    {
+        this->ni = grid->x.size();
+        std::cout << "ni = " << ni << "\n";
+
+        std::vector<double> & x = grid->x;
+        this->dx = x[ 1 ] - x[ 0 ];
+        this->dt = dx / 10.0;
+        this->t = 1.0;
+        int nt = static_cast<int>( t / dt ) + 1;
+        std::cout << "nt = " << nt << "\n";
+
+        this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+        this->beta = this->alpha * dt / ( dx * dx );
+        std::cout << "alpha = " << std::setprecision(15) << this->alpha << "\n";
+        std::cout << "beta = " << std::setprecision(15) << this->beta << "\n";
+
+        u_e.resize( ni );
+        u.resize( ni );
+        un.resize( ni );
+
+        for ( int i = 0; i < ni; ++ i )
+        {
+            u_e[ i ] = - std::exp( -t ) * std::sin( std::numbers::pi * x[i] ); //theory solution
+            un[ i ] = - std::sin( std::numbers::pi * x[ i ] ); //initial condition @ t=0
+        }
+        un[ 0 ] = 0.0;
+        un[ ni - 1 ] = 0.0;
+    }
+
+    void Solve( Grid * grid )
+    {
+        for ( int it = 0; it < nt; ++ it )
+        {
+            for ( int i = 1; i < ni - 1; ++ i )
+            {
+                u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+            }
+            //boundary
+            u[ 0 ] = 0.0; // boundary condition at x = -1
+            u[ ni - 1 ] = 0.0; // boundary condition at x = 1
+            this->update( un, u );
+        }
+    }
+
+    void PostProcess( Grid * grid )
+    {
+        std::vector<double> & x = grid->x;
+        //compute L2 norm of the error
+        std::vector<double> u_error( ni );
+        for ( int i = 0; i < ni; ++ i )
+        {
+            u_error[ i ] = un[ i ] - u_e[ i ];
+        }
+
+        this->DumpErrorDetails( u_error );
+
+        std::string csvname = "field_final" + std::to_string( grid->zoneIndex ) + ".csv";
+        this->DumpCsvFile( csvname, x, u_e, un, u_error );
+    }
+
+    void update( std::vector<double> &un, std::vector<double> &u )
+    {
+        for ( int i = 0; i < u.size(); ++ i )
+        {
+            un[ i ] = u[ i ];
+        }
+    }
+
+    void DumpErrorDetails( std::vector<double> &u_error )
+    {
+        int ni = u_error.size();
+        double rms_error = compute_l2norm( ni, u_error );
+        double max_error = compute_max_error( ni, u_error );
+        std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+        //create output file for L2-norm
+        std::fstream file;
+        file.open("output.txt", std::fstream::out);
+        std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+        std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+        std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+        file.close();
+    }
+
+    void DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+    {
+        std::fstream file;
+        file.open(filename.c_str(), std::fstream::out);
+        std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+        for ( int i = 0; i < x.size(); ++ i )
+        {
+            std::format_to(std::ostream_iterator<char>(file), "{:.16f} {:.16f} {:.16f} {:.16f}\n", x[i], ue[i], un[i], uerror[i] );
+        }
+        file.close();
+    }
+
+    double compute_l2norm( int ni, std::vector<double> & r )
+    {
+        double rms = 0.0;
+        for ( int i = 1; i < ni - 1; ++ i )
+        {
+            rms += r[ i ] * r[ i ];
+        }
+        rms = std::sqrt( rms / ( ni - 2 ) );
+        return rms;
+    }
+
+    double compute_max_error( int ni, std::vector<double> & u_error )
+    {
+        double val_max = -1;
+        int ipos = -1;
+        for ( int i = 1; i < ni - 1; ++ i )
+        {
+            //val_max = std::max( val_max, std::abs( u_error[ i ] ) );
+            if ( val_max < std::abs( u_error[ i ] ) )
+            {
+                ipos = i;
+                val_max = std::abs( u_error[ i ] );
+            }
+        }
+        std::cout << " ipos = " << ipos << "\n";
+        return val_max;
+    }
+};
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+};
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+
+class Solver
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u,un;
+    std::vector<double> error;
+public:
+    void Run()
+    {
+        this->ReadGrid();
+        this->InitFields();
+        this->SolveMultiZones();
+        this->PostProcess();
+    }
+
+    void ReadGrid()
+    {
+        ReadCgnsGrid( "../heat1d2blocks.cgns" );
+        int nZones = Global::grids.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Grid * grid = Global::grids[ iZone ];
+            grid->zoneIndex = iZone;
+        }
+    }
+
+    void InitFields()
+    {
+        int nZones = Global::grids.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Grid * grid = Global::grids[ iZone ];
+            Field * field = new Field();
+            Global::fields.push_back( field );
+            field->Init( grid );
+        }
+    }
+
+    void SolveMultiZones()
+    {
+        int nZones = Global::grids.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Grid * grid = Global::grids[ iZone ];
+            Field * field = Global::fields[ iZone ];
+            field->Solve( grid );
+        }
+    }
+
+    void PostProcess()
+    {
+        int nZones = Global::grids.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Grid * grid = Global::grids[ iZone ];
+            Field * field = Global::fields[ iZone ];
+            field->PostProcess( grid );
+        }
+    }
+
+    void PrintField( std::vector<double> &f )
+    {
+        int icount = 0;
+        for ( int i = 0; i < f.size(); ++ i )
+        {
+            std::cout << std::setprecision(15) << f[ i ] << " ";
+            icount ++;
+            if ( icount % 5 == 0 )
+            {
+                std::cout << "\n";
+            }
+        }
+        std::cout << "\n";
+        std::cout << "\n";
+    }
+};
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones(fileId, baseId, &nzones);
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize(index_dim*3);
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            Grid * grid = new Grid();
+            Global::grids.push_back( grid );
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[33];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                //std::vector<double> coord( nNodes );
+                std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coord.data() );
+                double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+                for ( int i = 0; i < nNodes; ++ i )
+                {
+                    //std::cout << coord[i] << " ";
+                    std::cout << xd[i] << " ";
+                    grid->x[ i ] = xd[ i ];
+                    if( (i+1)%5 == 0 ) std::cout << "\n";
+                }
+                std::cout << "\n";
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex(index_dim,-1);
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type, 
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset);
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[i] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[normalDataType] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList(nNodes*iphysdim*sizeof(double));
+
+                std::vector<cgsize_t> pnts(npnts*index_dim);
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double*>(const_cast<char *>(normalList.data()));
+
+                //std::cout << "normalList = ";
+                //for ( int i = 0; i < nNodes*iphysdim; ++ i )
+                //{
+                //    std::cout << normal_d[ i ] << " ";
+                //}
+                //std::cout << "\n";
+            }
+        }
+    }
+    cg_close(fileId);
+}
+
+int main(int argc, char **argv)
+{
+    Solver solver;
+    solver.Run();
+    //solver.solve();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/02/plot.py b/example/1d-heat-equation/ftcs/cpp/02/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/02/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/02/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/02/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/02/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/02a/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/02a/CMakeLists.txt
new file mode 100644
index 00000000..bfdbab14
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/02a/CMakeLists.txt
@@ -0,0 +1,75 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/02a/README.txt b/example/1d-heat-equation/ftcs/cpp/02a/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/02a/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/02a/heat1d2blocks.cgns b/example/1d-heat-equation/ftcs/cpp/02a/heat1d2blocks.cgns
new file mode 100644
index 00000000..4f4441f0
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/02a/heat1d2blocks.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/02a/main.cpp b/example/1d-heat-equation/ftcs/cpp/02a/main.cpp
new file mode 100644
index 00000000..cd6b53d5
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/02a/main.cpp
@@ -0,0 +1,506 @@
+#include "cgnslib.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip> 
+#include <string> 
+
+class Grid;
+void ReadCgnsGrid( const std::string & filename );
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+void DumpErrorDetails( std::vector<double> & u_error );
+void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        //val_max = std::max( val_max, std::abs( u_error[ i ] ) );
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+void DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.16f} {:.16f} {:.16f} {:.16f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid )
+    {
+        this->ni = grid->x.size();
+        std::cout << "ni = " << ni << "\n";
+
+        std::vector<double> & x = grid->x;
+        this->dx = x[ 1 ] - x[ 0 ];
+        this->dt = dx / 10.0;
+        //this->t = 1.0;
+        this->t = 0.2;
+        int nt = static_cast<int>( t / dt ) + 1;
+        std::cout << "nt = " << nt << "\n";
+
+        this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+        this->beta = this->alpha * dt / ( dx * dx );
+        std::cout << "alpha = " << std::setprecision(15) << this->alpha << "\n";
+        std::cout << "beta = " << std::setprecision(15) << this->beta << "\n";
+
+        u_e.resize( ni );
+        u.resize( ni );
+        un.resize( ni );
+
+        for ( int i = 0; i < ni; ++ i )
+        {
+            u_e[ i ] = - std::exp( -t ) * std::sin( std::numbers::pi * x[i] ); //theory solution
+            un[ i ] = - std::sin( std::numbers::pi * x[ i ] ); //initial condition @ t=0
+        }
+        un[ 0 ] = 0.0;
+        un[ ni - 1 ] = 0.0;
+    }
+
+    void Solve( Grid * grid )
+    {
+        for ( int it = 0; it < nt; ++ it )
+        {
+            for ( int i = 1; i < ni - 1; ++ i )
+            {
+                u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+            }
+            //boundary
+            u[ 0 ] = 0.0; // boundary condition at x = -1
+            u[ ni - 1 ] = 0.0; // boundary condition at x = 1
+            this->update( un, u );
+        }
+    }
+
+    void PostProcess( Grid * grid )
+    {
+        std::vector<double> & x = grid->x;
+        //compute L2 norm of the error
+        std::vector<double> u_error( ni );
+        for ( int i = 0; i < ni; ++ i )
+        {
+            u_error[ i ] = un[ i ] - u_e[ i ];
+        }
+
+        //this->DumpErrorDetails( u_error );
+
+        //std::string csvname = "field_final" + std::to_string( grid->zoneIndex ) + ".csv";
+        //this->DumpCsvFile( csvname, x, u_e, un, u_error );
+    }
+
+    void AddData( Grid * grid, std::vector<double> &global_x, std::vector<double> &global_ue, std::vector<double> &global_un )
+    {
+        int ni = grid->x.size();
+        for ( int i = 0; i < ni; ++ i )
+        {
+            global_x.push_back( grid->x[ i ] );
+            global_ue.push_back( this->u_e[ i ] );
+            global_un.push_back( this->un[ i ] );
+        }
+    }
+
+    void update( std::vector<double> &un, std::vector<double> &u )
+    {
+        for ( int i = 0; i < u.size(); ++ i )
+        {
+            un[ i ] = u[ i ];
+        }
+    }
+
+    //void DumpErrorDetails( std::vector<double> &u_error )
+    //{
+    //    int ni = u_error.size();
+    //    double rms_error = compute_l2norm( ni, u_error );
+    //    double max_error = compute_max_error( ni, u_error );
+    //    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //    //create output file for L2-norm
+    //    std::fstream file;
+    //    file.open("output.txt", std::fstream::out);
+    //    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    //    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    //    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    //    file.close();
+    //}
+
+    //void DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+    //{
+    //    std::fstream file;
+    //    file.open(filename.c_str(), std::fstream::out);
+    //    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    //    for ( int i = 0; i < x.size(); ++ i )
+    //    {
+    //        std::format_to(std::ostream_iterator<char>(file), "{:.16f} {:.16f} {:.16f} {:.16f}\n", x[i], ue[i], un[i], uerror[i] );
+    //    }
+    //    file.close();
+    //}
+
+    //double compute_l2norm( int ni, std::vector<double> & r )
+    //{
+    //    double rms = 0.0;
+    //    for ( int i = 1; i < ni - 1; ++ i )
+    //    {
+    //        rms += r[ i ] * r[ i ];
+    //    }
+    //    rms = std::sqrt( rms / ( ni - 2 ) );
+    //    return rms;
+    //}
+
+    //double compute_max_error( int ni, std::vector<double> & u_error )
+    //{
+    //    double val_max = -1;
+    //    int ipos = -1;
+    //    for ( int i = 1; i < ni - 1; ++ i )
+    //    {
+    //        //val_max = std::max( val_max, std::abs( u_error[ i ] ) );
+    //        if ( val_max < std::abs( u_error[ i ] ) )
+    //        {
+    //            ipos = i;
+    //            val_max = std::abs( u_error[ i ] );
+    //        }
+    //    }
+    //    std::cout << " ipos = " << ipos << "\n";
+    //    return val_max;
+    //}
+};
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+};
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+
+class Solver
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u,un;
+    std::vector<double> error;
+public:
+    void Run()
+    {
+        this->ReadGrid();
+        this->InitFields();
+        this->SolveMultiZones();
+        this->PostProcess();
+    }
+
+    void ReadGrid()
+    {
+        ReadCgnsGrid( "../heat1d2blocks.cgns" );
+        int nZones = Global::grids.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Grid * grid = Global::grids[ iZone ];
+            grid->zoneIndex = iZone;
+        }
+    }
+
+    void InitFields()
+    {
+        int nZones = Global::grids.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Grid * grid = Global::grids[ iZone ];
+            Field * field = new Field();
+            Global::fields.push_back( field );
+            field->Init( grid );
+        }
+    }
+
+    void SolveMultiZones()
+    {
+        int nZones = Global::grids.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Grid * grid = Global::grids[ iZone ];
+            Field * field = Global::fields[ iZone ];
+            field->Solve( grid );
+        }
+    }
+
+    void PostProcess()
+    {
+        int nZones = Global::grids.size();
+        std::vector<double> u_e;
+        std::vector<double> un;
+        std::vector<double> x;
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Grid * grid = Global::grids[ iZone ];
+            Field * field = Global::fields[ iZone ];
+            field->AddData( grid, x, u_e, un );
+        }
+
+        std::cout << " x.size() = " << x.size() << "\n";
+
+        PostProcess( x, u_e, un );
+
+        //for ( int iZone = 0; iZone < nZones; ++ iZone )
+        //{
+        //    Grid * grid = Global::grids[ iZone ];
+        //    Field * field = Global::fields[ iZone ];
+        //    field->PostProcess( grid );
+        //}
+    }
+
+    void PostProcess( std::vector<double> &x, std::vector<double> &u_e, std::vector<double> &un )
+    {
+        int ni = x.size();
+        //compute L2 norm of the error
+        std::vector<double> u_error( ni );
+        for ( int i = 0; i < ni; ++ i )
+        {
+            u_error[ i ] = un[ i ] - u_e[ i ];
+        }
+
+        ::DumpErrorDetails( u_error );
+
+        std::string csvname = "field_final.csv";
+        ::DumpCsvFile( csvname, x, u_e, un, u_error );
+    }
+
+    //void DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+    //{
+    //    std::fstream file;
+    //    file.open(filename.c_str(), std::fstream::out);
+    //    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    //    for ( int i = 0; i < x.size(); ++ i )
+    //    {
+    //        std::format_to(std::ostream_iterator<char>(file), "{:.16f} {:.16f} {:.16f} {:.16f}\n", x[i], ue[i], un[i], uerror[i] );
+    //    }
+    //    file.close();
+    //}
+
+    void PrintField( std::vector<double> &f )
+    {
+        int icount = 0;
+        for ( int i = 0; i < f.size(); ++ i )
+        {
+            std::cout << std::setprecision(15) << f[ i ] << " ";
+            icount ++;
+            if ( icount % 5 == 0 )
+            {
+                std::cout << "\n";
+            }
+        }
+        std::cout << "\n";
+        std::cout << "\n";
+    }
+};
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones(fileId, baseId, &nzones);
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize(index_dim*3);
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            Grid * grid = new Grid();
+            Global::grids.push_back( grid );
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[33];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                //std::vector<double> coord( nNodes );
+                std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coord.data() );
+                double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+                for ( int i = 0; i < nNodes; ++ i )
+                {
+                    //std::cout << coord[i] << " ";
+                    std::cout << xd[i] << " ";
+                    grid->x[ i ] = xd[ i ];
+                    if( (i+1)%5 == 0 ) std::cout << "\n";
+                }
+                std::cout << "\n";
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex(index_dim,-1);
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type, 
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset);
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[i] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[normalDataType] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList(nNodes*iphysdim*sizeof(double));
+
+                std::vector<cgsize_t> pnts(npnts*index_dim);
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double*>(const_cast<char *>(normalList.data()));
+
+                //std::cout << "normalList = ";
+                //for ( int i = 0; i < nNodes*iphysdim; ++ i )
+                //{
+                //    std::cout << normal_d[ i ] << " ";
+                //}
+                //std::cout << "\n";
+            }
+        }
+    }
+    cg_close(fileId);
+}
+
+int main(int argc, char **argv)
+{
+    Solver solver;
+    solver.Run();
+    //solver.solve();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/02a/plot.py b/example/1d-heat-equation/ftcs/cpp/02a/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/02a/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/02a/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/02a/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/02a/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/02b/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/02b/CMakeLists.txt
new file mode 100644
index 00000000..bfdbab14
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/02b/CMakeLists.txt
@@ -0,0 +1,75 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/02b/README.txt b/example/1d-heat-equation/ftcs/cpp/02b/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/02b/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/02b/heat1d2blocks.cgns b/example/1d-heat-equation/ftcs/cpp/02b/heat1d2blocks.cgns
new file mode 100644
index 00000000..4f4441f0
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/02b/heat1d2blocks.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/02b/main.cpp b/example/1d-heat-equation/ftcs/cpp/02b/main.cpp
new file mode 100644
index 00000000..32ccdc23
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/02b/main.cpp
@@ -0,0 +1,834 @@
+#include "cgnslib.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip> 
+#include <string>
+#include <map>
+#include <algorithm>
+
+class Grid;
+void ReadCgnsGrid( const std::string & filename );
+void ReadCgnsGridBaseZone( const std::string & filename );
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+void DumpErrorDetails( std::vector<double> & u_error );
+void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        //val_max = std::max( val_max, std::abs( u_error[ i ] ) );
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+void DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.16f} {:.16f} {:.16f} {:.16f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
+
+class Face
+{
+public:
+    std::vector<int> nodes;
+    std::vector<int> sorted_nodes;
+public:
+    void AddFace( std::vector<int> & nodes )
+    {
+        this->nodes = nodes;
+        this->sorted_nodes = nodes;
+        std::sort( this->sorted_nodes.begin(), this->sorted_nodes.end() );
+    }
+    bool operator < ( const Face & rhs ) const
+    {
+        return this->sorted_nodes < rhs.sorted_nodes;
+    } 
+};
+
+class FaceList
+{
+public:
+    std::map<Face, int> face_map;
+public:
+    void AddFace( const Face & face )
+    {
+        std::map<Face, int>::iterator iter;
+        iter = face_map.find( face );
+        if ( iter == face_map.end() )
+        {
+            int id = face_map.size();
+            face_map.insert( std::make_pair( face, id ) );
+        }
+    }
+};
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Point
+{
+public:
+    typedef Point point_type;
+    using value_type = double;
+public:
+    Point()
+    {
+        this->x = 0;
+    }
+    Point(const value_type &x)
+    {
+        this->x = x;
+    }
+public:
+    value_type x;
+public:
+    bool operator < ( const Point & rhs ) const
+    {
+        value_type dx = x - rhs.x;
+        value_type diff = 1.0e-10;
+
+        if ( std::abs( dx ) > diff ) return x < rhs.x;
+
+        return false;
+    }
+};
+
+class PointFactory
+{
+public:
+    using value_type = double;
+    using point_type = Point;
+    using iterator = std::map< point_type, int >::iterator;
+protected:
+    std::map< point_type, int > pointList;
+    std::vector<point_type> pointArray;
+public:
+    int GetNPoints() { return pointArray.size(); }
+    bool FindPoint( const point_type & point, iterator & iter )
+    {
+        iter = pointList.find( point );
+        if ( iter == pointList.end() )
+        {
+            return false;
+        }
+        return true;
+    }
+
+    int AddPoint( const point_type & point )
+    {
+        PointFactory::iterator iter;
+        if ( FindPoint( point, iter ) )
+        {
+            return iter->second;
+        }
+        else
+        {
+            int index = this->GetNPoints();
+
+            pointList.insert( std::make_pair(point, index) );
+            pointArray.push_back( point );
+
+            return index;
+        }
+    }
+};
+
+class InterFaceZone
+{
+public:
+    std::vector<int> face_ids;
+    std::vector<int> left_zones;
+    std::vector<int> right_zones;
+    std::vector<int> left_cells;
+    std::vector<int> right_cells;
+    std::vector<double> left_u;
+    std::vector<double> right_u;
+};
+
+class BC
+{
+public:
+    std::vector<int> bctypes;
+    std::vector<int> faceids;
+};
+
+class Grid;
+class Field;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+    static std::vector<BC *> bcs;
+    static std::vector<InterFaceZone *> interfacezones;
+    static PointFactory boundary_points;
+    static FaceList boundary_faces;
+    static FaceList inter_faces;
+    static BaseZoneList zone_names;
+    static int nt;
+};
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+std::vector<BC *> Global::bcs;
+std::vector<InterFaceZone *> Global::interfacezones;
+PointFactory Global::boundary_points;
+FaceList Global::boundary_faces;
+FaceList Global::inter_faces;
+BaseZoneList Global::zone_names;
+int Global::nt = -1;
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid )
+    {
+        this->ni = grid->x.size();
+        std::cout << "ni = " << ni << "\n";
+
+        std::vector<double> & x = grid->x;
+        this->dx = x[ 1 ] - x[ 0 ];
+        this->dt = dx / 10.0;
+        this->t = 1.0;
+        this->nt = static_cast<int>( t / dt ) + 1;
+        std::cout << "nt = " << nt << "\n";
+
+        Global::nt = nt;
+
+        this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+        this->beta = this->alpha * dt / ( dx * dx );
+        std::cout << "alpha = " << std::setprecision( 15 ) << this->alpha << "\n";
+        std::cout << "beta = " << std::setprecision( 15 ) << this->beta << "\n";
+
+        int nghost = 2;
+        int ni_total = ni + nghost;
+
+        u_e.resize( ni_total );
+        u.resize( ni_total );
+        un.resize( ni_total );
+
+        int ist = 0;
+        int ied = ni - 1;
+
+        // 0(bc) 1(ist) 2 3 ... ni
+
+        //int ist = 0 + 1;
+        //int ied = ni;
+
+        for ( int i = ist; i <= ied; ++ i )
+        {
+            u_e[ i ] = - std::exp( -t ) * std::sin( std::numbers::pi * x[i] ); //theory solution
+            un[ i ] = - std::sin( std::numbers::pi * x[ i ] ); //initial condition @ t=0
+        }
+        //un[ ist - 1 ] = 0.0;
+        //un[ ied + 1 ] = 0.0;
+        un[ 0 ] = 0.0;
+        un[ ni - 1 ] = 0.0;
+    }
+
+    void Solve( Grid * grid )
+    {
+        Boundary( grid );
+        for ( int i = 1; i < ni - 1; ++ i )
+        {
+            u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+        }
+        this->update( un, u );
+    }
+
+    void Boundary( Grid * grid )
+    {
+        this->InterfaceBoundary( grid );
+        this->PhysicalBoundary( grid );
+    }
+
+    void PhysicalBoundary( Grid * grid )
+    {
+        BC * bc = Global::bcs[ grid->zoneIndex ];
+
+        int nBFace = bc->bctypes.size();
+        for ( int i = 0; i < nBFace; ++ i )
+        {
+            int bctype = bc->bctypes[ i ];
+            int faceId = bc->faceids[ i ];
+            if ( bctype == BCInflow )
+            {
+                u[ faceId ] = 0.0;
+            }
+            else if ( bctype == BCOutflow )
+            {
+                u[ faceId ] = 0.0;
+            }
+        }
+    }
+
+    void InterfaceBoundary( Grid * grid )
+    {
+        InterFaceZone * interfacezone = Global::interfacezones[ grid->zoneIndex ];
+        int nInterfaces = interfacezone->left_u.size();
+        for ( int i = 0; i < nInterfaces; ++ i )
+        {
+            double ul = interfacezone->left_u[ i ];
+            double ur = interfacezone->right_u[ i ];
+            double um = 0.5 * ( ul + ur );
+
+            int faceId = interfacezone->face_ids[ i ];
+
+            u[ faceId ] = um;
+            int kkk = 1;
+        }
+    }
+
+    void PostProcess( Grid * grid )
+    {
+        std::vector<double> & x = grid->x;
+        //compute L2 norm of the error
+        std::vector<double> u_error( ni );
+        for ( int i = 0; i < ni; ++ i )
+        {
+            u_error[ i ] = un[ i ] - u_e[ i ];
+        }
+    }
+
+    void AddData( Grid * grid, std::vector<double> &global_x, std::vector<double> &global_ue, std::vector<double> &global_un )
+    {
+        int ni = grid->x.size();
+        for ( int i = 0; i < ni; ++ i )
+        {
+            global_x.push_back( grid->x[ i ] );
+            global_ue.push_back( this->u_e[ i ] );
+            global_un.push_back( this->un[ i ] );
+        }
+    }
+
+    void update( std::vector<double> &un, std::vector<double> &u )
+    {
+        for ( int i = 0; i < u.size(); ++ i )
+        {
+            un[ i ] = u[ i ];
+        }
+    }
+};
+
+class Solver
+{
+public:
+    void Run()
+    {
+        this->ReadGrid();
+        this->InitFields();
+        this->SolveMultiZones();
+        this->PostProcess();
+    }
+
+    void ReadGrid()
+    {
+        ReadCgnsGridBaseZone( "../heat1d2blocks.cgns" );
+        int kkk = 1;
+        ReadCgnsGrid( "../heat1d2blocks.cgns" );
+        int nZones = Global::grids.size();
+        PointFactory ptfactory;
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Grid * grid = Global::grids[ iZone ];
+            grid->zoneIndex = iZone;
+            int ni = grid->x.size();
+            for ( int i = 0; i < ni; ++ i )
+            {
+                int pid = ptfactory.AddPoint( Point(grid->x[i]) );
+                //face.nodes.push_back( pid );
+            }
+            int kkk = 1;
+        }
+    }
+
+    void InitFields()
+    {
+        int nZones = Global::grids.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Grid * grid = Global::grids[ iZone ];
+            Field * field = new Field();
+            Global::fields.push_back( field );
+            field->Init( grid );
+        }
+    }
+
+    void SolveMultiZones()
+    {
+        for ( int it = 0; it < Global::nt; ++ it )
+        {
+            ExchangeInterfaceValue();
+            int nZones = Global::grids.size();
+            for ( int iZone = 0; iZone < nZones; ++ iZone )
+            {
+                Grid * grid = Global::grids[ iZone ];
+                Field * field = Global::fields[ iZone ];
+                field->Solve( grid );
+            }
+        }
+    }
+
+    void ExchangeInterfaceValue()
+    {
+        int nZones = Global::grids.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            InterFaceZone * interfacezone = Global::interfacezones[ iZone ];
+            int nInterFace = interfacezone->left_zones.size();
+            interfacezone->left_u.resize( nInterFace );
+            interfacezone->right_u.resize( nInterFace );
+        }
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Field * field = Global::fields[ iZone ];
+
+            InterFaceZone * interfacezone = Global::interfacezones[ iZone ];
+            int nInterFace = interfacezone->left_zones.size();
+
+            for ( int i = 0; i < nInterFace; ++ i )
+            {
+                int left_cell = interfacezone->left_cells[ i ];
+                int donor_zoneid = interfacezone->right_zones[ i ];
+                int donor_cell = interfacezone->right_cells[ i ];
+                Field * donor_field = Global::fields[ donor_zoneid ];
+
+                interfacezone->left_u[ i ] = field->u[ left_cell ];
+                interfacezone->right_u[ i ] = donor_field->u[ donor_cell ];
+            }
+        }
+    }
+
+    void PostProcess()
+    {
+        int nZones = Global::grids.size();
+        std::vector<double> u_e;
+        std::vector<double> un;
+        std::vector<double> x;
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Grid * grid = Global::grids[ iZone ];
+            Field * field = Global::fields[ iZone ];
+            field->AddData( grid, x, u_e, un );
+        }
+
+        std::cout << " x.size() = " << x.size() << "\n";
+
+        this->PostProcess( x, u_e, un );
+    }
+
+    void PostProcess( std::vector<double> &x, std::vector<double> &u_e, std::vector<double> &un )
+    {
+        int ni = x.size();
+        //compute L2 norm of the error
+        std::vector<double> u_error( ni );
+        for ( int i = 0; i < ni; ++ i )
+        {
+            u_error[ i ] = un[ i ] - u_e[ i ];
+        }
+
+        ::DumpErrorDetails( u_error );
+
+        std::string csvname = "field_final.csv";
+        ::DumpCsvFile( csvname, x, u_e, un, u_error );
+    }
+
+    void PrintField( std::vector<double> &f )
+    {
+        int icount = 0;
+        for ( int i = 0; i < f.size(); ++ i )
+        {
+            std::cout << std::setprecision(15) << f[ i ] << " ";
+            icount ++;
+            if ( icount % 5 == 0 )
+            {
+                std::cout << "\n";
+            }
+        }
+        std::cout << "\n";
+        std::cout << "\n";
+    }
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            //baseZone.baseId = baseId;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones(fileId, baseId, &nzones);
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            Grid * grid = new Grid();
+            Global::grids.push_back( grid );
+
+            BC * bc = new BC();
+            Global::bcs.push_back( bc );
+
+            InterFaceZone * interfacezone = new InterFaceZone();
+            Global::interfacezones.push_back( interfacezone );
+
+            BaseZone baseZone;
+            //baseZone.baseId = baseId;
+            baseZone.zone_name = zonename;
+
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[33];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                //std::vector<double> coord( nNodes );
+                std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coord.data() );
+                double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+                for ( int i = 0; i < nNodes; ++ i )
+                {
+                    //std::cout << coord[i] << " ";
+                    std::cout << xd[i] << " ";
+                    grid->x[ i ] = xd[ i ];
+                    if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+                }
+                std::cout << "\n";
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex(index_dim,-1);
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                }
+                std::cout << "\n";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    Global::boundary_points.AddPoint( grid->x[ pnts[ i ] - 1 ] );
+                }
+
+                if ( index_dim == 1 )
+                {
+                    int p1 = pnts[ 0 ];
+                    double x1 = grid->x[ p1 - 1 ];
+                    int id = Global::boundary_points.AddPoint( x1 );
+                    Face face;
+                    std::vector<int> nodes;
+                    nodes.push_back( id );
+                    face.AddFace( nodes );
+                    Global::boundary_faces.AddFace( face );
+
+                    bc->bctypes.push_back( bocotype );
+                    bc->faceids.push_back( p1 - 1 );
+                }
+                
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+
+                //std::cout << "normalList = ";
+                //for ( int i = 0; i < nNodes*iphysdim; ++ i )
+                //{
+                //    std::cout << normal_d[ i ] << " ";
+                //}
+                //std::cout << "\n";
+            }
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    Global::boundary_points.AddPoint( grid->x[ range[ i ] - 1 ] );
+                }
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                if ( index_dim == 1 )
+                {
+                    int p1 = range[ 0 ];
+                    double x1 = grid->x[ p1 - 1 ];
+                    int id = Global::boundary_points.AddPoint( x1 );
+                    Face face;
+                    std::vector<int> nodes;
+                    nodes.push_back( id );
+                    face.AddFace( nodes );
+                    Global::boundary_faces.AddFace( face );
+                    Global::inter_faces.AddFace( face );
+
+                    bc->bctypes.push_back( BCTypeUserDefined );
+                    bc->faceids.push_back( p1 - 1 );
+
+                    interfacezone->face_ids.push_back( p1 );
+
+                    interfacezone->left_zones.push_back( gZoneId );
+                    interfacezone->left_cells.push_back( p1 - 1 );
+
+                    int q = donor_range[ 0 ];
+                    interfacezone->right_zones.push_back( gDonorZoneId );
+                    interfacezone->right_cells.push_back( q - 1 );
+                }
+            }
+            int kkk = 1;
+        }
+    }
+    int kkk = 1;
+    cg_close(fileId);
+}
+
+int main(int argc, char **argv)
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/02b/plot.py b/example/1d-heat-equation/ftcs/cpp/02b/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/02b/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/02b/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/02b/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/02b/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/02c/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/02c/CMakeLists.txt
new file mode 100644
index 00000000..bfdbab14
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/02c/CMakeLists.txt
@@ -0,0 +1,75 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/02c/README.txt b/example/1d-heat-equation/ftcs/cpp/02c/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/02c/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/02c/heat1d2blocks.cgns b/example/1d-heat-equation/ftcs/cpp/02c/heat1d2blocks.cgns
new file mode 100644
index 00000000..4f4441f0
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/02c/heat1d2blocks.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/02c/main.cpp b/example/1d-heat-equation/ftcs/cpp/02c/main.cpp
new file mode 100644
index 00000000..cbfda796
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/02c/main.cpp
@@ -0,0 +1,860 @@
+#include "cgnslib.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip> 
+#include <string>
+#include <map>
+#include <algorithm>
+
+class Grid;
+void ReadCgnsGrid( const std::string & filename );
+void ReadCgnsGridBaseZone( const std::string & filename );
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+void DumpErrorDetails( std::vector<double> & u_error );
+void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        //val_max = std::max( val_max, std::abs( u_error[ i ] ) );
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+void DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.16f} {:.16f} {:.16f} {:.16f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
+
+class Face
+{
+public:
+    std::vector<int> nodes;
+    std::vector<int> sorted_nodes;
+public:
+    void AddFace( std::vector<int> & nodes )
+    {
+        this->nodes = nodes;
+        this->sorted_nodes = nodes;
+        std::sort( this->sorted_nodes.begin(), this->sorted_nodes.end() );
+    }
+    bool operator < ( const Face & rhs ) const
+    {
+        return this->sorted_nodes < rhs.sorted_nodes;
+    } 
+};
+
+class FaceList
+{
+public:
+    std::map<Face, int> face_map;
+public:
+    void AddFace( const Face & face )
+    {
+        std::map<Face, int>::iterator iter;
+        iter = face_map.find( face );
+        if ( iter == face_map.end() )
+        {
+            int id = face_map.size();
+            face_map.insert( std::make_pair( face, id ) );
+        }
+    }
+};
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Point
+{
+public:
+    typedef Point point_type;
+    using value_type = double;
+public:
+    Point()
+    {
+        this->x = 0;
+    }
+    Point(const value_type &x)
+    {
+        this->x = x;
+    }
+public:
+    value_type x;
+public:
+    bool operator < ( const Point & rhs ) const
+    {
+        value_type dx = x - rhs.x;
+        value_type diff = 1.0e-10;
+
+        if ( std::abs( dx ) > diff ) return x < rhs.x;
+
+        return false;
+    }
+};
+
+class PointFactory
+{
+public:
+    using value_type = double;
+    using point_type = Point;
+    using iterator = std::map< point_type, int >::iterator;
+protected:
+    std::map< point_type, int > pointList;
+    std::vector<point_type> pointArray;
+public:
+    int GetNPoints() { return pointArray.size(); }
+    bool FindPoint( const point_type & point )
+    {
+        iterator iter = pointList.find( point );
+        if ( iter == pointList.end() )
+        {
+            return false;
+        }
+        return true;
+    }
+private:
+    bool FindPoint( const point_type & point, iterator & iter )
+    {
+        iter = pointList.find( point );
+        if ( iter == pointList.end() )
+        {
+            return false;
+        }
+        return true;
+    }
+public:
+    int AddPoint( const point_type & point )
+    {
+        PointFactory::iterator iter;
+        if ( FindPoint( point, iter ) )
+        {
+            return iter->second;
+        }
+        else
+        {
+            int index = this->GetNPoints();
+
+            pointList.insert( std::make_pair(point, index) );
+            pointArray.push_back( point );
+
+            return index;
+        }
+    }
+};
+
+class InterFaceZone
+{
+public:
+    std::vector<int> face_ids;
+    std::vector<int> left_zones;
+    std::vector<int> right_zones;
+    std::vector<int> left_cells;
+    std::vector<int> right_cells;
+    std::vector<double> left_u;
+    std::vector<double> right_u;
+};
+
+class BC
+{
+public:
+    std::vector<int> bctypes;
+    std::vector<int> faceids;
+};
+
+class Grid;
+class Field;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+    static std::vector<BC *> bcs;
+    static std::vector<InterFaceZone *> interfacezones;
+    static PointFactory boundary_points;
+    static FaceList boundary_faces;
+    static FaceList inter_faces;
+    static BaseZoneList zone_names;
+    static int nt;
+};
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+std::vector<BC *> Global::bcs;
+std::vector<InterFaceZone *> Global::interfacezones;
+PointFactory Global::boundary_points;
+FaceList Global::boundary_faces;
+FaceList Global::inter_faces;
+BaseZoneList Global::zone_names;
+int Global::nt = -1;
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid )
+    {
+        this->ni = grid->x.size();
+        std::cout << "ni = " << ni << "\n";
+
+        std::vector<double> & x = grid->x;
+        this->dx = x[ 1 ] - x[ 0 ];
+        this->dt = dx / 10.0;
+        this->t = 1.0;
+        this->nt = static_cast<int>( t / dt ) + 1;
+        std::cout << "nt = " << nt << "\n";
+
+        Global::nt = nt;
+
+        this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+        this->beta = this->alpha * dt / ( dx * dx );
+        std::cout << "alpha = " << std::setprecision( 15 ) << this->alpha << "\n";
+        std::cout << "beta = " << std::setprecision( 15 ) << this->beta << "\n";
+
+        int nghost = 2;
+        int ni_total = ni + nghost;
+
+        u_e.resize( ni_total );
+        u.resize( ni_total );
+        un.resize( ni_total );
+
+        int ist = 0;
+        int ied = ni - 1;
+
+        // 0(bc) 1(ist) 2 3 ... ni
+
+        //int ist = 0 + 1;
+        //int ied = ni;
+
+        for ( int i = ist; i <= ied; ++ i )
+        {
+            u_e[ i ] = - std::exp( -t ) * std::sin( std::numbers::pi * x[i] ); //theory solution
+            un[ i ] = - std::sin( std::numbers::pi * x[ i ] ); //initial condition @ t=0
+        }
+        //un[ ist - 1 ] = 0.0;
+        //un[ ied + 1 ] = 0.0;
+        un[ 0 ] = 0.0;
+        un[ ni - 1 ] = 0.0;
+    }
+
+    void Solve( Grid * grid )
+    {
+        Boundary( grid );
+        for ( int i = 1; i < ni - 1; ++ i )
+        {
+            u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+        }
+        this->update( un, u );
+    }
+
+    void Boundary( Grid * grid )
+    {
+        this->InterfaceBoundary( grid );
+        this->PhysicalBoundary( grid );
+    }
+
+    void PhysicalBoundary( Grid * grid )
+    {
+        BC * bc = Global::bcs[ grid->zoneIndex ];
+
+        int nBFace = bc->bctypes.size();
+        for ( int i = 0; i < nBFace; ++ i )
+        {
+            int bctype = bc->bctypes[ i ];
+            int faceId = bc->faceids[ i ];
+            if ( bctype == BCInflow )
+            {
+                u[ faceId ] = 0.0;
+            }
+            else if ( bctype == BCOutflow )
+            {
+                u[ faceId ] = 0.0;
+            }
+        }
+    }
+
+    void InterfaceBoundary( Grid * grid )
+    {
+        InterFaceZone * interfacezone = Global::interfacezones[ grid->zoneIndex ];
+        int nInterfaces = interfacezone->left_u.size();
+        for ( int i = 0; i < nInterfaces; ++ i )
+        {
+            double ul = interfacezone->left_u[ i ];
+            double ur = interfacezone->right_u[ i ];
+            double um = 0.5 * ( ul + ur );
+
+            int faceId = interfacezone->face_ids[ i ];
+
+            u[ faceId ] = um;
+            int kkk = 1;
+        }
+    }
+
+    void PostProcess( Grid * grid )
+    {
+        std::vector<double> & x = grid->x;
+        //compute L2 norm of the error
+        std::vector<double> u_error( ni );
+        for ( int i = 0; i < ni; ++ i )
+        {
+            u_error[ i ] = un[ i ] - u_e[ i ];
+        }
+    }
+
+    void AddData( PointFactory &ptfactory, Grid * grid, std::vector<double> &global_x, std::vector<double> &global_ue, std::vector<double> &global_un )
+    {
+        int ni = grid->x.size();
+        for ( int i = 0; i < ni; ++ i )
+        {
+            double xm = grid->x[ i ];
+            bool flag = ptfactory.FindPoint( Point( xm ) );
+            if ( i == 0 || ( i == ni - 1 ) )
+            {
+                if ( ! flag )
+                {
+                    ptfactory.AddPoint( Point( xm ) );
+                    global_x.push_back( grid->x[ i ] );
+                    global_ue.push_back( this->u_e[ i ] );
+                    global_un.push_back( this->un[ i ] );
+                }
+            }
+            else
+            {
+                global_x.push_back( grid->x[ i ] );
+                global_ue.push_back( this->u_e[ i ] );
+                global_un.push_back( this->un[ i ] );
+            }
+        }
+    }
+
+    void update( std::vector<double> &un, std::vector<double> &u )
+    {
+        for ( int i = 0; i < u.size(); ++ i )
+        {
+            un[ i ] = u[ i ];
+        }
+    }
+};
+
+class Solver
+{
+public:
+    void Run()
+    {
+        this->ReadGrid();
+        this->InitFields();
+        this->SolveMultiZones();
+        this->PostProcess();
+    }
+
+    void ReadGrid()
+    {
+        ReadCgnsGridBaseZone( "../heat1d2blocks.cgns" );
+        int kkk = 1;
+        ReadCgnsGrid( "../heat1d2blocks.cgns" );
+        int nZones = Global::grids.size();
+        PointFactory ptfactory;
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Grid * grid = Global::grids[ iZone ];
+            grid->zoneIndex = iZone;
+            int ni = grid->x.size();
+            for ( int i = 0; i < ni; ++ i )
+            {
+                int pid = ptfactory.AddPoint( Point(grid->x[i]) );
+                //face.nodes.push_back( pid );
+            }
+            int kkk = 1;
+        }
+    }
+
+    void InitFields()
+    {
+        int nZones = Global::grids.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Grid * grid = Global::grids[ iZone ];
+            Field * field = new Field();
+            Global::fields.push_back( field );
+            field->Init( grid );
+        }
+    }
+
+    void SolveMultiZones()
+    {
+        for ( int it = 0; it < Global::nt; ++ it )
+        {
+            ExchangeInterfaceValue();
+            int nZones = Global::grids.size();
+            for ( int iZone = 0; iZone < nZones; ++ iZone )
+            {
+                Grid * grid = Global::grids[ iZone ];
+                Field * field = Global::fields[ iZone ];
+                field->Solve( grid );
+            }
+        }
+    }
+
+    void ExchangeInterfaceValue()
+    {
+        int nZones = Global::grids.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            InterFaceZone * interfacezone = Global::interfacezones[ iZone ];
+            int nInterFace = interfacezone->left_zones.size();
+            interfacezone->left_u.resize( nInterFace );
+            interfacezone->right_u.resize( nInterFace );
+        }
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Field * field = Global::fields[ iZone ];
+
+            InterFaceZone * interfacezone = Global::interfacezones[ iZone ];
+            int nInterFace = interfacezone->left_zones.size();
+
+            for ( int i = 0; i < nInterFace; ++ i )
+            {
+                int left_cell = interfacezone->left_cells[ i ];
+                int donor_zoneid = interfacezone->right_zones[ i ];
+                int donor_cell = interfacezone->right_cells[ i ];
+                Field * donor_field = Global::fields[ donor_zoneid ];
+
+                interfacezone->left_u[ i ] = field->u[ left_cell ];
+                interfacezone->right_u[ i ] = donor_field->u[ donor_cell ];
+            }
+        }
+    }
+
+    void PostProcess()
+    {
+        int nZones = Global::grids.size();
+        std::vector<double> u_e;
+        std::vector<double> un;
+        std::vector<double> x;
+
+        PointFactory ptfactory;
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Grid * grid = Global::grids[ iZone ];
+            Field * field = Global::fields[ iZone ];
+            field->AddData( ptfactory, grid, x, u_e, un );
+        }
+
+        std::cout << " x.size() = " << x.size() << "\n";
+
+        this->PostProcess( x, u_e, un );
+    }
+
+    void PostProcess( std::vector<double> &x, std::vector<double> &u_e, std::vector<double> &un )
+    {
+        int ni = x.size();
+        //compute L2 norm of the error
+        std::vector<double> u_error( ni );
+        for ( int i = 0; i < ni; ++ i )
+        {
+            u_error[ i ] = un[ i ] - u_e[ i ];
+        }
+
+        ::DumpErrorDetails( u_error );
+
+        std::string csvname = "field_final.csv";
+        ::DumpCsvFile( csvname, x, u_e, un, u_error );
+    }
+
+    void PrintField( std::vector<double> &f )
+    {
+        int icount = 0;
+        for ( int i = 0; i < f.size(); ++ i )
+        {
+            std::cout << std::setprecision(15) << f[ i ] << " ";
+            icount ++;
+            if ( icount % 5 == 0 )
+            {
+                std::cout << "\n";
+            }
+        }
+        std::cout << "\n";
+        std::cout << "\n";
+    }
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            //baseZone.baseId = baseId;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones(fileId, baseId, &nzones);
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            Grid * grid = new Grid();
+            Global::grids.push_back( grid );
+
+            BC * bc = new BC();
+            Global::bcs.push_back( bc );
+
+            InterFaceZone * interfacezone = new InterFaceZone();
+            Global::interfacezones.push_back( interfacezone );
+
+            BaseZone baseZone;
+            //baseZone.baseId = baseId;
+            baseZone.zone_name = zonename;
+
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[33];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                //std::vector<double> coord( nNodes );
+                std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coord.data() );
+                double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+                for ( int i = 0; i < nNodes; ++ i )
+                {
+                    //std::cout << coord[i] << " ";
+                    std::cout << xd[i] << " ";
+                    grid->x[ i ] = xd[ i ];
+                    if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+                }
+                std::cout << "\n";
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex(index_dim,-1);
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                }
+                std::cout << "\n";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    Global::boundary_points.AddPoint( grid->x[ pnts[ i ] - 1 ] );
+                }
+
+                if ( index_dim == 1 )
+                {
+                    int p1 = pnts[ 0 ];
+                    double x1 = grid->x[ p1 - 1 ];
+                    int id = Global::boundary_points.AddPoint( x1 );
+                    Face face;
+                    std::vector<int> nodes;
+                    nodes.push_back( id );
+                    face.AddFace( nodes );
+                    Global::boundary_faces.AddFace( face );
+
+                    bc->bctypes.push_back( bocotype );
+                    bc->faceids.push_back( p1 - 1 );
+                }
+                
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+
+                //std::cout << "normalList = ";
+                //for ( int i = 0; i < nNodes*iphysdim; ++ i )
+                //{
+                //    std::cout << normal_d[ i ] << " ";
+                //}
+                //std::cout << "\n";
+            }
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    Global::boundary_points.AddPoint( grid->x[ range[ i ] - 1 ] );
+                }
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                if ( index_dim == 1 )
+                {
+                    int p1 = range[ 0 ];
+                    double x1 = grid->x[ p1 - 1 ];
+                    int id = Global::boundary_points.AddPoint( x1 );
+                    Face face;
+                    std::vector<int> nodes;
+                    nodes.push_back( id );
+                    face.AddFace( nodes );
+                    Global::boundary_faces.AddFace( face );
+                    Global::inter_faces.AddFace( face );
+
+                    bc->bctypes.push_back( BCTypeUserDefined );
+                    bc->faceids.push_back( p1 - 1 );
+
+                    interfacezone->face_ids.push_back( p1 );
+
+                    interfacezone->left_zones.push_back( gZoneId );
+                    interfacezone->left_cells.push_back( p1 - 1 );
+
+                    int q = donor_range[ 0 ];
+                    interfacezone->right_zones.push_back( gDonorZoneId );
+                    interfacezone->right_cells.push_back( q - 1 );
+                }
+            }
+            int kkk = 1;
+        }
+    }
+    int kkk = 1;
+    cg_close(fileId);
+}
+
+int main(int argc, char **argv)
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/02c/plot.py b/example/1d-heat-equation/ftcs/cpp/02c/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/02c/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/02c/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/02c/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/02c/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/03/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/03/CMakeLists.txt
new file mode 100644
index 00000000..22d3b209
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03/CMakeLists.txt
@@ -0,0 +1,77 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/03/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/03/CgnsGrid.cpp
new file mode 100644
index 00000000..10c9381e
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03/CgnsGrid.cpp
@@ -0,0 +1,266 @@
+#include "CgnsGrid.h"
+#include "cgnslib.h"
+#include "global.h"
+#include <iostream>
+#include <vector>
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            Grid * grid = new Grid();
+            Global::grids.push_back( grid );
+
+            BC * bc = new BC();
+            Global::bcs.push_back( bc );
+
+            InterFaceZone * interfacezone = new InterFaceZone();
+            Global::interfacezones.push_back( interfacezone );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[33];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                //std::vector<double> coord( nNodes );
+                std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coord.data() );
+                double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+                for ( int i = 0; i < nNodes; ++ i )
+                {
+                    //std::cout << coord[i] << " ";
+                    std::cout << xd[i] << " ";
+                    grid->x[ i ] = xd[ i ];
+                    if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+                }
+                std::cout << "\n";
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                }
+                std::cout << "\n";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    Global::boundary_points.AddPoint( grid->x[ pnts[ i ] - 1 ] );
+                }
+
+                if ( index_dim == 1 )
+                {
+                    int p1 = pnts[ 0 ];
+                    double x1 = grid->x[ p1 - 1 ];
+                    int id = Global::boundary_points.AddPoint( x1 );
+                    Face face;
+                    std::vector<int> nodes;
+                    nodes.push_back( id );
+                    face.AddFace( nodes );
+                    Global::boundary_faces.AddFace( face );
+
+                    bc->bctypes.push_back( bocotype );
+                    bc->faceids.push_back( p1 - 1 );
+                }
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    Global::boundary_points.AddPoint( grid->x[ range[ i ] - 1 ] );
+                }
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                if ( index_dim == 1 )
+                {
+                    int p1 = range[ 0 ];
+                    double x1 = grid->x[ p1 - 1 ];
+                    int id = Global::boundary_points.AddPoint( x1 );
+                    Face face;
+                    std::vector<int> nodes;
+                    nodes.push_back( id );
+                    face.AddFace( nodes );
+                    Global::boundary_faces.AddFace( face );
+                    Global::inter_faces.AddFace( face );
+
+                    bc->bctypes.push_back( BCTypeUserDefined );
+                    bc->faceids.push_back( p1 - 1 );
+
+                    interfacezone->face_ids.push_back( p1 );
+
+                    interfacezone->left_zones.push_back( gZoneId );
+                    interfacezone->left_cells.push_back( p1 - 1 );
+
+                    int q = donor_range[ 0 ];
+                    interfacezone->right_zones.push_back( gDonorZoneId );
+                    interfacezone->right_cells.push_back( q - 1 );
+                }
+            }
+        }
+    }
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/03/CgnsGrid.h
new file mode 100644
index 00000000..8b188125
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03/CgnsGrid.h
@@ -0,0 +1,5 @@
+#pragma once
+#include <string>
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03/README.txt b/example/1d-heat-equation/ftcs/cpp/03/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/03/global.cpp b/example/1d-heat-equation/ftcs/cpp/03/global.cpp
new file mode 100644
index 00000000..960f3c65
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03/global.cpp
@@ -0,0 +1,11 @@
+#include "global.h"
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+std::vector<BC *> Global::bcs;
+std::vector<InterFaceZone *> Global::interfacezones;
+PointFactory Global::boundary_points;
+FaceList Global::boundary_faces;
+FaceList Global::inter_faces;
+BaseZoneList Global::zone_names;
+int Global::nt = -1;
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03/global.h b/example/1d-heat-equation/ftcs/cpp/03/global.h
new file mode 100644
index 00000000..e0a26c36
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03/global.h
@@ -0,0 +1,209 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <algorithm>
+#include <string>
+
+class Grid;
+
+class Point
+{
+public:
+    typedef Point point_type;
+    using value_type = double;
+public:
+    Point()
+    {
+        this->x = 0;
+    }
+    Point(const value_type &x)
+    {
+        this->x = x;
+    }
+public:
+    value_type x;
+public:
+    bool operator < ( const Point & rhs ) const
+    {
+        value_type dx = x - rhs.x;
+        value_type diff = 1.0e-10;
+
+        if ( std::abs( dx ) > diff ) return x < rhs.x;
+
+        return false;
+    }
+};
+
+class PointFactory
+{
+public:
+    using value_type = double;
+    using point_type = Point;
+    using iterator = std::map< point_type, int >::iterator;
+protected:
+    std::map< point_type, int > pointList;
+    std::vector<point_type> pointArray;
+public:
+    int GetNPoints() { return pointArray.size(); }
+    bool FindPoint( const point_type & point )
+    {
+        iterator iter = pointList.find( point );
+        if ( iter == pointList.end() )
+        {
+            return false;
+        }
+        return true;
+    }
+private:
+    bool FindPoint( const point_type & point, iterator & iter )
+    {
+        iter = pointList.find( point );
+        if ( iter == pointList.end() )
+        {
+            return false;
+        }
+        return true;
+    }
+public:
+    int AddPoint( const point_type & point )
+    {
+        PointFactory::iterator iter;
+        if ( FindPoint( point, iter ) )
+        {
+            return iter->second;
+        }
+        else
+        {
+            int index = this->GetNPoints();
+
+            pointList.insert( std::make_pair(point, index) );
+            pointArray.push_back( point );
+
+            return index;
+        }
+    }
+};
+
+class Face
+{
+public:
+    std::vector<int> nodes;
+    std::vector<int> sorted_nodes;
+public:
+    void AddFace( std::vector<int> & nodes )
+    {
+        this->nodes = nodes;
+        this->sorted_nodes = nodes;
+        std::sort( this->sorted_nodes.begin(), this->sorted_nodes.end() );
+    }
+    bool operator < ( const Face & rhs ) const
+    {
+        return this->sorted_nodes < rhs.sorted_nodes;
+    } 
+};
+
+class FaceList
+{
+public:
+    std::map<Face, int> face_map;
+public:
+    void AddFace( const Face & face )
+    {
+        std::map<Face, int>::iterator iter;
+        iter = face_map.find( face );
+        if ( iter == face_map.end() )
+        {
+            int id = face_map.size();
+            face_map.insert( std::make_pair( face, id ) );
+        }
+    }
+};
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class BC
+{
+public:
+    std::vector<int> bctypes;
+    std::vector<int> faceids;
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class InterFaceZone
+{
+public:
+    std::vector<int> face_ids;
+    std::vector<int> left_zones;
+    std::vector<int> right_zones;
+    std::vector<int> left_cells;
+    std::vector<int> right_cells;
+    std::vector<double> left_u;
+    std::vector<double> right_u;
+};
+
+
+class Field;
+class BC;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+    static std::vector<BC *> bcs;
+    static std::vector<InterFaceZone *> interfacezones;
+    static PointFactory boundary_points;
+    static FaceList boundary_faces;
+    static FaceList inter_faces;
+    static BaseZoneList zone_names;
+    static int nt;
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/03/heat1d2blocksv3.cgns b/example/1d-heat-equation/ftcs/cpp/03/heat1d2blocksv3.cgns
new file mode 100644
index 00000000..1621b92e
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/03/heat1d2blocksv3.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/03/main.cpp b/example/1d-heat-equation/ftcs/cpp/03/main.cpp
new file mode 100644
index 00000000..9ce65500
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03/main.cpp
@@ -0,0 +1,383 @@
+#include "cgnslib.h"
+#include "global.h"
+#include "CgnsGrid.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip> 
+#include <string>
+#include <map>
+#include <algorithm>
+
+class Grid;
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+void DumpErrorDetails( std::vector<double> & u_error );
+void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        //val_max = std::max( val_max, std::abs( u_error[ i ] ) );
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+void DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.16f} {:.16f} {:.16f} {:.16f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
+
+class Grid;
+class Field;
+
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid )
+    {
+        this->ni = grid->x.size();
+        std::cout << "ni = " << ni << "\n";
+
+        std::vector<double> & x = grid->x;
+        this->dx = x[ 1 ] - x[ 0 ];
+        this->dt = dx / 10.0;
+        this->t = 1.0;
+        this->nt = static_cast<int>( t / dt ) + 1;
+        std::cout << "nt = " << nt << "\n";
+
+        Global::nt = nt;
+
+        this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+        this->beta = this->alpha * dt / ( dx * dx );
+        std::cout << "alpha = " << std::setprecision( 15 ) << this->alpha << "\n";
+        std::cout << "beta = " << std::setprecision( 15 ) << this->beta << "\n";
+
+        int nghost = 2;
+        int ni_total = ni + nghost;
+
+        u_e.resize( ni_total );
+        u.resize( ni_total );
+        un.resize( ni_total );
+
+        int ist = 0;
+        int ied = ni - 1;
+
+        // 0(bc) 1(ist) 2 3 ... ni
+
+        //int ist = 0 + 1;
+        //int ied = ni;
+
+        for ( int i = ist; i <= ied; ++ i )
+        {
+            u_e[ i ] = - std::exp( -t ) * std::sin( std::numbers::pi * x[i] ); //theory solution
+            un[ i ] = - std::sin( std::numbers::pi * x[ i ] ); //initial condition @ t=0
+        }
+        //un[ ist - 1 ] = 0.0;
+        //un[ ied + 1 ] = 0.0;
+        un[ 0 ] = 0.0;
+        un[ ni - 1 ] = 0.0;
+    }
+
+    void Solve( Grid * grid )
+    {
+        Boundary( grid );
+        for ( int i = 1; i < ni - 1; ++ i )
+        {
+            u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+        }
+        this->update( un, u );
+    }
+
+    void Boundary( Grid * grid )
+    {
+        this->InterfaceBoundary( grid );
+        this->PhysicalBoundary( grid );
+    }
+
+    void PhysicalBoundary( Grid * grid )
+    {
+        BC * bc = Global::bcs[ grid->zoneIndex ];
+
+        int nBFace = bc->bctypes.size();
+        for ( int i = 0; i < nBFace; ++ i )
+        {
+            int bctype = bc->bctypes[ i ];
+            int faceId = bc->faceids[ i ];
+            if ( bctype == BCInflow )
+            {
+                u[ faceId ] = 0.0;
+            }
+            else if ( bctype == BCOutflow )
+            {
+                u[ faceId ] = 0.0;
+            }
+        }
+    }
+
+    void InterfaceBoundary( Grid * grid )
+    {
+        InterFaceZone * interfacezone = Global::interfacezones[ grid->zoneIndex ];
+        int nInterfaces = interfacezone->left_u.size();
+        for ( int i = 0; i < nInterfaces; ++ i )
+        {
+            double ul = interfacezone->left_u[ i ];
+            double ur = interfacezone->right_u[ i ];
+            double um = 0.5 * ( ul + ur );
+
+            int faceId = interfacezone->face_ids[ i ];
+
+            u[ faceId ] = um;
+            int kkk = 1;
+        }
+    }
+
+    void PostProcess( Grid * grid )
+    {
+        std::vector<double> & x = grid->x;
+        //compute L2 norm of the error
+        std::vector<double> u_error( ni );
+        for ( int i = 0; i < ni; ++ i )
+        {
+            u_error[ i ] = un[ i ] - u_e[ i ];
+        }
+    }
+
+    void AddData( PointFactory &ptfactory, Grid * grid, std::vector<double> &global_x, std::vector<double> &global_ue, std::vector<double> &global_un )
+    {
+        int ni = grid->x.size();
+        for ( int i = 0; i < ni; ++ i )
+        {
+            double xm = grid->x[ i ];
+            bool flag = ptfactory.FindPoint( Point( xm ) );
+            if ( i == 0 || ( i == ni - 1 ) )
+            {
+                if ( ! flag )
+                {
+                    ptfactory.AddPoint( Point( xm ) );
+                    global_x.push_back( grid->x[ i ] );
+                    global_ue.push_back( this->u_e[ i ] );
+                    global_un.push_back( this->un[ i ] );
+                }
+            }
+            else
+            {
+                global_x.push_back( grid->x[ i ] );
+                global_ue.push_back( this->u_e[ i ] );
+                global_un.push_back( this->un[ i ] );
+            }
+        }
+    }
+
+    void update( std::vector<double> &un, std::vector<double> &u )
+    {
+        for ( int i = 0; i < u.size(); ++ i )
+        {
+            un[ i ] = u[ i ];
+        }
+    }
+};
+
+class Solver
+{
+public:
+    void Run()
+    {
+        this->ReadGrid();
+        this->InitFields();
+        this->SolveMultiZones();
+        this->PostProcess();
+    }
+
+    void ReadGrid()
+    {
+        std::string fileName = "../heat1d2blocksv3.cgns";
+        ReadCgnsGridBaseZone( fileName );
+        int kkk = 1;
+        ReadCgnsGrid( fileName );
+        int nZones = Global::grids.size();
+        PointFactory ptfactory;
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Grid * grid = Global::grids[ iZone ];
+            grid->zoneIndex = iZone;
+            int ni = grid->x.size();
+            for ( int i = 0; i < ni; ++ i )
+            {
+                int pid = ptfactory.AddPoint( Point(grid->x[i]) );
+            }
+            int kkk = 1;
+        }
+    }
+
+    void InitFields()
+    {
+        int nZones = Global::grids.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Grid * grid = Global::grids[ iZone ];
+            Field * field = new Field();
+            Global::fields.push_back( field );
+            field->Init( grid );
+        }
+    }
+
+    void SolveMultiZones()
+    {
+        for ( int it = 0; it < Global::nt; ++ it )
+        {
+            ExchangeInterfaceValue();
+            int nZones = Global::grids.size();
+            for ( int iZone = 0; iZone < nZones; ++ iZone )
+            {
+                Grid * grid = Global::grids[ iZone ];
+                Field * field = Global::fields[ iZone ];
+                field->Solve( grid );
+            }
+        }
+    }
+
+    void ExchangeInterfaceValue()
+    {
+        int nZones = Global::grids.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            InterFaceZone * interfacezone = Global::interfacezones[ iZone ];
+            int nInterFace = interfacezone->left_zones.size();
+            interfacezone->left_u.resize( nInterFace );
+            interfacezone->right_u.resize( nInterFace );
+        }
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Field * field = Global::fields[ iZone ];
+
+            InterFaceZone * interfacezone = Global::interfacezones[ iZone ];
+            int nInterFace = interfacezone->left_zones.size();
+
+            for ( int i = 0; i < nInterFace; ++ i )
+            {
+                int left_cell = interfacezone->left_cells[ i ];
+                int donor_zoneid = interfacezone->right_zones[ i ];
+                int donor_cell = interfacezone->right_cells[ i ];
+                Field * donor_field = Global::fields[ donor_zoneid ];
+
+                interfacezone->left_u[ i ] = field->u[ left_cell ];
+                interfacezone->right_u[ i ] = donor_field->u[ donor_cell ];
+            }
+        }
+    }
+
+    void PostProcess()
+    {
+        int nZones = Global::grids.size();
+        std::vector<double> u_e;
+        std::vector<double> un;
+        std::vector<double> x;
+
+        PointFactory ptfactory;
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Grid * grid = Global::grids[ iZone ];
+            Field * field = Global::fields[ iZone ];
+            field->AddData( ptfactory, grid, x, u_e, un );
+        }
+
+        std::cout << " x.size() = " << x.size() << "\n";
+
+        this->PostProcess( x, u_e, un );
+    }
+
+    void PostProcess( std::vector<double> &x, std::vector<double> &u_e, std::vector<double> &un )
+    {
+        int ni = x.size();
+        //compute L2 norm of the error
+        std::vector<double> u_error( ni );
+        for ( int i = 0; i < ni; ++ i )
+        {
+            u_error[ i ] = un[ i ] - u_e[ i ];
+        }
+
+        ::DumpErrorDetails( u_error );
+
+        std::string csvname = "field_final.csv";
+        ::DumpCsvFile( csvname, x, u_e, un, u_error );
+    }
+
+    void PrintField( std::vector<double> &f )
+    {
+        int icount = 0;
+        for ( int i = 0; i < f.size(); ++ i )
+        {
+            std::cout << std::setprecision(15) << f[ i ] << " ";
+            icount ++;
+            if ( icount % 5 == 0 )
+            {
+                std::cout << "\n";
+            }
+        }
+        std::cout << "\n";
+        std::cout << "\n";
+    }
+};
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/03/plot.py b/example/1d-heat-equation/ftcs/cpp/03/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/03/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/03/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/03a/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/03a/CMakeLists.txt
new file mode 100644
index 00000000..ee758c31
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03a/CMakeLists.txt
@@ -0,0 +1,79 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	Solver.h Solver.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/03a/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/03a/CgnsGrid.cpp
new file mode 100644
index 00000000..10c9381e
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03a/CgnsGrid.cpp
@@ -0,0 +1,266 @@
+#include "CgnsGrid.h"
+#include "cgnslib.h"
+#include "global.h"
+#include <iostream>
+#include <vector>
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            Grid * grid = new Grid();
+            Global::grids.push_back( grid );
+
+            BC * bc = new BC();
+            Global::bcs.push_back( bc );
+
+            InterFaceZone * interfacezone = new InterFaceZone();
+            Global::interfacezones.push_back( interfacezone );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[33];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                //std::vector<double> coord( nNodes );
+                std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coord.data() );
+                double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+                for ( int i = 0; i < nNodes; ++ i )
+                {
+                    //std::cout << coord[i] << " ";
+                    std::cout << xd[i] << " ";
+                    grid->x[ i ] = xd[ i ];
+                    if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+                }
+                std::cout << "\n";
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                }
+                std::cout << "\n";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    Global::boundary_points.AddPoint( grid->x[ pnts[ i ] - 1 ] );
+                }
+
+                if ( index_dim == 1 )
+                {
+                    int p1 = pnts[ 0 ];
+                    double x1 = grid->x[ p1 - 1 ];
+                    int id = Global::boundary_points.AddPoint( x1 );
+                    Face face;
+                    std::vector<int> nodes;
+                    nodes.push_back( id );
+                    face.AddFace( nodes );
+                    Global::boundary_faces.AddFace( face );
+
+                    bc->bctypes.push_back( bocotype );
+                    bc->faceids.push_back( p1 - 1 );
+                }
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    Global::boundary_points.AddPoint( grid->x[ range[ i ] - 1 ] );
+                }
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                if ( index_dim == 1 )
+                {
+                    int p1 = range[ 0 ];
+                    double x1 = grid->x[ p1 - 1 ];
+                    int id = Global::boundary_points.AddPoint( x1 );
+                    Face face;
+                    std::vector<int> nodes;
+                    nodes.push_back( id );
+                    face.AddFace( nodes );
+                    Global::boundary_faces.AddFace( face );
+                    Global::inter_faces.AddFace( face );
+
+                    bc->bctypes.push_back( BCTypeUserDefined );
+                    bc->faceids.push_back( p1 - 1 );
+
+                    interfacezone->face_ids.push_back( p1 );
+
+                    interfacezone->left_zones.push_back( gZoneId );
+                    interfacezone->left_cells.push_back( p1 - 1 );
+
+                    int q = donor_range[ 0 ];
+                    interfacezone->right_zones.push_back( gDonorZoneId );
+                    interfacezone->right_cells.push_back( q - 1 );
+                }
+            }
+        }
+    }
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03a/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/03a/CgnsGrid.h
new file mode 100644
index 00000000..8b188125
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03a/CgnsGrid.h
@@ -0,0 +1,5 @@
+#pragma once
+#include <string>
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03a/Field.cpp b/example/1d-heat-equation/ftcs/cpp/03a/Field.cpp
new file mode 100644
index 00000000..63ab0c34
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03a/Field.cpp
@@ -0,0 +1 @@
+#include "Field.h"
diff --git a/example/1d-heat-equation/ftcs/cpp/03a/Field.h b/example/1d-heat-equation/ftcs/cpp/03a/Field.h
new file mode 100644
index 00000000..9c6cfb64
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03a/Field.h
@@ -0,0 +1,163 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid )
+    {
+        this->ni = grid->x.size();
+        std::cout << "ni = " << ni << "\n";
+
+        std::vector<double> & x = grid->x;
+        this->dx = x[ 1 ] - x[ 0 ];
+        this->dt = dx / 10.0;
+        this->t = 1.0;
+        this->nt = static_cast<int>( t / dt ) + 1;
+        std::cout << "nt = " << nt << "\n";
+
+        Global::nt = nt;
+
+        this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+        this->beta = this->alpha * dt / ( dx * dx );
+        std::cout << "alpha = " << std::setprecision( 15 ) << this->alpha << "\n";
+        std::cout << "beta = " << std::setprecision( 15 ) << this->beta << "\n";
+
+        int nghost = 2;
+        int ni_total = ni + nghost;
+
+        u_e.resize( ni_total );
+        u.resize( ni_total );
+        un.resize( ni_total );
+
+        int ist = 0;
+        int ied = ni - 1;
+
+        // 0(bc) 1(ist) 2 3 ... ni
+
+        //int ist = 0 + 1;
+        //int ied = ni;
+
+        for ( int i = ist; i <= ied; ++ i )
+        {
+            u_e[ i ] = - std::exp( -t ) * std::sin( std::numbers::pi * x[i] ); //theory solution
+            un[ i ] = - std::sin( std::numbers::pi * x[ i ] ); //initial condition @ t=0
+        }
+        //un[ ist - 1 ] = 0.0;
+        //un[ ied + 1 ] = 0.0;
+        un[ 0 ] = 0.0;
+        un[ ni - 1 ] = 0.0;
+    }
+
+    void Solve( Grid * grid )
+    {
+        Boundary( grid );
+        for ( int i = 1; i < ni - 1; ++ i )
+        {
+            u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+        }
+        this->update( un, u );
+    }
+
+    void Boundary( Grid * grid )
+    {
+        this->InterfaceBoundary( grid );
+        this->PhysicalBoundary( grid );
+    }
+
+    void PhysicalBoundary( Grid * grid )
+    {
+        BC * bc = Global::bcs[ grid->zoneIndex ];
+
+        int nBFace = bc->bctypes.size();
+        for ( int i = 0; i < nBFace; ++ i )
+        {
+            int bctype = bc->bctypes[ i ];
+            int faceId = bc->faceids[ i ];
+            if ( bctype == BCInflow )
+            {
+                u[ faceId ] = 0.0;
+            }
+            else if ( bctype == BCOutflow )
+            {
+                u[ faceId ] = 0.0;
+            }
+        }
+    }
+
+    void InterfaceBoundary( Grid * grid )
+    {
+        InterFaceZone * interfacezone = Global::interfacezones[ grid->zoneIndex ];
+        int nInterfaces = interfacezone->left_u.size();
+        for ( int i = 0; i < nInterfaces; ++ i )
+        {
+            double ul = interfacezone->left_u[ i ];
+            double ur = interfacezone->right_u[ i ];
+            double um = 0.5 * ( ul + ur );
+
+            int faceId = interfacezone->face_ids[ i ];
+
+            u[ faceId ] = um;
+            int kkk = 1;
+        }
+    }
+
+    void PostProcess( Grid * grid )
+    {
+        std::vector<double> & x = grid->x;
+        //compute L2 norm of the error
+        std::vector<double> u_error( ni );
+        for ( int i = 0; i < ni; ++ i )
+        {
+            u_error[ i ] = un[ i ] - u_e[ i ];
+        }
+    }
+
+    void AddData( PointFactory &ptfactory, Grid * grid, std::vector<double> &global_x, std::vector<double> &global_ue, std::vector<double> &global_un )
+    {
+        int ni = grid->x.size();
+        for ( int i = 0; i < ni; ++ i )
+        {
+            double xm = grid->x[ i ];
+            bool flag = ptfactory.FindPoint( Point( xm ) );
+            if ( i == 0 || ( i == ni - 1 ) )
+            {
+                if ( ! flag )
+                {
+                    ptfactory.AddPoint( Point( xm ) );
+                    global_x.push_back( grid->x[ i ] );
+                    global_ue.push_back( this->u_e[ i ] );
+                    global_un.push_back( this->un[ i ] );
+                }
+            }
+            else
+            {
+                global_x.push_back( grid->x[ i ] );
+                global_ue.push_back( this->u_e[ i ] );
+                global_un.push_back( this->un[ i ] );
+            }
+        }
+    }
+
+    void update( std::vector<double> &un, std::vector<double> &u )
+    {
+        for ( int i = 0; i < u.size(); ++ i )
+        {
+            un[ i ] = u[ i ];
+        }
+    }
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03a/README.txt b/example/1d-heat-equation/ftcs/cpp/03a/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03a/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/03a/Solver.cpp b/example/1d-heat-equation/ftcs/cpp/03a/Solver.cpp
new file mode 100644
index 00000000..77b572c6
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03a/Solver.cpp
@@ -0,0 +1,57 @@
+#include "Solver.h"
+#include <fstream>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        //val_max = std::max( val_max, std::abs( u_error[ i ] ) );
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+void DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.16f} {:.16f} {:.16f} {:.16f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03a/Solver.h b/example/1d-heat-equation/ftcs/cpp/03a/Solver.h
new file mode 100644
index 00000000..aef7a8a3
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03a/Solver.h
@@ -0,0 +1,153 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+void DumpErrorDetails( std::vector<double> & u_error );
+void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+
+class Solver
+{
+public:
+    void Run()
+    {
+        this->ReadGrid();
+        this->InitFields();
+        this->SolveMultiZones();
+        this->PostProcess();
+    }
+
+    void ReadGrid()
+    {
+        std::string fileName = "../heat1d2blocksv3.cgns";
+        ReadCgnsGridBaseZone( fileName );
+        int kkk = 1;
+        ReadCgnsGrid( fileName );
+        int nZones = Global::grids.size();
+        PointFactory ptfactory;
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Grid * grid = Global::grids[ iZone ];
+            grid->zoneIndex = iZone;
+            int ni = grid->x.size();
+            for ( int i = 0; i < ni; ++ i )
+            {
+                int pid = ptfactory.AddPoint( Point(grid->x[i]) );
+            }
+            int kkk = 1;
+        }
+    }
+
+    void InitFields()
+    {
+        int nZones = Global::grids.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Grid * grid = Global::grids[ iZone ];
+            Field * field = new Field();
+            Global::fields.push_back( field );
+            field->Init( grid );
+        }
+    }
+
+    void SolveMultiZones()
+    {
+        for ( int it = 0; it < Global::nt; ++ it )
+        {
+            ExchangeInterfaceValue();
+            int nZones = Global::grids.size();
+            for ( int iZone = 0; iZone < nZones; ++ iZone )
+            {
+                Grid * grid = Global::grids[ iZone ];
+                Field * field = Global::fields[ iZone ];
+                field->Solve( grid );
+            }
+        }
+    }
+
+    void ExchangeInterfaceValue()
+    {
+        int nZones = Global::grids.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            InterFaceZone * interfacezone = Global::interfacezones[ iZone ];
+            int nInterFace = interfacezone->left_zones.size();
+            interfacezone->left_u.resize( nInterFace );
+            interfacezone->right_u.resize( nInterFace );
+        }
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Field * field = Global::fields[ iZone ];
+
+            InterFaceZone * interfacezone = Global::interfacezones[ iZone ];
+            int nInterFace = interfacezone->left_zones.size();
+
+            for ( int i = 0; i < nInterFace; ++ i )
+            {
+                int left_cell = interfacezone->left_cells[ i ];
+                int donor_zoneid = interfacezone->right_zones[ i ];
+                int donor_cell = interfacezone->right_cells[ i ];
+                Field * donor_field = Global::fields[ donor_zoneid ];
+
+                interfacezone->left_u[ i ] = field->u[ left_cell ];
+                interfacezone->right_u[ i ] = donor_field->u[ donor_cell ];
+            }
+        }
+    }
+
+    void PostProcess()
+    {
+        int nZones = Global::grids.size();
+        std::vector<double> u_e;
+        std::vector<double> un;
+        std::vector<double> x;
+
+        PointFactory ptfactory;
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Grid * grid = Global::grids[ iZone ];
+            Field * field = Global::fields[ iZone ];
+            field->AddData( ptfactory, grid, x, u_e, un );
+        }
+
+        std::cout << " x.size() = " << x.size() << "\n";
+
+        this->PostProcess( x, u_e, un );
+    }
+
+    void PostProcess( std::vector<double> &x, std::vector<double> &u_e, std::vector<double> &un )
+    {
+        int ni = x.size();
+        //compute L2 norm of the error
+        std::vector<double> u_error( ni );
+        for ( int i = 0; i < ni; ++ i )
+        {
+            u_error[ i ] = un[ i ] - u_e[ i ];
+        }
+
+        ::DumpErrorDetails( u_error );
+
+        std::string csvname = "field_final.csv";
+        ::DumpCsvFile( csvname, x, u_e, un, u_error );
+    }
+
+    void PrintField( std::vector<double> &f )
+    {
+        int icount = 0;
+        for ( int i = 0; i < f.size(); ++ i )
+        {
+            std::cout << std::setprecision(15) << f[ i ] << " ";
+            icount ++;
+            if ( icount % 5 == 0 )
+            {
+                std::cout << "\n";
+            }
+        }
+        std::cout << "\n";
+        std::cout << "\n";
+    }
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03a/global.cpp b/example/1d-heat-equation/ftcs/cpp/03a/global.cpp
new file mode 100644
index 00000000..960f3c65
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03a/global.cpp
@@ -0,0 +1,11 @@
+#include "global.h"
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+std::vector<BC *> Global::bcs;
+std::vector<InterFaceZone *> Global::interfacezones;
+PointFactory Global::boundary_points;
+FaceList Global::boundary_faces;
+FaceList Global::inter_faces;
+BaseZoneList Global::zone_names;
+int Global::nt = -1;
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03a/global.h b/example/1d-heat-equation/ftcs/cpp/03a/global.h
new file mode 100644
index 00000000..e0a26c36
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03a/global.h
@@ -0,0 +1,209 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <algorithm>
+#include <string>
+
+class Grid;
+
+class Point
+{
+public:
+    typedef Point point_type;
+    using value_type = double;
+public:
+    Point()
+    {
+        this->x = 0;
+    }
+    Point(const value_type &x)
+    {
+        this->x = x;
+    }
+public:
+    value_type x;
+public:
+    bool operator < ( const Point & rhs ) const
+    {
+        value_type dx = x - rhs.x;
+        value_type diff = 1.0e-10;
+
+        if ( std::abs( dx ) > diff ) return x < rhs.x;
+
+        return false;
+    }
+};
+
+class PointFactory
+{
+public:
+    using value_type = double;
+    using point_type = Point;
+    using iterator = std::map< point_type, int >::iterator;
+protected:
+    std::map< point_type, int > pointList;
+    std::vector<point_type> pointArray;
+public:
+    int GetNPoints() { return pointArray.size(); }
+    bool FindPoint( const point_type & point )
+    {
+        iterator iter = pointList.find( point );
+        if ( iter == pointList.end() )
+        {
+            return false;
+        }
+        return true;
+    }
+private:
+    bool FindPoint( const point_type & point, iterator & iter )
+    {
+        iter = pointList.find( point );
+        if ( iter == pointList.end() )
+        {
+            return false;
+        }
+        return true;
+    }
+public:
+    int AddPoint( const point_type & point )
+    {
+        PointFactory::iterator iter;
+        if ( FindPoint( point, iter ) )
+        {
+            return iter->second;
+        }
+        else
+        {
+            int index = this->GetNPoints();
+
+            pointList.insert( std::make_pair(point, index) );
+            pointArray.push_back( point );
+
+            return index;
+        }
+    }
+};
+
+class Face
+{
+public:
+    std::vector<int> nodes;
+    std::vector<int> sorted_nodes;
+public:
+    void AddFace( std::vector<int> & nodes )
+    {
+        this->nodes = nodes;
+        this->sorted_nodes = nodes;
+        std::sort( this->sorted_nodes.begin(), this->sorted_nodes.end() );
+    }
+    bool operator < ( const Face & rhs ) const
+    {
+        return this->sorted_nodes < rhs.sorted_nodes;
+    } 
+};
+
+class FaceList
+{
+public:
+    std::map<Face, int> face_map;
+public:
+    void AddFace( const Face & face )
+    {
+        std::map<Face, int>::iterator iter;
+        iter = face_map.find( face );
+        if ( iter == face_map.end() )
+        {
+            int id = face_map.size();
+            face_map.insert( std::make_pair( face, id ) );
+        }
+    }
+};
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class BC
+{
+public:
+    std::vector<int> bctypes;
+    std::vector<int> faceids;
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class InterFaceZone
+{
+public:
+    std::vector<int> face_ids;
+    std::vector<int> left_zones;
+    std::vector<int> right_zones;
+    std::vector<int> left_cells;
+    std::vector<int> right_cells;
+    std::vector<double> left_u;
+    std::vector<double> right_u;
+};
+
+
+class Field;
+class BC;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+    static std::vector<BC *> bcs;
+    static std::vector<InterFaceZone *> interfacezones;
+    static PointFactory boundary_points;
+    static FaceList boundary_faces;
+    static FaceList inter_faces;
+    static BaseZoneList zone_names;
+    static int nt;
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/03a/heat1d2blocksv3.cgns b/example/1d-heat-equation/ftcs/cpp/03a/heat1d2blocksv3.cgns
new file mode 100644
index 00000000..1621b92e
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/03a/heat1d2blocksv3.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/03a/main.cpp b/example/1d-heat-equation/ftcs/cpp/03a/main.cpp
new file mode 100644
index 00000000..5ff48a4e
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03a/main.cpp
@@ -0,0 +1,12 @@
+#include "cgnslib.h"
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+#include "Solver.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/03a/plot.py b/example/1d-heat-equation/ftcs/cpp/03a/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03a/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/03a/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/03a/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03a/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/03b/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/03b/CMakeLists.txt
new file mode 100644
index 00000000..ee758c31
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03b/CMakeLists.txt
@@ -0,0 +1,79 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	Solver.h Solver.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/03b/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/03b/CgnsGrid.cpp
new file mode 100644
index 00000000..9afd6e1b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03b/CgnsGrid.cpp
@@ -0,0 +1,383 @@
+#include "CgnsGrid.h"
+#include "cgnslib.h"
+#include "global.h"
+#include <iostream>
+#include <vector>
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBcPatch::ZoneBcPatch()
+{
+    ;
+}
+
+ZoneBcPatch::~ZoneBcPatch()
+{
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+    delete this->patch;
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            Grid * grid = new Grid();
+            Global::grids.push_back( grid );
+
+            BC * bc = new BC();
+            Global::bcs.push_back( bc );
+
+            InterFaceZone * interfacezone = new InterFaceZone();
+            Global::interfacezones.push_back( interfacezone );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[33];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                //std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+
+                coor->DumpCoor();
+                if ( icoord == 0 )
+                {
+                    coor->DumpCoorX( grid->x );
+                }
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    Global::boundary_points.AddPoint( grid->x[ pnts[ i ] - 1 ] );
+                }
+
+                if ( index_dim == 1 )
+                {
+                    int p1 = pnts[ 0 ];
+                    double x1 = grid->x[ p1 - 1 ];
+                    int id = Global::boundary_points.AddPoint( x1 );
+                    Face face;
+                    std::vector<int> nodes;
+                    nodes.push_back( id );
+                    face.AddFace( nodes );
+                    Global::boundary_faces.AddFace( face );
+
+                    bc->bctypes.push_back( bocotype );
+                    bc->faceids.push_back( p1 - 1 );
+                }
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    Global::boundary_points.AddPoint( grid->x[ range[ i ] - 1 ] );
+                }
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+                if ( index_dim == 1 )
+                {
+                    int p1 = range[ 0 ];
+                    double x1 = grid->x[ p1 - 1 ];
+                    int id = Global::boundary_points.AddPoint( x1 );
+                    Face face;
+                    std::vector<int> nodes;
+                    nodes.push_back( id );
+                    face.AddFace( nodes );
+                    Global::boundary_faces.AddFace( face );
+                    Global::inter_faces.AddFace( face );
+
+                    bc->bctypes.push_back( BCTypeUserDefined );
+                    bc->faceids.push_back( p1 - 1 );
+
+                    interfacezone->face_ids.push_back( p1 );
+
+                    interfacezone->left_zones.push_back( gZoneId );
+                    interfacezone->left_cells.push_back( p1 - 1 );
+
+                    int q = donor_range[ 0 ];
+                    interfacezone->right_zones.push_back( gDonorZoneId );
+                    interfacezone->right_cells.push_back( q - 1 );
+                }
+            }
+        }
+    }
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03b/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/03b/CgnsGrid.h
new file mode 100644
index 00000000..bc2e037c
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03b/CgnsGrid.h
@@ -0,0 +1,71 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBcPatch
+{
+public:
+    ZoneBcPatch();
+    ~ZoneBcPatch();
+public:
+    int donor_zoneid;
+    std::vector<int> transform;
+    std::vector<int> donor_pnts;
+};
+
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+    ZoneBcPatch * patch = nullptr;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03b/Field.cpp b/example/1d-heat-equation/ftcs/cpp/03b/Field.cpp
new file mode 100644
index 00000000..63ab0c34
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03b/Field.cpp
@@ -0,0 +1 @@
+#include "Field.h"
diff --git a/example/1d-heat-equation/ftcs/cpp/03b/Field.h b/example/1d-heat-equation/ftcs/cpp/03b/Field.h
new file mode 100644
index 00000000..9c6cfb64
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03b/Field.h
@@ -0,0 +1,163 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid )
+    {
+        this->ni = grid->x.size();
+        std::cout << "ni = " << ni << "\n";
+
+        std::vector<double> & x = grid->x;
+        this->dx = x[ 1 ] - x[ 0 ];
+        this->dt = dx / 10.0;
+        this->t = 1.0;
+        this->nt = static_cast<int>( t / dt ) + 1;
+        std::cout << "nt = " << nt << "\n";
+
+        Global::nt = nt;
+
+        this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+        this->beta = this->alpha * dt / ( dx * dx );
+        std::cout << "alpha = " << std::setprecision( 15 ) << this->alpha << "\n";
+        std::cout << "beta = " << std::setprecision( 15 ) << this->beta << "\n";
+
+        int nghost = 2;
+        int ni_total = ni + nghost;
+
+        u_e.resize( ni_total );
+        u.resize( ni_total );
+        un.resize( ni_total );
+
+        int ist = 0;
+        int ied = ni - 1;
+
+        // 0(bc) 1(ist) 2 3 ... ni
+
+        //int ist = 0 + 1;
+        //int ied = ni;
+
+        for ( int i = ist; i <= ied; ++ i )
+        {
+            u_e[ i ] = - std::exp( -t ) * std::sin( std::numbers::pi * x[i] ); //theory solution
+            un[ i ] = - std::sin( std::numbers::pi * x[ i ] ); //initial condition @ t=0
+        }
+        //un[ ist - 1 ] = 0.0;
+        //un[ ied + 1 ] = 0.0;
+        un[ 0 ] = 0.0;
+        un[ ni - 1 ] = 0.0;
+    }
+
+    void Solve( Grid * grid )
+    {
+        Boundary( grid );
+        for ( int i = 1; i < ni - 1; ++ i )
+        {
+            u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+        }
+        this->update( un, u );
+    }
+
+    void Boundary( Grid * grid )
+    {
+        this->InterfaceBoundary( grid );
+        this->PhysicalBoundary( grid );
+    }
+
+    void PhysicalBoundary( Grid * grid )
+    {
+        BC * bc = Global::bcs[ grid->zoneIndex ];
+
+        int nBFace = bc->bctypes.size();
+        for ( int i = 0; i < nBFace; ++ i )
+        {
+            int bctype = bc->bctypes[ i ];
+            int faceId = bc->faceids[ i ];
+            if ( bctype == BCInflow )
+            {
+                u[ faceId ] = 0.0;
+            }
+            else if ( bctype == BCOutflow )
+            {
+                u[ faceId ] = 0.0;
+            }
+        }
+    }
+
+    void InterfaceBoundary( Grid * grid )
+    {
+        InterFaceZone * interfacezone = Global::interfacezones[ grid->zoneIndex ];
+        int nInterfaces = interfacezone->left_u.size();
+        for ( int i = 0; i < nInterfaces; ++ i )
+        {
+            double ul = interfacezone->left_u[ i ];
+            double ur = interfacezone->right_u[ i ];
+            double um = 0.5 * ( ul + ur );
+
+            int faceId = interfacezone->face_ids[ i ];
+
+            u[ faceId ] = um;
+            int kkk = 1;
+        }
+    }
+
+    void PostProcess( Grid * grid )
+    {
+        std::vector<double> & x = grid->x;
+        //compute L2 norm of the error
+        std::vector<double> u_error( ni );
+        for ( int i = 0; i < ni; ++ i )
+        {
+            u_error[ i ] = un[ i ] - u_e[ i ];
+        }
+    }
+
+    void AddData( PointFactory &ptfactory, Grid * grid, std::vector<double> &global_x, std::vector<double> &global_ue, std::vector<double> &global_un )
+    {
+        int ni = grid->x.size();
+        for ( int i = 0; i < ni; ++ i )
+        {
+            double xm = grid->x[ i ];
+            bool flag = ptfactory.FindPoint( Point( xm ) );
+            if ( i == 0 || ( i == ni - 1 ) )
+            {
+                if ( ! flag )
+                {
+                    ptfactory.AddPoint( Point( xm ) );
+                    global_x.push_back( grid->x[ i ] );
+                    global_ue.push_back( this->u_e[ i ] );
+                    global_un.push_back( this->un[ i ] );
+                }
+            }
+            else
+            {
+                global_x.push_back( grid->x[ i ] );
+                global_ue.push_back( this->u_e[ i ] );
+                global_un.push_back( this->un[ i ] );
+            }
+        }
+    }
+
+    void update( std::vector<double> &un, std::vector<double> &u )
+    {
+        for ( int i = 0; i < u.size(); ++ i )
+        {
+            un[ i ] = u[ i ];
+        }
+    }
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03b/README.txt b/example/1d-heat-equation/ftcs/cpp/03b/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03b/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/03b/Solver.cpp b/example/1d-heat-equation/ftcs/cpp/03b/Solver.cpp
new file mode 100644
index 00000000..77b572c6
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03b/Solver.cpp
@@ -0,0 +1,57 @@
+#include "Solver.h"
+#include <fstream>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        //val_max = std::max( val_max, std::abs( u_error[ i ] ) );
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+void DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.16f} {:.16f} {:.16f} {:.16f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03b/Solver.h b/example/1d-heat-equation/ftcs/cpp/03b/Solver.h
new file mode 100644
index 00000000..aef7a8a3
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03b/Solver.h
@@ -0,0 +1,153 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+void DumpErrorDetails( std::vector<double> & u_error );
+void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+
+class Solver
+{
+public:
+    void Run()
+    {
+        this->ReadGrid();
+        this->InitFields();
+        this->SolveMultiZones();
+        this->PostProcess();
+    }
+
+    void ReadGrid()
+    {
+        std::string fileName = "../heat1d2blocksv3.cgns";
+        ReadCgnsGridBaseZone( fileName );
+        int kkk = 1;
+        ReadCgnsGrid( fileName );
+        int nZones = Global::grids.size();
+        PointFactory ptfactory;
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Grid * grid = Global::grids[ iZone ];
+            grid->zoneIndex = iZone;
+            int ni = grid->x.size();
+            for ( int i = 0; i < ni; ++ i )
+            {
+                int pid = ptfactory.AddPoint( Point(grid->x[i]) );
+            }
+            int kkk = 1;
+        }
+    }
+
+    void InitFields()
+    {
+        int nZones = Global::grids.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Grid * grid = Global::grids[ iZone ];
+            Field * field = new Field();
+            Global::fields.push_back( field );
+            field->Init( grid );
+        }
+    }
+
+    void SolveMultiZones()
+    {
+        for ( int it = 0; it < Global::nt; ++ it )
+        {
+            ExchangeInterfaceValue();
+            int nZones = Global::grids.size();
+            for ( int iZone = 0; iZone < nZones; ++ iZone )
+            {
+                Grid * grid = Global::grids[ iZone ];
+                Field * field = Global::fields[ iZone ];
+                field->Solve( grid );
+            }
+        }
+    }
+
+    void ExchangeInterfaceValue()
+    {
+        int nZones = Global::grids.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            InterFaceZone * interfacezone = Global::interfacezones[ iZone ];
+            int nInterFace = interfacezone->left_zones.size();
+            interfacezone->left_u.resize( nInterFace );
+            interfacezone->right_u.resize( nInterFace );
+        }
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Field * field = Global::fields[ iZone ];
+
+            InterFaceZone * interfacezone = Global::interfacezones[ iZone ];
+            int nInterFace = interfacezone->left_zones.size();
+
+            for ( int i = 0; i < nInterFace; ++ i )
+            {
+                int left_cell = interfacezone->left_cells[ i ];
+                int donor_zoneid = interfacezone->right_zones[ i ];
+                int donor_cell = interfacezone->right_cells[ i ];
+                Field * donor_field = Global::fields[ donor_zoneid ];
+
+                interfacezone->left_u[ i ] = field->u[ left_cell ];
+                interfacezone->right_u[ i ] = donor_field->u[ donor_cell ];
+            }
+        }
+    }
+
+    void PostProcess()
+    {
+        int nZones = Global::grids.size();
+        std::vector<double> u_e;
+        std::vector<double> un;
+        std::vector<double> x;
+
+        PointFactory ptfactory;
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Grid * grid = Global::grids[ iZone ];
+            Field * field = Global::fields[ iZone ];
+            field->AddData( ptfactory, grid, x, u_e, un );
+        }
+
+        std::cout << " x.size() = " << x.size() << "\n";
+
+        this->PostProcess( x, u_e, un );
+    }
+
+    void PostProcess( std::vector<double> &x, std::vector<double> &u_e, std::vector<double> &un )
+    {
+        int ni = x.size();
+        //compute L2 norm of the error
+        std::vector<double> u_error( ni );
+        for ( int i = 0; i < ni; ++ i )
+        {
+            u_error[ i ] = un[ i ] - u_e[ i ];
+        }
+
+        ::DumpErrorDetails( u_error );
+
+        std::string csvname = "field_final.csv";
+        ::DumpCsvFile( csvname, x, u_e, un, u_error );
+    }
+
+    void PrintField( std::vector<double> &f )
+    {
+        int icount = 0;
+        for ( int i = 0; i < f.size(); ++ i )
+        {
+            std::cout << std::setprecision(15) << f[ i ] << " ";
+            icount ++;
+            if ( icount % 5 == 0 )
+            {
+                std::cout << "\n";
+            }
+        }
+        std::cout << "\n";
+        std::cout << "\n";
+    }
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03b/global.cpp b/example/1d-heat-equation/ftcs/cpp/03b/global.cpp
new file mode 100644
index 00000000..15b26cf9
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03b/global.cpp
@@ -0,0 +1,16 @@
+#include "global.h"
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+std::vector<BC *> Global::bcs;
+std::vector<InterFaceZone *> Global::interfacezones;
+PointFactory Global::boundary_points;
+FaceList Global::boundary_faces;
+FaceList Global::inter_faces;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03b/global.h b/example/1d-heat-equation/ftcs/cpp/03b/global.h
new file mode 100644
index 00000000..1d39b9b5
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03b/global.h
@@ -0,0 +1,216 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <algorithm>
+#include <string>
+
+class Grid;
+
+class Point
+{
+public:
+    typedef Point point_type;
+    using value_type = double;
+public:
+    Point()
+    {
+        this->x = 0;
+    }
+    Point(const value_type &x)
+    {
+        this->x = x;
+    }
+public:
+    value_type x;
+public:
+    bool operator < ( const Point & rhs ) const
+    {
+        value_type dx = x - rhs.x;
+        value_type diff = 1.0e-10;
+
+        if ( std::abs( dx ) > diff ) return x < rhs.x;
+
+        return false;
+    }
+};
+
+class PointFactory
+{
+public:
+    using value_type = double;
+    using point_type = Point;
+    using iterator = std::map< point_type, int >::iterator;
+protected:
+    std::map< point_type, int > pointList;
+    std::vector<point_type> pointArray;
+public:
+    int GetNPoints() { return pointArray.size(); }
+    bool FindPoint( const point_type & point )
+    {
+        iterator iter = pointList.find( point );
+        if ( iter == pointList.end() )
+        {
+            return false;
+        }
+        return true;
+    }
+private:
+    bool FindPoint( const point_type & point, iterator & iter )
+    {
+        iter = pointList.find( point );
+        if ( iter == pointList.end() )
+        {
+            return false;
+        }
+        return true;
+    }
+public:
+    int AddPoint( const point_type & point )
+    {
+        PointFactory::iterator iter;
+        if ( FindPoint( point, iter ) )
+        {
+            return iter->second;
+        }
+        else
+        {
+            int index = this->GetNPoints();
+
+            pointList.insert( std::make_pair(point, index) );
+            pointArray.push_back( point );
+
+            return index;
+        }
+    }
+};
+
+class Face
+{
+public:
+    std::vector<int> nodes;
+    std::vector<int> sorted_nodes;
+public:
+    void AddFace( std::vector<int> & nodes )
+    {
+        this->nodes = nodes;
+        this->sorted_nodes = nodes;
+        std::sort( this->sorted_nodes.begin(), this->sorted_nodes.end() );
+    }
+    bool operator < ( const Face & rhs ) const
+    {
+        return this->sorted_nodes < rhs.sorted_nodes;
+    } 
+};
+
+class FaceList
+{
+public:
+    std::map<Face, int> face_map;
+public:
+    void AddFace( const Face & face )
+    {
+        std::map<Face, int>::iterator iter;
+        iter = face_map.find( face );
+        if ( iter == face_map.end() )
+        {
+            int id = face_map.size();
+            face_map.insert( std::make_pair( face, id ) );
+        }
+    }
+};
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class BC
+{
+public:
+    std::vector<int> bctypes;
+    std::vector<int> faceids;
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class InterFaceZone
+{
+public:
+    std::vector<int> face_ids;
+    std::vector<int> left_zones;
+    std::vector<int> right_zones;
+    std::vector<int> left_cells;
+    std::vector<int> right_cells;
+    std::vector<double> left_u;
+    std::vector<double> right_u;
+};
+
+
+class Field;
+class BC;
+class InterFaceZone;
+
+class Zone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+    static std::vector<BC *> bcs;
+    static std::vector<InterFaceZone *> interfacezones;
+    static PointFactory boundary_points;
+    static FaceList boundary_faces;
+    static FaceList inter_faces;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/03b/heat1d2blocksv3.cgns b/example/1d-heat-equation/ftcs/cpp/03b/heat1d2blocksv3.cgns
new file mode 100644
index 00000000..1621b92e
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/03b/heat1d2blocksv3.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/03b/main.cpp b/example/1d-heat-equation/ftcs/cpp/03b/main.cpp
new file mode 100644
index 00000000..5ff48a4e
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03b/main.cpp
@@ -0,0 +1,12 @@
+#include "cgnslib.h"
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+#include "Solver.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/03b/plot.py b/example/1d-heat-equation/ftcs/cpp/03b/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03b/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/03b/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/03b/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03b/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/03c/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/03c/CMakeLists.txt
new file mode 100644
index 00000000..ee758c31
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03c/CMakeLists.txt
@@ -0,0 +1,79 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	Solver.h Solver.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/03c/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/03c/CgnsGrid.cpp
new file mode 100644
index 00000000..9afd6e1b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03c/CgnsGrid.cpp
@@ -0,0 +1,383 @@
+#include "CgnsGrid.h"
+#include "cgnslib.h"
+#include "global.h"
+#include <iostream>
+#include <vector>
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBcPatch::ZoneBcPatch()
+{
+    ;
+}
+
+ZoneBcPatch::~ZoneBcPatch()
+{
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+    delete this->patch;
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            Grid * grid = new Grid();
+            Global::grids.push_back( grid );
+
+            BC * bc = new BC();
+            Global::bcs.push_back( bc );
+
+            InterFaceZone * interfacezone = new InterFaceZone();
+            Global::interfacezones.push_back( interfacezone );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[33];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                //std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+
+                coor->DumpCoor();
+                if ( icoord == 0 )
+                {
+                    coor->DumpCoorX( grid->x );
+                }
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    Global::boundary_points.AddPoint( grid->x[ pnts[ i ] - 1 ] );
+                }
+
+                if ( index_dim == 1 )
+                {
+                    int p1 = pnts[ 0 ];
+                    double x1 = grid->x[ p1 - 1 ];
+                    int id = Global::boundary_points.AddPoint( x1 );
+                    Face face;
+                    std::vector<int> nodes;
+                    nodes.push_back( id );
+                    face.AddFace( nodes );
+                    Global::boundary_faces.AddFace( face );
+
+                    bc->bctypes.push_back( bocotype );
+                    bc->faceids.push_back( p1 - 1 );
+                }
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    Global::boundary_points.AddPoint( grid->x[ range[ i ] - 1 ] );
+                }
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+                if ( index_dim == 1 )
+                {
+                    int p1 = range[ 0 ];
+                    double x1 = grid->x[ p1 - 1 ];
+                    int id = Global::boundary_points.AddPoint( x1 );
+                    Face face;
+                    std::vector<int> nodes;
+                    nodes.push_back( id );
+                    face.AddFace( nodes );
+                    Global::boundary_faces.AddFace( face );
+                    Global::inter_faces.AddFace( face );
+
+                    bc->bctypes.push_back( BCTypeUserDefined );
+                    bc->faceids.push_back( p1 - 1 );
+
+                    interfacezone->face_ids.push_back( p1 );
+
+                    interfacezone->left_zones.push_back( gZoneId );
+                    interfacezone->left_cells.push_back( p1 - 1 );
+
+                    int q = donor_range[ 0 ];
+                    interfacezone->right_zones.push_back( gDonorZoneId );
+                    interfacezone->right_cells.push_back( q - 1 );
+                }
+            }
+        }
+    }
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03c/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/03c/CgnsGrid.h
new file mode 100644
index 00000000..bc2e037c
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03c/CgnsGrid.h
@@ -0,0 +1,71 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBcPatch
+{
+public:
+    ZoneBcPatch();
+    ~ZoneBcPatch();
+public:
+    int donor_zoneid;
+    std::vector<int> transform;
+    std::vector<int> donor_pnts;
+};
+
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+    ZoneBcPatch * patch = nullptr;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03c/Field.cpp b/example/1d-heat-equation/ftcs/cpp/03c/Field.cpp
new file mode 100644
index 00000000..157f362c
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03c/Field.cpp
@@ -0,0 +1,145 @@
+#include "Field.h"
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+
+    std::vector<double> & x = grid->x;
+    this->dx = x[ 1 ] - x[ 0 ];
+    this->dt = dx / 10.0;
+    this->t = 1.0;
+    this->nt = static_cast<int>( t / dt ) + 1;
+    std::cout << "nt = " << nt << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+    std::cout << "alpha = " << std::setprecision( 15 ) << this->alpha << "\n";
+    std::cout << "beta = " << std::setprecision( 15 ) << this->beta << "\n";
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+
+    int ist = 0;
+    int ied = ni - 1;
+
+    // 0(bc) 1(ist) 2 3 ... ni
+
+    //int ist = 0 + 1;
+    //int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u_e[ i ] = - std::exp( -t ) * std::sin( std::numbers::pi * x[i] ); //theory solution
+        un[ i ] = - std::sin( std::numbers::pi * x[ i ] ); //initial condition @ t=0
+    }
+    //un[ ist - 1 ] = 0.0;
+    //un[ ied + 1 ] = 0.0;
+    un[ 0 ] = 0.0;
+    un[ ni - 1 ] = 0.0;
+}
+
+void Field::Solve( Grid * grid )
+{
+    Boundary( grid );
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+    }
+    this->update( un, u );
+}
+
+void Field::Boundary( Grid * grid )
+{
+    this->InterfaceBoundary( grid );
+    this->PhysicalBoundary( grid );
+}
+
+void Field::PhysicalBoundary( Grid * grid )
+{
+    BC * bc = Global::bcs[ grid->zoneIndex ];
+
+    int nBFace = bc->bctypes.size();
+    for ( int i = 0; i < nBFace; ++ i )
+    {
+        int bctype = bc->bctypes[ i ];
+        int faceId = bc->faceids[ i ];
+        if ( bctype == BCInflow )
+        {
+            u[ faceId ] = 0.0;
+        }
+        else if ( bctype == BCOutflow )
+        {
+            u[ faceId ] = 0.0;
+        }
+    }
+}
+
+void Field::InterfaceBoundary( Grid * grid )
+{
+    InterFaceZone * interfacezone = Global::interfacezones[ grid->zoneIndex ];
+    int nInterfaces = interfacezone->left_u.size();
+    for ( int i = 0; i < nInterfaces; ++ i )
+    {
+        double ul = interfacezone->left_u[ i ];
+        double ur = interfacezone->right_u[ i ];
+        double um = 0.5 * ( ul + ur );
+
+        int faceId = interfacezone->face_ids[ i ];
+
+        u[ faceId ] = um;
+        int kkk = 1;
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
+
+void Field::AddData( PointFactory &ptfactory, Grid * grid, std::vector<double> &global_x, std::vector<double> &global_ue, std::vector<double> &global_un )
+{
+    int ni = grid->x.size();
+    for ( int i = 0; i < ni; ++ i )
+    {
+        double xm = grid->x[ i ];
+        bool flag = ptfactory.FindPoint( Point( xm ) );
+        if ( i == 0 || ( i == ni - 1 ) )
+        {
+            if ( ! flag )
+            {
+                ptfactory.AddPoint( Point( xm ) );
+                global_x.push_back( grid->x[ i ] );
+                global_ue.push_back( this->u_e[ i ] );
+                global_un.push_back( this->un[ i ] );
+            }
+        }
+        else
+        {
+            global_x.push_back( grid->x[ i ] );
+            global_ue.push_back( this->u_e[ i ] );
+            global_un.push_back( this->un[ i ] );
+        }
+    }
+}
+
+void Field::update( std::vector<double> &un, std::vector<double> &u )
+{
+    for ( int i = 0; i < u.size(); ++ i )
+    {
+        un[ i ] = u[ i ];
+    }
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03c/Field.h b/example/1d-heat-equation/ftcs/cpp/03c/Field.h
new file mode 100644
index 00000000..d406764c
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03c/Field.h
@@ -0,0 +1,31 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid );
+    void Solve( Grid * grid );
+
+    void Boundary( Grid * grid );
+    void PhysicalBoundary( Grid * grid );
+    void InterfaceBoundary( Grid * grid );
+
+    void PostProcess( Grid * grid );
+    void AddData( PointFactory & ptfactory, Grid * grid, std::vector<double> & global_x, std::vector<double> & global_ue, std::vector<double> & global_un );
+    void update( std::vector<double> & un, std::vector<double> & u );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03c/README.txt b/example/1d-heat-equation/ftcs/cpp/03c/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03c/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/03c/Solver.cpp b/example/1d-heat-equation/ftcs/cpp/03c/Solver.cpp
new file mode 100644
index 00000000..1ad96c33
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03c/Solver.cpp
@@ -0,0 +1,196 @@
+#include "Solver.h"
+#include <fstream>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        //val_max = std::max( val_max, std::abs( u_error[ i ] ) );
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+void DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.16f} {:.16f} {:.16f} {:.16f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    this->InitFields();
+    this->SolveMultiZones();
+    this->PostProcess();
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d2blocksv3.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    int kkk = 1;
+    ReadCgnsGrid( fileName );
+    int nZones = Global::grids.size();
+    PointFactory ptfactory;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        grid->zoneIndex = iZone;
+        int ni = grid->x.size();
+        for ( int i = 0; i < ni; ++ i )
+        {
+            int pid = ptfactory.AddPoint( Point( grid->x[ i ] ) );
+        }
+        int kkk = 1;
+    }
+}
+
+void Solver::InitFields()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = new Field();
+        Global::fields.push_back( field );
+        field->Init( grid );
+    }
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        ExchangeInterfaceValue();
+        int nZones = Global::grids.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Grid * grid = Global::grids[ iZone ];
+            Field * field = Global::fields[ iZone ];
+            field->Solve( grid );
+        }
+    }
+}
+
+void Solver::ExchangeInterfaceValue()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        InterFaceZone * interfacezone = Global::interfacezones[ iZone ];
+        int nInterFace = interfacezone->left_zones.size();
+        interfacezone->left_u.resize( nInterFace );
+        interfacezone->right_u.resize( nInterFace );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        InterFaceZone * interfacezone = Global::interfacezones[ iZone ];
+        int nInterFace = interfacezone->left_zones.size();
+
+        for ( int i = 0; i < nInterFace; ++ i )
+        {
+            int left_cell = interfacezone->left_cells[ i ];
+            int donor_zoneid = interfacezone->right_zones[ i ];
+            int donor_cell = interfacezone->right_cells[ i ];
+            Field * donor_field = Global::fields[ donor_zoneid ];
+
+            interfacezone->left_u[ i ] = field->u[ left_cell ];
+            interfacezone->right_u[ i ] = donor_field->u[ donor_cell ];
+        }
+    }
+}
+
+void Solver::PostProcess()
+{
+    int nZones = Global::grids.size();
+    std::vector<double> u_e;
+    std::vector<double> un;
+    std::vector<double> x;
+
+    PointFactory ptfactory;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->AddData( ptfactory, grid, x, u_e, un );
+    }
+
+    std::cout << " x.size() = " << x.size() << "\n";
+
+    this->PostProcess( x, u_e, un );
+}
+
+void Solver::PostProcess( std::vector<double> &x, std::vector<double> &u_e, std::vector<double> &un )
+{
+    int ni = x.size();
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    ::DumpErrorDetails( u_error );
+
+    std::string csvname = "field_final.csv";
+    ::DumpCsvFile( csvname, x, u_e, un, u_error );
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03c/Solver.h b/example/1d-heat-equation/ftcs/cpp/03c/Solver.h
new file mode 100644
index 00000000..aa90b98a
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03c/Solver.h
@@ -0,0 +1,24 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+void DumpErrorDetails( std::vector<double> & u_error );
+void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+
+class Solver
+{
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void SolveMultiZones();
+    void ExchangeInterfaceValue();
+    void PostProcess();
+    void PostProcess( std::vector<double> & x, std::vector<double> & u_e, std::vector<double> & un );
+    void PrintField( std::vector<double> & f );
+
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03c/global.cpp b/example/1d-heat-equation/ftcs/cpp/03c/global.cpp
new file mode 100644
index 00000000..15b26cf9
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03c/global.cpp
@@ -0,0 +1,16 @@
+#include "global.h"
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+std::vector<BC *> Global::bcs;
+std::vector<InterFaceZone *> Global::interfacezones;
+PointFactory Global::boundary_points;
+FaceList Global::boundary_faces;
+FaceList Global::inter_faces;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03c/global.h b/example/1d-heat-equation/ftcs/cpp/03c/global.h
new file mode 100644
index 00000000..db2d1ad1
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03c/global.h
@@ -0,0 +1,216 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <algorithm>
+#include <string>
+
+class Grid;
+
+class Point
+{
+public:
+    typedef Point point_type;
+    using value_type = double;
+public:
+    Point()
+    {
+        this->x = 0;
+    }
+    Point( const value_type & x )
+    {
+        this->x = x;
+    }
+public:
+    value_type x;
+public:
+    bool operator < ( const Point & rhs ) const
+    {
+        value_type dx = x - rhs.x;
+        value_type diff = 1.0e-10;
+
+        if ( std::abs( dx ) > diff ) return x < rhs.x;
+
+        return false;
+    }
+};
+
+class PointFactory
+{
+public:
+    using value_type = double;
+    using point_type = Point;
+    using iterator = std::map< point_type, int >::iterator;
+protected:
+    std::map< point_type, int > pointList;
+    std::vector<point_type> pointArray;
+public:
+    int GetNPoints() { return pointArray.size(); }
+    bool FindPoint( const point_type & point )
+    {
+        iterator iter = pointList.find( point );
+        if ( iter == pointList.end() )
+        {
+            return false;
+        }
+        return true;
+    }
+private:
+    bool FindPoint( const point_type & point, iterator & iter )
+    {
+        iter = pointList.find( point );
+        if ( iter == pointList.end() )
+        {
+            return false;
+        }
+        return true;
+    }
+public:
+    int AddPoint( const point_type & point )
+    {
+        PointFactory::iterator iter;
+        if ( FindPoint( point, iter ) )
+        {
+            return iter->second;
+        }
+        else
+        {
+            int index = this->GetNPoints();
+
+            pointList.insert( std::make_pair(point, index) );
+            pointArray.push_back( point );
+
+            return index;
+        }
+    }
+};
+
+class Face
+{
+public:
+    std::vector<int> nodes;
+    std::vector<int> sorted_nodes;
+public:
+    void AddFace( std::vector<int> & nodes )
+    {
+        this->nodes = nodes;
+        this->sorted_nodes = nodes;
+        std::sort( this->sorted_nodes.begin(), this->sorted_nodes.end() );
+    }
+    bool operator < ( const Face & rhs ) const
+    {
+        return this->sorted_nodes < rhs.sorted_nodes;
+    } 
+};
+
+class FaceList
+{
+public:
+    std::map<Face, int> face_map;
+public:
+    void AddFace( const Face & face )
+    {
+        std::map<Face, int>::iterator iter;
+        iter = face_map.find( face );
+        if ( iter == face_map.end() )
+        {
+            int id = face_map.size();
+            face_map.insert( std::make_pair( face, id ) );
+        }
+    }
+};
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class BC
+{
+public:
+    std::vector<int> bctypes;
+    std::vector<int> faceids;
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class InterFaceZone
+{
+public:
+    std::vector<int> face_ids;
+    std::vector<int> left_zones;
+    std::vector<int> right_zones;
+    std::vector<int> left_cells;
+    std::vector<int> right_cells;
+    std::vector<double> left_u;
+    std::vector<double> right_u;
+};
+
+
+class Field;
+class BC;
+class InterFaceZone;
+
+class Zone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+    static std::vector<BC *> bcs;
+    static std::vector<InterFaceZone *> interfacezones;
+    static PointFactory boundary_points;
+    static FaceList boundary_faces;
+    static FaceList inter_faces;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/03c/heat1d2blocksv3.cgns b/example/1d-heat-equation/ftcs/cpp/03c/heat1d2blocksv3.cgns
new file mode 100644
index 00000000..1621b92e
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/03c/heat1d2blocksv3.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/03c/main.cpp b/example/1d-heat-equation/ftcs/cpp/03c/main.cpp
new file mode 100644
index 00000000..5ff48a4e
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03c/main.cpp
@@ -0,0 +1,12 @@
+#include "cgnslib.h"
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+#include "Solver.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/03c/plot.py b/example/1d-heat-equation/ftcs/cpp/03c/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03c/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/03c/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/03c/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03c/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/03d/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/03d/CMakeLists.txt
new file mode 100644
index 00000000..ee758c31
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03d/CMakeLists.txt
@@ -0,0 +1,79 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	Solver.h Solver.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/03d/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/03d/CgnsGrid.cpp
new file mode 100644
index 00000000..e186c2f4
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03d/CgnsGrid.cpp
@@ -0,0 +1,578 @@
+#include "CgnsGrid.h"
+#include "cgnslib.h"
+#include "global.h"
+#include <iostream>
+#include <vector>
+
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            Grid * grid = new Grid();
+            Global::grids.push_back( grid );
+
+            BC * bc = new BC();
+            Global::bcs.push_back( bc );
+
+            InterFaceZone * interfacezone = new InterFaceZone();
+            Global::interfacezones.push_back( interfacezone );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                //std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+
+                coor->DumpCoor();
+                if ( icoord == 0 )
+                {
+                    coor->DumpCoorX( grid->x );
+                }
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    Global::boundary_points.AddPoint( grid->x[ pnts[ i ] - 1 ] );
+                }
+
+                if ( index_dim == 1 )
+                {
+                    int p1 = pnts[ 0 ];
+                    double x1 = grid->x[ p1 - 1 ];
+                    int id = Global::boundary_points.AddPoint( x1 );
+                    Face face;
+                    std::vector<int> nodes;
+                    nodes.push_back( id );
+                    face.AddFace( nodes );
+                    Global::boundary_faces.AddFace( face );
+
+                    bc->bctypes.push_back( bocotype );
+                    bc->faceids.push_back( p1 - 1 );
+                }
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    Global::boundary_points.AddPoint( grid->x[ range[ i ] - 1 ] );
+                }
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+                if ( index_dim == 1 )
+                {
+                    int p1 = range[ 0 ];
+                    double x1 = grid->x[ p1 - 1 ];
+                    int id = Global::boundary_points.AddPoint( x1 );
+                    Face face;
+                    std::vector<int> nodes;
+                    nodes.push_back( id );
+                    face.AddFace( nodes );
+                    Global::boundary_faces.AddFace( face );
+                    Global::inter_faces.AddFace( face );
+
+                    bc->bctypes.push_back( BCTypeUserDefined );
+                    bc->faceids.push_back( p1 - 1 );
+
+                    interfacezone->face_ids.push_back( p1 );
+
+                    interfacezone->left_zones.push_back( gZoneId );
+                    interfacezone->left_cells.push_back( p1 - 1 );
+
+                    int q = donor_range[ 0 ];
+                    interfacezone->right_zones.push_back( gDonorZoneId );
+                    interfacezone->right_cells.push_back( q - 1 );
+                }
+            }
+        }
+    }
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03d/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/03d/CgnsGrid.h
new file mode 100644
index 00000000..42633021
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03d/CgnsGrid.h
@@ -0,0 +1,102 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03d/Field.cpp b/example/1d-heat-equation/ftcs/cpp/03d/Field.cpp
new file mode 100644
index 00000000..b4fe1304
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03d/Field.cpp
@@ -0,0 +1,220 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+
+    std::vector<double> & x = grid->x;
+    this->dx = x[ 1 ] - x[ 0 ];
+    this->dt = dx / 10.0;
+    this->t = 1.0;
+    this->nt = static_cast<int>( t / dt ) + 1;
+    std::cout << "nt = " << nt << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+    std::cout << "alpha = " << std::setprecision( 15 ) << this->alpha << "\n";
+    std::cout << "beta = " << std::setprecision( 15 ) << this->beta << "\n";
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+
+    int ist = 1;
+    int ied = ni;
+
+    // 0(bc) 1(ist) 2 3 ... ni
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        u_e[ i ] = - std::exp( -t ) * std::sin( std::numbers::pi * xm ); //theory solution
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+}
+
+void Field::Solve( Grid * grid )
+{
+    Boundary( grid );
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+    }
+    this->Update( un, u );
+}
+
+void Field::Boundary( Grid * grid )
+{
+    this->InterfaceBoundary( grid );
+    this->PhysicalBoundary( grid );
+}
+
+void Field::PhysicalBoundary( Grid * grid )
+{
+    BC * bc = Global::bcs[ grid->zoneIndex ];
+
+    int nBFace = bc->bctypes.size();
+    for ( int i = 0; i < nBFace; ++ i )
+    {
+        int bctype = bc->bctypes[ i ];
+        int faceId = bc->faceids[ i ];
+        if ( bctype == BCInflow )
+        {
+            u[ faceId ] = 0.0;
+        }
+        else if ( bctype == BCOutflow )
+        {
+            u[ faceId ] = 0.0;
+        }
+    }
+}
+
+void Field::InterfaceBoundary( Grid * grid )
+{
+    InterFaceZone * interfacezone = Global::interfacezones[ grid->zoneIndex ];
+    int nInterfaces = interfacezone->left_u.size();
+    for ( int i = 0; i < nInterfaces; ++ i )
+    {
+        double ul = interfacezone->left_u[ i ];
+        double ur = interfacezone->right_u[ i ];
+        double um = 0.5 * ( ul + ur );
+
+        int faceId = interfacezone->face_ids[ i ];
+
+        u[ faceId ] = um;
+        int kkk = 1;
+    }
+}
+
+void Field::Solve( Zone * zone )
+{
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+    }
+
+    this->PhysicalBoundary( zone );
+
+    this->Update( un, u );
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int id = i + 1;
+        if ( i == 1 )
+        {
+            id = i - 1;
+        }
+        this->u[ id ] = 0.0;
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int id = i + 1;
+        if ( i == 1 )
+        {
+            id = i - 1;
+        }
+        this->u[ id ] = 0.0;
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
+
+void Field::AddData( PointFactory &ptfactory, Grid * grid, std::vector<double> &global_x, std::vector<double> &global_ue, std::vector<double> &global_un )
+{
+    int ni = grid->x.size();
+    for ( int i = 0; i < ni; ++ i )
+    {
+        double xm = grid->x[ i ];
+        bool flag = ptfactory.FindPoint( Point( xm ) );
+        if ( i == 0 || ( i == ni - 1 ) )
+        {
+            if ( ! flag )
+            {
+                ptfactory.AddPoint( Point( xm ) );
+                global_x.push_back( grid->x[ i ] );
+                global_ue.push_back( this->u_e[ i ] );
+                global_un.push_back( this->un[ i ] );
+            }
+        }
+        else
+        {
+            global_x.push_back( grid->x[ i ] );
+            global_ue.push_back( this->u_e[ i ] );
+            global_un.push_back( this->un[ i ] );
+        }
+    }
+}
+
+void Field::Update( std::vector<double> &un, std::vector<double> &u )
+{
+    for ( int i = 0; i < u.size(); ++ i )
+    {
+        un[ i ] = u[ i ];
+    }
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03d/Field.h b/example/1d-heat-equation/ftcs/cpp/03d/Field.h
new file mode 100644
index 00000000..83a79354
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03d/Field.h
@@ -0,0 +1,43 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid );
+    void Solve( Grid * grid );
+
+    void Solve( Zone * zone );
+
+    void Boundary( Grid * grid );
+    void PhysicalBoundary( Grid * grid );
+    void InterfaceBoundary( Grid * grid );
+
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void AddData( PointFactory & ptfactory, Grid * grid, std::vector<double> & global_x, std::vector<double> & global_ue, std::vector<double> & global_un );
+    void Update( std::vector<double> & un, std::vector<double> & u );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03d/README.txt b/example/1d-heat-equation/ftcs/cpp/03d/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03d/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/03d/Solver.cpp b/example/1d-heat-equation/ftcs/cpp/03d/Solver.cpp
new file mode 100644
index 00000000..c0373f45
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03d/Solver.cpp
@@ -0,0 +1,451 @@
+#include "Solver.h"
+#include <fstream>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        //val_max = std::max( val_max, std::abs( u_error[ i ] ) );
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+void DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.16f} {:.16f} {:.16f} {:.16f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    this->InitTopo();
+    this->InitFields();
+    this->SolveMultiZones();
+    this->PostProcess();
+    //this->PostProcessNewVersion();
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d2blocksv3.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    ReadCgnsGrid( fileName );
+    int nZones = Global::grids.size();
+    PointFactory ptfactory;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        grid->zoneIndex = iZone;
+        int ni = grid->x.size();
+        for ( int i = 0; i < ni; ++ i )
+        {
+            int pid = ptfactory.AddPoint( Point( grid->x[ i ] ) );
+        }
+        int kkk = 1;
+    }
+}
+
+void Solver::InitTopo()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Interface * interface = new Interface();
+        Global::interfaces.push_back( interface );
+
+        IJK * ijk = new IJK();
+        Global::ijks.push_back( ijk );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+        Interface * interface = Global::interfaces[ iZone ];
+
+        int nbc1to1s = zone->bc1to1s.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+    }
+}
+
+void Solver::InitFields()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+
+    ExchangeInterfaceField();
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        field->Update( field->un, field->u );
+    }
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        ExchangeInterfaceValue();
+        ExchangeInterfaceField();
+        int nZones = Global::grids.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Grid * grid = Global::grids[ iZone ];
+            Field * field = Global::fields[ iZone ];
+            Zone * zone = Global::zones[ iZone ];
+            field->Solve( grid );
+            //field->Solve( zone );
+        }
+    }
+}
+
+void Solver::InitInterfaceField()
+{
+    int nZones = Global::interfaces.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        interface->uList.resize( nInterFaces );
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    int nZones = Global::interfaces.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+            int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+            
+            Field * donor_field = Global::fields[ donor_zoneid ];
+
+            double donor_value = donor_field->u[ i_donor_cell ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::ExchangeInterfaceValue()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        InterFaceZone * interfacezone = Global::interfacezones[ iZone ];
+        int nInterFace = interfacezone->left_zones.size();
+        interfacezone->left_u.resize( nInterFace );
+        interfacezone->right_u.resize( nInterFace );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        InterFaceZone * interfacezone = Global::interfacezones[ iZone ];
+        int nInterFace = interfacezone->left_zones.size();
+
+        for ( int i = 0; i < nInterFace; ++ i )
+        {
+            int left_cell = interfacezone->left_cells[ i ];
+            int donor_zoneid = interfacezone->right_zones[ i ];
+            int donor_cell = interfacezone->right_cells[ i ];
+            Field * donor_field = Global::fields[ donor_zoneid ];
+
+            interfacezone->left_u[ i ] = field->u[ left_cell ];
+            interfacezone->right_u[ i ] = donor_field->u[ donor_cell ];
+        }
+    }
+}
+
+void Solver::PostProcess()
+{
+    int nZones = Global::grids.size();
+    std::vector<double> u_e;
+    std::vector<double> un;
+    std::vector<double> x;
+
+    PointFactory ptfactory;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->AddData( ptfactory, grid, x, u_e, un );
+    }
+
+    std::cout << " x.size() = " << x.size() << "\n";
+
+    this->PostProcess( x, u_e, un );
+}
+
+void Solver::PostProcessNewVersion()
+{
+    Post post;
+    post.Process();
+    //int nZones = Global::grids.size();
+    //std::vector<double> u_e;
+    //std::vector<double> un;
+    //std::vector<double> x;
+
+    //PointFactory ptfactory;
+    //for ( int iZone = 0; iZone < nZones; ++ iZone )
+    //{
+    //    Grid * grid = Global::grids[ iZone ];
+    //    Field * field = Global::fields[ iZone ];
+    //    field->AddData( ptfactory, grid, x, u_e, un );
+    //}
+
+    //std::cout << " x.size() = " << x.size() << "\n";
+
+    //this->PostProcess( x, u_e, un );
+}
+
+void Solver::PostProcess( std::vector<double> &x, std::vector<double> &u_e, std::vector<double> &un )
+{
+    int ni = x.size();
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    ::DumpErrorDetails( u_error );
+
+    std::string csvname = "field_final.csv";
+    ::DumpCsvFile( csvname, x, u_e, un, u_error );
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    int nZones = Global::grids.size();
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        int ni = grid->x.size();
+        double xmin = grid->x[ 0 ];
+        double xmax = grid->x[ 0 ];
+        int imin = 0;
+        int imax = 0;
+        for ( int i = 0; i < ni; ++ i )
+        {
+            if ( xmin > grid->x[ i ] )
+            {
+                xmin = grid->x[ i ];
+                imin = i;
+            }
+            if ( xmax < grid->x[ i ] )
+            {
+                xmax = grid->x[ i ];
+                imax = i;
+            }
+        }
+        xmin_list.push_back( xmin );
+        xmax_list.push_back( xmax );
+    }
+    std::vector<std::pair<double, int>> pairs;
+    int nSize = xmin_list.size();
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        pairs.push_back( std::make_pair( xmin_list[i], i ) );
+    }
+
+    std::sort( pairs.begin(), pairs.end() );
+
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        this->zoneids.push_back( pairs[i].second );
+    }
+
+    int kkk = 1;
+}
+
+void Post::GatherField()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+        Grid * grid = Global::grids[ zoneid ];
+        Field * field = Global::fields[ zoneid ];
+
+        int ni = grid->x.size();
+
+        int ist = 1;
+        int ied = ni;
+
+        int dir = 1;
+        if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+        if ( dir == 1 )
+        {
+            for ( int i = ist; i <= ied; ++ i )
+            {
+                double xm = grid->x[ i - ist ];
+                this->x.push_back( xm );
+                this->u_e.push_back( field->u_e[ i ] );
+                this->un.push_back( field->un[ i ] );
+            }
+        }
+        else
+        {
+            for ( int i = ied; i >= ist; -- i )
+            {
+                double xm = grid->x[ i - ist ];
+                this->x.push_back( xm );
+                this->u_e.push_back( field->u_e[ i ] );
+                this->un.push_back( field->un[ i ] );
+            }
+        }
+    }
+}
+
+void Post::DumpField()
+{
+    int ni_total = this->x.size();
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    ::DumpErrorDetails( u_error );
+
+    std::string csvname = "field_final.csv";
+    ::DumpCsvFile( csvname, x, u_e, un, u_error );
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.16f} {:.16f} {:.16f} {:.16f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03d/Solver.h b/example/1d-heat-equation/ftcs/cpp/03d/Solver.h
new file mode 100644
index 00000000..552774bb
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03d/Solver.h
@@ -0,0 +1,46 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+void DumpErrorDetails( std::vector<double> & u_error );
+void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+
+class Solver
+{
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveMultiZones();
+    void ExchangeInterfaceValue();
+public:
+    void InitInterfaceField();
+    void ExchangeInterfaceField();
+    void PostProcess();
+    void PostProcess( std::vector<double> & x, std::vector<double> & u_e, std::vector<double> & un );
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcessNewVersion();
+};
+
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03d/global.cpp b/example/1d-heat-equation/ftcs/cpp/03d/global.cpp
new file mode 100644
index 00000000..be237bec
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03d/global.cpp
@@ -0,0 +1,59 @@
+#include "global.h"
+#include "CgnsGrid.h"
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+std::vector<BC *> Global::bcs;
+std::vector<InterFaceZone *> Global::interfacezones;
+PointFactory Global::boundary_points;
+FaceList Global::boundary_faces;
+FaceList Global::inter_faces;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *>  Global::interfaces;
+std::vector<IJK *> Global::ijks;
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> &start,  std::vector<int> &end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->faceidList.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        int i_donor = index2[ 0 ];
+
+        int i_ghost_cell = i + 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+
+        int i_donor_cell = i_donor - 1;
+
+        if ( i_donor == 1 )
+        {
+            i_donor_cell = i_donor + 1;
+        }
+
+        this->ijk_donors.push_back( i_donor_cell );
+
+
+        icount ++;
+    }
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03d/global.h b/example/1d-heat-equation/ftcs/cpp/03d/global.h
new file mode 100644
index 00000000..665ba466
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03d/global.h
@@ -0,0 +1,239 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class Point
+{
+public:
+    typedef Point point_type;
+    using value_type = double;
+public:
+    Point()
+    {
+        this->x = 0;
+    }
+    Point( const value_type & x )
+    {
+        this->x = x;
+    }
+public:
+    value_type x;
+public:
+    bool operator < ( const Point & rhs ) const
+    {
+        value_type dx = x - rhs.x;
+        value_type diff = 1.0e-10;
+
+        if ( std::abs( dx ) > diff ) return x < rhs.x;
+
+        return false;
+    }
+};
+
+class PointFactory
+{
+public:
+    using value_type = double;
+    using point_type = Point;
+    using iterator = std::map< point_type, int >::iterator;
+protected:
+    std::map< point_type, int > pointList;
+    std::vector<point_type> pointArray;
+public:
+    int GetNPoints() { return pointArray.size(); }
+    bool FindPoint( const point_type & point )
+    {
+        iterator iter = pointList.find( point );
+        if ( iter == pointList.end() )
+        {
+            return false;
+        }
+        return true;
+    }
+private:
+    bool FindPoint( const point_type & point, iterator & iter )
+    {
+        iter = pointList.find( point );
+        if ( iter == pointList.end() )
+        {
+            return false;
+        }
+        return true;
+    }
+public:
+    int AddPoint( const point_type & point )
+    {
+        PointFactory::iterator iter;
+        if ( FindPoint( point, iter ) )
+        {
+            return iter->second;
+        }
+        else
+        {
+            int index = this->GetNPoints();
+
+            pointList.insert( std::make_pair(point, index) );
+            pointArray.push_back( point );
+
+            return index;
+        }
+    }
+};
+
+class Face
+{
+public:
+    std::vector<int> nodes;
+    std::vector<int> sorted_nodes;
+public:
+    void AddFace( std::vector<int> & nodes )
+    {
+        this->nodes = nodes;
+        this->sorted_nodes = nodes;
+        std::sort( this->sorted_nodes.begin(), this->sorted_nodes.end() );
+    }
+    bool operator < ( const Face & rhs ) const
+    {
+        return this->sorted_nodes < rhs.sorted_nodes;
+    } 
+};
+
+class FaceList
+{
+public:
+    std::map<Face, int> face_map;
+public:
+    void AddFace( const Face & face )
+    {
+        std::map<Face, int>::iterator iter;
+        iter = face_map.find( face );
+        if ( iter == face_map.end() )
+        {
+            int id = face_map.size();
+            face_map.insert( std::make_pair( face, id ) );
+        }
+    }
+};
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class BC
+{
+public:
+    std::vector<int> bctypes;
+    std::vector<int> faceids;
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class InterFaceZone
+{
+public:
+    std::vector<int> face_ids;
+    std::vector<int> left_zones;
+    std::vector<int> right_zones;
+    std::vector<int> left_cells;
+    std::vector<int> right_cells;
+    std::vector<double> left_u;
+    std::vector<double> right_u;
+};
+
+class Transform;
+
+class Interface
+{
+public:
+    std::vector<int> zoneList;
+    std::vector<int> faceidList;
+    std::vector<int> ijkList;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+    std::vector<double> uList;
+public:
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+};
+
+class IJK
+{
+public:
+    std::vector<int> iList;
+    std::vector<int> jList;
+    std::vector<int> kList;
+};
+
+class Field;
+class BC;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+    static std::vector<BC *> bcs;
+    static std::vector<InterFaceZone *> interfacezones;
+    static PointFactory boundary_points;
+    static FaceList boundary_faces;
+    static FaceList inter_faces;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+    static std::vector<IJK *> ijks;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/03d/heat1d2blocksv3.cgns b/example/1d-heat-equation/ftcs/cpp/03d/heat1d2blocksv3.cgns
new file mode 100644
index 00000000..1621b92e
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/03d/heat1d2blocksv3.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/03d/main.cpp b/example/1d-heat-equation/ftcs/cpp/03d/main.cpp
new file mode 100644
index 00000000..5ff48a4e
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03d/main.cpp
@@ -0,0 +1,12 @@
+#include "cgnslib.h"
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+#include "Solver.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/03d/plot.py b/example/1d-heat-equation/ftcs/cpp/03d/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03d/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/03d/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/03d/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03d/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/03e/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/03e/CMakeLists.txt
new file mode 100644
index 00000000..ee758c31
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03e/CMakeLists.txt
@@ -0,0 +1,79 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	Solver.h Solver.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/03e/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/03e/CgnsGrid.cpp
new file mode 100644
index 00000000..e186c2f4
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03e/CgnsGrid.cpp
@@ -0,0 +1,578 @@
+#include "CgnsGrid.h"
+#include "cgnslib.h"
+#include "global.h"
+#include <iostream>
+#include <vector>
+
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            Grid * grid = new Grid();
+            Global::grids.push_back( grid );
+
+            BC * bc = new BC();
+            Global::bcs.push_back( bc );
+
+            InterFaceZone * interfacezone = new InterFaceZone();
+            Global::interfacezones.push_back( interfacezone );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                //std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+
+                coor->DumpCoor();
+                if ( icoord == 0 )
+                {
+                    coor->DumpCoorX( grid->x );
+                }
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    Global::boundary_points.AddPoint( grid->x[ pnts[ i ] - 1 ] );
+                }
+
+                if ( index_dim == 1 )
+                {
+                    int p1 = pnts[ 0 ];
+                    double x1 = grid->x[ p1 - 1 ];
+                    int id = Global::boundary_points.AddPoint( x1 );
+                    Face face;
+                    std::vector<int> nodes;
+                    nodes.push_back( id );
+                    face.AddFace( nodes );
+                    Global::boundary_faces.AddFace( face );
+
+                    bc->bctypes.push_back( bocotype );
+                    bc->faceids.push_back( p1 - 1 );
+                }
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    Global::boundary_points.AddPoint( grid->x[ range[ i ] - 1 ] );
+                }
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+                if ( index_dim == 1 )
+                {
+                    int p1 = range[ 0 ];
+                    double x1 = grid->x[ p1 - 1 ];
+                    int id = Global::boundary_points.AddPoint( x1 );
+                    Face face;
+                    std::vector<int> nodes;
+                    nodes.push_back( id );
+                    face.AddFace( nodes );
+                    Global::boundary_faces.AddFace( face );
+                    Global::inter_faces.AddFace( face );
+
+                    bc->bctypes.push_back( BCTypeUserDefined );
+                    bc->faceids.push_back( p1 - 1 );
+
+                    interfacezone->face_ids.push_back( p1 );
+
+                    interfacezone->left_zones.push_back( gZoneId );
+                    interfacezone->left_cells.push_back( p1 - 1 );
+
+                    int q = donor_range[ 0 ];
+                    interfacezone->right_zones.push_back( gDonorZoneId );
+                    interfacezone->right_cells.push_back( q - 1 );
+                }
+            }
+        }
+    }
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03e/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/03e/CgnsGrid.h
new file mode 100644
index 00000000..42633021
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03e/CgnsGrid.h
@@ -0,0 +1,102 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03e/Field.cpp b/example/1d-heat-equation/ftcs/cpp/03e/Field.cpp
new file mode 100644
index 00000000..a5a2d44e
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03e/Field.cpp
@@ -0,0 +1,171 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+
+    std::vector<double> & x = grid->x;
+    this->dx = x[ 1 ] - x[ 0 ];
+    this->dt = dx / 10.0;
+    this->t = 1.0;
+    this->nt = static_cast<int>( t / dt ) + 1;
+    std::cout << "nt = " << nt << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+    std::cout << "alpha = " << std::setprecision( 15 ) << this->alpha << "\n";
+    std::cout << "beta = " << std::setprecision( 15 ) << this->beta << "\n";
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+
+    int ist = 1;
+    int ied = ni;
+
+    // 0(bc) 1(ist) 2 3 ... ni
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        u_e[ i ] = - std::exp( -t ) * std::sin( std::numbers::pi * xm ); //theory solution
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+}
+
+void Field::Solve( Zone * zone )
+{
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+    }
+
+    this->PhysicalBoundary( zone );
+
+    this->Update( un, u );
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
+
+void Field::AddData( PointFactory &ptfactory, Grid * grid, std::vector<double> &global_x, std::vector<double> &global_ue, std::vector<double> &global_un )
+{
+    int ni = grid->x.size();
+    for ( int i = 0; i < ni; ++ i )
+    {
+        double xm = grid->x[ i ];
+        bool flag = ptfactory.FindPoint( Point( xm ) );
+        if ( i == 0 || ( i == ni - 1 ) )
+        {
+            if ( ! flag )
+            {
+                ptfactory.AddPoint( Point( xm ) );
+                global_x.push_back( grid->x[ i ] );
+                global_ue.push_back( this->u_e[ i ] );
+                global_un.push_back( this->un[ i ] );
+            }
+        }
+        else
+        {
+            global_x.push_back( grid->x[ i ] );
+            global_ue.push_back( this->u_e[ i ] );
+            global_un.push_back( this->un[ i ] );
+        }
+    }
+}
+
+void Field::Update( std::vector<double> &un, std::vector<double> &u )
+{
+    for ( int i = 0; i < u.size(); ++ i )
+    {
+        un[ i ] = u[ i ];
+    }
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03e/Field.h b/example/1d-heat-equation/ftcs/cpp/03e/Field.h
new file mode 100644
index 00000000..fd3c5004
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03e/Field.h
@@ -0,0 +1,37 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid );
+
+    void Solve( Zone * zone );
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void AddData( PointFactory & ptfactory, Grid * grid, std::vector<double> & global_x, std::vector<double> & global_ue, std::vector<double> & global_un );
+    void Update( std::vector<double> & un, std::vector<double> & u );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03e/README.txt b/example/1d-heat-equation/ftcs/cpp/03e/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03e/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/03e/Solver.cpp b/example/1d-heat-equation/ftcs/cpp/03e/Solver.cpp
new file mode 100644
index 00000000..a9cc0764
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03e/Solver.cpp
@@ -0,0 +1,386 @@
+#include "Solver.h"
+#include <fstream>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        //val_max = std::max( val_max, std::abs( u_error[ i ] ) );
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+void DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.16f} {:.16f} {:.16f} {:.16f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    this->InitTopo();
+    this->InitFields();
+    this->SolveMultiZones();
+    this->PostProcessNewVersion();
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d2blocksv3.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    ReadCgnsGrid( fileName );
+    int nZones = Global::grids.size();
+    PointFactory ptfactory;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        grid->zoneIndex = iZone;
+        int ni = grid->x.size();
+        for ( int i = 0; i < ni; ++ i )
+        {
+            int pid = ptfactory.AddPoint( Point( grid->x[ i ] ) );
+        }
+        int kkk = 1;
+    }
+}
+
+void Solver::InitTopo()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Interface * interface = new Interface();
+        Global::interfaces.push_back( interface );
+
+        IJK * ijk = new IJK();
+        Global::ijks.push_back( ijk );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+        Interface * interface = Global::interfaces[ iZone ];
+
+        int nbc1to1s = zone->bc1to1s.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+    }
+}
+
+void Solver::InitFields()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+
+    ExchangeInterfaceField();
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        field->Update( field->un, field->u );
+    }
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        ExchangeInterfaceField();
+        int nZones = Global::grids.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Grid * grid = Global::grids[ iZone ];
+            Field * field = Global::fields[ iZone ];
+            Zone * zone = Global::zones[ iZone ];
+            field->Solve( zone );
+        }
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    int nZones = Global::interfaces.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+            int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+            
+            Field * donor_field = Global::fields[ donor_zoneid ];
+
+            double donor_value = donor_field->u[ i_donor_cell ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::ExchangeInterfaceValue()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        InterFaceZone * interfacezone = Global::interfacezones[ iZone ];
+        int nInterFace = interfacezone->left_zones.size();
+        interfacezone->left_u.resize( nInterFace );
+        interfacezone->right_u.resize( nInterFace );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        InterFaceZone * interfacezone = Global::interfacezones[ iZone ];
+        int nInterFace = interfacezone->left_zones.size();
+
+        for ( int i = 0; i < nInterFace; ++ i )
+        {
+            int left_cell = interfacezone->left_cells[ i ];
+            int donor_zoneid = interfacezone->right_zones[ i ];
+            int donor_cell = interfacezone->right_cells[ i ];
+            Field * donor_field = Global::fields[ donor_zoneid ];
+
+            interfacezone->left_u[ i ] = field->u[ left_cell ];
+            interfacezone->right_u[ i ] = donor_field->u[ donor_cell ];
+        }
+    }
+}
+
+void Solver::PostProcessNewVersion()
+{
+    Post post;
+    post.Process();
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    int nZones = Global::grids.size();
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        int ni = grid->x.size();
+        double xmin = grid->x[ 0 ];
+        double xmax = grid->x[ 0 ];
+        int imin = 0;
+        int imax = 0;
+        for ( int i = 0; i < ni; ++ i )
+        {
+            if ( xmin > grid->x[ i ] )
+            {
+                xmin = grid->x[ i ];
+                imin = i;
+            }
+            if ( xmax < grid->x[ i ] )
+            {
+                xmax = grid->x[ i ];
+                imax = i;
+            }
+        }
+        xmin_list.push_back( xmin );
+        xmax_list.push_back( xmax );
+    }
+    std::vector<std::pair<double, int>> pairs;
+    int nSize = xmin_list.size();
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        pairs.push_back( std::make_pair( xmin_list[i], i ) );
+    }
+
+    std::sort( pairs.begin(), pairs.end() );
+
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        this->zoneids.push_back( pairs[i].second );
+    }
+
+    int kkk = 1;
+}
+
+void Post::GatherField()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+        Grid * grid = Global::grids[ zoneid ];
+        Field * field = Global::fields[ zoneid ];
+
+        int ni = grid->x.size();
+
+        int ist = 1;
+        int ied = ni;
+
+        int dir = 1;
+        if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+        if ( dir == 1 )
+        {
+            for ( int i = ist; i <= ied; ++ i )
+            {
+                double xm = grid->x[ i - ist ];
+                this->x.push_back( xm );
+                this->u_e.push_back( field->u_e[ i ] );
+                this->un.push_back( field->un[ i ] );
+            }
+        }
+        else
+        {
+            for ( int i = ied; i >= ist; -- i )
+            {
+                double xm = grid->x[ i - ist ];
+                this->x.push_back( xm );
+                this->u_e.push_back( field->u_e[ i ] );
+                this->un.push_back( field->un[ i ] );
+            }
+        }
+    }
+}
+
+void Post::DumpField()
+{
+    int ni_total = this->x.size();
+    std::cout << " DumpField x.size() = " << x.size() << "\n";
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    ::DumpErrorDetails( u_error );
+
+    std::string csvname = "field_final.csv";
+    ::DumpCsvFile( csvname, x, u_e, un, u_error );
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.16f} {:.16f} {:.16f} {:.16f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03e/Solver.h b/example/1d-heat-equation/ftcs/cpp/03e/Solver.h
new file mode 100644
index 00000000..b9a668a0
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03e/Solver.h
@@ -0,0 +1,43 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+void DumpErrorDetails( std::vector<double> & u_error );
+void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+
+class Solver
+{
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveMultiZones();
+    void ExchangeInterfaceValue();
+public:
+    void ExchangeInterfaceField();
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcessNewVersion();
+};
+
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03e/global.cpp b/example/1d-heat-equation/ftcs/cpp/03e/global.cpp
new file mode 100644
index 00000000..be237bec
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03e/global.cpp
@@ -0,0 +1,59 @@
+#include "global.h"
+#include "CgnsGrid.h"
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+std::vector<BC *> Global::bcs;
+std::vector<InterFaceZone *> Global::interfacezones;
+PointFactory Global::boundary_points;
+FaceList Global::boundary_faces;
+FaceList Global::inter_faces;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *>  Global::interfaces;
+std::vector<IJK *> Global::ijks;
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> &start,  std::vector<int> &end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->faceidList.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        int i_donor = index2[ 0 ];
+
+        int i_ghost_cell = i + 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+
+        int i_donor_cell = i_donor - 1;
+
+        if ( i_donor == 1 )
+        {
+            i_donor_cell = i_donor + 1;
+        }
+
+        this->ijk_donors.push_back( i_donor_cell );
+
+
+        icount ++;
+    }
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03e/global.h b/example/1d-heat-equation/ftcs/cpp/03e/global.h
new file mode 100644
index 00000000..665ba466
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03e/global.h
@@ -0,0 +1,239 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class Point
+{
+public:
+    typedef Point point_type;
+    using value_type = double;
+public:
+    Point()
+    {
+        this->x = 0;
+    }
+    Point( const value_type & x )
+    {
+        this->x = x;
+    }
+public:
+    value_type x;
+public:
+    bool operator < ( const Point & rhs ) const
+    {
+        value_type dx = x - rhs.x;
+        value_type diff = 1.0e-10;
+
+        if ( std::abs( dx ) > diff ) return x < rhs.x;
+
+        return false;
+    }
+};
+
+class PointFactory
+{
+public:
+    using value_type = double;
+    using point_type = Point;
+    using iterator = std::map< point_type, int >::iterator;
+protected:
+    std::map< point_type, int > pointList;
+    std::vector<point_type> pointArray;
+public:
+    int GetNPoints() { return pointArray.size(); }
+    bool FindPoint( const point_type & point )
+    {
+        iterator iter = pointList.find( point );
+        if ( iter == pointList.end() )
+        {
+            return false;
+        }
+        return true;
+    }
+private:
+    bool FindPoint( const point_type & point, iterator & iter )
+    {
+        iter = pointList.find( point );
+        if ( iter == pointList.end() )
+        {
+            return false;
+        }
+        return true;
+    }
+public:
+    int AddPoint( const point_type & point )
+    {
+        PointFactory::iterator iter;
+        if ( FindPoint( point, iter ) )
+        {
+            return iter->second;
+        }
+        else
+        {
+            int index = this->GetNPoints();
+
+            pointList.insert( std::make_pair(point, index) );
+            pointArray.push_back( point );
+
+            return index;
+        }
+    }
+};
+
+class Face
+{
+public:
+    std::vector<int> nodes;
+    std::vector<int> sorted_nodes;
+public:
+    void AddFace( std::vector<int> & nodes )
+    {
+        this->nodes = nodes;
+        this->sorted_nodes = nodes;
+        std::sort( this->sorted_nodes.begin(), this->sorted_nodes.end() );
+    }
+    bool operator < ( const Face & rhs ) const
+    {
+        return this->sorted_nodes < rhs.sorted_nodes;
+    } 
+};
+
+class FaceList
+{
+public:
+    std::map<Face, int> face_map;
+public:
+    void AddFace( const Face & face )
+    {
+        std::map<Face, int>::iterator iter;
+        iter = face_map.find( face );
+        if ( iter == face_map.end() )
+        {
+            int id = face_map.size();
+            face_map.insert( std::make_pair( face, id ) );
+        }
+    }
+};
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class BC
+{
+public:
+    std::vector<int> bctypes;
+    std::vector<int> faceids;
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class InterFaceZone
+{
+public:
+    std::vector<int> face_ids;
+    std::vector<int> left_zones;
+    std::vector<int> right_zones;
+    std::vector<int> left_cells;
+    std::vector<int> right_cells;
+    std::vector<double> left_u;
+    std::vector<double> right_u;
+};
+
+class Transform;
+
+class Interface
+{
+public:
+    std::vector<int> zoneList;
+    std::vector<int> faceidList;
+    std::vector<int> ijkList;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+    std::vector<double> uList;
+public:
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+};
+
+class IJK
+{
+public:
+    std::vector<int> iList;
+    std::vector<int> jList;
+    std::vector<int> kList;
+};
+
+class Field;
+class BC;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+    static std::vector<BC *> bcs;
+    static std::vector<InterFaceZone *> interfacezones;
+    static PointFactory boundary_points;
+    static FaceList boundary_faces;
+    static FaceList inter_faces;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+    static std::vector<IJK *> ijks;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/03e/heat1d2blocksv3.cgns b/example/1d-heat-equation/ftcs/cpp/03e/heat1d2blocksv3.cgns
new file mode 100644
index 00000000..1621b92e
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/03e/heat1d2blocksv3.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/03e/main.cpp b/example/1d-heat-equation/ftcs/cpp/03e/main.cpp
new file mode 100644
index 00000000..5ff48a4e
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03e/main.cpp
@@ -0,0 +1,12 @@
+#include "cgnslib.h"
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+#include "Solver.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/03e/plot.py b/example/1d-heat-equation/ftcs/cpp/03e/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03e/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/03e/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/03e/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03e/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/03f/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/03f/CMakeLists.txt
new file mode 100644
index 00000000..ee758c31
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03f/CMakeLists.txt
@@ -0,0 +1,79 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	Solver.h Solver.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/03f/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/03f/CgnsGrid.cpp
new file mode 100644
index 00000000..e186c2f4
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03f/CgnsGrid.cpp
@@ -0,0 +1,578 @@
+#include "CgnsGrid.h"
+#include "cgnslib.h"
+#include "global.h"
+#include <iostream>
+#include <vector>
+
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            Grid * grid = new Grid();
+            Global::grids.push_back( grid );
+
+            BC * bc = new BC();
+            Global::bcs.push_back( bc );
+
+            InterFaceZone * interfacezone = new InterFaceZone();
+            Global::interfacezones.push_back( interfacezone );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                //std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+
+                coor->DumpCoor();
+                if ( icoord == 0 )
+                {
+                    coor->DumpCoorX( grid->x );
+                }
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    Global::boundary_points.AddPoint( grid->x[ pnts[ i ] - 1 ] );
+                }
+
+                if ( index_dim == 1 )
+                {
+                    int p1 = pnts[ 0 ];
+                    double x1 = grid->x[ p1 - 1 ];
+                    int id = Global::boundary_points.AddPoint( x1 );
+                    Face face;
+                    std::vector<int> nodes;
+                    nodes.push_back( id );
+                    face.AddFace( nodes );
+                    Global::boundary_faces.AddFace( face );
+
+                    bc->bctypes.push_back( bocotype );
+                    bc->faceids.push_back( p1 - 1 );
+                }
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    Global::boundary_points.AddPoint( grid->x[ range[ i ] - 1 ] );
+                }
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+                if ( index_dim == 1 )
+                {
+                    int p1 = range[ 0 ];
+                    double x1 = grid->x[ p1 - 1 ];
+                    int id = Global::boundary_points.AddPoint( x1 );
+                    Face face;
+                    std::vector<int> nodes;
+                    nodes.push_back( id );
+                    face.AddFace( nodes );
+                    Global::boundary_faces.AddFace( face );
+                    Global::inter_faces.AddFace( face );
+
+                    bc->bctypes.push_back( BCTypeUserDefined );
+                    bc->faceids.push_back( p1 - 1 );
+
+                    interfacezone->face_ids.push_back( p1 );
+
+                    interfacezone->left_zones.push_back( gZoneId );
+                    interfacezone->left_cells.push_back( p1 - 1 );
+
+                    int q = donor_range[ 0 ];
+                    interfacezone->right_zones.push_back( gDonorZoneId );
+                    interfacezone->right_cells.push_back( q - 1 );
+                }
+            }
+        }
+    }
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03f/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/03f/CgnsGrid.h
new file mode 100644
index 00000000..42633021
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03f/CgnsGrid.h
@@ -0,0 +1,102 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03f/Field.cpp b/example/1d-heat-equation/ftcs/cpp/03f/Field.cpp
new file mode 100644
index 00000000..a5a2d44e
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03f/Field.cpp
@@ -0,0 +1,171 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+
+    std::vector<double> & x = grid->x;
+    this->dx = x[ 1 ] - x[ 0 ];
+    this->dt = dx / 10.0;
+    this->t = 1.0;
+    this->nt = static_cast<int>( t / dt ) + 1;
+    std::cout << "nt = " << nt << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+    std::cout << "alpha = " << std::setprecision( 15 ) << this->alpha << "\n";
+    std::cout << "beta = " << std::setprecision( 15 ) << this->beta << "\n";
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+
+    int ist = 1;
+    int ied = ni;
+
+    // 0(bc) 1(ist) 2 3 ... ni
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        u_e[ i ] = - std::exp( -t ) * std::sin( std::numbers::pi * xm ); //theory solution
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+}
+
+void Field::Solve( Zone * zone )
+{
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+    }
+
+    this->PhysicalBoundary( zone );
+
+    this->Update( un, u );
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
+
+void Field::AddData( PointFactory &ptfactory, Grid * grid, std::vector<double> &global_x, std::vector<double> &global_ue, std::vector<double> &global_un )
+{
+    int ni = grid->x.size();
+    for ( int i = 0; i < ni; ++ i )
+    {
+        double xm = grid->x[ i ];
+        bool flag = ptfactory.FindPoint( Point( xm ) );
+        if ( i == 0 || ( i == ni - 1 ) )
+        {
+            if ( ! flag )
+            {
+                ptfactory.AddPoint( Point( xm ) );
+                global_x.push_back( grid->x[ i ] );
+                global_ue.push_back( this->u_e[ i ] );
+                global_un.push_back( this->un[ i ] );
+            }
+        }
+        else
+        {
+            global_x.push_back( grid->x[ i ] );
+            global_ue.push_back( this->u_e[ i ] );
+            global_un.push_back( this->un[ i ] );
+        }
+    }
+}
+
+void Field::Update( std::vector<double> &un, std::vector<double> &u )
+{
+    for ( int i = 0; i < u.size(); ++ i )
+    {
+        un[ i ] = u[ i ];
+    }
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03f/Field.h b/example/1d-heat-equation/ftcs/cpp/03f/Field.h
new file mode 100644
index 00000000..fd3c5004
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03f/Field.h
@@ -0,0 +1,37 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid );
+
+    void Solve( Zone * zone );
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void AddData( PointFactory & ptfactory, Grid * grid, std::vector<double> & global_x, std::vector<double> & global_ue, std::vector<double> & global_un );
+    void Update( std::vector<double> & un, std::vector<double> & u );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03f/README.txt b/example/1d-heat-equation/ftcs/cpp/03f/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03f/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/03f/Solver.cpp b/example/1d-heat-equation/ftcs/cpp/03f/Solver.cpp
new file mode 100644
index 00000000..1c1c4d10
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03f/Solver.cpp
@@ -0,0 +1,383 @@
+#include "Solver.h"
+#include <fstream>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        //val_max = std::max( val_max, std::abs( u_error[ i ] ) );
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    this->InitTopo();
+    this->InitFields();
+    this->SolveMultiZones();
+    this->PostProcessNewVersion();
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d2blocksv3.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    ReadCgnsGrid( fileName );
+    int nZones = Global::grids.size();
+    PointFactory ptfactory;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        grid->zoneIndex = iZone;
+        int ni = grid->x.size();
+        for ( int i = 0; i < ni; ++ i )
+        {
+            int pid = ptfactory.AddPoint( Point( grid->x[ i ] ) );
+        }
+        int kkk = 1;
+    }
+}
+
+void Solver::InitTopo()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Interface * interface = new Interface();
+        Global::interfaces.push_back( interface );
+
+        IJK * ijk = new IJK();
+        Global::ijks.push_back( ijk );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+        Interface * interface = Global::interfaces[ iZone ];
+
+        int nbc1to1s = zone->bc1to1s.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+    }
+}
+
+void Solver::InitFields()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+
+    ExchangeInterfaceField();
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        field->Update( field->un, field->u );
+    }
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        ExchangeInterfaceField();
+        int nZones = Global::grids.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Grid * grid = Global::grids[ iZone ];
+            Field * field = Global::fields[ iZone ];
+            Zone * zone = Global::zones[ iZone ];
+            field->Solve( zone );
+        }
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    int nZones = Global::interfaces.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+            int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+            
+            Field * donor_field = Global::fields[ donor_zoneid ];
+
+            double donor_value = donor_field->u[ i_donor_cell ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::ExchangeInterfaceValue()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        InterFaceZone * interfacezone = Global::interfacezones[ iZone ];
+        int nInterFace = interfacezone->left_zones.size();
+        interfacezone->left_u.resize( nInterFace );
+        interfacezone->right_u.resize( nInterFace );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        InterFaceZone * interfacezone = Global::interfacezones[ iZone ];
+        int nInterFace = interfacezone->left_zones.size();
+
+        for ( int i = 0; i < nInterFace; ++ i )
+        {
+            int left_cell = interfacezone->left_cells[ i ];
+            int donor_zoneid = interfacezone->right_zones[ i ];
+            int donor_cell = interfacezone->right_cells[ i ];
+            Field * donor_field = Global::fields[ donor_zoneid ];
+
+            interfacezone->left_u[ i ] = field->u[ left_cell ];
+            interfacezone->right_u[ i ] = donor_field->u[ donor_cell ];
+        }
+    }
+}
+
+void Solver::PostProcessNewVersion()
+{
+    Post post;
+    post.Process();
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    int nZones = Global::grids.size();
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        int ni = grid->x.size();
+        double xmin = grid->x[ 0 ];
+        double xmax = grid->x[ 0 ];
+        int imin = 0;
+        int imax = 0;
+        for ( int i = 0; i < ni; ++ i )
+        {
+            if ( xmin > grid->x[ i ] )
+            {
+                xmin = grid->x[ i ];
+                imin = i;
+            }
+            if ( xmax < grid->x[ i ] )
+            {
+                xmax = grid->x[ i ];
+                imax = i;
+            }
+        }
+        xmin_list.push_back( xmin );
+        xmax_list.push_back( xmax );
+    }
+    std::vector<std::pair<double, int>> pairs;
+    int nSize = xmin_list.size();
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        pairs.push_back( std::make_pair( xmin_list[i], i ) );
+    }
+
+    std::sort( pairs.begin(), pairs.end() );
+
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        this->zoneids.push_back( pairs[i].second );
+    }
+
+    int kkk = 1;
+}
+
+void Post::GatherField()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+        Grid * grid = Global::grids[ zoneid ];
+        Field * field = Global::fields[ zoneid ];
+
+        int ni = grid->x.size();
+
+        int ist = 1;
+        int ied = ni;
+
+        int dir = 1;
+        if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+        if ( dir == 1 )
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ist; i <= ied; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                }
+
+            }
+            else
+            {
+                for ( int i = ist; i <= ied - 1; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                }
+            }
+        }
+        else
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ied; i >= ist; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                }
+            }
+            for ( int i = ied; i >= ist + 1; -- i )
+            {
+                double xm = grid->x[ i - ist ];
+                this->x.push_back( xm );
+                this->u_e.push_back( field->u_e[ i ] );
+                this->un.push_back( field->un[ i ] );
+            }
+        }
+    }
+}
+
+void Post::DumpField()
+{
+    int ni_total = this->x.size();
+    std::cout << " DumpField x.size() = " << x.size() << "\n";
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    this->DumpErrorDetails( u_error );
+
+    std::string csvname = "field_final.csv";
+    this->DumpCsvFile( csvname, x, u_e, un, u_error );
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.16f} {:.16f} {:.16f} {:.16f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03f/Solver.h b/example/1d-heat-equation/ftcs/cpp/03f/Solver.h
new file mode 100644
index 00000000..a9cf6554
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03f/Solver.h
@@ -0,0 +1,41 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+
+class Solver
+{
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveMultiZones();
+    void ExchangeInterfaceValue();
+public:
+    void ExchangeInterfaceField();
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcessNewVersion();
+};
+
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03f/global.cpp b/example/1d-heat-equation/ftcs/cpp/03f/global.cpp
new file mode 100644
index 00000000..be237bec
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03f/global.cpp
@@ -0,0 +1,59 @@
+#include "global.h"
+#include "CgnsGrid.h"
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+std::vector<BC *> Global::bcs;
+std::vector<InterFaceZone *> Global::interfacezones;
+PointFactory Global::boundary_points;
+FaceList Global::boundary_faces;
+FaceList Global::inter_faces;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *>  Global::interfaces;
+std::vector<IJK *> Global::ijks;
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> &start,  std::vector<int> &end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->faceidList.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        int i_donor = index2[ 0 ];
+
+        int i_ghost_cell = i + 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+
+        int i_donor_cell = i_donor - 1;
+
+        if ( i_donor == 1 )
+        {
+            i_donor_cell = i_donor + 1;
+        }
+
+        this->ijk_donors.push_back( i_donor_cell );
+
+
+        icount ++;
+    }
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03f/global.h b/example/1d-heat-equation/ftcs/cpp/03f/global.h
new file mode 100644
index 00000000..665ba466
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03f/global.h
@@ -0,0 +1,239 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class Point
+{
+public:
+    typedef Point point_type;
+    using value_type = double;
+public:
+    Point()
+    {
+        this->x = 0;
+    }
+    Point( const value_type & x )
+    {
+        this->x = x;
+    }
+public:
+    value_type x;
+public:
+    bool operator < ( const Point & rhs ) const
+    {
+        value_type dx = x - rhs.x;
+        value_type diff = 1.0e-10;
+
+        if ( std::abs( dx ) > diff ) return x < rhs.x;
+
+        return false;
+    }
+};
+
+class PointFactory
+{
+public:
+    using value_type = double;
+    using point_type = Point;
+    using iterator = std::map< point_type, int >::iterator;
+protected:
+    std::map< point_type, int > pointList;
+    std::vector<point_type> pointArray;
+public:
+    int GetNPoints() { return pointArray.size(); }
+    bool FindPoint( const point_type & point )
+    {
+        iterator iter = pointList.find( point );
+        if ( iter == pointList.end() )
+        {
+            return false;
+        }
+        return true;
+    }
+private:
+    bool FindPoint( const point_type & point, iterator & iter )
+    {
+        iter = pointList.find( point );
+        if ( iter == pointList.end() )
+        {
+            return false;
+        }
+        return true;
+    }
+public:
+    int AddPoint( const point_type & point )
+    {
+        PointFactory::iterator iter;
+        if ( FindPoint( point, iter ) )
+        {
+            return iter->second;
+        }
+        else
+        {
+            int index = this->GetNPoints();
+
+            pointList.insert( std::make_pair(point, index) );
+            pointArray.push_back( point );
+
+            return index;
+        }
+    }
+};
+
+class Face
+{
+public:
+    std::vector<int> nodes;
+    std::vector<int> sorted_nodes;
+public:
+    void AddFace( std::vector<int> & nodes )
+    {
+        this->nodes = nodes;
+        this->sorted_nodes = nodes;
+        std::sort( this->sorted_nodes.begin(), this->sorted_nodes.end() );
+    }
+    bool operator < ( const Face & rhs ) const
+    {
+        return this->sorted_nodes < rhs.sorted_nodes;
+    } 
+};
+
+class FaceList
+{
+public:
+    std::map<Face, int> face_map;
+public:
+    void AddFace( const Face & face )
+    {
+        std::map<Face, int>::iterator iter;
+        iter = face_map.find( face );
+        if ( iter == face_map.end() )
+        {
+            int id = face_map.size();
+            face_map.insert( std::make_pair( face, id ) );
+        }
+    }
+};
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class BC
+{
+public:
+    std::vector<int> bctypes;
+    std::vector<int> faceids;
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class InterFaceZone
+{
+public:
+    std::vector<int> face_ids;
+    std::vector<int> left_zones;
+    std::vector<int> right_zones;
+    std::vector<int> left_cells;
+    std::vector<int> right_cells;
+    std::vector<double> left_u;
+    std::vector<double> right_u;
+};
+
+class Transform;
+
+class Interface
+{
+public:
+    std::vector<int> zoneList;
+    std::vector<int> faceidList;
+    std::vector<int> ijkList;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+    std::vector<double> uList;
+public:
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+};
+
+class IJK
+{
+public:
+    std::vector<int> iList;
+    std::vector<int> jList;
+    std::vector<int> kList;
+};
+
+class Field;
+class BC;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+    static std::vector<BC *> bcs;
+    static std::vector<InterFaceZone *> interfacezones;
+    static PointFactory boundary_points;
+    static FaceList boundary_faces;
+    static FaceList inter_faces;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+    static std::vector<IJK *> ijks;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/03f/heat1d2blocksv3.cgns b/example/1d-heat-equation/ftcs/cpp/03f/heat1d2blocksv3.cgns
new file mode 100644
index 00000000..1621b92e
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/03f/heat1d2blocksv3.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/03f/main.cpp b/example/1d-heat-equation/ftcs/cpp/03f/main.cpp
new file mode 100644
index 00000000..5ff48a4e
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03f/main.cpp
@@ -0,0 +1,12 @@
+#include "cgnslib.h"
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+#include "Solver.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/03f/plot.py b/example/1d-heat-equation/ftcs/cpp/03f/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03f/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/03f/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/03f/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03f/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/03g/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/03g/CMakeLists.txt
new file mode 100644
index 00000000..ee758c31
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03g/CMakeLists.txt
@@ -0,0 +1,79 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	Solver.h Solver.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/03g/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/03g/CgnsGrid.cpp
new file mode 100644
index 00000000..e186c2f4
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03g/CgnsGrid.cpp
@@ -0,0 +1,578 @@
+#include "CgnsGrid.h"
+#include "cgnslib.h"
+#include "global.h"
+#include <iostream>
+#include <vector>
+
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            Grid * grid = new Grid();
+            Global::grids.push_back( grid );
+
+            BC * bc = new BC();
+            Global::bcs.push_back( bc );
+
+            InterFaceZone * interfacezone = new InterFaceZone();
+            Global::interfacezones.push_back( interfacezone );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                //std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+
+                coor->DumpCoor();
+                if ( icoord == 0 )
+                {
+                    coor->DumpCoorX( grid->x );
+                }
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    Global::boundary_points.AddPoint( grid->x[ pnts[ i ] - 1 ] );
+                }
+
+                if ( index_dim == 1 )
+                {
+                    int p1 = pnts[ 0 ];
+                    double x1 = grid->x[ p1 - 1 ];
+                    int id = Global::boundary_points.AddPoint( x1 );
+                    Face face;
+                    std::vector<int> nodes;
+                    nodes.push_back( id );
+                    face.AddFace( nodes );
+                    Global::boundary_faces.AddFace( face );
+
+                    bc->bctypes.push_back( bocotype );
+                    bc->faceids.push_back( p1 - 1 );
+                }
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    Global::boundary_points.AddPoint( grid->x[ range[ i ] - 1 ] );
+                }
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+                if ( index_dim == 1 )
+                {
+                    int p1 = range[ 0 ];
+                    double x1 = grid->x[ p1 - 1 ];
+                    int id = Global::boundary_points.AddPoint( x1 );
+                    Face face;
+                    std::vector<int> nodes;
+                    nodes.push_back( id );
+                    face.AddFace( nodes );
+                    Global::boundary_faces.AddFace( face );
+                    Global::inter_faces.AddFace( face );
+
+                    bc->bctypes.push_back( BCTypeUserDefined );
+                    bc->faceids.push_back( p1 - 1 );
+
+                    interfacezone->face_ids.push_back( p1 );
+
+                    interfacezone->left_zones.push_back( gZoneId );
+                    interfacezone->left_cells.push_back( p1 - 1 );
+
+                    int q = donor_range[ 0 ];
+                    interfacezone->right_zones.push_back( gDonorZoneId );
+                    interfacezone->right_cells.push_back( q - 1 );
+                }
+            }
+        }
+    }
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03g/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/03g/CgnsGrid.h
new file mode 100644
index 00000000..42633021
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03g/CgnsGrid.h
@@ -0,0 +1,102 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03g/Field.cpp b/example/1d-heat-equation/ftcs/cpp/03g/Field.cpp
new file mode 100644
index 00000000..af25e484
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03g/Field.cpp
@@ -0,0 +1,173 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+
+    std::vector<double> & x = grid->x;
+    this->dx = x[ 1 ] - x[ 0 ];
+    this->dt = dx / 10.0;
+    this->t = 1.0;
+    this->nt = static_cast<int>( t / dt ) + 1;
+    std::cout << "nt = " << nt << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+    std::cout << "alpha = " << std::setprecision( 15 ) << this->alpha << "\n";
+    std::cout << "beta = " << std::setprecision( 15 ) << this->beta << "\n";
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+
+    int ist = 1;
+    int ied = ni;
+
+    // 0(bc) 1(ist) 2 3 ... ni
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        u_e[ i ] = - std::exp( -t ) * std::sin( std::numbers::pi * xm ); //theory solution
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+}
+
+void Field::Solve( Zone * zone )
+{
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+    }
+
+    this->PhysicalBoundary( zone );
+
+    this->Update( un, u );
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ i ] = 0.0;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ i ] = 0.0;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
+
+void Field::AddData( PointFactory &ptfactory, Grid * grid, std::vector<double> &global_x, std::vector<double> &global_ue, std::vector<double> &global_un )
+{
+    int ni = grid->x.size();
+    for ( int i = 0; i < ni; ++ i )
+    {
+        double xm = grid->x[ i ];
+        bool flag = ptfactory.FindPoint( Point( xm ) );
+        if ( i == 0 || ( i == ni - 1 ) )
+        {
+            if ( ! flag )
+            {
+                ptfactory.AddPoint( Point( xm ) );
+                global_x.push_back( grid->x[ i ] );
+                global_ue.push_back( this->u_e[ i ] );
+                global_un.push_back( this->un[ i ] );
+            }
+        }
+        else
+        {
+            global_x.push_back( grid->x[ i ] );
+            global_ue.push_back( this->u_e[ i ] );
+            global_un.push_back( this->un[ i ] );
+        }
+    }
+}
+
+void Field::Update( std::vector<double> &un, std::vector<double> &u )
+{
+    for ( int i = 0; i < u.size(); ++ i )
+    {
+        un[ i ] = u[ i ];
+    }
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03g/Field.h b/example/1d-heat-equation/ftcs/cpp/03g/Field.h
new file mode 100644
index 00000000..fd3c5004
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03g/Field.h
@@ -0,0 +1,37 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid );
+
+    void Solve( Zone * zone );
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void AddData( PointFactory & ptfactory, Grid * grid, std::vector<double> & global_x, std::vector<double> & global_ue, std::vector<double> & global_un );
+    void Update( std::vector<double> & un, std::vector<double> & u );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03g/README.txt b/example/1d-heat-equation/ftcs/cpp/03g/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03g/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/03g/Solver.cpp b/example/1d-heat-equation/ftcs/cpp/03g/Solver.cpp
new file mode 100644
index 00000000..af074429
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03g/Solver.cpp
@@ -0,0 +1,381 @@
+#include "Solver.h"
+#include <fstream>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    this->InitTopo();
+    this->InitFields();
+    this->SolveMultiZones();
+    this->PostProcess();
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d2blocksv3.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    ReadCgnsGrid( fileName );
+    int nZones = Global::grids.size();
+    PointFactory ptfactory;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        grid->zoneIndex = iZone;
+        int ni = grid->x.size();
+        for ( int i = 0; i < ni; ++ i )
+        {
+            int pid = ptfactory.AddPoint( Point( grid->x[ i ] ) );
+        }
+        int kkk = 1;
+    }
+}
+
+void Solver::InitTopo()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Interface * interface = new Interface();
+        Global::interfaces.push_back( interface );
+
+        IJK * ijk = new IJK();
+        Global::ijks.push_back( ijk );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+        Interface * interface = Global::interfaces[ iZone ];
+
+        int nbc1to1s = zone->bc1to1s.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+    }
+}
+
+void Solver::InitFields()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+
+    ExchangeInterfaceField();
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        field->Update( field->un, field->u );
+    }
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        ExchangeInterfaceField();
+        int nZones = Global::grids.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Field * field = Global::fields[ iZone ];
+            Zone * zone = Global::zones[ iZone ];
+            field->Solve( zone );
+        }
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    int nZones = Global::interfaces.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+            int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+            
+            Field * donor_field = Global::fields[ donor_zoneid ];
+
+            double donor_value = donor_field->u[ i_donor_cell ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::ExchangeInterfaceValue()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        InterFaceZone * interfacezone = Global::interfacezones[ iZone ];
+        int nInterFace = interfacezone->left_zones.size();
+        interfacezone->left_u.resize( nInterFace );
+        interfacezone->right_u.resize( nInterFace );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        InterFaceZone * interfacezone = Global::interfacezones[ iZone ];
+        int nInterFace = interfacezone->left_zones.size();
+
+        for ( int i = 0; i < nInterFace; ++ i )
+        {
+            int left_cell = interfacezone->left_cells[ i ];
+            int donor_zoneid = interfacezone->right_zones[ i ];
+            int donor_cell = interfacezone->right_cells[ i ];
+            Field * donor_field = Global::fields[ donor_zoneid ];
+
+            interfacezone->left_u[ i ] = field->u[ left_cell ];
+            interfacezone->right_u[ i ] = donor_field->u[ donor_cell ];
+        }
+    }
+}
+
+void Solver::PostProcess()
+{
+    Post post;
+    post.Process();
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    int nZones = Global::grids.size();
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        int ni = grid->x.size();
+        double xmin = grid->x[ 0 ];
+        double xmax = grid->x[ 0 ];
+        int imin = 0;
+        int imax = 0;
+        for ( int i = 0; i < ni; ++ i )
+        {
+            if ( xmin > grid->x[ i ] )
+            {
+                xmin = grid->x[ i ];
+                imin = i;
+            }
+            if ( xmax < grid->x[ i ] )
+            {
+                xmax = grid->x[ i ];
+                imax = i;
+            }
+        }
+        xmin_list.push_back( xmin );
+        xmax_list.push_back( xmax );
+    }
+    std::vector<std::pair<double, int>> pairs;
+    int nSize = xmin_list.size();
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        pairs.push_back( std::make_pair( xmin_list[i], i ) );
+    }
+
+    std::sort( pairs.begin(), pairs.end() );
+
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        this->zoneids.push_back( pairs[i].second );
+    }
+
+    int kkk = 1;
+}
+
+void Post::GatherField()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+        Grid * grid = Global::grids[ zoneid ];
+        Field * field = Global::fields[ zoneid ];
+
+        int ni = grid->x.size();
+
+        int ist = 1;
+        int ied = ni;
+
+        int dir = 1;
+        if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+        if ( dir == 1 )
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ist; i <= ied; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                }
+
+            }
+            else
+            {
+                for ( int i = ist; i <= ied - 1; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                }
+            }
+        }
+        else
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ied; i >= ist; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                }
+            }
+            for ( int i = ied; i >= ist + 1; -- i )
+            {
+                double xm = grid->x[ i - ist ];
+                this->x.push_back( xm );
+                this->u_e.push_back( field->u_e[ i ] );
+                this->un.push_back( field->un[ i ] );
+            }
+        }
+    }
+}
+
+void Post::DumpField()
+{
+    int ni_total = this->x.size();
+    std::cout << " DumpField x.size() = " << x.size() << "\n";
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    this->DumpErrorDetails( u_error );
+
+    std::string csvname = "field_final.csv";
+    this->DumpCsvFile( csvname, x, u_e, un, u_error );
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.16f} {:.16f} {:.16f} {:.16f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03g/Solver.h b/example/1d-heat-equation/ftcs/cpp/03g/Solver.h
new file mode 100644
index 00000000..3ce472a7
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03g/Solver.h
@@ -0,0 +1,41 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+
+class Solver
+{
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveMultiZones();
+    void ExchangeInterfaceValue();
+public:
+    void ExchangeInterfaceField();
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcess();
+};
+
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03g/global.cpp b/example/1d-heat-equation/ftcs/cpp/03g/global.cpp
new file mode 100644
index 00000000..be237bec
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03g/global.cpp
@@ -0,0 +1,59 @@
+#include "global.h"
+#include "CgnsGrid.h"
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+std::vector<BC *> Global::bcs;
+std::vector<InterFaceZone *> Global::interfacezones;
+PointFactory Global::boundary_points;
+FaceList Global::boundary_faces;
+FaceList Global::inter_faces;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *>  Global::interfaces;
+std::vector<IJK *> Global::ijks;
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> &start,  std::vector<int> &end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->faceidList.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        int i_donor = index2[ 0 ];
+
+        int i_ghost_cell = i + 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+
+        int i_donor_cell = i_donor - 1;
+
+        if ( i_donor == 1 )
+        {
+            i_donor_cell = i_donor + 1;
+        }
+
+        this->ijk_donors.push_back( i_donor_cell );
+
+
+        icount ++;
+    }
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/03g/global.h b/example/1d-heat-equation/ftcs/cpp/03g/global.h
new file mode 100644
index 00000000..665ba466
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03g/global.h
@@ -0,0 +1,239 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class Point
+{
+public:
+    typedef Point point_type;
+    using value_type = double;
+public:
+    Point()
+    {
+        this->x = 0;
+    }
+    Point( const value_type & x )
+    {
+        this->x = x;
+    }
+public:
+    value_type x;
+public:
+    bool operator < ( const Point & rhs ) const
+    {
+        value_type dx = x - rhs.x;
+        value_type diff = 1.0e-10;
+
+        if ( std::abs( dx ) > diff ) return x < rhs.x;
+
+        return false;
+    }
+};
+
+class PointFactory
+{
+public:
+    using value_type = double;
+    using point_type = Point;
+    using iterator = std::map< point_type, int >::iterator;
+protected:
+    std::map< point_type, int > pointList;
+    std::vector<point_type> pointArray;
+public:
+    int GetNPoints() { return pointArray.size(); }
+    bool FindPoint( const point_type & point )
+    {
+        iterator iter = pointList.find( point );
+        if ( iter == pointList.end() )
+        {
+            return false;
+        }
+        return true;
+    }
+private:
+    bool FindPoint( const point_type & point, iterator & iter )
+    {
+        iter = pointList.find( point );
+        if ( iter == pointList.end() )
+        {
+            return false;
+        }
+        return true;
+    }
+public:
+    int AddPoint( const point_type & point )
+    {
+        PointFactory::iterator iter;
+        if ( FindPoint( point, iter ) )
+        {
+            return iter->second;
+        }
+        else
+        {
+            int index = this->GetNPoints();
+
+            pointList.insert( std::make_pair(point, index) );
+            pointArray.push_back( point );
+
+            return index;
+        }
+    }
+};
+
+class Face
+{
+public:
+    std::vector<int> nodes;
+    std::vector<int> sorted_nodes;
+public:
+    void AddFace( std::vector<int> & nodes )
+    {
+        this->nodes = nodes;
+        this->sorted_nodes = nodes;
+        std::sort( this->sorted_nodes.begin(), this->sorted_nodes.end() );
+    }
+    bool operator < ( const Face & rhs ) const
+    {
+        return this->sorted_nodes < rhs.sorted_nodes;
+    } 
+};
+
+class FaceList
+{
+public:
+    std::map<Face, int> face_map;
+public:
+    void AddFace( const Face & face )
+    {
+        std::map<Face, int>::iterator iter;
+        iter = face_map.find( face );
+        if ( iter == face_map.end() )
+        {
+            int id = face_map.size();
+            face_map.insert( std::make_pair( face, id ) );
+        }
+    }
+};
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class BC
+{
+public:
+    std::vector<int> bctypes;
+    std::vector<int> faceids;
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class InterFaceZone
+{
+public:
+    std::vector<int> face_ids;
+    std::vector<int> left_zones;
+    std::vector<int> right_zones;
+    std::vector<int> left_cells;
+    std::vector<int> right_cells;
+    std::vector<double> left_u;
+    std::vector<double> right_u;
+};
+
+class Transform;
+
+class Interface
+{
+public:
+    std::vector<int> zoneList;
+    std::vector<int> faceidList;
+    std::vector<int> ijkList;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+    std::vector<double> uList;
+public:
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+};
+
+class IJK
+{
+public:
+    std::vector<int> iList;
+    std::vector<int> jList;
+    std::vector<int> kList;
+};
+
+class Field;
+class BC;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+    static std::vector<BC *> bcs;
+    static std::vector<InterFaceZone *> interfacezones;
+    static PointFactory boundary_points;
+    static FaceList boundary_faces;
+    static FaceList inter_faces;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+    static std::vector<IJK *> ijks;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/03g/heat1d2blocksv3.cgns b/example/1d-heat-equation/ftcs/cpp/03g/heat1d2blocksv3.cgns
new file mode 100644
index 00000000..1621b92e
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/03g/heat1d2blocksv3.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/03g/main.cpp b/example/1d-heat-equation/ftcs/cpp/03g/main.cpp
new file mode 100644
index 00000000..5ff48a4e
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03g/main.cpp
@@ -0,0 +1,12 @@
+#include "cgnslib.h"
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+#include "Solver.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/03g/plot.py b/example/1d-heat-equation/ftcs/cpp/03g/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03g/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/03g/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/03g/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/03g/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/01/CMakeLists.txt
new file mode 100644
index 00000000..ee758c31
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01/CMakeLists.txt
@@ -0,0 +1,79 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	Solver.h Solver.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/01/CgnsGrid.cpp
new file mode 100644
index 00000000..e186c2f4
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01/CgnsGrid.cpp
@@ -0,0 +1,578 @@
+#include "CgnsGrid.h"
+#include "cgnslib.h"
+#include "global.h"
+#include <iostream>
+#include <vector>
+
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            Grid * grid = new Grid();
+            Global::grids.push_back( grid );
+
+            BC * bc = new BC();
+            Global::bcs.push_back( bc );
+
+            InterFaceZone * interfacezone = new InterFaceZone();
+            Global::interfacezones.push_back( interfacezone );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                //std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+
+                coor->DumpCoor();
+                if ( icoord == 0 )
+                {
+                    coor->DumpCoorX( grid->x );
+                }
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    Global::boundary_points.AddPoint( grid->x[ pnts[ i ] - 1 ] );
+                }
+
+                if ( index_dim == 1 )
+                {
+                    int p1 = pnts[ 0 ];
+                    double x1 = grid->x[ p1 - 1 ];
+                    int id = Global::boundary_points.AddPoint( x1 );
+                    Face face;
+                    std::vector<int> nodes;
+                    nodes.push_back( id );
+                    face.AddFace( nodes );
+                    Global::boundary_faces.AddFace( face );
+
+                    bc->bctypes.push_back( bocotype );
+                    bc->faceids.push_back( p1 - 1 );
+                }
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    Global::boundary_points.AddPoint( grid->x[ range[ i ] - 1 ] );
+                }
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+                if ( index_dim == 1 )
+                {
+                    int p1 = range[ 0 ];
+                    double x1 = grid->x[ p1 - 1 ];
+                    int id = Global::boundary_points.AddPoint( x1 );
+                    Face face;
+                    std::vector<int> nodes;
+                    nodes.push_back( id );
+                    face.AddFace( nodes );
+                    Global::boundary_faces.AddFace( face );
+                    Global::inter_faces.AddFace( face );
+
+                    bc->bctypes.push_back( BCTypeUserDefined );
+                    bc->faceids.push_back( p1 - 1 );
+
+                    interfacezone->face_ids.push_back( p1 );
+
+                    interfacezone->left_zones.push_back( gZoneId );
+                    interfacezone->left_cells.push_back( p1 - 1 );
+
+                    int q = donor_range[ 0 ];
+                    interfacezone->right_zones.push_back( gDonorZoneId );
+                    interfacezone->right_cells.push_back( q - 1 );
+                }
+            }
+        }
+    }
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/multiblock/01/CgnsGrid.h
new file mode 100644
index 00000000..42633021
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01/CgnsGrid.h
@@ -0,0 +1,102 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01/Field.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/01/Field.cpp
new file mode 100644
index 00000000..c48fc14e
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01/Field.cpp
@@ -0,0 +1,156 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+
+    std::vector<double> & x = grid->x;
+    this->dx = std::abs( x[ 1 ] - x[ 0 ] );
+    this->dt = dx / 10.0;
+    this->t = 1.0;
+    this->nt = std::round( t / dt );
+
+    //this->nt = 1;
+    double total_time = nt * dt;
+
+    std::cout << "this->dt = " << this->dt << "\n";
+    std::cout << "this->t = " << this->t << "\n";
+    std::cout << "this->nt = " << this->nt << "\n";
+    std::cout << "this->ni = " << this->ni << "\n";
+    std::cout << "total_time = " << total_time << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+    std::cout << "alpha = " << std::setprecision( 15 ) << this->alpha << "\n";
+    std::cout << "beta = " << std::setprecision( 15 ) << this->beta << "\n";
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+    int ist = 1;
+    int ied = ni;
+
+    // 0(bc) 1(ist) 2 3 ... ni
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        //u_e[ i ] = - std::exp( -t ) * std::sin( std::numbers::pi * xm ); //theory solution
+        u_e[ i ] = - std::exp( -total_time ) * std::sin( std::numbers::pi * xm ); //theory solution
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+}
+
+void Field::Solve( Zone * zone )
+{
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+    }
+
+    this->PhysicalBoundary( zone );
+
+    this->Update( un, u );
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        //std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        //region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        //this->u[ i ] = 0.0;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+        int kkk = 1;
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        //this->u[ i ] = 0.0;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
+
+void Field::Update( std::vector<double> &un, std::vector<double> &u )
+{
+    for ( int i = 0; i < u.size(); ++ i )
+    {
+        un[ i ] = u[ i ];
+    }
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01/Field.h b/example/1d-heat-equation/ftcs/cpp/multiblock/01/Field.h
new file mode 100644
index 00000000..0645e99d
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01/Field.h
@@ -0,0 +1,36 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid );
+
+    void Solve( Zone * zone );
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void Update( std::vector<double> & un, std::vector<double> & u );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01/README.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/01/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01/Solver.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/01/Solver.cpp
new file mode 100644
index 00000000..aa9703cc
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01/Solver.cpp
@@ -0,0 +1,372 @@
+#include "Solver.h"
+#include <fstream>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    this->InitTopo();
+    this->InitFields();
+    this->SolveMultiZones();
+    this->PostProcess();
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d2blocksv3.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    ReadCgnsGrid( fileName );
+    int nZones = Global::grids.size();
+    PointFactory ptfactory;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        grid->zoneIndex = iZone;
+        int ni = grid->x.size();
+        for ( int i = 0; i < ni; ++ i )
+        {
+            int pid = ptfactory.AddPoint( Point( grid->x[ i ] ) );
+        }
+        int kkk = 1;
+    }
+}
+
+void Solver::InitTopo()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Interface * interface = new Interface();
+        Global::interfaces.push_back( interface );
+
+        IJK * ijk = new IJK();
+        Global::ijks.push_back( ijk );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+        Interface * interface = Global::interfaces[ iZone ];
+
+        int nbc1to1s = zone->bc1to1s.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+    }
+}
+
+void Solver::InitFields()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+
+    ExchangeInterfaceField();
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        field->Update( field->un, field->u );
+    }
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        ExchangeInterfaceField();
+        int nZones = Global::grids.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Field * field = Global::fields[ iZone ];
+            Zone * zone = Global::zones[ iZone ];
+            field->Solve( zone );
+        }
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    int nZones = Global::interfaces.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+            int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+            
+            Field * donor_field = Global::fields[ donor_zoneid ];
+
+            double donor_value = donor_field->u[ i_donor_cell ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::PostProcess()
+{
+    Post post;
+    post.Process();
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    int nZones = Global::grids.size();
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        int ni = grid->x.size();
+        double xmin = grid->x[ 0 ];
+        double xmax = grid->x[ 0 ];
+        int imin = 0;
+        int imax = 0;
+        for ( int i = 0; i < ni; ++ i )
+        {
+            if ( xmin > grid->x[ i ] )
+            {
+                xmin = grid->x[ i ];
+                imin = i;
+            }
+            if ( xmax < grid->x[ i ] )
+            {
+                xmax = grid->x[ i ];
+                imax = i;
+            }
+        }
+        xmin_list.push_back( xmin );
+        xmax_list.push_back( xmax );
+    }
+    std::vector<std::pair<double, int>> pairs;
+    int nSize = xmin_list.size();
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        pairs.push_back( std::make_pair( xmin_list[i], i ) );
+    }
+
+    std::sort( pairs.begin(), pairs.end() );
+
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        this->zoneids.push_back( pairs[i].second );
+    }
+
+    int kkk = 1;
+}
+
+void Post::GatherField()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+        Grid * grid = Global::grids[ zoneid ];
+        Field * field = Global::fields[ zoneid ];
+
+        int ni = grid->x.size();
+
+        int ist = 1;
+        int ied = ni;
+
+        int dir = 1;
+        if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+        if ( dir == 1 )
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ist; i <= ied; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+
+            }
+            else
+            {
+                for ( int i = ist; i <= ied - 1; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+        else
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ied; i >= ist; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+            else
+            {
+                for ( int i = ied; i >= ist + 1; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+    }
+}
+
+void Post::DumpField()
+{
+    int ni_total = this->x.size();
+    std::cout << " DumpField x.size() = " << x.size() << "\n";
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    this->DumpErrorDetails( u_error );
+
+    std::string csvname = "field_final.csv";
+    this->DumpCsvFile( csvname, x, u_e, un, u_error );
+    //this->DumpCsvFile( csvname, x, u_e, un, u, u_error );
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        //std::format_to(std::ostream_iterator<char>(file), "{:.16f} {:.16f} {:.16f} {:.16f}\n", x[i], ue[i], un[i], uerror[i] );
+        std::format_to(std::ostream_iterator<char>(file), "{:.20f} {:.20f} {:.20f} {:.20f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &u, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un u uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        //std::format_to(std::ostream_iterator<char>(file), "{:.16f} {:.16f} {:.16f} {:.16f}\n", x[i], ue[i], un[i], uerror[i] );
+        std::format_to(std::ostream_iterator<char>(file), "{:.20f} {:.20f} {:.20f} {:.20f} {:.20f}\n", x[i], ue[i], un[i], u[i], uerror[i] );
+    }
+    file.close();
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01/Solver.h b/example/1d-heat-equation/ftcs/cpp/multiblock/01/Solver.h
new file mode 100644
index 00000000..a0d8ad69
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01/Solver.h
@@ -0,0 +1,42 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+
+class Solver
+{
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveMultiZones();
+public:
+    void ExchangeInterfaceField();
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcess();
+};
+
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+    std::vector<double> u;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & u, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01/global.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/01/global.cpp
new file mode 100644
index 00000000..be237bec
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01/global.cpp
@@ -0,0 +1,59 @@
+#include "global.h"
+#include "CgnsGrid.h"
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+std::vector<BC *> Global::bcs;
+std::vector<InterFaceZone *> Global::interfacezones;
+PointFactory Global::boundary_points;
+FaceList Global::boundary_faces;
+FaceList Global::inter_faces;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *>  Global::interfaces;
+std::vector<IJK *> Global::ijks;
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> &start,  std::vector<int> &end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->faceidList.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        int i_donor = index2[ 0 ];
+
+        int i_ghost_cell = i + 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+
+        int i_donor_cell = i_donor - 1;
+
+        if ( i_donor == 1 )
+        {
+            i_donor_cell = i_donor + 1;
+        }
+
+        this->ijk_donors.push_back( i_donor_cell );
+
+
+        icount ++;
+    }
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01/global.h b/example/1d-heat-equation/ftcs/cpp/multiblock/01/global.h
new file mode 100644
index 00000000..665ba466
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01/global.h
@@ -0,0 +1,239 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class Point
+{
+public:
+    typedef Point point_type;
+    using value_type = double;
+public:
+    Point()
+    {
+        this->x = 0;
+    }
+    Point( const value_type & x )
+    {
+        this->x = x;
+    }
+public:
+    value_type x;
+public:
+    bool operator < ( const Point & rhs ) const
+    {
+        value_type dx = x - rhs.x;
+        value_type diff = 1.0e-10;
+
+        if ( std::abs( dx ) > diff ) return x < rhs.x;
+
+        return false;
+    }
+};
+
+class PointFactory
+{
+public:
+    using value_type = double;
+    using point_type = Point;
+    using iterator = std::map< point_type, int >::iterator;
+protected:
+    std::map< point_type, int > pointList;
+    std::vector<point_type> pointArray;
+public:
+    int GetNPoints() { return pointArray.size(); }
+    bool FindPoint( const point_type & point )
+    {
+        iterator iter = pointList.find( point );
+        if ( iter == pointList.end() )
+        {
+            return false;
+        }
+        return true;
+    }
+private:
+    bool FindPoint( const point_type & point, iterator & iter )
+    {
+        iter = pointList.find( point );
+        if ( iter == pointList.end() )
+        {
+            return false;
+        }
+        return true;
+    }
+public:
+    int AddPoint( const point_type & point )
+    {
+        PointFactory::iterator iter;
+        if ( FindPoint( point, iter ) )
+        {
+            return iter->second;
+        }
+        else
+        {
+            int index = this->GetNPoints();
+
+            pointList.insert( std::make_pair(point, index) );
+            pointArray.push_back( point );
+
+            return index;
+        }
+    }
+};
+
+class Face
+{
+public:
+    std::vector<int> nodes;
+    std::vector<int> sorted_nodes;
+public:
+    void AddFace( std::vector<int> & nodes )
+    {
+        this->nodes = nodes;
+        this->sorted_nodes = nodes;
+        std::sort( this->sorted_nodes.begin(), this->sorted_nodes.end() );
+    }
+    bool operator < ( const Face & rhs ) const
+    {
+        return this->sorted_nodes < rhs.sorted_nodes;
+    } 
+};
+
+class FaceList
+{
+public:
+    std::map<Face, int> face_map;
+public:
+    void AddFace( const Face & face )
+    {
+        std::map<Face, int>::iterator iter;
+        iter = face_map.find( face );
+        if ( iter == face_map.end() )
+        {
+            int id = face_map.size();
+            face_map.insert( std::make_pair( face, id ) );
+        }
+    }
+};
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class BC
+{
+public:
+    std::vector<int> bctypes;
+    std::vector<int> faceids;
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class InterFaceZone
+{
+public:
+    std::vector<int> face_ids;
+    std::vector<int> left_zones;
+    std::vector<int> right_zones;
+    std::vector<int> left_cells;
+    std::vector<int> right_cells;
+    std::vector<double> left_u;
+    std::vector<double> right_u;
+};
+
+class Transform;
+
+class Interface
+{
+public:
+    std::vector<int> zoneList;
+    std::vector<int> faceidList;
+    std::vector<int> ijkList;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+    std::vector<double> uList;
+public:
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+};
+
+class IJK
+{
+public:
+    std::vector<int> iList;
+    std::vector<int> jList;
+    std::vector<int> kList;
+};
+
+class Field;
+class BC;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+    static std::vector<BC *> bcs;
+    static std::vector<InterFaceZone *> interfacezones;
+    static PointFactory boundary_points;
+    static FaceList boundary_faces;
+    static FaceList inter_faces;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+    static std::vector<IJK *> ijks;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01/heat1d2blocksv3.cgns b/example/1d-heat-equation/ftcs/cpp/multiblock/01/heat1d2blocksv3.cgns
new file mode 100644
index 00000000..1621b92e
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/multiblock/01/heat1d2blocksv3.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01/main.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/01/main.cpp
new file mode 100644
index 00000000..5ff48a4e
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01/main.cpp
@@ -0,0 +1,12 @@
+#include "cgnslib.h"
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+#include "Solver.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01/plot.py b/example/1d-heat-equation/ftcs/cpp/multiblock/01/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/multiblock/01/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01a/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/01a/CMakeLists.txt
new file mode 100644
index 00000000..ee758c31
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01a/CMakeLists.txt
@@ -0,0 +1,79 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	Solver.h Solver.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01a/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/01a/CgnsGrid.cpp
new file mode 100644
index 00000000..e186c2f4
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01a/CgnsGrid.cpp
@@ -0,0 +1,578 @@
+#include "CgnsGrid.h"
+#include "cgnslib.h"
+#include "global.h"
+#include <iostream>
+#include <vector>
+
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            Grid * grid = new Grid();
+            Global::grids.push_back( grid );
+
+            BC * bc = new BC();
+            Global::bcs.push_back( bc );
+
+            InterFaceZone * interfacezone = new InterFaceZone();
+            Global::interfacezones.push_back( interfacezone );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                //std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+
+                coor->DumpCoor();
+                if ( icoord == 0 )
+                {
+                    coor->DumpCoorX( grid->x );
+                }
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    Global::boundary_points.AddPoint( grid->x[ pnts[ i ] - 1 ] );
+                }
+
+                if ( index_dim == 1 )
+                {
+                    int p1 = pnts[ 0 ];
+                    double x1 = grid->x[ p1 - 1 ];
+                    int id = Global::boundary_points.AddPoint( x1 );
+                    Face face;
+                    std::vector<int> nodes;
+                    nodes.push_back( id );
+                    face.AddFace( nodes );
+                    Global::boundary_faces.AddFace( face );
+
+                    bc->bctypes.push_back( bocotype );
+                    bc->faceids.push_back( p1 - 1 );
+                }
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    Global::boundary_points.AddPoint( grid->x[ range[ i ] - 1 ] );
+                }
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+                if ( index_dim == 1 )
+                {
+                    int p1 = range[ 0 ];
+                    double x1 = grid->x[ p1 - 1 ];
+                    int id = Global::boundary_points.AddPoint( x1 );
+                    Face face;
+                    std::vector<int> nodes;
+                    nodes.push_back( id );
+                    face.AddFace( nodes );
+                    Global::boundary_faces.AddFace( face );
+                    Global::inter_faces.AddFace( face );
+
+                    bc->bctypes.push_back( BCTypeUserDefined );
+                    bc->faceids.push_back( p1 - 1 );
+
+                    interfacezone->face_ids.push_back( p1 );
+
+                    interfacezone->left_zones.push_back( gZoneId );
+                    interfacezone->left_cells.push_back( p1 - 1 );
+
+                    int q = donor_range[ 0 ];
+                    interfacezone->right_zones.push_back( gDonorZoneId );
+                    interfacezone->right_cells.push_back( q - 1 );
+                }
+            }
+        }
+    }
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01a/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/multiblock/01a/CgnsGrid.h
new file mode 100644
index 00000000..42633021
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01a/CgnsGrid.h
@@ -0,0 +1,102 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01a/Field.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/01a/Field.cpp
new file mode 100644
index 00000000..ef15f943
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01a/Field.cpp
@@ -0,0 +1,226 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+int Para::nt = -1;
+double Para::dx = 0;
+double Para::dt = 0;
+double Para::t = 0;
+double Para::alpha = 0;
+double Para::beta = 0;
+
+void Para::Init()
+{
+    Para::dx = 0.025;
+    Para::dt = dx / 10.0;
+    Para::t = 1.0;
+    Para::nt = std::round( t / dt );
+}
+
+void GenGrid( std::vector<double> & gx );
+void GenGrid( std::vector<double> & gx )
+{
+    const int ni = 81;
+    gx.resize( ni );
+
+    double x_l = -1.0;
+    double x_r = 1.0;
+
+    double dx = ( x_r - x_l ) / ( ni - 1 );
+
+    for ( int i = 0; i < ni; ++ i )
+    {
+        gx[ i ] = x_l + i * dx;
+    }
+}
+
+void Field::ModifyGrid( Grid * grid )
+{
+    std::vector<double> globalx;
+    GenGrid( globalx );
+
+    this->ni = grid->x.size();
+
+    int ishift = 0;
+
+    if ( grid->zoneIndex == 1 )
+    {
+        ishift = ni - 1;
+    }
+
+    for ( int i = 0; i < ni; ++ i )
+    {
+        grid->x[ i ] = globalx[ i + ishift ];
+    }
+}
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+    this->ModifyGrid( grid );
+
+    std::vector<double> & x = grid->x;
+    //this->dx = std::abs( x[ 1 ] - x[ 0 ] );
+    //this->dt = dx / 10.0;
+    //this->t = 1.0;
+    //this->nt = std::round( t / dt );
+
+    this->dx = Para::dx;
+    this->dt = Para::dt;
+    this->t = Para::t;
+    this->nt = Para::nt;
+
+    double total_time = nt * dt;
+
+    std::cout << "this->dt = " << this->dt << "\n";
+    std::cout << "this->t = " << this->t << "\n";
+    std::cout << "this->nt = " << this->nt << "\n";
+    std::cout << "this->ni = " << this->ni << "\n";
+    std::cout << "total_time = " << std::setprecision( 25 ) << total_time << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+    std::cout << "alpha = " << std::setprecision( 15 ) << this->alpha << "\n";
+    std::cout << "beta = " << std::setprecision( 15 ) << this->beta << "\n";
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+    int ist = 1;
+    int ied = ni;
+
+    // 0(bc) 1(ist) 2 3 ... ni
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        u_e[ i ] = - std::exp( -total_time ) * std::sin( std::numbers::pi * xm ); //theory solution
+        if ( std::abs( xm - 0.2 ) < 1.0e-5 )
+        {
+            double term1 = xm;
+            double term2 = std::sin( std::numbers::pi * xm );
+            double term3 = std::exp( -total_time );
+            double term4 = term2 * term3;
+            std::cout << "this->dx = " << std::setprecision( 25 ) << this->dx << "\n";
+            std::cout << "this->dt = " << std::setprecision( 25 ) << this->dt << "\n";
+            std::cout << "total_time = " << std::setprecision( 25 ) << total_time << "\n";
+            std::cout << "term1 = " << std::setprecision( 25 ) << term1 << "\n";
+            std::cout << "term2 = " << std::setprecision( 25 ) << term2 << "\n";
+            std::cout << "term3 = " << std::setprecision( 25 ) << term3 << "\n";
+            std::cout << "term4 = " << std::setprecision( 25 ) << term4 << "\n";
+        }
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+}
+
+void Field::Solve( Zone * zone )
+{
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+    }
+
+    this->PhysicalBoundary( zone );
+
+    this->Update( un, u );
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        //std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        //region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        //this->u[ i ] = 0.0;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+        int kkk = 1;
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        //this->u[ i ] = 0.0;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
+
+void Field::Update( std::vector<double> &un, std::vector<double> &u )
+{
+    for ( int i = 0; i < u.size(); ++ i )
+    {
+        un[ i ] = u[ i ];
+    }
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01a/Field.h b/example/1d-heat-equation/ftcs/cpp/multiblock/01a/Field.h
new file mode 100644
index 00000000..45c9da82
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01a/Field.h
@@ -0,0 +1,47 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Para
+{
+public:
+    static int nt;
+    static double dx, dt, t;
+    static double alpha, beta;
+public:
+    static void Init();
+};
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void ModifyGrid( Grid * grid );
+    void Init( Grid * grid );
+
+    void Solve( Zone * zone );
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void Update( std::vector<double> & un, std::vector<double> & u );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01a/README.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/01a/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01a/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01a/Solver.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/01a/Solver.cpp
new file mode 100644
index 00000000..8c62b5f7
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01a/Solver.cpp
@@ -0,0 +1,373 @@
+#include "Solver.h"
+#include <fstream>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    this->InitTopo();
+    this->InitFields();
+    this->SolveMultiZones();
+    this->PostProcess();
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d2blocksv3.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    ReadCgnsGrid( fileName );
+    int nZones = Global::grids.size();
+    PointFactory ptfactory;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        grid->zoneIndex = iZone;
+        int ni = grid->x.size();
+        for ( int i = 0; i < ni; ++ i )
+        {
+            int pid = ptfactory.AddPoint( Point( grid->x[ i ] ) );
+        }
+        int kkk = 1;
+    }
+}
+
+void Solver::InitTopo()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Interface * interface = new Interface();
+        Global::interfaces.push_back( interface );
+
+        IJK * ijk = new IJK();
+        Global::ijks.push_back( ijk );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+        Interface * interface = Global::interfaces[ iZone ];
+
+        int nbc1to1s = zone->bc1to1s.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+    }
+}
+
+void Solver::InitFields()
+{
+    Para::Init();
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+
+    ExchangeInterfaceField();
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        field->Update( field->un, field->u );
+    }
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        ExchangeInterfaceField();
+        int nZones = Global::grids.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Field * field = Global::fields[ iZone ];
+            Zone * zone = Global::zones[ iZone ];
+            field->Solve( zone );
+        }
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    int nZones = Global::interfaces.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+            int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+            
+            Field * donor_field = Global::fields[ donor_zoneid ];
+
+            double donor_value = donor_field->u[ i_donor_cell ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::PostProcess()
+{
+    Post post;
+    post.Process();
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    int nZones = Global::grids.size();
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        int ni = grid->x.size();
+        double xmin = grid->x[ 0 ];
+        double xmax = grid->x[ 0 ];
+        int imin = 0;
+        int imax = 0;
+        for ( int i = 0; i < ni; ++ i )
+        {
+            if ( xmin > grid->x[ i ] )
+            {
+                xmin = grid->x[ i ];
+                imin = i;
+            }
+            if ( xmax < grid->x[ i ] )
+            {
+                xmax = grid->x[ i ];
+                imax = i;
+            }
+        }
+        xmin_list.push_back( xmin );
+        xmax_list.push_back( xmax );
+    }
+    std::vector<std::pair<double, int>> pairs;
+    int nSize = xmin_list.size();
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        pairs.push_back( std::make_pair( xmin_list[i], i ) );
+    }
+
+    std::sort( pairs.begin(), pairs.end() );
+
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        this->zoneids.push_back( pairs[i].second );
+    }
+
+    int kkk = 1;
+}
+
+void Post::GatherField()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+        Grid * grid = Global::grids[ zoneid ];
+        Field * field = Global::fields[ zoneid ];
+
+        int ni = grid->x.size();
+
+        int ist = 1;
+        int ied = ni;
+
+        int dir = 1;
+        if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+        if ( dir == 1 )
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ist; i <= ied; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+
+            }
+            else
+            {
+                for ( int i = ist; i <= ied - 1; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+        else
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ied; i >= ist; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+            else
+            {
+                for ( int i = ied; i >= ist + 1; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+    }
+}
+
+void Post::DumpField()
+{
+    int ni_total = this->x.size();
+    std::cout << " DumpField x.size() = " << x.size() << "\n";
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    this->DumpErrorDetails( u_error );
+
+    std::string csvname = "field_final.csv";
+    this->DumpCsvFile( csvname, x, u_e, un, u_error );
+    //this->DumpCsvFile( csvname, x, u_e, un, u, u_error );
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        //std::format_to(std::ostream_iterator<char>(file), "{:.16f} {:.16f} {:.16f} {:.16f}\n", x[i], ue[i], un[i], uerror[i] );
+        std::format_to(std::ostream_iterator<char>(file), "{:.20f} {:.20f} {:.20f} {:.20f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &u, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un u uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        //std::format_to(std::ostream_iterator<char>(file), "{:.16f} {:.16f} {:.16f} {:.16f}\n", x[i], ue[i], un[i], uerror[i] );
+        std::format_to(std::ostream_iterator<char>(file), "{:.20f} {:.20f} {:.20f} {:.20f} {:.20f}\n", x[i], ue[i], un[i], u[i], uerror[i] );
+    }
+    file.close();
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01a/Solver.h b/example/1d-heat-equation/ftcs/cpp/multiblock/01a/Solver.h
new file mode 100644
index 00000000..a0d8ad69
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01a/Solver.h
@@ -0,0 +1,42 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+
+class Solver
+{
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveMultiZones();
+public:
+    void ExchangeInterfaceField();
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcess();
+};
+
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+    std::vector<double> u;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & u, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01a/global.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/01a/global.cpp
new file mode 100644
index 00000000..be237bec
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01a/global.cpp
@@ -0,0 +1,59 @@
+#include "global.h"
+#include "CgnsGrid.h"
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+std::vector<BC *> Global::bcs;
+std::vector<InterFaceZone *> Global::interfacezones;
+PointFactory Global::boundary_points;
+FaceList Global::boundary_faces;
+FaceList Global::inter_faces;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *>  Global::interfaces;
+std::vector<IJK *> Global::ijks;
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> &start,  std::vector<int> &end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->faceidList.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        int i_donor = index2[ 0 ];
+
+        int i_ghost_cell = i + 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+
+        int i_donor_cell = i_donor - 1;
+
+        if ( i_donor == 1 )
+        {
+            i_donor_cell = i_donor + 1;
+        }
+
+        this->ijk_donors.push_back( i_donor_cell );
+
+
+        icount ++;
+    }
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01a/global.h b/example/1d-heat-equation/ftcs/cpp/multiblock/01a/global.h
new file mode 100644
index 00000000..665ba466
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01a/global.h
@@ -0,0 +1,239 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class Point
+{
+public:
+    typedef Point point_type;
+    using value_type = double;
+public:
+    Point()
+    {
+        this->x = 0;
+    }
+    Point( const value_type & x )
+    {
+        this->x = x;
+    }
+public:
+    value_type x;
+public:
+    bool operator < ( const Point & rhs ) const
+    {
+        value_type dx = x - rhs.x;
+        value_type diff = 1.0e-10;
+
+        if ( std::abs( dx ) > diff ) return x < rhs.x;
+
+        return false;
+    }
+};
+
+class PointFactory
+{
+public:
+    using value_type = double;
+    using point_type = Point;
+    using iterator = std::map< point_type, int >::iterator;
+protected:
+    std::map< point_type, int > pointList;
+    std::vector<point_type> pointArray;
+public:
+    int GetNPoints() { return pointArray.size(); }
+    bool FindPoint( const point_type & point )
+    {
+        iterator iter = pointList.find( point );
+        if ( iter == pointList.end() )
+        {
+            return false;
+        }
+        return true;
+    }
+private:
+    bool FindPoint( const point_type & point, iterator & iter )
+    {
+        iter = pointList.find( point );
+        if ( iter == pointList.end() )
+        {
+            return false;
+        }
+        return true;
+    }
+public:
+    int AddPoint( const point_type & point )
+    {
+        PointFactory::iterator iter;
+        if ( FindPoint( point, iter ) )
+        {
+            return iter->second;
+        }
+        else
+        {
+            int index = this->GetNPoints();
+
+            pointList.insert( std::make_pair(point, index) );
+            pointArray.push_back( point );
+
+            return index;
+        }
+    }
+};
+
+class Face
+{
+public:
+    std::vector<int> nodes;
+    std::vector<int> sorted_nodes;
+public:
+    void AddFace( std::vector<int> & nodes )
+    {
+        this->nodes = nodes;
+        this->sorted_nodes = nodes;
+        std::sort( this->sorted_nodes.begin(), this->sorted_nodes.end() );
+    }
+    bool operator < ( const Face & rhs ) const
+    {
+        return this->sorted_nodes < rhs.sorted_nodes;
+    } 
+};
+
+class FaceList
+{
+public:
+    std::map<Face, int> face_map;
+public:
+    void AddFace( const Face & face )
+    {
+        std::map<Face, int>::iterator iter;
+        iter = face_map.find( face );
+        if ( iter == face_map.end() )
+        {
+            int id = face_map.size();
+            face_map.insert( std::make_pair( face, id ) );
+        }
+    }
+};
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class BC
+{
+public:
+    std::vector<int> bctypes;
+    std::vector<int> faceids;
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class InterFaceZone
+{
+public:
+    std::vector<int> face_ids;
+    std::vector<int> left_zones;
+    std::vector<int> right_zones;
+    std::vector<int> left_cells;
+    std::vector<int> right_cells;
+    std::vector<double> left_u;
+    std::vector<double> right_u;
+};
+
+class Transform;
+
+class Interface
+{
+public:
+    std::vector<int> zoneList;
+    std::vector<int> faceidList;
+    std::vector<int> ijkList;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+    std::vector<double> uList;
+public:
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+};
+
+class IJK
+{
+public:
+    std::vector<int> iList;
+    std::vector<int> jList;
+    std::vector<int> kList;
+};
+
+class Field;
+class BC;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+    static std::vector<BC *> bcs;
+    static std::vector<InterFaceZone *> interfacezones;
+    static PointFactory boundary_points;
+    static FaceList boundary_faces;
+    static FaceList inter_faces;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+    static std::vector<IJK *> ijks;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01a/heat1d2blocksv3.cgns b/example/1d-heat-equation/ftcs/cpp/multiblock/01a/heat1d2blocksv3.cgns
new file mode 100644
index 00000000..1621b92e
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/multiblock/01a/heat1d2blocksv3.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01a/main.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/01a/main.cpp
new file mode 100644
index 00000000..5ff48a4e
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01a/main.cpp
@@ -0,0 +1,12 @@
+#include "cgnslib.h"
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+#include "Solver.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01a/plot.py b/example/1d-heat-equation/ftcs/cpp/multiblock/01a/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01a/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01a/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/multiblock/01a/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01a/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01b/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/01b/CMakeLists.txt
new file mode 100644
index 00000000..ee758c31
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01b/CMakeLists.txt
@@ -0,0 +1,79 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	Solver.h Solver.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01b/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/01b/CgnsGrid.cpp
new file mode 100644
index 00000000..e186c2f4
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01b/CgnsGrid.cpp
@@ -0,0 +1,578 @@
+#include "CgnsGrid.h"
+#include "cgnslib.h"
+#include "global.h"
+#include <iostream>
+#include <vector>
+
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            Grid * grid = new Grid();
+            Global::grids.push_back( grid );
+
+            BC * bc = new BC();
+            Global::bcs.push_back( bc );
+
+            InterFaceZone * interfacezone = new InterFaceZone();
+            Global::interfacezones.push_back( interfacezone );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                //std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+
+                coor->DumpCoor();
+                if ( icoord == 0 )
+                {
+                    coor->DumpCoorX( grid->x );
+                }
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    Global::boundary_points.AddPoint( grid->x[ pnts[ i ] - 1 ] );
+                }
+
+                if ( index_dim == 1 )
+                {
+                    int p1 = pnts[ 0 ];
+                    double x1 = grid->x[ p1 - 1 ];
+                    int id = Global::boundary_points.AddPoint( x1 );
+                    Face face;
+                    std::vector<int> nodes;
+                    nodes.push_back( id );
+                    face.AddFace( nodes );
+                    Global::boundary_faces.AddFace( face );
+
+                    bc->bctypes.push_back( bocotype );
+                    bc->faceids.push_back( p1 - 1 );
+                }
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    Global::boundary_points.AddPoint( grid->x[ range[ i ] - 1 ] );
+                }
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+                if ( index_dim == 1 )
+                {
+                    int p1 = range[ 0 ];
+                    double x1 = grid->x[ p1 - 1 ];
+                    int id = Global::boundary_points.AddPoint( x1 );
+                    Face face;
+                    std::vector<int> nodes;
+                    nodes.push_back( id );
+                    face.AddFace( nodes );
+                    Global::boundary_faces.AddFace( face );
+                    Global::inter_faces.AddFace( face );
+
+                    bc->bctypes.push_back( BCTypeUserDefined );
+                    bc->faceids.push_back( p1 - 1 );
+
+                    interfacezone->face_ids.push_back( p1 );
+
+                    interfacezone->left_zones.push_back( gZoneId );
+                    interfacezone->left_cells.push_back( p1 - 1 );
+
+                    int q = donor_range[ 0 ];
+                    interfacezone->right_zones.push_back( gDonorZoneId );
+                    interfacezone->right_cells.push_back( q - 1 );
+                }
+            }
+        }
+    }
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01b/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/multiblock/01b/CgnsGrid.h
new file mode 100644
index 00000000..fddf1db6
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01b/CgnsGrid.h
@@ -0,0 +1,103 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    int zoneIndex;
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01b/Field.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/01b/Field.cpp
new file mode 100644
index 00000000..a4ccd6d0
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01b/Field.cpp
@@ -0,0 +1,256 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+int Para::nt = -1;
+double Para::dx = 0;
+double Para::dt = 0;
+double Para::t = 0;
+double Para::alpha = 0;
+double Para::beta = 0;
+
+void Para::Init()
+{
+    Para::dx = 0.025;
+    Para::dt = dx / 10.0;
+    Para::t = 1.0;
+    Para::nt = std::round( t / dt );
+    //Para::nt = 2;
+    //Para::nt = 1;
+
+}
+
+void GenGrid( std::vector<double> & gx );
+void GenGrid( std::vector<double> & gx )
+{
+    const int ni = 81;
+    gx.resize( ni );
+
+    double x_l = -1.0;
+    double x_r = 1.0;
+
+    double dx = ( x_r - x_l ) / ( ni - 1 );
+
+    for ( int i = 0; i < ni; ++ i )
+    {
+        gx[ i ] = x_l + i * dx;
+    }
+}
+
+void Field::ModifyGrid( Grid * grid )
+{
+    std::vector<double> globalx;
+    GenGrid( globalx );
+
+    this->ni = grid->x.size();
+
+    int ishift = 0;
+
+    if ( grid->zoneIndex == 1 )
+    {
+        ishift = ni - 1;
+    }
+
+    for ( int i = 0; i < ni; ++ i )
+    {
+        grid->x[ i ] = globalx[ i + ishift ];
+    }
+}
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+    this->ModifyGrid( grid );
+
+    std::vector<double> & x = grid->x;
+    //this->dx = std::abs( x[ 1 ] - x[ 0 ] );
+    //this->dt = dx / 10.0;
+    //this->t = 1.0;
+    //this->nt = std::round( t / dt );
+
+    this->dx = Para::dx;
+    this->dt = Para::dt;
+    this->t = Para::t;
+    this->nt = Para::nt;
+
+    double total_time = nt * dt;
+
+    std::cout << "this->dt = " << this->dt << "\n";
+    std::cout << "this->t = " << this->t << "\n";
+    std::cout << "this->nt = " << this->nt << "\n";
+    std::cout << "this->ni = " << this->ni << "\n";
+    std::cout << "total_time = " << std::setprecision( 25 ) << total_time << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+    std::cout << "alpha = " << std::setprecision( 25 ) << this->alpha << "\n";
+    std::cout << "beta = " << std::setprecision( 25 ) << this->beta << "\n";
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+    int ist = 1;
+    int ied = ni;
+
+    // 0(bc) 1(ist) 2 3 ... ni
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        u_e[ i ] = - std::exp( -total_time ) * std::sin( std::numbers::pi * xm ); //theory solution
+        if ( std::abs( xm - 0.2 ) < 1.0e-5 )
+        {
+            double term1 = xm;
+            double term2 = std::sin( std::numbers::pi * xm );
+            double term3 = std::exp( -total_time );
+            double term4 = term2 * term3;
+            std::cout << "this->dx = " << std::setprecision( 25 ) << this->dx << "\n";
+            std::cout << "this->dt = " << std::setprecision( 25 ) << this->dt << "\n";
+            std::cout << "total_time = " << std::setprecision( 25 ) << total_time << "\n";
+            std::cout << "term1 = " << std::setprecision( 25 ) << term1 << "\n";
+            std::cout << "term2 = " << std::setprecision( 25 ) << term2 << "\n";
+            std::cout << "term3 = " << std::setprecision( 25 ) << term3 << "\n";
+            std::cout << "term4 = " << std::setprecision( 25 ) << term4 << "\n";
+        }
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+}
+
+void Field::Solve( Zone * zone )
+{
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double term1 = un[ i - 1 ];
+        double term2 = un[ i ];
+        double term3 = un[ i + 1 ];
+        double term4 = term1 -2.0 * term2 + term3;
+        double term5 = beta * term4;
+        double term6 = term2 + term5;
+        if ( ( zone->zoneIndex == 0 && i== ied ) || 
+             ( zone->zoneIndex == 1 && i== ist ) )
+        {
+            std::cout << "zone->zoneIndex = " << zone->zoneIndex << "\n";
+            std::cout << "term1 = " << std::setprecision( 25 ) << term1 << "\n";
+            std::cout << "term2 = " << std::setprecision( 25 ) << term2 << "\n";
+            std::cout << "term3 = " << std::setprecision( 25 ) << term3 << "\n";
+            std::cout << "term4 = " << std::setprecision( 25 ) << term4 << "\n";
+            std::cout << "term5 = " << std::setprecision( 25 ) << term5 << "\n";
+            std::cout << "term6 = " << std::setprecision( 25 ) << term6 << "\n";
+        }
+
+        //u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+        u[ i ] = term6;
+    }
+
+    //this->PhysicalBoundary( zone );
+
+    //this->Update( un, u );
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        //std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        //region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        //this->u[ i ] = 0.0;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+        int kkk = 1;
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        //this->u[ i ] = 0.0;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
+
+void Field::UpdateOldField()
+{
+    for ( int i = 0; i < this->u.size(); ++ i )
+    {
+        this->un[ i ] = this->u[ i ];
+    }
+}
+
+void Field::Update( std::vector<double> &un, std::vector<double> &u )
+{
+    for ( int i = 0; i < u.size(); ++ i )
+    {
+        un[ i ] = u[ i ];
+    }
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01b/Field.h b/example/1d-heat-equation/ftcs/cpp/multiblock/01b/Field.h
new file mode 100644
index 00000000..756154a3
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01b/Field.h
@@ -0,0 +1,48 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Para
+{
+public:
+    static int nt;
+    static double dx, dt, t;
+    static double alpha, beta;
+public:
+    static void Init();
+};
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void ModifyGrid( Grid * grid );
+    void Init( Grid * grid );
+
+    void Solve( Zone * zone );
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void UpdateOldField();
+    void Update( std::vector<double> & un, std::vector<double> & u );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01b/README.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/01b/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01b/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01b/Solver.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/01b/Solver.cpp
new file mode 100644
index 00000000..d5d054b4
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01b/Solver.cpp
@@ -0,0 +1,398 @@
+#include "Solver.h"
+#include <fstream>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    this->InitTopo();
+    this->InitFields();
+    this->SolveMultiZones();
+    this->PostProcess();
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d2blocksv3.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    ReadCgnsGrid( fileName );
+    int nZones = Global::grids.size();
+    PointFactory ptfactory;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        grid->zoneIndex = iZone;
+        int ni = grid->x.size();
+        for ( int i = 0; i < ni; ++ i )
+        {
+            int pid = ptfactory.AddPoint( Point( grid->x[ i ] ) );
+        }
+        int kkk = 1;
+    }
+}
+
+void Solver::InitTopo()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Interface * interface = new Interface();
+        Global::interfaces.push_back( interface );
+
+        IJK * ijk = new IJK();
+        Global::ijks.push_back( ijk );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+        Interface * interface = Global::interfaces[ iZone ];
+
+        int nbc1to1s = zone->bc1to1s.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+    }
+}
+
+void Solver::InitFields()
+{
+    Para::Init();
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+
+    ExchangeInterfaceField();
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        field->Update( field->un, field->u );
+    }
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        int nZones = Global::grids.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Field * field = Global::fields[ iZone ];
+            Zone * zone = Global::zones[ iZone ];
+            zone->zoneIndex = iZone;
+            field->Solve( zone );
+        }
+        Boundary();
+    }
+}
+
+void Solver::Boundary()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+    ExchangeInterfaceField();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->UpdateOldField();
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    int nZones = Global::interfaces.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+            int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+            
+            Field * donor_field = Global::fields[ donor_zoneid ];
+
+            double donor_value = donor_field->u[ i_donor_cell ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::PostProcess()
+{
+    Post post;
+    post.Process();
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    int nZones = Global::grids.size();
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        int ni = grid->x.size();
+        double xmin = grid->x[ 0 ];
+        double xmax = grid->x[ 0 ];
+        int imin = 0;
+        int imax = 0;
+        for ( int i = 0; i < ni; ++ i )
+        {
+            if ( xmin > grid->x[ i ] )
+            {
+                xmin = grid->x[ i ];
+                imin = i;
+            }
+            if ( xmax < grid->x[ i ] )
+            {
+                xmax = grid->x[ i ];
+                imax = i;
+            }
+        }
+        xmin_list.push_back( xmin );
+        xmax_list.push_back( xmax );
+    }
+    std::vector<std::pair<double, int>> pairs;
+    int nSize = xmin_list.size();
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        pairs.push_back( std::make_pair( xmin_list[i], i ) );
+    }
+
+    std::sort( pairs.begin(), pairs.end() );
+
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        this->zoneids.push_back( pairs[i].second );
+    }
+
+    int kkk = 1;
+}
+
+void Post::GatherField()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+        Grid * grid = Global::grids[ zoneid ];
+        Field * field = Global::fields[ zoneid ];
+
+        int ni = grid->x.size();
+
+        int ist = 1;
+        int ied = ni;
+
+        int dir = 1;
+        if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+        if ( dir == 1 )
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ist; i <= ied; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+
+            }
+            else
+            {
+                for ( int i = ist; i <= ied - 1; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+        else
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ied; i >= ist; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+            else
+            {
+                for ( int i = ied; i >= ist + 1; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+    }
+}
+
+void Post::DumpField()
+{
+    int ni_total = this->x.size();
+    std::cout << " DumpField x.size() = " << x.size() << "\n";
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    this->DumpErrorDetails( u_error );
+
+    //std::string csvname = "field_final.csv";
+    //this->DumpCsvFile( csvname, x, u_e, un, u_error );
+    //std::string csvname_test = "field_final_test.csv";
+    //this->DumpCsvFile( csvname_test, x, u_e, un, u, u_error );
+
+    std::string csvname = "field_final0.csv";
+    this->DumpCsvFile( csvname, x, u_e, un, u_error );
+    std::string csvname_test = "field_final_test0.csv";
+    this->DumpCsvFile( csvname_test, x, u_e, un, u, u_error );
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        //std::format_to(std::ostream_iterator<char>(file), "{:.16f} {:.16f} {:.16f} {:.16f}\n", x[i], ue[i], un[i], uerror[i] );
+        std::format_to(std::ostream_iterator<char>(file), "{:.20f} {:.20f} {:.20f} {:.20f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &u, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un u uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        //std::format_to(std::ostream_iterator<char>(file), "{:.16f} {:.16f} {:.16f} {:.16f}\n", x[i], ue[i], un[i], uerror[i] );
+        std::format_to(std::ostream_iterator<char>(file), "{:.20f} {:.20f} {:.20f} {:.20f} {:.20f}\n", x[i], ue[i], un[i], u[i], uerror[i] );
+    }
+    file.close();
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01b/Solver.h b/example/1d-heat-equation/ftcs/cpp/multiblock/01b/Solver.h
new file mode 100644
index 00000000..6bcc4ef4
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01b/Solver.h
@@ -0,0 +1,43 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+
+class Solver
+{
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveMultiZones();
+public:
+    void Boundary();
+    void ExchangeInterfaceField();
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcess();
+};
+
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+    std::vector<double> u;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & u, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01b/global.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/01b/global.cpp
new file mode 100644
index 00000000..be237bec
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01b/global.cpp
@@ -0,0 +1,59 @@
+#include "global.h"
+#include "CgnsGrid.h"
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+std::vector<BC *> Global::bcs;
+std::vector<InterFaceZone *> Global::interfacezones;
+PointFactory Global::boundary_points;
+FaceList Global::boundary_faces;
+FaceList Global::inter_faces;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *>  Global::interfaces;
+std::vector<IJK *> Global::ijks;
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> &start,  std::vector<int> &end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->faceidList.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        int i_donor = index2[ 0 ];
+
+        int i_ghost_cell = i + 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+
+        int i_donor_cell = i_donor - 1;
+
+        if ( i_donor == 1 )
+        {
+            i_donor_cell = i_donor + 1;
+        }
+
+        this->ijk_donors.push_back( i_donor_cell );
+
+
+        icount ++;
+    }
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01b/global.h b/example/1d-heat-equation/ftcs/cpp/multiblock/01b/global.h
new file mode 100644
index 00000000..665ba466
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01b/global.h
@@ -0,0 +1,239 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class Point
+{
+public:
+    typedef Point point_type;
+    using value_type = double;
+public:
+    Point()
+    {
+        this->x = 0;
+    }
+    Point( const value_type & x )
+    {
+        this->x = x;
+    }
+public:
+    value_type x;
+public:
+    bool operator < ( const Point & rhs ) const
+    {
+        value_type dx = x - rhs.x;
+        value_type diff = 1.0e-10;
+
+        if ( std::abs( dx ) > diff ) return x < rhs.x;
+
+        return false;
+    }
+};
+
+class PointFactory
+{
+public:
+    using value_type = double;
+    using point_type = Point;
+    using iterator = std::map< point_type, int >::iterator;
+protected:
+    std::map< point_type, int > pointList;
+    std::vector<point_type> pointArray;
+public:
+    int GetNPoints() { return pointArray.size(); }
+    bool FindPoint( const point_type & point )
+    {
+        iterator iter = pointList.find( point );
+        if ( iter == pointList.end() )
+        {
+            return false;
+        }
+        return true;
+    }
+private:
+    bool FindPoint( const point_type & point, iterator & iter )
+    {
+        iter = pointList.find( point );
+        if ( iter == pointList.end() )
+        {
+            return false;
+        }
+        return true;
+    }
+public:
+    int AddPoint( const point_type & point )
+    {
+        PointFactory::iterator iter;
+        if ( FindPoint( point, iter ) )
+        {
+            return iter->second;
+        }
+        else
+        {
+            int index = this->GetNPoints();
+
+            pointList.insert( std::make_pair(point, index) );
+            pointArray.push_back( point );
+
+            return index;
+        }
+    }
+};
+
+class Face
+{
+public:
+    std::vector<int> nodes;
+    std::vector<int> sorted_nodes;
+public:
+    void AddFace( std::vector<int> & nodes )
+    {
+        this->nodes = nodes;
+        this->sorted_nodes = nodes;
+        std::sort( this->sorted_nodes.begin(), this->sorted_nodes.end() );
+    }
+    bool operator < ( const Face & rhs ) const
+    {
+        return this->sorted_nodes < rhs.sorted_nodes;
+    } 
+};
+
+class FaceList
+{
+public:
+    std::map<Face, int> face_map;
+public:
+    void AddFace( const Face & face )
+    {
+        std::map<Face, int>::iterator iter;
+        iter = face_map.find( face );
+        if ( iter == face_map.end() )
+        {
+            int id = face_map.size();
+            face_map.insert( std::make_pair( face, id ) );
+        }
+    }
+};
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class BC
+{
+public:
+    std::vector<int> bctypes;
+    std::vector<int> faceids;
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class InterFaceZone
+{
+public:
+    std::vector<int> face_ids;
+    std::vector<int> left_zones;
+    std::vector<int> right_zones;
+    std::vector<int> left_cells;
+    std::vector<int> right_cells;
+    std::vector<double> left_u;
+    std::vector<double> right_u;
+};
+
+class Transform;
+
+class Interface
+{
+public:
+    std::vector<int> zoneList;
+    std::vector<int> faceidList;
+    std::vector<int> ijkList;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+    std::vector<double> uList;
+public:
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+};
+
+class IJK
+{
+public:
+    std::vector<int> iList;
+    std::vector<int> jList;
+    std::vector<int> kList;
+};
+
+class Field;
+class BC;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+    static std::vector<BC *> bcs;
+    static std::vector<InterFaceZone *> interfacezones;
+    static PointFactory boundary_points;
+    static FaceList boundary_faces;
+    static FaceList inter_faces;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+    static std::vector<IJK *> ijks;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01b/heat1d2blocksv3.cgns b/example/1d-heat-equation/ftcs/cpp/multiblock/01b/heat1d2blocksv3.cgns
new file mode 100644
index 00000000..1621b92e
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/multiblock/01b/heat1d2blocksv3.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01b/main.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/01b/main.cpp
new file mode 100644
index 00000000..5ff48a4e
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01b/main.cpp
@@ -0,0 +1,12 @@
+#include "cgnslib.h"
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+#include "Solver.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01b/plot.py b/example/1d-heat-equation/ftcs/cpp/multiblock/01b/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01b/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01b/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/multiblock/01b/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01b/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01c/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/01c/CMakeLists.txt
new file mode 100644
index 00000000..ee758c31
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01c/CMakeLists.txt
@@ -0,0 +1,79 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	Solver.h Solver.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01c/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/01c/CgnsGrid.cpp
new file mode 100644
index 00000000..ef59dfcd
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01c/CgnsGrid.cpp
@@ -0,0 +1,551 @@
+#include "CgnsGrid.h"
+#include "cgnslib.h"
+#include "global.h"
+#include <iostream>
+#include <vector>
+
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            Grid * grid = new Grid();
+            Global::grids.push_back( grid );
+
+            BC * bc = new BC();
+            Global::bcs.push_back( bc );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                //std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+
+                coor->DumpCoor();
+                if ( icoord == 0 )
+                {
+                    coor->DumpCoorX( grid->x );
+                }
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    Global::boundary_points.AddPoint( grid->x[ pnts[ i ] - 1 ] );
+                }
+
+                if ( index_dim == 1 )
+                {
+                    int p1 = pnts[ 0 ];
+                    double x1 = grid->x[ p1 - 1 ];
+                    int id = Global::boundary_points.AddPoint( x1 );
+                    Face face;
+                    std::vector<int> nodes;
+                    nodes.push_back( id );
+                    face.AddFace( nodes );
+                    Global::boundary_faces.AddFace( face );
+
+                    bc->bctypes.push_back( bocotype );
+                    bc->faceids.push_back( p1 - 1 );
+                }
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    Global::boundary_points.AddPoint( grid->x[ range[ i ] - 1 ] );
+                }
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+            }
+        }
+    }
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01c/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/multiblock/01c/CgnsGrid.h
new file mode 100644
index 00000000..fddf1db6
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01c/CgnsGrid.h
@@ -0,0 +1,103 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    int zoneIndex;
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01c/Field.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/01c/Field.cpp
new file mode 100644
index 00000000..d7cbd0d7
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01c/Field.cpp
@@ -0,0 +1,170 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+int Para::nt = -1;
+double Para::dx = 0;
+double Para::dt = 0;
+double Para::t = 0;
+double Para::alpha = 0;
+double Para::beta = 0;
+
+void Para::Init()
+{
+    Para::dx = 0.025;
+    Para::dt = dx / 10.0;
+    Para::t = 1.0;
+    Para::nt = std::round( t / dt );
+}
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+
+    std::vector<double> & x = grid->x;
+    //this->dx = std::abs( x[ 1 ] - x[ 0 ] );
+    //this->dt = dx / 10.0;
+    //this->t = 1.0;
+    //this->nt = std::round( t / dt );
+
+    this->dx = Para::dx;
+    this->dt = Para::dt;
+    this->t = Para::t;
+    this->nt = Para::nt;
+
+    double total_time = nt * dt;
+
+    std::cout << "this->dt = " << this->dt << "\n";
+    std::cout << "this->t = " << this->t << "\n";
+    std::cout << "this->nt = " << this->nt << "\n";
+    std::cout << "this->ni = " << this->ni << "\n";
+    std::cout << "total_time = " << std::setprecision( 25 ) << total_time << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+    std::cout << "alpha = " << std::setprecision( 25 ) << this->alpha << "\n";
+    std::cout << "beta = " << std::setprecision( 25 ) << this->beta << "\n";
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+    int ist = 1;
+    int ied = ni;
+
+    // 0(bc) 1(ist) 2 3 ... ni
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        u_e[ i ] = - std::exp( -total_time ) * std::sin( std::numbers::pi * xm ); //theory solution
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+}
+
+void Field::Solve( Zone * zone )
+{
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+    }
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        //std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        //region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        //this->u[ i ] = 0.0;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+        int kkk = 1;
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        //this->u[ i ] = 0.0;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
+
+void Field::UpdateOldField()
+{
+    for ( int i = 0; i < this->u.size(); ++ i )
+    {
+        this->un[ i ] = this->u[ i ];
+    }
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01c/Field.h b/example/1d-heat-equation/ftcs/cpp/multiblock/01c/Field.h
new file mode 100644
index 00000000..21441ef6
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01c/Field.h
@@ -0,0 +1,46 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Para
+{
+public:
+    static int nt;
+    static double dx, dt, t;
+    static double alpha, beta;
+public:
+    static void Init();
+};
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid );
+
+    void Solve( Zone * zone );
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void UpdateOldField();
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01c/README.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/01c/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01c/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01c/Solver.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/01c/Solver.cpp
new file mode 100644
index 00000000..0b659536
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01c/Solver.cpp
@@ -0,0 +1,353 @@
+#include "Solver.h"
+#include <fstream>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    this->InitTopo();
+    this->InitFields();
+    this->SolveMultiZones();
+    this->PostProcess();
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d2blocksv3.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    ReadCgnsGrid( fileName );
+}
+
+void Solver::InitTopo()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Interface * interface = new Interface();
+        Global::interfaces.push_back( interface );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+        Interface * interface = Global::interfaces[ iZone ];
+
+        int nbc1to1s = zone->bc1to1s.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+    }
+}
+
+void Solver::InitFields()
+{
+    Para::Init();
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+    }
+
+    Boundary();
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        int nZones = Global::grids.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Field * field = Global::fields[ iZone ];
+            Zone * zone = Global::zones[ iZone ];
+            zone->zoneIndex = iZone;
+            field->Solve( zone );
+        }
+        Boundary();
+    }
+}
+
+void Solver::Boundary()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+    ExchangeInterfaceField();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->UpdateOldField();
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    int nZones = Global::interfaces.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+            int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+            
+            Field * donor_field = Global::fields[ donor_zoneid ];
+
+            double donor_value = donor_field->u[ i_donor_cell ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::PostProcess()
+{
+    Post post;
+    post.Process();
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    int nZones = Global::grids.size();
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        int ni = grid->x.size();
+        double xmin = grid->x[ 0 ];
+        double xmax = grid->x[ 0 ];
+        int imin = 0;
+        int imax = 0;
+        for ( int i = 0; i < ni; ++ i )
+        {
+            if ( xmin > grid->x[ i ] )
+            {
+                xmin = grid->x[ i ];
+                imin = i;
+            }
+            if ( xmax < grid->x[ i ] )
+            {
+                xmax = grid->x[ i ];
+                imax = i;
+            }
+        }
+        xmin_list.push_back( xmin );
+        xmax_list.push_back( xmax );
+    }
+    std::vector<std::pair<double, int>> pairs;
+    int nSize = xmin_list.size();
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        pairs.push_back( std::make_pair( xmin_list[i], i ) );
+    }
+
+    std::sort( pairs.begin(), pairs.end() );
+
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        this->zoneids.push_back( pairs[i].second );
+    }
+
+    int kkk = 1;
+}
+
+void Post::GatherField()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+        Grid * grid = Global::grids[ zoneid ];
+        Field * field = Global::fields[ zoneid ];
+
+        int ni = grid->x.size();
+
+        int ist = 1;
+        int ied = ni;
+
+        int dir = 1;
+        if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+        if ( dir == 1 )
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ist; i <= ied; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+
+            }
+            else
+            {
+                for ( int i = ist; i <= ied - 1; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+        else
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ied; i >= ist; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+            else
+            {
+                for ( int i = ied; i >= ist + 1; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+    }
+}
+
+void Post::DumpField()
+{
+    int ni_total = this->x.size();
+    std::cout << " DumpField x.size() = " << x.size() << "\n";
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    this->DumpErrorDetails( u_error );
+
+    std::string csvname = "field_final.csv";
+    this->DumpCsvFile( csvname, x, u_e, un, u_error );
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.20f} {:.20f} {:.20f} {:.20f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01c/Solver.h b/example/1d-heat-equation/ftcs/cpp/multiblock/01c/Solver.h
new file mode 100644
index 00000000..6bcc4ef4
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01c/Solver.h
@@ -0,0 +1,43 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+
+class Solver
+{
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveMultiZones();
+public:
+    void Boundary();
+    void ExchangeInterfaceField();
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcess();
+};
+
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+    std::vector<double> u;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & u, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01c/global.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/01c/global.cpp
new file mode 100644
index 00000000..be237bec
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01c/global.cpp
@@ -0,0 +1,59 @@
+#include "global.h"
+#include "CgnsGrid.h"
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+std::vector<BC *> Global::bcs;
+std::vector<InterFaceZone *> Global::interfacezones;
+PointFactory Global::boundary_points;
+FaceList Global::boundary_faces;
+FaceList Global::inter_faces;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *>  Global::interfaces;
+std::vector<IJK *> Global::ijks;
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> &start,  std::vector<int> &end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->faceidList.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        int i_donor = index2[ 0 ];
+
+        int i_ghost_cell = i + 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+
+        int i_donor_cell = i_donor - 1;
+
+        if ( i_donor == 1 )
+        {
+            i_donor_cell = i_donor + 1;
+        }
+
+        this->ijk_donors.push_back( i_donor_cell );
+
+
+        icount ++;
+    }
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01c/global.h b/example/1d-heat-equation/ftcs/cpp/multiblock/01c/global.h
new file mode 100644
index 00000000..665ba466
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01c/global.h
@@ -0,0 +1,239 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class Point
+{
+public:
+    typedef Point point_type;
+    using value_type = double;
+public:
+    Point()
+    {
+        this->x = 0;
+    }
+    Point( const value_type & x )
+    {
+        this->x = x;
+    }
+public:
+    value_type x;
+public:
+    bool operator < ( const Point & rhs ) const
+    {
+        value_type dx = x - rhs.x;
+        value_type diff = 1.0e-10;
+
+        if ( std::abs( dx ) > diff ) return x < rhs.x;
+
+        return false;
+    }
+};
+
+class PointFactory
+{
+public:
+    using value_type = double;
+    using point_type = Point;
+    using iterator = std::map< point_type, int >::iterator;
+protected:
+    std::map< point_type, int > pointList;
+    std::vector<point_type> pointArray;
+public:
+    int GetNPoints() { return pointArray.size(); }
+    bool FindPoint( const point_type & point )
+    {
+        iterator iter = pointList.find( point );
+        if ( iter == pointList.end() )
+        {
+            return false;
+        }
+        return true;
+    }
+private:
+    bool FindPoint( const point_type & point, iterator & iter )
+    {
+        iter = pointList.find( point );
+        if ( iter == pointList.end() )
+        {
+            return false;
+        }
+        return true;
+    }
+public:
+    int AddPoint( const point_type & point )
+    {
+        PointFactory::iterator iter;
+        if ( FindPoint( point, iter ) )
+        {
+            return iter->second;
+        }
+        else
+        {
+            int index = this->GetNPoints();
+
+            pointList.insert( std::make_pair(point, index) );
+            pointArray.push_back( point );
+
+            return index;
+        }
+    }
+};
+
+class Face
+{
+public:
+    std::vector<int> nodes;
+    std::vector<int> sorted_nodes;
+public:
+    void AddFace( std::vector<int> & nodes )
+    {
+        this->nodes = nodes;
+        this->sorted_nodes = nodes;
+        std::sort( this->sorted_nodes.begin(), this->sorted_nodes.end() );
+    }
+    bool operator < ( const Face & rhs ) const
+    {
+        return this->sorted_nodes < rhs.sorted_nodes;
+    } 
+};
+
+class FaceList
+{
+public:
+    std::map<Face, int> face_map;
+public:
+    void AddFace( const Face & face )
+    {
+        std::map<Face, int>::iterator iter;
+        iter = face_map.find( face );
+        if ( iter == face_map.end() )
+        {
+            int id = face_map.size();
+            face_map.insert( std::make_pair( face, id ) );
+        }
+    }
+};
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class BC
+{
+public:
+    std::vector<int> bctypes;
+    std::vector<int> faceids;
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class InterFaceZone
+{
+public:
+    std::vector<int> face_ids;
+    std::vector<int> left_zones;
+    std::vector<int> right_zones;
+    std::vector<int> left_cells;
+    std::vector<int> right_cells;
+    std::vector<double> left_u;
+    std::vector<double> right_u;
+};
+
+class Transform;
+
+class Interface
+{
+public:
+    std::vector<int> zoneList;
+    std::vector<int> faceidList;
+    std::vector<int> ijkList;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+    std::vector<double> uList;
+public:
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+};
+
+class IJK
+{
+public:
+    std::vector<int> iList;
+    std::vector<int> jList;
+    std::vector<int> kList;
+};
+
+class Field;
+class BC;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+    static std::vector<BC *> bcs;
+    static std::vector<InterFaceZone *> interfacezones;
+    static PointFactory boundary_points;
+    static FaceList boundary_faces;
+    static FaceList inter_faces;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+    static std::vector<IJK *> ijks;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01c/heat1d2blocksv3.cgns b/example/1d-heat-equation/ftcs/cpp/multiblock/01c/heat1d2blocksv3.cgns
new file mode 100644
index 00000000..1621b92e
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/multiblock/01c/heat1d2blocksv3.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01c/main.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/01c/main.cpp
new file mode 100644
index 00000000..5ff48a4e
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01c/main.cpp
@@ -0,0 +1,12 @@
+#include "cgnslib.h"
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+#include "Solver.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01c/plot.py b/example/1d-heat-equation/ftcs/cpp/multiblock/01c/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01c/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01c/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/multiblock/01c/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01c/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01d/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/01d/CMakeLists.txt
new file mode 100644
index 00000000..ee758c31
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01d/CMakeLists.txt
@@ -0,0 +1,79 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	Solver.h Solver.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01d/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/01d/CgnsGrid.cpp
new file mode 100644
index 00000000..14e34203
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01d/CgnsGrid.cpp
@@ -0,0 +1,523 @@
+#include "CgnsGrid.h"
+#include "cgnslib.h"
+#include "global.h"
+#include <iostream>
+#include <vector>
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            Grid * grid = new Grid();
+            Global::grids.push_back( grid );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                //std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+
+                coor->DumpCoor();
+                if ( icoord == 0 )
+                {
+                    coor->DumpCoorX( grid->x );
+                }
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+            }
+        }
+    }
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01d/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/multiblock/01d/CgnsGrid.h
new file mode 100644
index 00000000..fddf1db6
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01d/CgnsGrid.h
@@ -0,0 +1,103 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    int zoneIndex;
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01d/Field.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/01d/Field.cpp
new file mode 100644
index 00000000..d7cbd0d7
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01d/Field.cpp
@@ -0,0 +1,170 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+int Para::nt = -1;
+double Para::dx = 0;
+double Para::dt = 0;
+double Para::t = 0;
+double Para::alpha = 0;
+double Para::beta = 0;
+
+void Para::Init()
+{
+    Para::dx = 0.025;
+    Para::dt = dx / 10.0;
+    Para::t = 1.0;
+    Para::nt = std::round( t / dt );
+}
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+
+    std::vector<double> & x = grid->x;
+    //this->dx = std::abs( x[ 1 ] - x[ 0 ] );
+    //this->dt = dx / 10.0;
+    //this->t = 1.0;
+    //this->nt = std::round( t / dt );
+
+    this->dx = Para::dx;
+    this->dt = Para::dt;
+    this->t = Para::t;
+    this->nt = Para::nt;
+
+    double total_time = nt * dt;
+
+    std::cout << "this->dt = " << this->dt << "\n";
+    std::cout << "this->t = " << this->t << "\n";
+    std::cout << "this->nt = " << this->nt << "\n";
+    std::cout << "this->ni = " << this->ni << "\n";
+    std::cout << "total_time = " << std::setprecision( 25 ) << total_time << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+    std::cout << "alpha = " << std::setprecision( 25 ) << this->alpha << "\n";
+    std::cout << "beta = " << std::setprecision( 25 ) << this->beta << "\n";
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+    int ist = 1;
+    int ied = ni;
+
+    // 0(bc) 1(ist) 2 3 ... ni
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        u_e[ i ] = - std::exp( -total_time ) * std::sin( std::numbers::pi * xm ); //theory solution
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+}
+
+void Field::Solve( Zone * zone )
+{
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+    }
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        //std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        //region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        //this->u[ i ] = 0.0;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+        int kkk = 1;
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        //this->u[ i ] = 0.0;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
+
+void Field::UpdateOldField()
+{
+    for ( int i = 0; i < this->u.size(); ++ i )
+    {
+        this->un[ i ] = this->u[ i ];
+    }
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01d/Field.h b/example/1d-heat-equation/ftcs/cpp/multiblock/01d/Field.h
new file mode 100644
index 00000000..21441ef6
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01d/Field.h
@@ -0,0 +1,46 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Para
+{
+public:
+    static int nt;
+    static double dx, dt, t;
+    static double alpha, beta;
+public:
+    static void Init();
+};
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid );
+
+    void Solve( Zone * zone );
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void UpdateOldField();
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01d/README.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/01d/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01d/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01d/Solver.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/01d/Solver.cpp
new file mode 100644
index 00000000..0b659536
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01d/Solver.cpp
@@ -0,0 +1,353 @@
+#include "Solver.h"
+#include <fstream>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    this->InitTopo();
+    this->InitFields();
+    this->SolveMultiZones();
+    this->PostProcess();
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d2blocksv3.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    ReadCgnsGrid( fileName );
+}
+
+void Solver::InitTopo()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Interface * interface = new Interface();
+        Global::interfaces.push_back( interface );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+        Interface * interface = Global::interfaces[ iZone ];
+
+        int nbc1to1s = zone->bc1to1s.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+    }
+}
+
+void Solver::InitFields()
+{
+    Para::Init();
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+    }
+
+    Boundary();
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        int nZones = Global::grids.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Field * field = Global::fields[ iZone ];
+            Zone * zone = Global::zones[ iZone ];
+            zone->zoneIndex = iZone;
+            field->Solve( zone );
+        }
+        Boundary();
+    }
+}
+
+void Solver::Boundary()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+    ExchangeInterfaceField();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->UpdateOldField();
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    int nZones = Global::interfaces.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+            int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+            
+            Field * donor_field = Global::fields[ donor_zoneid ];
+
+            double donor_value = donor_field->u[ i_donor_cell ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::PostProcess()
+{
+    Post post;
+    post.Process();
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    int nZones = Global::grids.size();
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        int ni = grid->x.size();
+        double xmin = grid->x[ 0 ];
+        double xmax = grid->x[ 0 ];
+        int imin = 0;
+        int imax = 0;
+        for ( int i = 0; i < ni; ++ i )
+        {
+            if ( xmin > grid->x[ i ] )
+            {
+                xmin = grid->x[ i ];
+                imin = i;
+            }
+            if ( xmax < grid->x[ i ] )
+            {
+                xmax = grid->x[ i ];
+                imax = i;
+            }
+        }
+        xmin_list.push_back( xmin );
+        xmax_list.push_back( xmax );
+    }
+    std::vector<std::pair<double, int>> pairs;
+    int nSize = xmin_list.size();
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        pairs.push_back( std::make_pair( xmin_list[i], i ) );
+    }
+
+    std::sort( pairs.begin(), pairs.end() );
+
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        this->zoneids.push_back( pairs[i].second );
+    }
+
+    int kkk = 1;
+}
+
+void Post::GatherField()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+        Grid * grid = Global::grids[ zoneid ];
+        Field * field = Global::fields[ zoneid ];
+
+        int ni = grid->x.size();
+
+        int ist = 1;
+        int ied = ni;
+
+        int dir = 1;
+        if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+        if ( dir == 1 )
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ist; i <= ied; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+
+            }
+            else
+            {
+                for ( int i = ist; i <= ied - 1; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+        else
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ied; i >= ist; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+            else
+            {
+                for ( int i = ied; i >= ist + 1; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+    }
+}
+
+void Post::DumpField()
+{
+    int ni_total = this->x.size();
+    std::cout << " DumpField x.size() = " << x.size() << "\n";
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    this->DumpErrorDetails( u_error );
+
+    std::string csvname = "field_final.csv";
+    this->DumpCsvFile( csvname, x, u_e, un, u_error );
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.20f} {:.20f} {:.20f} {:.20f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01d/Solver.h b/example/1d-heat-equation/ftcs/cpp/multiblock/01d/Solver.h
new file mode 100644
index 00000000..6bcc4ef4
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01d/Solver.h
@@ -0,0 +1,43 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+
+class Solver
+{
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveMultiZones();
+public:
+    void Boundary();
+    void ExchangeInterfaceField();
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcess();
+};
+
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+    std::vector<double> u;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & u, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01d/global.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/01d/global.cpp
new file mode 100644
index 00000000..4e1c2242
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01d/global.cpp
@@ -0,0 +1,52 @@
+#include "global.h"
+#include "CgnsGrid.h"
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *>  Global::interfaces;
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> &start,  std::vector<int> &end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->faceidList.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        int i_donor = index2[ 0 ];
+
+        int i_ghost_cell = i + 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+
+        int i_donor_cell = i_donor - 1;
+
+        if ( i_donor == 1 )
+        {
+            i_donor_cell = i_donor + 1;
+        }
+
+        this->ijk_donors.push_back( i_donor_cell );
+
+        icount ++;
+    }
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01d/global.h b/example/1d-heat-equation/ftcs/cpp/multiblock/01d/global.h
new file mode 100644
index 00000000..95708796
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01d/global.h
@@ -0,0 +1,91 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class Transform;
+
+class Interface
+{
+public:
+    std::vector<int> zoneList;
+    std::vector<int> faceidList;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+public:
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+};
+
+class Field;
+class BC;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01d/heat1d2blocksv3.cgns b/example/1d-heat-equation/ftcs/cpp/multiblock/01d/heat1d2blocksv3.cgns
new file mode 100644
index 00000000..1621b92e
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/multiblock/01d/heat1d2blocksv3.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01d/main.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/01d/main.cpp
new file mode 100644
index 00000000..5ff48a4e
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01d/main.cpp
@@ -0,0 +1,12 @@
+#include "cgnslib.h"
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+#include "Solver.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01d/plot.py b/example/1d-heat-equation/ftcs/cpp/multiblock/01d/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01d/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01d/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/multiblock/01d/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01d/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01e/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/01e/CMakeLists.txt
new file mode 100644
index 00000000..ee758c31
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01e/CMakeLists.txt
@@ -0,0 +1,79 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	Solver.h Solver.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01e/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/01e/CgnsGrid.cpp
new file mode 100644
index 00000000..14e34203
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01e/CgnsGrid.cpp
@@ -0,0 +1,523 @@
+#include "CgnsGrid.h"
+#include "cgnslib.h"
+#include "global.h"
+#include <iostream>
+#include <vector>
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            Grid * grid = new Grid();
+            Global::grids.push_back( grid );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                //std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+
+                coor->DumpCoor();
+                if ( icoord == 0 )
+                {
+                    coor->DumpCoorX( grid->x );
+                }
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+            }
+        }
+    }
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01e/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/multiblock/01e/CgnsGrid.h
new file mode 100644
index 00000000..fddf1db6
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01e/CgnsGrid.h
@@ -0,0 +1,103 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    int zoneIndex;
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01e/Field.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/01e/Field.cpp
new file mode 100644
index 00000000..16b28ddc
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01e/Field.cpp
@@ -0,0 +1,141 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+
+    std::vector<double> & x = grid->x;
+    this->dx = std::abs( x[ 1 ] - x[ 0 ] );
+    this->dt = dx / 10.0;
+    this->t = 1.0;
+    this->nt = std::round( t / dt );
+
+    double total_time = nt * dt;
+
+    std::cout << "this->dt   = " << this->dt << "\n";
+    std::cout << "this->t    = " << this->t << "\n";
+    std::cout << "this->nt   = " << this->nt << "\n";
+    std::cout << "this->ni   = " << this->ni << "\n";
+    std::cout << "total_time = " << total_time << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        u_e[ i ] = - std::exp( -total_time ) * std::sin( std::numbers::pi * xm ); //theory solution
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+}
+
+void Field::Solve( Zone * zone )
+{
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+    }
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        //std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        //region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+        int kkk = 1;
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
+
+void Field::UpdateOldField()
+{
+    for ( int i = 0; i < this->u.size(); ++ i )
+    {
+        this->un[ i ] = this->u[ i ];
+    }
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01e/Field.h b/example/1d-heat-equation/ftcs/cpp/multiblock/01e/Field.h
new file mode 100644
index 00000000..084ec9bd
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01e/Field.h
@@ -0,0 +1,36 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid );
+
+    void Solve( Zone * zone );
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void UpdateOldField();
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01e/README.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/01e/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01e/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01e/Solver.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/01e/Solver.cpp
new file mode 100644
index 00000000..b275e660
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01e/Solver.cpp
@@ -0,0 +1,352 @@
+#include "Solver.h"
+#include <fstream>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    this->InitTopo();
+    this->InitFields();
+    this->SolveMultiZones();
+    this->PostProcess();
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d2blocksv3.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    ReadCgnsGrid( fileName );
+}
+
+void Solver::InitTopo()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Interface * interface = new Interface();
+        Global::interfaces.push_back( interface );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+        Interface * interface = Global::interfaces[ iZone ];
+
+        int nbc1to1s = zone->bc1to1s.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+    }
+}
+
+void Solver::InitFields()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+    }
+
+    Boundary();
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        int nZones = Global::grids.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Field * field = Global::fields[ iZone ];
+            Zone * zone = Global::zones[ iZone ];
+            zone->zoneIndex = iZone;
+            field->Solve( zone );
+        }
+        Boundary();
+    }
+}
+
+void Solver::Boundary()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+    ExchangeInterfaceField();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->UpdateOldField();
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    int nZones = Global::interfaces.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+            int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+            
+            Field * donor_field = Global::fields[ donor_zoneid ];
+
+            double donor_value = donor_field->u[ i_donor_cell ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::PostProcess()
+{
+    Post post;
+    post.Process();
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    int nZones = Global::grids.size();
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        int ni = grid->x.size();
+        double xmin = grid->x[ 0 ];
+        double xmax = grid->x[ 0 ];
+        int imin = 0;
+        int imax = 0;
+        for ( int i = 0; i < ni; ++ i )
+        {
+            if ( xmin > grid->x[ i ] )
+            {
+                xmin = grid->x[ i ];
+                imin = i;
+            }
+            if ( xmax < grid->x[ i ] )
+            {
+                xmax = grid->x[ i ];
+                imax = i;
+            }
+        }
+        xmin_list.push_back( xmin );
+        xmax_list.push_back( xmax );
+    }
+    std::vector<std::pair<double, int>> pairs;
+    int nSize = xmin_list.size();
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        pairs.push_back( std::make_pair( xmin_list[i], i ) );
+    }
+
+    std::sort( pairs.begin(), pairs.end() );
+
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        this->zoneids.push_back( pairs[i].second );
+    }
+
+    int kkk = 1;
+}
+
+void Post::GatherField()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+        Grid * grid = Global::grids[ zoneid ];
+        Field * field = Global::fields[ zoneid ];
+
+        int ni = grid->x.size();
+
+        int ist = 1;
+        int ied = ni;
+
+        int dir = 1;
+        if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+        if ( dir == 1 )
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ist; i <= ied; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+
+            }
+            else
+            {
+                for ( int i = ist; i <= ied - 1; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+        else
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ied; i >= ist; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+            else
+            {
+                for ( int i = ied; i >= ist + 1; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+    }
+}
+
+void Post::DumpField()
+{
+    int ni_total = this->x.size();
+    std::cout << " DumpField x.size() = " << x.size() << "\n";
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    this->DumpErrorDetails( u_error );
+
+    std::string csvname = "field_final.csv";
+    this->DumpCsvFile( csvname, x, u_e, un, u_error );
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.20f} {:.20f} {:.20f} {:.20f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01e/Solver.h b/example/1d-heat-equation/ftcs/cpp/multiblock/01e/Solver.h
new file mode 100644
index 00000000..c50415cf
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01e/Solver.h
@@ -0,0 +1,41 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+
+class Solver
+{
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveMultiZones();
+public:
+    void Boundary();
+    void ExchangeInterfaceField();
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcess();
+};
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+    std::vector<double> u;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01e/global.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/01e/global.cpp
new file mode 100644
index 00000000..4e1c2242
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01e/global.cpp
@@ -0,0 +1,52 @@
+#include "global.h"
+#include "CgnsGrid.h"
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *>  Global::interfaces;
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> &start,  std::vector<int> &end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->faceidList.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        int i_donor = index2[ 0 ];
+
+        int i_ghost_cell = i + 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+
+        int i_donor_cell = i_donor - 1;
+
+        if ( i_donor == 1 )
+        {
+            i_donor_cell = i_donor + 1;
+        }
+
+        this->ijk_donors.push_back( i_donor_cell );
+
+        icount ++;
+    }
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01e/global.h b/example/1d-heat-equation/ftcs/cpp/multiblock/01e/global.h
new file mode 100644
index 00000000..95708796
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01e/global.h
@@ -0,0 +1,91 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class Transform;
+
+class Interface
+{
+public:
+    std::vector<int> zoneList;
+    std::vector<int> faceidList;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+public:
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+};
+
+class Field;
+class BC;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01e/heat1d2blocksv3.cgns b/example/1d-heat-equation/ftcs/cpp/multiblock/01e/heat1d2blocksv3.cgns
new file mode 100644
index 00000000..1621b92e
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/multiblock/01e/heat1d2blocksv3.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01e/main.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/01e/main.cpp
new file mode 100644
index 00000000..5ff48a4e
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01e/main.cpp
@@ -0,0 +1,12 @@
+#include "cgnslib.h"
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+#include "Solver.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01e/plot.py b/example/1d-heat-equation/ftcs/cpp/multiblock/01e/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01e/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/01e/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/multiblock/01e/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/01e/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/CMakeLists.txt
new file mode 100644
index 00000000..ee758c31
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/CMakeLists.txt
@@ -0,0 +1,79 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	Solver.h Solver.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/CgnsGrid.cpp
new file mode 100644
index 00000000..14e34203
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/CgnsGrid.cpp
@@ -0,0 +1,523 @@
+#include "CgnsGrid.h"
+#include "cgnslib.h"
+#include "global.h"
+#include <iostream>
+#include <vector>
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            Grid * grid = new Grid();
+            Global::grids.push_back( grid );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                //std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+
+                coor->DumpCoor();
+                if ( icoord == 0 )
+                {
+                    coor->DumpCoorX( grid->x );
+                }
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+            }
+        }
+    }
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/CgnsGrid.h
new file mode 100644
index 00000000..fddf1db6
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/CgnsGrid.h
@@ -0,0 +1,103 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    int zoneIndex;
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/Field.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/Field.cpp
new file mode 100644
index 00000000..16b28ddc
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/Field.cpp
@@ -0,0 +1,141 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+
+    std::vector<double> & x = grid->x;
+    this->dx = std::abs( x[ 1 ] - x[ 0 ] );
+    this->dt = dx / 10.0;
+    this->t = 1.0;
+    this->nt = std::round( t / dt );
+
+    double total_time = nt * dt;
+
+    std::cout << "this->dt   = " << this->dt << "\n";
+    std::cout << "this->t    = " << this->t << "\n";
+    std::cout << "this->nt   = " << this->nt << "\n";
+    std::cout << "this->ni   = " << this->ni << "\n";
+    std::cout << "total_time = " << total_time << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        u_e[ i ] = - std::exp( -total_time ) * std::sin( std::numbers::pi * xm ); //theory solution
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+}
+
+void Field::Solve( Zone * zone )
+{
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+    }
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        //std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        //region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+        int kkk = 1;
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
+
+void Field::UpdateOldField()
+{
+    for ( int i = 0; i < this->u.size(); ++ i )
+    {
+        this->un[ i ] = this->u[ i ];
+    }
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/Field.h b/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/Field.h
new file mode 100644
index 00000000..084ec9bd
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/Field.h
@@ -0,0 +1,36 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid );
+
+    void Solve( Zone * zone );
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void UpdateOldField();
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/README.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/Solver.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/Solver.cpp
new file mode 100644
index 00000000..7fc4555e
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/Solver.cpp
@@ -0,0 +1,352 @@
+#include "Solver.h"
+#include <fstream>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    this->InitTopo();
+    this->InitFields();
+    this->SolveMultiZones();
+    this->PostProcess();
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d4blocksv1.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    ReadCgnsGrid( fileName );
+}
+
+void Solver::InitTopo()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Interface * interface = new Interface();
+        Global::interfaces.push_back( interface );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+        Interface * interface = Global::interfaces[ iZone ];
+
+        int nbc1to1s = zone->bc1to1s.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+    }
+}
+
+void Solver::InitFields()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+    }
+
+    Boundary();
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        int nZones = Global::grids.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Field * field = Global::fields[ iZone ];
+            Zone * zone = Global::zones[ iZone ];
+            zone->zoneIndex = iZone;
+            field->Solve( zone );
+        }
+        Boundary();
+    }
+}
+
+void Solver::Boundary()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+    ExchangeInterfaceField();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->UpdateOldField();
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    int nZones = Global::interfaces.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+            int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+            
+            Field * donor_field = Global::fields[ donor_zoneid ];
+
+            double donor_value = donor_field->u[ i_donor_cell ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::PostProcess()
+{
+    Post post;
+    post.Process();
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    int nZones = Global::grids.size();
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        int ni = grid->x.size();
+        double xmin = grid->x[ 0 ];
+        double xmax = grid->x[ 0 ];
+        int imin = 0;
+        int imax = 0;
+        for ( int i = 0; i < ni; ++ i )
+        {
+            if ( xmin > grid->x[ i ] )
+            {
+                xmin = grid->x[ i ];
+                imin = i;
+            }
+            if ( xmax < grid->x[ i ] )
+            {
+                xmax = grid->x[ i ];
+                imax = i;
+            }
+        }
+        xmin_list.push_back( xmin );
+        xmax_list.push_back( xmax );
+    }
+    std::vector<std::pair<double, int>> pairs;
+    int nSize = xmin_list.size();
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        pairs.push_back( std::make_pair( xmin_list[i], i ) );
+    }
+
+    std::sort( pairs.begin(), pairs.end() );
+
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        this->zoneids.push_back( pairs[i].second );
+    }
+
+    int kkk = 1;
+}
+
+void Post::GatherField()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+        Grid * grid = Global::grids[ zoneid ];
+        Field * field = Global::fields[ zoneid ];
+
+        int ni = grid->x.size();
+
+        int ist = 1;
+        int ied = ni;
+
+        int dir = 1;
+        if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+        if ( dir == 1 )
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ist; i <= ied; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+
+            }
+            else
+            {
+                for ( int i = ist; i <= ied - 1; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+        else
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ied; i >= ist; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+            else
+            {
+                for ( int i = ied; i >= ist + 1; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+    }
+}
+
+void Post::DumpField()
+{
+    int ni_total = this->x.size();
+    std::cout << " DumpField x.size() = " << x.size() << "\n";
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    this->DumpErrorDetails( u_error );
+
+    std::string csvname = "field_final.csv";
+    this->DumpCsvFile( csvname, x, u_e, un, u_error );
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.20f} {:.20f} {:.20f} {:.20f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/Solver.h b/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/Solver.h
new file mode 100644
index 00000000..c50415cf
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/Solver.h
@@ -0,0 +1,41 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+
+class Solver
+{
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveMultiZones();
+public:
+    void Boundary();
+    void ExchangeInterfaceField();
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcess();
+};
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+    std::vector<double> u;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/global.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/global.cpp
new file mode 100644
index 00000000..4e1c2242
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/global.cpp
@@ -0,0 +1,52 @@
+#include "global.h"
+#include "CgnsGrid.h"
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *>  Global::interfaces;
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> &start,  std::vector<int> &end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->faceidList.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        int i_donor = index2[ 0 ];
+
+        int i_ghost_cell = i + 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+
+        int i_donor_cell = i_donor - 1;
+
+        if ( i_donor == 1 )
+        {
+            i_donor_cell = i_donor + 1;
+        }
+
+        this->ijk_donors.push_back( i_donor_cell );
+
+        icount ++;
+    }
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/global.h b/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/global.h
new file mode 100644
index 00000000..ce3710b6
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/global.h
@@ -0,0 +1,90 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class Transform;
+
+class Interface
+{
+public:
+    std::vector<int> zoneList;
+    std::vector<int> faceidList;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+public:
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+};
+
+class Field;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/heat1d4blocksv1.cgns b/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/heat1d4blocksv1.cgns
new file mode 100644
index 00000000..df5ffc5f
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/heat1d4blocksv1.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/main.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/main.cpp
new file mode 100644
index 00000000..fcce6376
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/main.cpp
@@ -0,0 +1,8 @@
+#include "Solver.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/plot.py b/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/4blocks/01/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/CMakeLists.txt
new file mode 100644
index 00000000..ee758c31
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/CMakeLists.txt
@@ -0,0 +1,79 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	Solver.h Solver.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/CgnsGrid.cpp
new file mode 100644
index 00000000..14e34203
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/CgnsGrid.cpp
@@ -0,0 +1,523 @@
+#include "CgnsGrid.h"
+#include "cgnslib.h"
+#include "global.h"
+#include <iostream>
+#include <vector>
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            Grid * grid = new Grid();
+            Global::grids.push_back( grid );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                //std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+
+                coor->DumpCoor();
+                if ( icoord == 0 )
+                {
+                    coor->DumpCoorX( grid->x );
+                }
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+            }
+        }
+    }
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/CgnsGrid.h
new file mode 100644
index 00000000..fddf1db6
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/CgnsGrid.h
@@ -0,0 +1,103 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    int zoneIndex;
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/Field.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/Field.cpp
new file mode 100644
index 00000000..16b28ddc
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/Field.cpp
@@ -0,0 +1,141 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+
+    std::vector<double> & x = grid->x;
+    this->dx = std::abs( x[ 1 ] - x[ 0 ] );
+    this->dt = dx / 10.0;
+    this->t = 1.0;
+    this->nt = std::round( t / dt );
+
+    double total_time = nt * dt;
+
+    std::cout << "this->dt   = " << this->dt << "\n";
+    std::cout << "this->t    = " << this->t << "\n";
+    std::cout << "this->nt   = " << this->nt << "\n";
+    std::cout << "this->ni   = " << this->ni << "\n";
+    std::cout << "total_time = " << total_time << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        u_e[ i ] = - std::exp( -total_time ) * std::sin( std::numbers::pi * xm ); //theory solution
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+}
+
+void Field::Solve( Zone * zone )
+{
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+    }
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        //std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        //region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+        int kkk = 1;
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
+
+void Field::UpdateOldField()
+{
+    for ( int i = 0; i < this->u.size(); ++ i )
+    {
+        this->un[ i ] = this->u[ i ];
+    }
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/Field.h b/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/Field.h
new file mode 100644
index 00000000..084ec9bd
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/Field.h
@@ -0,0 +1,36 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid );
+
+    void Solve( Zone * zone );
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void UpdateOldField();
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/README.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/Solver.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/Solver.cpp
new file mode 100644
index 00000000..f1d05b41
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/Solver.cpp
@@ -0,0 +1,352 @@
+#include "Solver.h"
+#include <fstream>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    this->InitTopo();
+    this->InitFields();
+    this->SolveMultiZones();
+    this->PostProcess();
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d8blocksv1.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    ReadCgnsGrid( fileName );
+}
+
+void Solver::InitTopo()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Interface * interface = new Interface();
+        Global::interfaces.push_back( interface );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+        Interface * interface = Global::interfaces[ iZone ];
+
+        int nbc1to1s = zone->bc1to1s.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+    }
+}
+
+void Solver::InitFields()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+    }
+
+    Boundary();
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        int nZones = Global::grids.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Field * field = Global::fields[ iZone ];
+            Zone * zone = Global::zones[ iZone ];
+            zone->zoneIndex = iZone;
+            field->Solve( zone );
+        }
+        Boundary();
+    }
+}
+
+void Solver::Boundary()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+    ExchangeInterfaceField();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->UpdateOldField();
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    int nZones = Global::interfaces.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+            int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+            
+            Field * donor_field = Global::fields[ donor_zoneid ];
+
+            double donor_value = donor_field->u[ i_donor_cell ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::PostProcess()
+{
+    Post post;
+    post.Process();
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    int nZones = Global::grids.size();
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        int ni = grid->x.size();
+        double xmin = grid->x[ 0 ];
+        double xmax = grid->x[ 0 ];
+        int imin = 0;
+        int imax = 0;
+        for ( int i = 0; i < ni; ++ i )
+        {
+            if ( xmin > grid->x[ i ] )
+            {
+                xmin = grid->x[ i ];
+                imin = i;
+            }
+            if ( xmax < grid->x[ i ] )
+            {
+                xmax = grid->x[ i ];
+                imax = i;
+            }
+        }
+        xmin_list.push_back( xmin );
+        xmax_list.push_back( xmax );
+    }
+    std::vector<std::pair<double, int>> pairs;
+    int nSize = xmin_list.size();
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        pairs.push_back( std::make_pair( xmin_list[i], i ) );
+    }
+
+    std::sort( pairs.begin(), pairs.end() );
+
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        this->zoneids.push_back( pairs[i].second );
+    }
+
+    int kkk = 1;
+}
+
+void Post::GatherField()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+        Grid * grid = Global::grids[ zoneid ];
+        Field * field = Global::fields[ zoneid ];
+
+        int ni = grid->x.size();
+
+        int ist = 1;
+        int ied = ni;
+
+        int dir = 1;
+        if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+        if ( dir == 1 )
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ist; i <= ied; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+
+            }
+            else
+            {
+                for ( int i = ist; i <= ied - 1; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+        else
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ied; i >= ist; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+            else
+            {
+                for ( int i = ied; i >= ist + 1; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+    }
+}
+
+void Post::DumpField()
+{
+    int ni_total = this->x.size();
+    std::cout << " DumpField x.size() = " << x.size() << "\n";
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    this->DumpErrorDetails( u_error );
+
+    std::string csvname = "field_final.csv";
+    this->DumpCsvFile( csvname, x, u_e, un, u_error );
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.20f} {:.20f} {:.20f} {:.20f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/Solver.h b/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/Solver.h
new file mode 100644
index 00000000..c50415cf
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/Solver.h
@@ -0,0 +1,41 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+
+class Solver
+{
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveMultiZones();
+public:
+    void Boundary();
+    void ExchangeInterfaceField();
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcess();
+};
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+    std::vector<double> u;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/global.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/global.cpp
new file mode 100644
index 00000000..4e1c2242
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/global.cpp
@@ -0,0 +1,52 @@
+#include "global.h"
+#include "CgnsGrid.h"
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *>  Global::interfaces;
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> &start,  std::vector<int> &end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->faceidList.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        int i_donor = index2[ 0 ];
+
+        int i_ghost_cell = i + 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+
+        int i_donor_cell = i_donor - 1;
+
+        if ( i_donor == 1 )
+        {
+            i_donor_cell = i_donor + 1;
+        }
+
+        this->ijk_donors.push_back( i_donor_cell );
+
+        icount ++;
+    }
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/global.h b/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/global.h
new file mode 100644
index 00000000..ce3710b6
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/global.h
@@ -0,0 +1,90 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class Transform;
+
+class Interface
+{
+public:
+    std::vector<int> zoneList;
+    std::vector<int> faceidList;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+public:
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+};
+
+class Field;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/heat1d8blocksv1.cgns b/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/heat1d8blocksv1.cgns
new file mode 100644
index 00000000..4dc174d4
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/heat1d8blocksv1.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/main.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/main.cpp
new file mode 100644
index 00000000..fcce6376
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/main.cpp
@@ -0,0 +1,8 @@
+#include "Solver.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/plot.py b/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/8blocks/01/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/CMakeLists.txt
new file mode 100644
index 00000000..ee758c31
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/CMakeLists.txt
@@ -0,0 +1,79 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	Solver.h Solver.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/CgnsGrid.cpp
new file mode 100644
index 00000000..14e34203
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/CgnsGrid.cpp
@@ -0,0 +1,523 @@
+#include "CgnsGrid.h"
+#include "cgnslib.h"
+#include "global.h"
+#include <iostream>
+#include <vector>
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            Grid * grid = new Grid();
+            Global::grids.push_back( grid );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                //std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+
+                coor->DumpCoor();
+                if ( icoord == 0 )
+                {
+                    coor->DumpCoorX( grid->x );
+                }
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+            }
+        }
+    }
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/CgnsGrid.h
new file mode 100644
index 00000000..fddf1db6
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/CgnsGrid.h
@@ -0,0 +1,103 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    int zoneIndex;
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/Field.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/Field.cpp
new file mode 100644
index 00000000..16b28ddc
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/Field.cpp
@@ -0,0 +1,141 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+
+    std::vector<double> & x = grid->x;
+    this->dx = std::abs( x[ 1 ] - x[ 0 ] );
+    this->dt = dx / 10.0;
+    this->t = 1.0;
+    this->nt = std::round( t / dt );
+
+    double total_time = nt * dt;
+
+    std::cout << "this->dt   = " << this->dt << "\n";
+    std::cout << "this->t    = " << this->t << "\n";
+    std::cout << "this->nt   = " << this->nt << "\n";
+    std::cout << "this->ni   = " << this->ni << "\n";
+    std::cout << "total_time = " << total_time << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        u_e[ i ] = - std::exp( -total_time ) * std::sin( std::numbers::pi * xm ); //theory solution
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+}
+
+void Field::Solve( Zone * zone )
+{
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+    }
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        //std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        //region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+        int kkk = 1;
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
+
+void Field::UpdateOldField()
+{
+    for ( int i = 0; i < this->u.size(); ++ i )
+    {
+        this->un[ i ] = this->u[ i ];
+    }
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/Field.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/Field.h
new file mode 100644
index 00000000..084ec9bd
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/Field.h
@@ -0,0 +1,36 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid );
+
+    void Solve( Zone * zone );
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void UpdateOldField();
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/README.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/Solver.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/Solver.cpp
new file mode 100644
index 00000000..4728853b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/Solver.cpp
@@ -0,0 +1,388 @@
+#include "Solver.h"
+#include <fstream>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    this->InitTopo();
+    this->InitFields();
+    this->SolveMultiZones();
+    this->PostProcess();
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d4blocksv1.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    ReadCgnsGrid( fileName );
+}
+
+void Solver::InitTopo()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Interface * interface = new Interface();
+        Global::interfaces.push_back( interface );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+        Interface * interface = Global::interfaces[ iZone ];
+
+        int nbc1to1s = zone->bc1to1s.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+        int nInterfaces = interface->zoneList.size();
+        interface->data_recv.resize( nInterfaces );
+        interface->data_send.resize( nInterfaces );
+    }
+}
+
+void Solver::InitFields()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+    }
+
+    Boundary();
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        int nZones = Global::zones.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Field * field = Global::fields[ iZone ];
+            Zone * zone = Global::zones[ iZone ];
+            zone->zoneIndex = iZone;
+            field->Solve( zone );
+        }
+        Boundary();
+    }
+}
+
+void Solver::Boundary()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+    ExchangeInterfaceField();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->UpdateOldField();
+    }
+}
+
+void Solver::ExchangeInterfaceFieldOldVersion()
+{
+    int nZones = Global::interfaces.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+            int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+
+            Field * donor_field = Global::fields[ donor_zoneid ];
+
+            double donor_value = donor_field->u[ i_donor_cell ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    int nZones = Global::interfaces.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ijkpos = index_dim * iFace;
+            int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+
+            Field * donor_field = Global::fields[ donor_zoneid ];
+            double donor_value = donor_field->u[ i_donor_cell ];
+            interface->data_recv[ iFace ] = donor_value;
+        }
+
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+
+            double donor_value = interface->data_recv[ iFace ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::PostProcess()
+{
+    Post post;
+    post.Process();
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    int nZones = Global::grids.size();
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        int ni = grid->x.size();
+        double xmin = grid->x[ 0 ];
+        double xmax = grid->x[ 0 ];
+        int imin = 0;
+        int imax = 0;
+        for ( int i = 0; i < ni; ++ i )
+        {
+            if ( xmin > grid->x[ i ] )
+            {
+                xmin = grid->x[ i ];
+                imin = i;
+            }
+            if ( xmax < grid->x[ i ] )
+            {
+                xmax = grid->x[ i ];
+                imax = i;
+            }
+        }
+        xmin_list.push_back( xmin );
+        xmax_list.push_back( xmax );
+    }
+    std::vector<std::pair<double, int>> pairs;
+    int nSize = xmin_list.size();
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        pairs.push_back( std::make_pair( xmin_list[i], i ) );
+    }
+
+    std::sort( pairs.begin(), pairs.end() );
+
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        this->zoneids.push_back( pairs[i].second );
+    }
+
+    int kkk = 1;
+}
+
+void Post::GatherField()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+        Grid * grid = Global::grids[ zoneid ];
+        Field * field = Global::fields[ zoneid ];
+
+        int ni = grid->x.size();
+
+        int ist = 1;
+        int ied = ni;
+
+        int dir = 1;
+        if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+        if ( dir == 1 )
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ist; i <= ied; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+
+            }
+            else
+            {
+                for ( int i = ist; i <= ied - 1; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+        else
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ied; i >= ist; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+            else
+            {
+                for ( int i = ied; i >= ist + 1; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+    }
+}
+
+void Post::DumpField()
+{
+    int ni_total = this->x.size();
+    std::cout << " DumpField x.size() = " << x.size() << "\n";
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    this->DumpErrorDetails( u_error );
+
+    std::string csvname = "field_final.csv";
+    this->DumpCsvFile( csvname, x, u_e, un, u_error );
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.20f} {:.20f} {:.20f} {:.20f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/Solver.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/Solver.h
new file mode 100644
index 00000000..8ef894af
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/Solver.h
@@ -0,0 +1,42 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+
+class Solver
+{
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveMultiZones();
+public:
+    void Boundary();
+    void ExchangeInterfaceField();
+    void ExchangeInterfaceFieldOldVersion();
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcess();
+};
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+    std::vector<double> u;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/global.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/global.cpp
new file mode 100644
index 00000000..4e1c2242
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/global.cpp
@@ -0,0 +1,52 @@
+#include "global.h"
+#include "CgnsGrid.h"
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *>  Global::interfaces;
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> &start,  std::vector<int> &end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->faceidList.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        int i_donor = index2[ 0 ];
+
+        int i_ghost_cell = i + 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+
+        int i_donor_cell = i_donor - 1;
+
+        if ( i_donor == 1 )
+        {
+            i_donor_cell = i_donor + 1;
+        }
+
+        this->ijk_donors.push_back( i_donor_cell );
+
+        icount ++;
+    }
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/global.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/global.h
new file mode 100644
index 00000000..f6783581
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/global.h
@@ -0,0 +1,92 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class Transform;
+
+class Interface
+{
+public:
+    std::vector<int> zoneList;
+    std::vector<int> faceidList;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+    std::vector<double> data_recv;
+    std::vector<double> data_send;
+public:
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+};
+
+class Field;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/heat1d4blocksv1.cgns b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/heat1d4blocksv1.cgns
new file mode 100644
index 00000000..df5ffc5f
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/heat1d4blocksv1.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/main.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/main.cpp
new file mode 100644
index 00000000..fcce6376
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/main.cpp
@@ -0,0 +1,8 @@
+#include "Solver.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/plot.py b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/CMakeLists.txt
new file mode 100644
index 00000000..ee758c31
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/CMakeLists.txt
@@ -0,0 +1,79 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	Solver.h Solver.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/CgnsGrid.cpp
new file mode 100644
index 00000000..14e34203
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/CgnsGrid.cpp
@@ -0,0 +1,523 @@
+#include "CgnsGrid.h"
+#include "cgnslib.h"
+#include "global.h"
+#include <iostream>
+#include <vector>
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            Grid * grid = new Grid();
+            Global::grids.push_back( grid );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                //std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+
+                coor->DumpCoor();
+                if ( icoord == 0 )
+                {
+                    coor->DumpCoorX( grid->x );
+                }
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+            }
+        }
+    }
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/CgnsGrid.h
new file mode 100644
index 00000000..fddf1db6
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/CgnsGrid.h
@@ -0,0 +1,103 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    int zoneIndex;
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/Field.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/Field.cpp
new file mode 100644
index 00000000..16b28ddc
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/Field.cpp
@@ -0,0 +1,141 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+
+    std::vector<double> & x = grid->x;
+    this->dx = std::abs( x[ 1 ] - x[ 0 ] );
+    this->dt = dx / 10.0;
+    this->t = 1.0;
+    this->nt = std::round( t / dt );
+
+    double total_time = nt * dt;
+
+    std::cout << "this->dt   = " << this->dt << "\n";
+    std::cout << "this->t    = " << this->t << "\n";
+    std::cout << "this->nt   = " << this->nt << "\n";
+    std::cout << "this->ni   = " << this->ni << "\n";
+    std::cout << "total_time = " << total_time << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        u_e[ i ] = - std::exp( -total_time ) * std::sin( std::numbers::pi * xm ); //theory solution
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+}
+
+void Field::Solve( Zone * zone )
+{
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+    }
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        //std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        //region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+        int kkk = 1;
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
+
+void Field::UpdateOldField()
+{
+    for ( int i = 0; i < this->u.size(); ++ i )
+    {
+        this->un[ i ] = this->u[ i ];
+    }
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/Field.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/Field.h
new file mode 100644
index 00000000..084ec9bd
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/Field.h
@@ -0,0 +1,36 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid );
+
+    void Solve( Zone * zone );
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void UpdateOldField();
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/README.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/Solver.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/Solver.cpp
new file mode 100644
index 00000000..6c6672bc
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/Solver.cpp
@@ -0,0 +1,442 @@
+#include "Solver.h"
+#include <fstream>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    this->InitTopo();
+    this->InitFields();
+    this->SolveMultiZones();
+    this->PostProcess();
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d4blocksv1.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    ReadCgnsGrid( fileName );
+}
+
+void Solver::InitTopo()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = new Interface();
+        interface->zoneid = iZone;
+        Global::interfaces.push_back( interface );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+        Interface * interface = Global::interfaces[ iZone ];
+
+        int nbc1to1s = zone->bc1to1s.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+        int nInterfaces = interface->zoneList.size();
+        interface->data_recv.resize( nInterfaces );
+        interface->data_send.resize( nInterfaces );
+    }
+}
+
+void Solver::InitFields()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+    }
+
+    Boundary();
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        int nZones = Global::zones.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Field * field = Global::fields[ iZone ];
+            Zone * zone = Global::zones[ iZone ];
+            zone->zoneIndex = iZone;
+            field->Solve( zone );
+        }
+        Boundary();
+    }
+}
+
+void Solver::Boundary()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+    ExchangeInterfaceField();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->UpdateOldField();
+    }
+}
+
+void Solver::ExchangeInterfaceFieldOldVersion()
+{
+    int nZones = Global::interfaces.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+            int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+
+            Field * donor_field = Global::fields[ donor_zoneid ];
+
+            double donor_value = donor_field->u[ i_donor_cell ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::ExchangeInterfaceFieldOldVersion1()
+{
+    int nZones = Global::interfaces.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ijkpos = index_dim * iFace;
+            int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+
+            Field * donor_field = Global::fields[ donor_zoneid ];
+            double donor_value = donor_field->u[ i_donor_cell ];
+            interface->data_recv[ iFace ] = donor_value;
+        }
+
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+
+            double donor_value = interface->data_recv[ iFace ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    int nZones = Global::interfaces.size();
+
+    //for ( int iZone = 0; iZone < nZones; ++ iZone )
+    //{
+    //    Field * field = Global::fields[ iZone ];
+
+    //    Interface * interface = Global::interfaces[ iZone ];
+    //    int nInterFaces = interface->zoneList.size();
+    //    int index_dim = 1;
+    //    for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+    //    {
+    //        int donor_zoneid = interface->zoneList[ iFace ];
+    //        int ijkpos = index_dim * iFace;
+    //        int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+
+    //        Field * donor_field = Global::fields[ donor_zoneid ];
+    //        double donor_value = donor_field->u[ i_donor_cell ];
+    //        interface->data_recv[ iFace ] = donor_value;
+    //        //interface->data_send[ iFace ] = donor_value;
+    //    }
+    //}
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ijkpos = index_dim * iFace;
+            int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+
+            Field * donor_field = Global::fields[ donor_zoneid ];
+            double donor_value = donor_field->u[ i_donor_cell ];
+            interface->data_recv[ iFace ] = donor_value;
+        }
+
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+
+            double donor_value = interface->data_recv[ iFace ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::PostProcess()
+{
+    Post post;
+    post.Process();
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    int nZones = Global::grids.size();
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        int ni = grid->x.size();
+        double xmin = grid->x[ 0 ];
+        double xmax = grid->x[ 0 ];
+        int imin = 0;
+        int imax = 0;
+        for ( int i = 0; i < ni; ++ i )
+        {
+            if ( xmin > grid->x[ i ] )
+            {
+                xmin = grid->x[ i ];
+                imin = i;
+            }
+            if ( xmax < grid->x[ i ] )
+            {
+                xmax = grid->x[ i ];
+                imax = i;
+            }
+        }
+        xmin_list.push_back( xmin );
+        xmax_list.push_back( xmax );
+    }
+    std::vector<std::pair<double, int>> pairs;
+    int nSize = xmin_list.size();
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        pairs.push_back( std::make_pair( xmin_list[i], i ) );
+    }
+
+    std::sort( pairs.begin(), pairs.end() );
+
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        this->zoneids.push_back( pairs[i].second );
+    }
+
+    int kkk = 1;
+}
+
+void Post::GatherField()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+        Grid * grid = Global::grids[ zoneid ];
+        Field * field = Global::fields[ zoneid ];
+
+        int ni = grid->x.size();
+
+        int ist = 1;
+        int ied = ni;
+
+        int dir = 1;
+        if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+        if ( dir == 1 )
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ist; i <= ied; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+
+            }
+            else
+            {
+                for ( int i = ist; i <= ied - 1; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+        else
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ied; i >= ist; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+            else
+            {
+                for ( int i = ied; i >= ist + 1; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+    }
+}
+
+void Post::DumpField()
+{
+    int ni_total = this->x.size();
+    std::cout << " DumpField x.size() = " << x.size() << "\n";
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    this->DumpErrorDetails( u_error );
+
+    std::string csvname = "field_final.csv";
+    this->DumpCsvFile( csvname, x, u_e, un, u_error );
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.20f} {:.20f} {:.20f} {:.20f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/Solver.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/Solver.h
new file mode 100644
index 00000000..e739edf7
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/Solver.h
@@ -0,0 +1,43 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+
+class Solver
+{
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveMultiZones();
+public:
+    void Boundary();
+    void ExchangeInterfaceField();
+    void ExchangeInterfaceFieldOldVersion();
+    void ExchangeInterfaceFieldOldVersion1();
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcess();
+};
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+    std::vector<double> u;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/global.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/global.cpp
new file mode 100644
index 00000000..93e76c83
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/global.cpp
@@ -0,0 +1,127 @@
+#include "global.h"
+#include "CgnsGrid.h"
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *> Global::interfaces;
+
+std::map<Face, int> Global::faceMap;
+std::map<FacePair, int> Global::facePairMap;
+std::vector<FacePair> Global::facePairList;
+
+bool Face::operator < ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return this->zone < rhs.zone;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return this->i < rhs.i;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return this->j < rhs.j;
+    }
+
+    return this->k < rhs.k;
+}
+
+bool Face::operator == ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return false;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return false;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return false;
+    }
+
+    return this->k == rhs.k;
+}
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->faceidList.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        Face face;
+        face.zone = zoneid;
+        face.i = i;
+
+        //std::map<Face, int>::iterator iter;
+        //iter = Global::faceMap.find( face );
+        //if ( iter == Global::faceMap.end() )
+        //{
+        //    int faceid = Global::faceMap.size();
+        //    Global::faceMap.insert( std::make_pair( face, faceid ) );
+        //}
+
+        Global::InsertFaceMap( face );
+
+        int i_donor = index2[ 0 ];
+
+        Face face_donor;
+        face_donor.zone = donor_zoneid;
+        face_donor.i = i_donor;
+
+        Global::InsertFaceMap( face_donor );
+
+        int i_ghost_cell = i + 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+
+        int i_donor_cell = i_donor - 1;
+
+        if ( i_donor == 1 )
+        {
+            i_donor_cell = i_donor + 1;
+        }
+
+        this->ijk_donors.push_back( i_donor_cell );
+
+        icount ++;
+    }
+}
+
+void Global::InsertFaceMap( const Face & face )
+{
+    std::map<Face, int>::iterator iter;
+    iter = Global::faceMap.find( face );
+    if ( iter == Global::faceMap.end() )
+    {
+        int faceid = Global::faceMap.size();
+        Global::faceMap.insert( std::make_pair( face, faceid ) );
+    }
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/global.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/global.h
new file mode 100644
index 00000000..d5d20440
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/global.h
@@ -0,0 +1,120 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class Face
+{
+public:
+    int zone = 0;
+    int i = 0;
+    int j = 1;
+    int k = 1;
+public:
+    bool operator < ( const Face & rhs ) const;
+    bool operator == ( const Face & rhs ) const;
+};
+
+class FacePair
+{
+public:
+    Face left;
+    Face right;
+public:
+    //bool operator < ( const FacePair & rhs ) const;
+};
+
+class Transform;
+
+class Interface
+{
+public:
+    int zoneid;
+    std::vector<int> zoneList;
+    std::vector<int> faceidList;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+    std::vector<double> data_recv;
+    std::vector<double> data_send;
+public:
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+};
+
+class Field;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+public:
+    static std::map<Face, int> faceMap;
+    static std::map<FacePair, int> facePairMap;
+    static std::vector<FacePair> facePairList;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+public:
+    static void InsertFaceMap( const Face & face );
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/heat1d4blocksv1.cgns b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/heat1d4blocksv1.cgns
new file mode 100644
index 00000000..df5ffc5f
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/heat1d4blocksv1.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/main.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/main.cpp
new file mode 100644
index 00000000..fcce6376
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/main.cpp
@@ -0,0 +1,8 @@
+#include "Solver.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/plot.py b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01a/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/CMakeLists.txt
new file mode 100644
index 00000000..ee758c31
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/CMakeLists.txt
@@ -0,0 +1,79 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	Solver.h Solver.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/CgnsGrid.cpp
new file mode 100644
index 00000000..14e34203
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/CgnsGrid.cpp
@@ -0,0 +1,523 @@
+#include "CgnsGrid.h"
+#include "cgnslib.h"
+#include "global.h"
+#include <iostream>
+#include <vector>
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            Grid * grid = new Grid();
+            Global::grids.push_back( grid );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                //std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+
+                coor->DumpCoor();
+                if ( icoord == 0 )
+                {
+                    coor->DumpCoorX( grid->x );
+                }
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+            }
+        }
+    }
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/CgnsGrid.h
new file mode 100644
index 00000000..fddf1db6
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/CgnsGrid.h
@@ -0,0 +1,103 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    int zoneIndex;
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/Field.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/Field.cpp
new file mode 100644
index 00000000..16b28ddc
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/Field.cpp
@@ -0,0 +1,141 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+
+    std::vector<double> & x = grid->x;
+    this->dx = std::abs( x[ 1 ] - x[ 0 ] );
+    this->dt = dx / 10.0;
+    this->t = 1.0;
+    this->nt = std::round( t / dt );
+
+    double total_time = nt * dt;
+
+    std::cout << "this->dt   = " << this->dt << "\n";
+    std::cout << "this->t    = " << this->t << "\n";
+    std::cout << "this->nt   = " << this->nt << "\n";
+    std::cout << "this->ni   = " << this->ni << "\n";
+    std::cout << "total_time = " << total_time << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        u_e[ i ] = - std::exp( -total_time ) * std::sin( std::numbers::pi * xm ); //theory solution
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+}
+
+void Field::Solve( Zone * zone )
+{
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+    }
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        //std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        //region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+        int kkk = 1;
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
+
+void Field::UpdateOldField()
+{
+    for ( int i = 0; i < this->u.size(); ++ i )
+    {
+        this->un[ i ] = this->u[ i ];
+    }
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/Field.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/Field.h
new file mode 100644
index 00000000..084ec9bd
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/Field.h
@@ -0,0 +1,36 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid );
+
+    void Solve( Zone * zone );
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void UpdateOldField();
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/README.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/Solver.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/Solver.cpp
new file mode 100644
index 00000000..6c6672bc
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/Solver.cpp
@@ -0,0 +1,442 @@
+#include "Solver.h"
+#include <fstream>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    this->InitTopo();
+    this->InitFields();
+    this->SolveMultiZones();
+    this->PostProcess();
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d4blocksv1.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    ReadCgnsGrid( fileName );
+}
+
+void Solver::InitTopo()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = new Interface();
+        interface->zoneid = iZone;
+        Global::interfaces.push_back( interface );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+        Interface * interface = Global::interfaces[ iZone ];
+
+        int nbc1to1s = zone->bc1to1s.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+        int nInterfaces = interface->zoneList.size();
+        interface->data_recv.resize( nInterfaces );
+        interface->data_send.resize( nInterfaces );
+    }
+}
+
+void Solver::InitFields()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+    }
+
+    Boundary();
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        int nZones = Global::zones.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Field * field = Global::fields[ iZone ];
+            Zone * zone = Global::zones[ iZone ];
+            zone->zoneIndex = iZone;
+            field->Solve( zone );
+        }
+        Boundary();
+    }
+}
+
+void Solver::Boundary()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+    ExchangeInterfaceField();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->UpdateOldField();
+    }
+}
+
+void Solver::ExchangeInterfaceFieldOldVersion()
+{
+    int nZones = Global::interfaces.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+            int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+
+            Field * donor_field = Global::fields[ donor_zoneid ];
+
+            double donor_value = donor_field->u[ i_donor_cell ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::ExchangeInterfaceFieldOldVersion1()
+{
+    int nZones = Global::interfaces.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ijkpos = index_dim * iFace;
+            int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+
+            Field * donor_field = Global::fields[ donor_zoneid ];
+            double donor_value = donor_field->u[ i_donor_cell ];
+            interface->data_recv[ iFace ] = donor_value;
+        }
+
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+
+            double donor_value = interface->data_recv[ iFace ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    int nZones = Global::interfaces.size();
+
+    //for ( int iZone = 0; iZone < nZones; ++ iZone )
+    //{
+    //    Field * field = Global::fields[ iZone ];
+
+    //    Interface * interface = Global::interfaces[ iZone ];
+    //    int nInterFaces = interface->zoneList.size();
+    //    int index_dim = 1;
+    //    for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+    //    {
+    //        int donor_zoneid = interface->zoneList[ iFace ];
+    //        int ijkpos = index_dim * iFace;
+    //        int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+
+    //        Field * donor_field = Global::fields[ donor_zoneid ];
+    //        double donor_value = donor_field->u[ i_donor_cell ];
+    //        interface->data_recv[ iFace ] = donor_value;
+    //        //interface->data_send[ iFace ] = donor_value;
+    //    }
+    //}
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ijkpos = index_dim * iFace;
+            int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+
+            Field * donor_field = Global::fields[ donor_zoneid ];
+            double donor_value = donor_field->u[ i_donor_cell ];
+            interface->data_recv[ iFace ] = donor_value;
+        }
+
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+
+            double donor_value = interface->data_recv[ iFace ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::PostProcess()
+{
+    Post post;
+    post.Process();
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    int nZones = Global::grids.size();
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        int ni = grid->x.size();
+        double xmin = grid->x[ 0 ];
+        double xmax = grid->x[ 0 ];
+        int imin = 0;
+        int imax = 0;
+        for ( int i = 0; i < ni; ++ i )
+        {
+            if ( xmin > grid->x[ i ] )
+            {
+                xmin = grid->x[ i ];
+                imin = i;
+            }
+            if ( xmax < grid->x[ i ] )
+            {
+                xmax = grid->x[ i ];
+                imax = i;
+            }
+        }
+        xmin_list.push_back( xmin );
+        xmax_list.push_back( xmax );
+    }
+    std::vector<std::pair<double, int>> pairs;
+    int nSize = xmin_list.size();
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        pairs.push_back( std::make_pair( xmin_list[i], i ) );
+    }
+
+    std::sort( pairs.begin(), pairs.end() );
+
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        this->zoneids.push_back( pairs[i].second );
+    }
+
+    int kkk = 1;
+}
+
+void Post::GatherField()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+        Grid * grid = Global::grids[ zoneid ];
+        Field * field = Global::fields[ zoneid ];
+
+        int ni = grid->x.size();
+
+        int ist = 1;
+        int ied = ni;
+
+        int dir = 1;
+        if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+        if ( dir == 1 )
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ist; i <= ied; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+
+            }
+            else
+            {
+                for ( int i = ist; i <= ied - 1; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+        else
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ied; i >= ist; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+            else
+            {
+                for ( int i = ied; i >= ist + 1; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+    }
+}
+
+void Post::DumpField()
+{
+    int ni_total = this->x.size();
+    std::cout << " DumpField x.size() = " << x.size() << "\n";
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    this->DumpErrorDetails( u_error );
+
+    std::string csvname = "field_final.csv";
+    this->DumpCsvFile( csvname, x, u_e, un, u_error );
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.20f} {:.20f} {:.20f} {:.20f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/Solver.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/Solver.h
new file mode 100644
index 00000000..e739edf7
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/Solver.h
@@ -0,0 +1,43 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+
+class Solver
+{
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveMultiZones();
+public:
+    void Boundary();
+    void ExchangeInterfaceField();
+    void ExchangeInterfaceFieldOldVersion();
+    void ExchangeInterfaceFieldOldVersion1();
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcess();
+};
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+    std::vector<double> u;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/global.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/global.cpp
new file mode 100644
index 00000000..67e1bb0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/global.cpp
@@ -0,0 +1,160 @@
+#include "global.h"
+#include "CgnsGrid.h"
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *> Global::interfaces;
+
+std::map<Face, int> Global::faceMap;
+std::map<FacePair, int> Global::facePairMap;
+std::vector<FacePair> Global::facePairList;
+
+bool Face::operator < ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return this->zone < rhs.zone;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return this->i < rhs.i;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return this->j < rhs.j;
+    }
+
+    return this->k < rhs.k;
+}
+
+bool Face::operator == ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return false;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return false;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return false;
+    }
+
+    return this->k == rhs.k;
+}
+
+void FacePair::AddPair( const Face & face1, const Face & face2 )
+{
+    if ( face1 < face2 )
+    {
+        this->left = face1;
+        this->right = face2;
+    }
+    else
+    {
+        this->left = face2;
+        this->right = face1;
+    }
+}
+
+bool FacePair::operator < ( const FacePair & rhs ) const
+{
+    if ( this->left == rhs.left || this->left == rhs.right )
+    {
+        return false;
+    }
+
+    return this->left < rhs.left;
+}
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->faceidList.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        Face face;
+        face.zone = zoneid;
+        face.i = i;
+
+        Global::InsertFaceMap( face );
+
+        int i_donor = index2[ 0 ];
+
+        Face face_donor;
+        face_donor.zone = donor_zoneid;
+        face_donor.i = i_donor;
+
+        Global::InsertFaceMap( face_donor );
+
+        FacePair facePair;
+        facePair.AddPair( face, face_donor );
+
+        Global::facePairList.push_back( facePair );
+        Global::InsertFacePairMap( facePair );
+
+        int i_ghost_cell = i + 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+
+        int i_donor_cell = i_donor - 1;
+
+        if ( i_donor == 1 )
+        {
+            i_donor_cell = i_donor + 1;
+        }
+
+        this->ijk_donors.push_back( i_donor_cell );
+
+        icount ++;
+    }
+}
+
+void Global::InsertFaceMap( const Face & face )
+{
+    std::map<Face, int>::iterator iter;
+    iter = Global::faceMap.find( face );
+    if ( iter == Global::faceMap.end() )
+    {
+        int faceid = Global::faceMap.size();
+        Global::faceMap.insert( std::make_pair( face, faceid ) );
+    }
+}
+
+void Global::InsertFacePairMap( const FacePair & facePair )
+{
+    std::map<FacePair, int>::iterator iter;
+    iter = Global::facePairMap.find( facePair );
+    if ( iter == Global::facePairMap.end() )
+    {
+        int facePairId = Global::facePairMap.size();
+        Global::facePairMap.insert( std::make_pair( facePair, facePairId ) );
+    }
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/global.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/global.h
new file mode 100644
index 00000000..8f54626e
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/global.h
@@ -0,0 +1,122 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class Face
+{
+public:
+    int zone = 0;
+    int i = 0;
+    int j = 1;
+    int k = 1;
+public:
+    bool operator < ( const Face & rhs ) const;
+    bool operator == ( const Face & rhs ) const;
+};
+
+class FacePair
+{
+public:
+    Face left;
+    Face right;
+public:
+    bool operator < ( const FacePair & rhs ) const;
+    void AddPair( const Face &face1, const Face &face2);
+};
+
+class Transform;
+
+class Interface
+{
+public:
+    int zoneid;
+    std::vector<int> zoneList;
+    std::vector<int> faceidList;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+    std::vector<double> data_recv;
+    std::vector<double> data_send;
+public:
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+};
+
+class Field;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+public:
+    static std::map<Face, int> faceMap;
+    static std::map<FacePair, int> facePairMap;
+    static std::vector<FacePair> facePairList;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+public:
+    static void InsertFaceMap( const Face & face );
+    static void InsertFacePairMap( const FacePair & facePair );
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/heat1d4blocksv1.cgns b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/heat1d4blocksv1.cgns
new file mode 100644
index 00000000..df5ffc5f
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/heat1d4blocksv1.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/main.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/main.cpp
new file mode 100644
index 00000000..fcce6376
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/main.cpp
@@ -0,0 +1,8 @@
+#include "Solver.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/plot.py b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01b/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/CMakeLists.txt
new file mode 100644
index 00000000..ee758c31
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/CMakeLists.txt
@@ -0,0 +1,79 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	Solver.h Solver.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/CgnsGrid.cpp
new file mode 100644
index 00000000..14e34203
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/CgnsGrid.cpp
@@ -0,0 +1,523 @@
+#include "CgnsGrid.h"
+#include "cgnslib.h"
+#include "global.h"
+#include <iostream>
+#include <vector>
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            Grid * grid = new Grid();
+            Global::grids.push_back( grid );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                //std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+
+                coor->DumpCoor();
+                if ( icoord == 0 )
+                {
+                    coor->DumpCoorX( grid->x );
+                }
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+            }
+        }
+    }
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/CgnsGrid.h
new file mode 100644
index 00000000..fddf1db6
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/CgnsGrid.h
@@ -0,0 +1,103 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    int zoneIndex;
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/Field.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/Field.cpp
new file mode 100644
index 00000000..16b28ddc
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/Field.cpp
@@ -0,0 +1,141 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+
+    std::vector<double> & x = grid->x;
+    this->dx = std::abs( x[ 1 ] - x[ 0 ] );
+    this->dt = dx / 10.0;
+    this->t = 1.0;
+    this->nt = std::round( t / dt );
+
+    double total_time = nt * dt;
+
+    std::cout << "this->dt   = " << this->dt << "\n";
+    std::cout << "this->t    = " << this->t << "\n";
+    std::cout << "this->nt   = " << this->nt << "\n";
+    std::cout << "this->ni   = " << this->ni << "\n";
+    std::cout << "total_time = " << total_time << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        u_e[ i ] = - std::exp( -total_time ) * std::sin( std::numbers::pi * xm ); //theory solution
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+}
+
+void Field::Solve( Zone * zone )
+{
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+    }
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        //std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        //region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+        int kkk = 1;
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
+
+void Field::UpdateOldField()
+{
+    for ( int i = 0; i < this->u.size(); ++ i )
+    {
+        this->un[ i ] = this->u[ i ];
+    }
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/Field.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/Field.h
new file mode 100644
index 00000000..084ec9bd
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/Field.h
@@ -0,0 +1,36 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid );
+
+    void Solve( Zone * zone );
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void UpdateOldField();
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/README.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/Solver.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/Solver.cpp
new file mode 100644
index 00000000..bcba6407
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/Solver.cpp
@@ -0,0 +1,654 @@
+#include "Solver.h"
+#include <fstream>
+#include <set>
+#include <unordered_map>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    this->InitTopo();
+    this->InitFields();
+    this->SolveMultiZones();
+    this->PostProcess();
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d4blocksv1.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    ReadCgnsGrid( fileName );
+}
+
+void Solver::InitTopo()
+{
+    int nZones = Global::grids.size();
+    Global::donor_zone_sets.resize( nZones );
+    Global::donor_zones.resize( nZones );
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = new Interface();
+        interface->zoneid = iZone;
+        Global::interfaces.push_back( interface );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+        Interface * interface = Global::interfaces[ iZone ];
+
+        int nbc1to1s = zone->bc1to1s.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+        int nInterfaces = interface->zoneList.size();
+        interface->data_recv.resize( nInterfaces );
+        interface->data_send.resize( nInterfaces );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        std::set<int> &donor_zoneSet = Global::donor_zone_sets[ iZone ];
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            donor_zoneSet.insert( donor_zoneid );
+        }
+
+        std::vector<int> &donor_zones = Global::donor_zones[ iZone ];
+        for ( std::set<int>::iterator iter = donor_zoneSet.begin(); iter != donor_zoneSet.end(); ++ iter )
+        {
+            donor_zones.push_back( *iter );
+        }
+
+        interface->neighbor_donor_zones = donor_zones;
+
+        std::unordered_map<int, int> donor_zonelocal;
+
+        for ( int idonor = 0; idonor < donor_zones.size(); ++ idonor )
+        {
+            int donor_zone = donor_zones[ idonor ];
+            donor_zonelocal.insert( std::make_pair( donor_zone, idonor ) );
+        }
+        int index_dim = 1;
+        int ndonors = donor_zones.size();
+        std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+        neighbor_donorfaces.resize( ndonors );
+
+        std::vector<std::vector<int>> & sub_local_faceids = interface->sub_local_faceids;
+        sub_local_faceids.resize( ndonors );
+
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ineighbor = donor_zonelocal[ donor_zoneid ];
+            std::vector<int> &donorfaces = neighbor_donorfaces[ ineighbor ];
+            int global_faceid = interface->global_faceids[ iFace ];
+            donorfaces.push_back( global_faceid );
+            int local_faceid = interface->local_faceids[ iFace ];
+
+            std::vector<int> & sub_local_faces = sub_local_faceids[ ineighbor ];
+            sub_local_faces.push_back( local_faceid );
+        }
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> &neighbor_donor_zones = interface->neighbor_donor_zones;
+        int ndonor_zones = neighbor_donor_zones.size();
+
+        std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donorzone = neighbor_donor_zones[ iNei ];
+            //std::cout << "donorzone = " << donorzone << " donorfaces = ";
+            std::vector<int> & neighbor_donorface = neighbor_donorfaces[ iNei ];
+
+            Global::SendGeom( iZone, donorzone, neighbor_donorface );
+        }
+        int kkk = 1;
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+        std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+
+        std::vector<int> &neighbor_donor_zones = interface->neighbor_donor_zones;
+        int ndonor_zones = neighbor_donor_zones.size();
+        std::cout << "zone = " << iZone << " donorzone = ";
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donorzone = neighbor_donor_zones[ iNei ];
+            std::cout << donorzone;
+            if( iNei != ndonor_zones - 1 )
+            {
+                std::cout << ",";
+            }
+        }
+        std::cout << "\n";
+
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donorzone = neighbor_donor_zones[ iNei ];
+            std::cout << "donorzone = " << donorzone << " donorfaces = ";
+            std::vector<int> & neighbor_donorface = neighbor_donorfaces[ iNei ];
+            int ndonorfaces = neighbor_donorface.size();
+            for ( int idonorface = 0; idonorface < ndonorfaces; ++ idonorface )
+            {
+                std::cout <<  neighbor_donorface[ idonorface ];
+                if( idonorface != ndonorfaces - 1 )
+                {
+                    std::cout << ",";
+                }
+            }
+            std::cout << "\n";
+        }
+        std::cout << "\n";
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        std::cout << "zone = " << iZone << "\n";
+
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> & send_to_zones = interface->send_to_zones;
+        int nsend_zones = send_to_zones.size();
+
+        std::vector<std::vector<int>> & donorfaces_for_send = interface->donorfaces_for_send;
+
+        for ( int iSend = 0; iSend < nsend_zones; ++ iSend )
+        {
+            int zone_to_send = send_to_zones[ iSend ];
+            std::cout << "zone_to_send = " << zone_to_send << " donorfaces_for_send = ";
+            std::vector<int> & donorfaces = donorfaces_for_send[ iSend ];
+            int nFace = donorfaces.size();
+            for ( int iFace = 0; iFace < nFace; ++ iFace )
+            {
+                std::cout <<  donorfaces[ iFace ];
+                if( iFace != nFace - 1 )
+                {
+                    std::cout << ",";
+                }
+            }
+            std::cout << "\n";
+        }
+        int kkk = 1;
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        std::cout << "zone = " << iZone << "\n";
+
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> & send_to_zones = interface->send_to_zones;
+        int nsend_zones = send_to_zones.size();
+
+        std::vector<std::vector<int>> & donorfaces_for_send = interface->donorfaces_for_send;
+
+        for ( int iSend = 0; iSend < nsend_zones; ++ iSend )
+        {
+            int zone_to_send = send_to_zones[ iSend ];
+            std::vector<int> & donorfaces = donorfaces_for_send[ iSend ];
+            Global::ReSendGeomTest( iZone, zone_to_send, donorfaces );
+        }
+        int kkk = 1;
+    }
+
+    std::cout << "\n";
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        std::cout << "zone = " << iZone << "\n";
+
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> & neighbor_donor_zones = interface->neighbor_donor_zones;
+        int ndonor_zones = neighbor_donor_zones.size();
+
+        std::vector<std::vector<int>> & donorfaces_for_send = interface->donorfaces_for_send;
+
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donorzone = neighbor_donor_zones[ iNei ];
+            int tmp_recv_donor_zone = interface->tmp_recv_donor_zones[ iNei ];
+
+            std::cout << "donorzone = " << donorzone << " tmp_recv_donor_zone = " << tmp_recv_donor_zone << "\n";
+            std::vector<int> & neighbor_donorfaces = interface->neighbor_donorfaces[ iNei ];
+            std::cout << "neighbor_donorfaces\n";
+            for ( int i = 0; i < neighbor_donorfaces.size(); ++ i )
+            {
+                std::cout << neighbor_donorfaces[ i ] << " ";
+            }
+            std::cout << "\n";
+            std::vector<int> & tmp_recv_donorfaces = interface->tmp_recv_donorfaces[ iNei ];
+            std::cout << "tmp_recv_donorfaces\n";
+            for ( int i = 0; i < tmp_recv_donorfaces.size(); ++ i )
+            {
+                std::cout << tmp_recv_donorfaces[ i ] << " ";
+            }
+            std::cout << "\n";
+        }
+    }
+
+    int kkk = 1;
+}
+
+void Solver::InitFields()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+    }
+
+    Boundary();
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        int nZones = Global::zones.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Field * field = Global::fields[ iZone ];
+            Zone * zone = Global::zones[ iZone ];
+            zone->zoneIndex = iZone;
+            field->Solve( zone );
+        }
+        Boundary();
+    }
+}
+
+void Solver::Boundary()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+    ExchangeInterfaceField();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->UpdateOldField();
+    }
+}
+
+void Solver::ExchangeInterfaceFieldOldVersion()
+{
+    int nZones = Global::interfaces.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+            int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+
+            Field * donor_field = Global::fields[ donor_zoneid ];
+
+            double donor_value = donor_field->u[ i_donor_cell ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::ExchangeInterfaceFieldOldVersion1()
+{
+    int nZones = Global::interfaces.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ijkpos = index_dim * iFace;
+            int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+
+            Field * donor_field = Global::fields[ donor_zoneid ];
+            double donor_value = donor_field->u[ i_donor_cell ];
+            interface->data_recv[ iFace ] = donor_value;
+        }
+
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+
+            double donor_value = interface->data_recv[ iFace ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    int nZones = Global::interfaces.size();
+
+    //zone0:
+    //donor zone2 donorfaces(0)
+    //zone0->send_geom(zone=2,facelist(0)) : 
+    //  zone2->recv_geom(zone=0,facelist(0));
+    //  zone2->get_value(facelist(0),valuelist(200));
+    //  zone2->send_value(zone=0,valuelist(200));
+    //zone0->recv_value(zone=2,valuelist(200));
+    
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> & neighbor_donor_zones = interface->neighbor_donor_zones;
+        int ndonor_zones = neighbor_donor_zones.size();
+
+        std::cout << "zone = " << iZone << "\n";
+
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donorzone = neighbor_donor_zones[ iNei ];
+            std::cout << "donorzone = " << donorzone << "\n";
+            std::vector<int> & neighbor_donorfaces = interface->neighbor_donorfaces[ iNei ];
+            std::vector<int> & sub_local_faceids = interface->sub_local_faceids[ iNei ];
+            for ( int i = 0; i < neighbor_donorfaces.size(); ++ i )
+            {
+                int global_faceid = neighbor_donorfaces[ i ];
+                int local_faceid = interface->global_local_face_map[ global_faceid ];
+                int mylocal = sub_local_faceids[ i ];
+                std::cout << " global_faceid = " << global_faceid << " local_faceid = " << local_faceid 
+                    << " mylocal = " << mylocal << "\n";
+            }
+        }
+    }
+    int kkk = 1;
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ijkpos = index_dim * iFace;
+            int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+
+            Field * donor_field = Global::fields[ donor_zoneid ];
+            double donor_value = donor_field->u[ i_donor_cell ];
+            interface->data_recv[ iFace ] = donor_value;
+        }
+
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+
+            double donor_value = interface->data_recv[ iFace ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::PostProcess()
+{
+    Post post;
+    post.Process();
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    int nZones = Global::grids.size();
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        int ni = grid->x.size();
+        double xmin = grid->x[ 0 ];
+        double xmax = grid->x[ 0 ];
+        int imin = 0;
+        int imax = 0;
+        for ( int i = 0; i < ni; ++ i )
+        {
+            if ( xmin > grid->x[ i ] )
+            {
+                xmin = grid->x[ i ];
+                imin = i;
+            }
+            if ( xmax < grid->x[ i ] )
+            {
+                xmax = grid->x[ i ];
+                imax = i;
+            }
+        }
+        xmin_list.push_back( xmin );
+        xmax_list.push_back( xmax );
+    }
+    std::vector<std::pair<double, int>> pairs;
+    int nSize = xmin_list.size();
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        pairs.push_back( std::make_pair( xmin_list[i], i ) );
+    }
+
+    std::sort( pairs.begin(), pairs.end() );
+
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        this->zoneids.push_back( pairs[i].second );
+    }
+
+    int kkk = 1;
+}
+
+void Post::GatherField()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+        Grid * grid = Global::grids[ zoneid ];
+        Field * field = Global::fields[ zoneid ];
+
+        int ni = grid->x.size();
+
+        int ist = 1;
+        int ied = ni;
+
+        int dir = 1;
+        if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+        if ( dir == 1 )
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ist; i <= ied; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+
+            }
+            else
+            {
+                for ( int i = ist; i <= ied - 1; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+        else
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ied; i >= ist; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+            else
+            {
+                for ( int i = ied; i >= ist + 1; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+    }
+}
+
+void Post::DumpField()
+{
+    int ni_total = this->x.size();
+    std::cout << " DumpField x.size() = " << x.size() << "\n";
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    this->DumpErrorDetails( u_error );
+
+    std::string csvname = "field_final.csv";
+    this->DumpCsvFile( csvname, x, u_e, un, u_error );
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.20f} {:.20f} {:.20f} {:.20f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/Solver.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/Solver.h
new file mode 100644
index 00000000..e739edf7
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/Solver.h
@@ -0,0 +1,43 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+
+class Solver
+{
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveMultiZones();
+public:
+    void Boundary();
+    void ExchangeInterfaceField();
+    void ExchangeInterfaceFieldOldVersion();
+    void ExchangeInterfaceFieldOldVersion1();
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcess();
+};
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+    std::vector<double> u;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/global.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/global.cpp
new file mode 100644
index 00000000..236b90d7
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/global.cpp
@@ -0,0 +1,185 @@
+#include "global.h"
+#include "CgnsGrid.h"
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *> Global::interfaces;
+
+std::map<Face, int> Global::faceMap;
+std::map<FacePair, int> Global::facePairMap;
+std::vector<FacePair> Global::facePairList;
+
+std::vector<std::set<int>> Global::donor_zone_sets;
+std::vector<std::vector<int>> Global::donor_zones;
+
+bool Face::operator < ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return this->zone < rhs.zone;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return this->i < rhs.i;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return this->j < rhs.j;
+    }
+
+    return this->k < rhs.k;
+}
+
+bool Face::operator == ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return false;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return false;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return false;
+    }
+
+    return this->k == rhs.k;
+}
+
+void FacePair::AddPair( const Face & face1, const Face & face2 )
+{
+    if ( face1 < face2 )
+    {
+        this->left = face1;
+        this->right = face2;
+    }
+    else
+    {
+        this->left = face2;
+        this->right = face1;
+    }
+}
+
+bool FacePair::operator < ( const FacePair & rhs ) const
+{
+    if ( this->left == rhs.left || this->left == rhs.right )
+    {
+        return false;
+    }
+
+    return this->left < rhs.left;
+}
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->local_faceids.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        Face face;
+        face.zone = zoneid;
+        face.i = i;
+
+        Global::InsertFaceMap( face );
+
+        int i_donor = index2[ 0 ];
+
+        Face face_donor;
+        face_donor.zone = donor_zoneid;
+        face_donor.i = i_donor;
+
+        Global::InsertFaceMap( face_donor );
+
+        FacePair facePair;
+        facePair.AddPair( face, face_donor );
+
+        Global::facePairList.push_back( facePair );
+        int global_faceid = Global::InsertFacePairMap( facePair );
+        this->global_faceids.push_back( global_faceid );
+
+        this->global_local_face_map.insert( std::make_pair( global_faceid, faceid ) );
+
+        int i_ghost_cell = i + 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+
+        int i_donor_cell = i_donor - 1;
+
+        if ( i_donor == 1 )
+        {
+            i_donor_cell = i_donor + 1;
+        }
+
+        this->ijk_donors.push_back( i_donor_cell );
+
+        icount ++;
+    }
+}
+
+void Global::InsertFaceMap( const Face & face )
+{
+    std::map<Face, int>::iterator iter;
+    iter = Global::faceMap.find( face );
+    if ( iter == Global::faceMap.end() )
+    {
+        int faceid = Global::faceMap.size();
+        Global::faceMap.insert( std::make_pair( face, faceid ) );
+    }
+}
+
+int Global::InsertFacePairMap( const FacePair & facePair )
+{
+    std::map<FacePair, int>::iterator iter;
+    iter = Global::facePairMap.find( facePair );
+    if ( iter == Global::facePairMap.end() )
+    {
+        int facePairId = Global::facePairMap.size();
+        Global::facePairMap.insert( std::make_pair( facePair, facePairId ) );
+        return facePairId;
+    }
+    return iter->second;
+}
+
+void Global::SendGeom( int zone, int donorzone, std::vector<int> & donorfaces )
+{
+    Interface * interface = Global::interfaces[ donorzone ];
+
+    std::vector<int> & send_to_zones = interface->send_to_zones;
+
+    send_to_zones.push_back( zone );
+    interface->donorfaces_for_send.push_back( donorfaces );
+}
+
+void Global::ReSendGeomTest( int zone, int zone_to_send, std::vector<int> & donorfaces )
+{
+    Interface * interface = Global::interfaces[ zone_to_send ];
+    interface->tmp_recv_donor_zones.push_back( zone );
+    interface->tmp_recv_donorfaces.push_back( donorfaces );
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/global.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/global.h
new file mode 100644
index 00000000..ed0a20ff
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/global.h
@@ -0,0 +1,142 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <unordered_map>
+#include <set>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class Face
+{
+public:
+    int zone = 0;
+    int i = 0;
+    int j = 1;
+    int k = 1;
+public:
+    bool operator < ( const Face & rhs ) const;
+    bool operator == ( const Face & rhs ) const;
+};
+
+class FacePair
+{
+public:
+    Face left;
+    Face right;
+public:
+    bool operator < ( const FacePair & rhs ) const;
+    void AddPair( const Face &face1, const Face &face2);
+};
+
+class Transform;
+
+
+class Interface
+{
+public:
+    int zoneid;
+    std::vector<int> zoneList;
+    std::vector<int> global_faceids;
+    std::vector<int> local_faceids;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+    std::vector<double> data_recv;
+    std::vector<double> data_send;
+    std::unordered_map<int, int> global_local_face_map;
+public:
+    std::vector<int> neighbor_donor_zones;
+    std::vector<std::vector<int>> neighbor_donorfaces;
+    std::vector<std::vector<int>> sub_local_faceids;
+    std::vector<int> send_to_zones;
+    std::vector<std::vector<int>> donorfaces_for_send;
+    std::vector<int> tmp_recv_donor_zones;
+    std::vector<std::vector<int>> tmp_recv_donorfaces;
+public:
+    std::vector<int> recv_donor_zones;
+    std::vector<std::vector<double>> recv_donor_fields;
+public:
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+};
+
+class Field;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+public:
+    static std::map<Face, int> faceMap;
+    static std::map<FacePair, int> facePairMap;
+    static std::vector<FacePair> facePairList;
+    static std::vector<std::set<int>> donor_zone_sets;
+    static std::vector<std::vector<int>> donor_zones;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+public:
+    static void InsertFaceMap( const Face & face );
+    static int InsertFacePairMap( const FacePair & facePair );
+    static void SendGeom( int zone, int donorzone, std::vector<int> & donorfaces );
+    static void ReSendGeomTest( int zone, int zone_to_send, std::vector<int> & donorfaces );
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/heat1d4blocksv1.cgns b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/heat1d4blocksv1.cgns
new file mode 100644
index 00000000..df5ffc5f
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/heat1d4blocksv1.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/main.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/main.cpp
new file mode 100644
index 00000000..fcce6376
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/main.cpp
@@ -0,0 +1,8 @@
+#include "Solver.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/plot.py b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01c/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/CMakeLists.txt
new file mode 100644
index 00000000..ee758c31
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/CMakeLists.txt
@@ -0,0 +1,79 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	Solver.h Solver.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/CgnsGrid.cpp
new file mode 100644
index 00000000..14e34203
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/CgnsGrid.cpp
@@ -0,0 +1,523 @@
+#include "CgnsGrid.h"
+#include "cgnslib.h"
+#include "global.h"
+#include <iostream>
+#include <vector>
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            Grid * grid = new Grid();
+            Global::grids.push_back( grid );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                //std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+
+                coor->DumpCoor();
+                if ( icoord == 0 )
+                {
+                    coor->DumpCoorX( grid->x );
+                }
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+            }
+        }
+    }
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/CgnsGrid.h
new file mode 100644
index 00000000..fddf1db6
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/CgnsGrid.h
@@ -0,0 +1,103 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    int zoneIndex;
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/Field.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/Field.cpp
new file mode 100644
index 00000000..c359a811
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/Field.cpp
@@ -0,0 +1,142 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+
+    std::vector<double> & x = grid->x;
+    this->dx = std::abs( x[ 1 ] - x[ 0 ] );
+    this->dt = dx / 10.0;
+    this->t = 1.0;
+    this->nt = std::round( t / dt );
+
+    double total_time = nt * dt;
+
+    std::cout << "this->dt   = " << this->dt << "\n";
+    std::cout << "this->t    = " << this->t << "\n";
+    std::cout << "this->nt   = " << this->nt << "\n";
+    std::cout << "this->ni   = " << this->ni << "\n";
+    std::cout << "total_time = " << total_time << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        u_e[ i ] = - std::exp( -total_time ) * std::sin( std::numbers::pi * xm ); //theory solution
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+    int kkk = 1;
+}
+
+void Field::Solve( Zone * zone )
+{
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+    }
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        //std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        //region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+        int kkk = 1;
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
+
+void Field::UpdateOldField()
+{
+    for ( int i = 0; i < this->u.size(); ++ i )
+    {
+        this->un[ i ] = this->u[ i ];
+    }
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/Field.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/Field.h
new file mode 100644
index 00000000..084ec9bd
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/Field.h
@@ -0,0 +1,36 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid );
+
+    void Solve( Zone * zone );
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void UpdateOldField();
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/README.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/Solver.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/Solver.cpp
new file mode 100644
index 00000000..f97e4454
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/Solver.cpp
@@ -0,0 +1,648 @@
+#include "Solver.h"
+#include <fstream>
+#include <set>
+#include <unordered_map>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    this->InitTopo();
+    this->InitFields();
+    this->SolveMultiZones();
+    this->PostProcess();
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d4blocksv1.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    ReadCgnsGrid( fileName );
+}
+
+void Solver::InitTopo()
+{
+    int nZones = Global::grids.size();
+    Global::donor_zone_sets.resize( nZones );
+    Global::donor_zones.resize( nZones );
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = new Interface();
+        interface->zoneid = iZone;
+        Global::interfaces.push_back( interface );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+        Interface * interface = Global::interfaces[ iZone ];
+
+        int nbc1to1s = zone->bc1to1s.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+        int nInterfaces = interface->zoneList.size();
+        interface->data_recv.resize( nInterfaces );
+        interface->data_send.resize( nInterfaces );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        std::set<int> &donor_zoneSet = Global::donor_zone_sets[ iZone ];
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            donor_zoneSet.insert( donor_zoneid );
+        }
+
+        std::vector<int> &donor_zones = Global::donor_zones[ iZone ];
+        for ( std::set<int>::iterator iter = donor_zoneSet.begin(); iter != donor_zoneSet.end(); ++ iter )
+        {
+            donor_zones.push_back( *iter );
+        }
+
+        interface->neighbor_donor_zones = donor_zones;
+
+        std::unordered_map<int, int> donor_zonelocal;
+
+        for ( int idonor = 0; idonor < donor_zones.size(); ++ idonor )
+        {
+            int donor_zone = donor_zones[ idonor ];
+            donor_zonelocal.insert( std::make_pair( donor_zone, idonor ) );
+        }
+        int index_dim = 1;
+        int ndonors = donor_zones.size();
+        std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+        neighbor_donorfaces.resize( ndonors );
+
+        std::vector<std::vector<int>> & sub_local_faceids = interface->sub_local_faceids;
+        sub_local_faceids.resize( ndonors );
+
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ineighbor = donor_zonelocal[ donor_zoneid ];
+            std::vector<int> &donorfaces = neighbor_donorfaces[ ineighbor ];
+            int global_faceid = interface->global_faceids[ iFace ];
+            donorfaces.push_back( global_faceid );
+            int local_faceid = interface->local_faceids[ iFace ];
+
+            std::vector<int> & sub_local_faces = sub_local_faceids[ ineighbor ];
+            sub_local_faces.push_back( local_faceid );
+        }
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> &neighbor_donor_zones = interface->neighbor_donor_zones;
+        int ndonor_zones = neighbor_donor_zones.size();
+
+        std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donorzone = neighbor_donor_zones[ iNei ];
+            //std::cout << "donorzone = " << donorzone << " donorfaces = ";
+            std::vector<int> & neighbor_donorface = neighbor_donorfaces[ iNei ];
+
+            Global::SendGeom( iZone, donorzone, neighbor_donorface );
+        }
+        int kkk = 1;
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+        std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+
+        std::vector<int> &neighbor_donor_zones = interface->neighbor_donor_zones;
+        int ndonor_zones = neighbor_donor_zones.size();
+        std::cout << "zone = " << iZone << " donorzone = ";
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donorzone = neighbor_donor_zones[ iNei ];
+            std::cout << donorzone;
+            if( iNei != ndonor_zones - 1 )
+            {
+                std::cout << ",";
+            }
+        }
+        std::cout << "\n";
+
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donorzone = neighbor_donor_zones[ iNei ];
+            std::cout << "donorzone = " << donorzone << " donorfaces = ";
+            std::vector<int> & neighbor_donorface = neighbor_donorfaces[ iNei ];
+            int ndonorfaces = neighbor_donorface.size();
+            for ( int idonorface = 0; idonorface < ndonorfaces; ++ idonorface )
+            {
+                std::cout <<  neighbor_donorface[ idonorface ];
+                if( idonorface != ndonorfaces - 1 )
+                {
+                    std::cout << ",";
+                }
+            }
+            std::cout << "\n";
+        }
+        std::cout << "\n";
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        std::cout << "zone = " << iZone << "\n";
+
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> & send_to_zones = interface->send_to_zones;
+        int nsend_zones = send_to_zones.size();
+
+        std::vector<std::vector<int>> & donorfaces_for_send = interface->donorfaces_for_send;
+
+        for ( int iSend = 0; iSend < nsend_zones; ++ iSend )
+        {
+            int zone_to_send = send_to_zones[ iSend ];
+            std::cout << "zone_to_send = " << zone_to_send << " donorfaces_for_send = ";
+            std::vector<int> & donorfaces = donorfaces_for_send[ iSend ];
+            int nFace = donorfaces.size();
+            for ( int iFace = 0; iFace < nFace; ++ iFace )
+            {
+                std::cout <<  donorfaces[ iFace ];
+                if( iFace != nFace - 1 )
+                {
+                    std::cout << ",";
+                }
+            }
+            std::cout << "\n";
+        }
+        int kkk = 1;
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        std::cout << "zone = " << iZone << "\n";
+
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> & send_to_zones = interface->send_to_zones;
+        int nsend_zones = send_to_zones.size();
+
+        std::vector<std::vector<int>> & donorfaces_for_send = interface->donorfaces_for_send;
+
+        for ( int iSend = 0; iSend < nsend_zones; ++ iSend )
+        {
+            int zone_to_send = send_to_zones[ iSend ];
+            std::vector<int> & donorfaces = donorfaces_for_send[ iSend ];
+            Global::ReSendGeomTest( iZone, zone_to_send, donorfaces );
+        }
+        int kkk = 1;
+    }
+
+    std::cout << "\n";
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        std::cout << "zone = " << iZone << "\n";
+
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> & neighbor_donor_zones = interface->neighbor_donor_zones;
+        int ndonor_zones = neighbor_donor_zones.size();
+
+        std::vector<std::vector<int>> & donorfaces_for_send = interface->donorfaces_for_send;
+
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donorzone = neighbor_donor_zones[ iNei ];
+            int tmp_recv_donor_zone = interface->tmp_recv_donor_zones[ iNei ];
+
+            std::cout << "donorzone = " << donorzone << " tmp_recv_donor_zone = " << tmp_recv_donor_zone << "\n";
+            std::vector<int> & neighbor_donorfaces = interface->neighbor_donorfaces[ iNei ];
+            std::cout << "neighbor_donorfaces\n";
+            for ( int i = 0; i < neighbor_donorfaces.size(); ++ i )
+            {
+                std::cout << neighbor_donorfaces[ i ] << " ";
+            }
+            std::cout << "\n";
+            std::vector<int> & tmp_recv_donorfaces = interface->tmp_recv_donorfaces[ iNei ];
+            std::cout << "tmp_recv_donorfaces\n";
+            for ( int i = 0; i < tmp_recv_donorfaces.size(); ++ i )
+            {
+                std::cout << tmp_recv_donorfaces[ i ] << " ";
+            }
+            std::cout << "\n";
+        }
+    }
+
+    int kkk = 1;
+}
+
+void Solver::InitFields()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+    }
+
+    Boundary();
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        int nZones = Global::zones.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Field * field = Global::fields[ iZone ];
+            Zone * zone = Global::zones[ iZone ];
+            zone->zoneIndex = iZone;
+            field->Solve( zone );
+        }
+        Boundary();
+    }
+}
+
+void Solver::Boundary()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+    ExchangeInterfaceField();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->UpdateOldField();
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    int nZones = Global::interfaces.size();
+
+    //zone0:
+    //donor zone2 donorfaces(0)
+    //zone0->send_geom(zone=2,facelist(0)) : 
+    //  zone2->recv_geom(zone=0,facelist(0));
+    //  zone2->get_value(facelist(0),valuelist(200));
+    //  zone2->send_value(zone=0,valuelist(200));
+    //zone0->recv_value(zone=2,valuelist(200));
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> & send_to_zones = interface->send_to_zones;
+        int nsend_zones = send_to_zones.size();
+
+        std::vector<std::vector<int>> & donorfaces_for_send = interface->donorfaces_for_send;
+        std::vector<std::vector<int>> & donorijk_for_send = interface->donorijk_for_send;
+        std::vector<std::vector<double>> & donordata_for_send = interface->donordata_for_send;
+
+        Field * field = Global::fields[ iZone ];
+
+        for ( int iSend = 0; iSend < nsend_zones; ++ iSend )
+        {
+            int zone_to_send = send_to_zones[ iSend ];
+            std::vector<int> & donorfaces = donorfaces_for_send[ iSend ];
+            std::vector<int> & donorijks = donorijk_for_send[ iSend ];
+            std::vector<double> & donordatas = donordata_for_send[ iSend ];
+
+            int nface = donorfaces.size();
+            int index_dim = 1;
+            for ( int i = 0; i < nface; ++ i )
+            {
+                int ijkpos = index_dim * i;
+                int i_donor_cell = donorijks[ ijkpos + 0 ];
+                donordatas[ i ] = field->u[ i_donor_cell ];
+            }
+        }
+    }
+    int kkk = 1;
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+
+        std::vector<int> & neighbor_donor_zones = interface->neighbor_donor_zones;
+        int ndonor_zones = neighbor_donor_zones.size();
+
+        std::vector<std::vector<double>> & recv_donor_fields = interface->recv_donor_fields;
+
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donorzone = neighbor_donor_zones[ iNei ];
+            std::cout << "donorzone = " << donorzone << "\n";
+            Interface * donor_interface = Global::interfaces[ donorzone ];
+            int nSize = donor_interface->send_to_zones.size();
+            int ipos = -1;
+            for ( int i = 0; i < nSize; ++ i )
+            {
+                int szone = donor_interface->send_to_zones[ i ];
+                if ( szone == iZone )
+                {
+                    ipos = i;
+                    break;
+                }
+            }
+            std::vector<double> & donordata = donor_interface->donordata_for_send[ ipos ];
+
+            std::vector<int> & neighbor_donorfaces = interface->neighbor_donorfaces[ iNei ];
+            std::vector<int> & sub_local_faceids = interface->sub_local_faceids[ iNei ];
+            for ( int i = 0; i < neighbor_donorfaces.size(); ++ i )
+            {
+                int local_faceid = sub_local_faceids[ i ];
+                double donor_value = donordata[ i ];
+                interface->data_recv[ local_faceid ] = donor_value;
+            }
+        }
+
+        //for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        //{
+        //    int donor_zoneid = interface->zoneList[ iFace ];
+        //    int ijkpos = index_dim * iFace;
+        //    int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+
+        //    Field * donor_field = Global::fields[ donor_zoneid ];
+        //    double donor_value = donor_field->u[ i_donor_cell ];
+        //    interface->data_recv[ iFace ] = donor_value;
+        //}
+
+        int index_dim = 1;
+        std::vector<double> rrr( nInterFaces );
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ijkpos = index_dim * iFace;
+            int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+
+            Field * donor_field = Global::fields[ donor_zoneid ];
+            double donor_value = donor_field->u[ i_donor_cell ];
+            rrr[ iFace ] = donor_value;
+        }
+
+
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+
+            double donor_value = interface->data_recv[ iFace ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::PostProcess()
+{
+    Post post;
+    post.Process();
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    int nZones = Global::grids.size();
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        int ni = grid->x.size();
+        double xmin = grid->x[ 0 ];
+        double xmax = grid->x[ 0 ];
+        int imin = 0;
+        int imax = 0;
+        for ( int i = 0; i < ni; ++ i )
+        {
+            if ( xmin > grid->x[ i ] )
+            {
+                xmin = grid->x[ i ];
+                imin = i;
+            }
+            if ( xmax < grid->x[ i ] )
+            {
+                xmax = grid->x[ i ];
+                imax = i;
+            }
+        }
+        xmin_list.push_back( xmin );
+        xmax_list.push_back( xmax );
+    }
+    std::vector<std::pair<double, int>> pairs;
+    int nSize = xmin_list.size();
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        pairs.push_back( std::make_pair( xmin_list[i], i ) );
+    }
+
+    std::sort( pairs.begin(), pairs.end() );
+
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        this->zoneids.push_back( pairs[i].second );
+    }
+
+    int kkk = 1;
+}
+
+void Post::GatherField()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+        Grid * grid = Global::grids[ zoneid ];
+        Field * field = Global::fields[ zoneid ];
+
+        int ni = grid->x.size();
+
+        int ist = 1;
+        int ied = ni;
+
+        int dir = 1;
+        if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+        if ( dir == 1 )
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ist; i <= ied; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+
+            }
+            else
+            {
+                for ( int i = ist; i <= ied - 1; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+        else
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ied; i >= ist; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+            else
+            {
+                for ( int i = ied; i >= ist + 1; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+    }
+}
+
+void Post::DumpField()
+{
+    int ni_total = this->x.size();
+    std::cout << " DumpField x.size() = " << x.size() << "\n";
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    this->DumpErrorDetails( u_error );
+
+    std::string csvname = "field_final.csv";
+    this->DumpCsvFile( csvname, x, u_e, un, u_error );
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.20f} {:.20f} {:.20f} {:.20f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/Solver.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/Solver.h
new file mode 100644
index 00000000..c50415cf
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/Solver.h
@@ -0,0 +1,41 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+
+class Solver
+{
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveMultiZones();
+public:
+    void Boundary();
+    void ExchangeInterfaceField();
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcess();
+};
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+    std::vector<double> u;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/global.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/global.cpp
new file mode 100644
index 00000000..27ae141f
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/global.cpp
@@ -0,0 +1,206 @@
+#include "global.h"
+#include "CgnsGrid.h"
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *> Global::interfaces;
+
+std::map<Face, int> Global::faceMap;
+std::map<FacePair, int> Global::facePairMap;
+std::vector<FacePair> Global::facePairList;
+
+std::vector<std::set<int>> Global::donor_zone_sets;
+std::vector<std::vector<int>> Global::donor_zones;
+
+bool Face::operator < ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return this->zone < rhs.zone;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return this->i < rhs.i;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return this->j < rhs.j;
+    }
+
+    return this->k < rhs.k;
+}
+
+bool Face::operator == ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return false;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return false;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return false;
+    }
+
+    return this->k == rhs.k;
+}
+
+void FacePair::AddPair( const Face & face1, const Face & face2 )
+{
+    if ( face1 < face2 )
+    {
+        this->left = face1;
+        this->right = face2;
+    }
+    else
+    {
+        this->left = face2;
+        this->right = face1;
+    }
+}
+
+bool FacePair::operator < ( const FacePair & rhs ) const
+{
+    if ( this->left == rhs.left || this->left == rhs.right )
+    {
+        return false;
+    }
+
+    return this->left < rhs.left;
+}
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->local_faceids.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        Face face;
+        face.zone = zoneid;
+        face.i = i;
+
+        Global::InsertFaceMap( face );
+
+        int i_donor = index2[ 0 ];
+
+        Face face_donor;
+        face_donor.zone = donor_zoneid;
+        face_donor.i = i_donor;
+
+        Global::InsertFaceMap( face_donor );
+
+        FacePair facePair;
+        facePair.AddPair( face, face_donor );
+
+        Global::facePairList.push_back( facePair );
+        int global_faceid = Global::InsertFacePairMap( facePair );
+        this->global_faceids.push_back( global_faceid );
+
+        this->global_local_face_map.insert( std::make_pair( global_faceid, faceid ) );
+
+        int i_ghost_cell = i + 1;
+        int i_local_donor_cell = i - 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+            i_local_donor_cell = i + 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+        ijk_local_donors.push_back( i_local_donor_cell );
+
+        int i_donor_cell = i_donor - 1;
+
+        if ( i_donor == 1 )
+        {
+            i_donor_cell = i_donor + 1;
+        }
+
+        this->ijk_donors.push_back( i_donor_cell );
+
+        icount ++;
+    }
+}
+
+void Global::InsertFaceMap( const Face & face )
+{
+    std::map<Face, int>::iterator iter;
+    iter = Global::faceMap.find( face );
+    if ( iter == Global::faceMap.end() )
+    {
+        int faceid = Global::faceMap.size();
+        Global::faceMap.insert( std::make_pair( face, faceid ) );
+    }
+}
+
+int Global::InsertFacePairMap( const FacePair & facePair )
+{
+    std::map<FacePair, int>::iterator iter;
+    iter = Global::facePairMap.find( facePair );
+    if ( iter == Global::facePairMap.end() )
+    {
+        int facePairId = Global::facePairMap.size();
+        Global::facePairMap.insert( std::make_pair( facePair, facePairId ) );
+        return facePairId;
+    }
+    return iter->second;
+}
+
+void Global::SendGeom( int zone, int donorzone, std::vector<int> & donorfaces )
+{
+    Interface * interface = Global::interfaces[ donorzone ];
+
+    std::vector<int> & send_to_zones = interface->send_to_zones;
+
+    send_to_zones.push_back( zone );
+    interface->donorfaces_for_send.push_back( donorfaces );
+
+    int nface = donorfaces.size();
+    std::vector<int> sub_donorijk;
+    int index_dim = 1;
+    for ( int i = 0; i < nface; ++ i )
+    {
+        int global_faceid = donorfaces[ i ];
+        int local_faceid = interface->global_local_face_map[ global_faceid ];
+        int ijkpos = index_dim * local_faceid;
+        int i_donor_cell = interface->ijk_local_donors[ ijkpos + 0 ];
+        sub_donorijk.push_back( i_donor_cell );
+        int kkk = 1;
+    }
+
+    interface->donorijk_for_send.push_back( sub_donorijk );
+
+    std::vector<double> sub_donordata( sub_donorijk.size() );
+    interface->donordata_for_send.push_back( sub_donordata );
+}
+
+void Global::ReSendGeomTest( int zone, int zone_to_send, std::vector<int> & donorfaces )
+{
+    Interface * interface = Global::interfaces[ zone_to_send ];
+    interface->tmp_recv_donor_zones.push_back( zone );
+    interface->tmp_recv_donorfaces.push_back( donorfaces );
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/global.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/global.h
new file mode 100644
index 00000000..7de16ba6
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/global.h
@@ -0,0 +1,145 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <unordered_map>
+#include <set>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class Face
+{
+public:
+    int zone = 0;
+    int i = 0;
+    int j = 1;
+    int k = 1;
+public:
+    bool operator < ( const Face & rhs ) const;
+    bool operator == ( const Face & rhs ) const;
+};
+
+class FacePair
+{
+public:
+    Face left;
+    Face right;
+public:
+    bool operator < ( const FacePair & rhs ) const;
+    void AddPair( const Face &face1, const Face &face2);
+};
+
+class Transform;
+
+
+class Interface
+{
+public:
+    int zoneid;
+    std::vector<int> zoneList;
+    std::vector<int> global_faceids;
+    std::vector<int> local_faceids;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+    std::vector<int> ijk_local_donors;
+    std::vector<double> data_recv;
+    std::vector<double> data_send;
+    std::unordered_map<int, int> global_local_face_map;
+public:
+    std::vector<int> neighbor_donor_zones;
+    std::vector<std::vector<int>> neighbor_donorfaces;
+    std::vector<std::vector<int>> sub_local_faceids;
+    std::vector<int> send_to_zones;
+    std::vector<std::vector<int>> donorfaces_for_send;
+    std::vector<std::vector<int>> donorijk_for_send;
+    std::vector<std::vector<double>> donordata_for_send;
+    std::vector<int> tmp_recv_donor_zones;
+    std::vector<std::vector<int>> tmp_recv_donorfaces;
+public:
+    std::vector<int> recv_donor_zones;
+    std::vector<std::vector<double>> recv_donor_fields;
+public:
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+};
+
+class Field;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+public:
+    static std::map<Face, int> faceMap;
+    static std::map<FacePair, int> facePairMap;
+    static std::vector<FacePair> facePairList;
+    static std::vector<std::set<int>> donor_zone_sets;
+    static std::vector<std::vector<int>> donor_zones;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+public:
+    static void InsertFaceMap( const Face & face );
+    static int InsertFacePairMap( const FacePair & facePair );
+    static void SendGeom( int zone, int donorzone, std::vector<int> & donorfaces );
+    static void ReSendGeomTest( int zone, int zone_to_send, std::vector<int> & donorfaces );
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/heat1d4blocksv1.cgns b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/heat1d4blocksv1.cgns
new file mode 100644
index 00000000..df5ffc5f
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/heat1d4blocksv1.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/main.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/main.cpp
new file mode 100644
index 00000000..fcce6376
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/main.cpp
@@ -0,0 +1,8 @@
+#include "Solver.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/plot.py b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01d/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/CMakeLists.txt
new file mode 100644
index 00000000..ee758c31
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/CMakeLists.txt
@@ -0,0 +1,79 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	Solver.h Solver.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/CgnsGrid.cpp
new file mode 100644
index 00000000..14e34203
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/CgnsGrid.cpp
@@ -0,0 +1,523 @@
+#include "CgnsGrid.h"
+#include "cgnslib.h"
+#include "global.h"
+#include <iostream>
+#include <vector>
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            Grid * grid = new Grid();
+            Global::grids.push_back( grid );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                //std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+
+                coor->DumpCoor();
+                if ( icoord == 0 )
+                {
+                    coor->DumpCoorX( grid->x );
+                }
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+            }
+        }
+    }
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/CgnsGrid.h
new file mode 100644
index 00000000..fddf1db6
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/CgnsGrid.h
@@ -0,0 +1,103 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    int zoneIndex;
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/Field.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/Field.cpp
new file mode 100644
index 00000000..c359a811
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/Field.cpp
@@ -0,0 +1,142 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+
+    std::vector<double> & x = grid->x;
+    this->dx = std::abs( x[ 1 ] - x[ 0 ] );
+    this->dt = dx / 10.0;
+    this->t = 1.0;
+    this->nt = std::round( t / dt );
+
+    double total_time = nt * dt;
+
+    std::cout << "this->dt   = " << this->dt << "\n";
+    std::cout << "this->t    = " << this->t << "\n";
+    std::cout << "this->nt   = " << this->nt << "\n";
+    std::cout << "this->ni   = " << this->ni << "\n";
+    std::cout << "total_time = " << total_time << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        u_e[ i ] = - std::exp( -total_time ) * std::sin( std::numbers::pi * xm ); //theory solution
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+    int kkk = 1;
+}
+
+void Field::Solve( Zone * zone )
+{
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+    }
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        //std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        //region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+        int kkk = 1;
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
+
+void Field::UpdateOldField()
+{
+    for ( int i = 0; i < this->u.size(); ++ i )
+    {
+        this->un[ i ] = this->u[ i ];
+    }
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/Field.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/Field.h
new file mode 100644
index 00000000..084ec9bd
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/Field.h
@@ -0,0 +1,36 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid );
+
+    void Solve( Zone * zone );
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void UpdateOldField();
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/README.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/Solver.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/Solver.cpp
new file mode 100644
index 00000000..292d9b24
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/Solver.cpp
@@ -0,0 +1,614 @@
+#include "Solver.h"
+#include <fstream>
+#include <set>
+#include <unordered_map>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    this->InitTopo();
+    this->InitFields();
+    this->SolveMultiZones();
+    this->PostProcess();
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d4blocksv1.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    ReadCgnsGrid( fileName );
+}
+
+void Solver::InitTopo()
+{
+    int nZones = Global::grids.size();
+    Global::donor_zone_sets.resize( nZones );
+    Global::donor_zones.resize( nZones );
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = new Interface();
+        interface->zoneid = iZone;
+        Global::interfaces.push_back( interface );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+        Interface * interface = Global::interfaces[ iZone ];
+
+        int nbc1to1s = zone->bc1to1s.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+        int nInterfaces = interface->zoneList.size();
+        interface->data_recv.resize( nInterfaces );
+        interface->data_send.resize( nInterfaces );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        std::set<int> &donor_zoneSet = Global::donor_zone_sets[ iZone ];
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            donor_zoneSet.insert( donor_zoneid );
+        }
+
+        std::vector<int> &donor_zones = Global::donor_zones[ iZone ];
+        for ( std::set<int>::iterator iter = donor_zoneSet.begin(); iter != donor_zoneSet.end(); ++ iter )
+        {
+            donor_zones.push_back( *iter );
+        }
+
+        interface->neighbor_donor_zones = donor_zones;
+
+        std::unordered_map<int, int> donor_zonelocal;
+
+        for ( int idonor = 0; idonor < donor_zones.size(); ++ idonor )
+        {
+            int donor_zone = donor_zones[ idonor ];
+            donor_zonelocal.insert( std::make_pair( donor_zone, idonor ) );
+        }
+        int index_dim = 1;
+        int ndonors = donor_zones.size();
+        std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+        neighbor_donorfaces.resize( ndonors );
+
+        std::vector<std::vector<int>> & sub_local_faceids = interface->sub_local_faceids;
+        sub_local_faceids.resize( ndonors );
+
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ineighbor = donor_zonelocal[ donor_zoneid ];
+            std::vector<int> &donorfaces = neighbor_donorfaces[ ineighbor ];
+            int global_faceid = interface->global_faceids[ iFace ];
+            donorfaces.push_back( global_faceid );
+            int local_faceid = interface->local_faceids[ iFace ];
+
+            std::vector<int> & sub_local_faces = sub_local_faceids[ ineighbor ];
+            sub_local_faces.push_back( local_faceid );
+        }
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> &neighbor_donor_zones = interface->neighbor_donor_zones;
+        int ndonor_zones = neighbor_donor_zones.size();
+
+        std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donorzone = neighbor_donor_zones[ iNei ];
+            //std::cout << "donorzone = " << donorzone << " donorfaces = ";
+            std::vector<int> & neighbor_donorface = neighbor_donorfaces[ iNei ];
+
+            Global::SendGeom( iZone, donorzone, neighbor_donorface );
+        }
+        int kkk = 1;
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+        std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+
+        std::vector<int> &neighbor_donor_zones = interface->neighbor_donor_zones;
+        int ndonor_zones = neighbor_donor_zones.size();
+        std::cout << "zone = " << iZone << " donorzone = ";
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donorzone = neighbor_donor_zones[ iNei ];
+            std::cout << donorzone;
+            if( iNei != ndonor_zones - 1 )
+            {
+                std::cout << ",";
+            }
+        }
+        std::cout << "\n";
+
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donorzone = neighbor_donor_zones[ iNei ];
+            std::cout << "donorzone = " << donorzone << " donorfaces = ";
+            std::vector<int> & neighbor_donorface = neighbor_donorfaces[ iNei ];
+            int ndonorfaces = neighbor_donorface.size();
+            for ( int idonorface = 0; idonorface < ndonorfaces; ++ idonorface )
+            {
+                std::cout <<  neighbor_donorface[ idonorface ];
+                if( idonorface != ndonorfaces - 1 )
+                {
+                    std::cout << ",";
+                }
+            }
+            std::cout << "\n";
+        }
+        std::cout << "\n";
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        std::cout << "zone = " << iZone << "\n";
+
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> & send_to_zones = interface->send_to_zones;
+        int nsend_zones = send_to_zones.size();
+
+        std::vector<std::vector<int>> & donorfaces_for_send = interface->donorfaces_for_send;
+
+        for ( int iSend = 0; iSend < nsend_zones; ++ iSend )
+        {
+            int zone_to_send = send_to_zones[ iSend ];
+            std::cout << "zone_to_send = " << zone_to_send << " donorfaces_for_send = ";
+            std::vector<int> & donorfaces = donorfaces_for_send[ iSend ];
+            int nFace = donorfaces.size();
+            for ( int iFace = 0; iFace < nFace; ++ iFace )
+            {
+                std::cout <<  donorfaces[ iFace ];
+                if( iFace != nFace - 1 )
+                {
+                    std::cout << ",";
+                }
+            }
+            std::cout << "\n";
+        }
+        int kkk = 1;
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        std::cout << "zone = " << iZone << "\n";
+
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> & send_to_zones = interface->send_to_zones;
+        int nsend_zones = send_to_zones.size();
+
+        std::vector<std::vector<int>> & donorfaces_for_send = interface->donorfaces_for_send;
+
+        for ( int iSend = 0; iSend < nsend_zones; ++ iSend )
+        {
+            int zone_to_send = send_to_zones[ iSend ];
+            std::vector<int> & donorfaces = donorfaces_for_send[ iSend ];
+            Global::ReSendGeomTest( iZone, zone_to_send, donorfaces );
+        }
+        int kkk = 1;
+    }
+
+    std::cout << "\n";
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        std::cout << "zone = " << iZone << "\n";
+
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> & neighbor_donor_zones = interface->neighbor_donor_zones;
+        int ndonor_zones = neighbor_donor_zones.size();
+
+        std::vector<std::vector<int>> & donorfaces_for_send = interface->donorfaces_for_send;
+
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donorzone = neighbor_donor_zones[ iNei ];
+            int tmp_recv_donor_zone = interface->tmp_recv_donor_zones[ iNei ];
+
+            std::cout << "donorzone = " << donorzone << " tmp_recv_donor_zone = " << tmp_recv_donor_zone << "\n";
+            std::vector<int> & neighbor_donorfaces = interface->neighbor_donorfaces[ iNei ];
+            std::cout << "neighbor_donorfaces\n";
+            for ( int i = 0; i < neighbor_donorfaces.size(); ++ i )
+            {
+                std::cout << neighbor_donorfaces[ i ] << " ";
+            }
+            std::cout << "\n";
+            std::vector<int> & tmp_recv_donorfaces = interface->tmp_recv_donorfaces[ iNei ];
+            std::cout << "tmp_recv_donorfaces\n";
+            for ( int i = 0; i < tmp_recv_donorfaces.size(); ++ i )
+            {
+                std::cout << tmp_recv_donorfaces[ i ] << " ";
+            }
+            std::cout << "\n";
+        }
+    }
+
+    int kkk = 1;
+}
+
+void Solver::InitFields()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+    }
+
+    Boundary();
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        int nZones = Global::zones.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Field * field = Global::fields[ iZone ];
+            Zone * zone = Global::zones[ iZone ];
+            zone->zoneIndex = iZone;
+            field->Solve( zone );
+        }
+        Boundary();
+    }
+}
+
+void Solver::Boundary()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+    ExchangeInterfaceField();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->UpdateOldField();
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    int nZones = Global::interfaces.size();
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> & send_to_zones = interface->send_to_zones;
+        int nsend_zones = send_to_zones.size();
+
+        std::vector<std::vector<int>> & donorfaces_for_send = interface->donorfaces_for_send;
+        std::vector<std::vector<int>> & donorijk_for_send = interface->donorijk_for_send;
+        std::vector<std::vector<double>> & donordata_for_send = interface->donordata_for_send;
+
+        Field * field = Global::fields[ iZone ];
+
+        for ( int iSend = 0; iSend < nsend_zones; ++ iSend )
+        {
+            int zone_to_send = send_to_zones[ iSend ];
+            std::vector<int> & donorfaces = donorfaces_for_send[ iSend ];
+            std::vector<int> & donorijks = donorijk_for_send[ iSend ];
+            std::vector<double> & donordatas = donordata_for_send[ iSend ];
+
+            int nface = donorfaces.size();
+            int index_dim = 1;
+            for ( int i = 0; i < nface; ++ i )
+            {
+                int ijkpos = index_dim * i;
+                int i_donor_cell = donorijks[ ijkpos + 0 ];
+                donordatas[ i ] = field->u[ i_donor_cell ];
+            }
+        }
+    }
+    int kkk = 1;
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+
+        std::vector<int> & neighbor_donor_zones = interface->neighbor_donor_zones;
+        int ndonor_zones = neighbor_donor_zones.size();
+
+        std::vector<std::vector<double>> & recv_donor_fields = interface->recv_donor_fields;
+
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donorzone = neighbor_donor_zones[ iNei ];
+            Interface * donor_interface = Global::interfaces[ donorzone ];
+            int nSize = donor_interface->send_to_zones.size();
+            int ipos = -1;
+            for ( int i = 0; i < nSize; ++ i )
+            {
+                int szone = donor_interface->send_to_zones[ i ];
+                if ( szone == iZone )
+                {
+                    ipos = i;
+                    break;
+                }
+            }
+            std::vector<double> & donordata = donor_interface->donordata_for_send[ ipos ];
+
+            std::vector<int> & neighbor_donorfaces = interface->neighbor_donorfaces[ iNei ];
+            std::vector<int> & sub_local_faceids = interface->sub_local_faceids[ iNei ];
+            for ( int i = 0; i < neighbor_donorfaces.size(); ++ i )
+            {
+                int local_faceid = sub_local_faceids[ i ];
+                double donor_value = donordata[ i ];
+                interface->data_recv[ local_faceid ] = donor_value;
+            }
+        }
+
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+
+            double donor_value = interface->data_recv[ iFace ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::PostProcess()
+{
+    Post post;
+    post.Process();
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    int nZones = Global::grids.size();
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        int ni = grid->x.size();
+        double xmin = grid->x[ 0 ];
+        double xmax = grid->x[ 0 ];
+        int imin = 0;
+        int imax = 0;
+        for ( int i = 0; i < ni; ++ i )
+        {
+            if ( xmin > grid->x[ i ] )
+            {
+                xmin = grid->x[ i ];
+                imin = i;
+            }
+            if ( xmax < grid->x[ i ] )
+            {
+                xmax = grid->x[ i ];
+                imax = i;
+            }
+        }
+        xmin_list.push_back( xmin );
+        xmax_list.push_back( xmax );
+    }
+    std::vector<std::pair<double, int>> pairs;
+    int nSize = xmin_list.size();
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        pairs.push_back( std::make_pair( xmin_list[i], i ) );
+    }
+
+    std::sort( pairs.begin(), pairs.end() );
+
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        this->zoneids.push_back( pairs[i].second );
+    }
+
+    int kkk = 1;
+}
+
+void Post::GatherField()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+        Grid * grid = Global::grids[ zoneid ];
+        Field * field = Global::fields[ zoneid ];
+
+        int ni = grid->x.size();
+
+        int ist = 1;
+        int ied = ni;
+
+        int dir = 1;
+        if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+        if ( dir == 1 )
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ist; i <= ied; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+
+            }
+            else
+            {
+                for ( int i = ist; i <= ied - 1; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+        else
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ied; i >= ist; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+            else
+            {
+                for ( int i = ied; i >= ist + 1; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+    }
+}
+
+void Post::DumpField()
+{
+    int ni_total = this->x.size();
+    std::cout << " DumpField x.size() = " << x.size() << "\n";
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    this->DumpErrorDetails( u_error );
+
+    std::string csvname = "field_final.csv";
+    this->DumpCsvFile( csvname, x, u_e, un, u_error );
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.20f} {:.20f} {:.20f} {:.20f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/Solver.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/Solver.h
new file mode 100644
index 00000000..c50415cf
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/Solver.h
@@ -0,0 +1,41 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+
+class Solver
+{
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveMultiZones();
+public:
+    void Boundary();
+    void ExchangeInterfaceField();
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcess();
+};
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+    std::vector<double> u;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/global.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/global.cpp
new file mode 100644
index 00000000..aef4b670
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/global.cpp
@@ -0,0 +1,197 @@
+#include "global.h"
+#include "CgnsGrid.h"
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *> Global::interfaces;
+
+std::map<Face, int> Global::faceMap;
+std::map<FacePair, int> Global::facePairMap;
+std::vector<FacePair> Global::facePairList;
+
+std::vector<std::set<int>> Global::donor_zone_sets;
+std::vector<std::vector<int>> Global::donor_zones;
+
+bool Face::operator < ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return this->zone < rhs.zone;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return this->i < rhs.i;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return this->j < rhs.j;
+    }
+
+    return this->k < rhs.k;
+}
+
+bool Face::operator == ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return false;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return false;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return false;
+    }
+
+    return this->k == rhs.k;
+}
+
+void FacePair::AddPair( const Face & face1, const Face & face2 )
+{
+    if ( face1 < face2 )
+    {
+        this->left = face1;
+        this->right = face2;
+    }
+    else
+    {
+        this->left = face2;
+        this->right = face1;
+    }
+}
+
+bool FacePair::operator < ( const FacePair & rhs ) const
+{
+    if ( this->left == rhs.left || this->left == rhs.right )
+    {
+        return false;
+    }
+
+    return this->left < rhs.left;
+}
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->local_faceids.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        Face face;
+        face.zone = zoneid;
+        face.i = i;
+
+        Global::InsertFaceMap( face );
+
+        int i_donor = index2[ 0 ];
+
+        Face face_donor;
+        face_donor.zone = donor_zoneid;
+        face_donor.i = i_donor;
+
+        Global::InsertFaceMap( face_donor );
+
+        FacePair facePair;
+        facePair.AddPair( face, face_donor );
+
+        Global::facePairList.push_back( facePair );
+        int global_faceid = Global::InsertFacePairMap( facePair );
+        this->global_faceids.push_back( global_faceid );
+
+        this->global_local_face_map.insert( std::make_pair( global_faceid, faceid ) );
+
+        int i_ghost_cell = i + 1;
+        int i_local_donor_cell = i - 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+            i_local_donor_cell = i + 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+        ijk_donors.push_back( i_local_donor_cell );
+
+        icount ++;
+    }
+}
+
+void Global::InsertFaceMap( const Face & face )
+{
+    std::map<Face, int>::iterator iter;
+    iter = Global::faceMap.find( face );
+    if ( iter == Global::faceMap.end() )
+    {
+        int faceid = Global::faceMap.size();
+        Global::faceMap.insert( std::make_pair( face, faceid ) );
+    }
+}
+
+int Global::InsertFacePairMap( const FacePair & facePair )
+{
+    std::map<FacePair, int>::iterator iter;
+    iter = Global::facePairMap.find( facePair );
+    if ( iter == Global::facePairMap.end() )
+    {
+        int facePairId = Global::facePairMap.size();
+        Global::facePairMap.insert( std::make_pair( facePair, facePairId ) );
+        return facePairId;
+    }
+    return iter->second;
+}
+
+void Global::SendGeom( int zone, int donorzone, std::vector<int> & donorfaces )
+{
+    Interface * interface = Global::interfaces[ donorzone ];
+
+    std::vector<int> & send_to_zones = interface->send_to_zones;
+
+    send_to_zones.push_back( zone );
+    interface->donorfaces_for_send.push_back( donorfaces );
+
+    int nface = donorfaces.size();
+    std::vector<int> sub_donorijk;
+    int index_dim = 1;
+    for ( int i = 0; i < nface; ++ i )
+    {
+        int global_faceid = donorfaces[ i ];
+        int local_faceid = interface->global_local_face_map[ global_faceid ];
+        int ijkpos = index_dim * local_faceid;
+        int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+        sub_donorijk.push_back( i_donor_cell );
+        int kkk = 1;
+    }
+
+    interface->donorijk_for_send.push_back( sub_donorijk );
+
+    std::vector<double> sub_donordata( sub_donorijk.size() );
+    interface->donordata_for_send.push_back( sub_donordata );
+}
+
+void Global::ReSendGeomTest( int zone, int zone_to_send, std::vector<int> & donorfaces )
+{
+    Interface * interface = Global::interfaces[ zone_to_send ];
+    interface->tmp_recv_donor_zones.push_back( zone );
+    interface->tmp_recv_donorfaces.push_back( donorfaces );
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/global.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/global.h
new file mode 100644
index 00000000..6736167a
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/global.h
@@ -0,0 +1,144 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <unordered_map>
+#include <set>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class Face
+{
+public:
+    int zone = 0;
+    int i = 0;
+    int j = 1;
+    int k = 1;
+public:
+    bool operator < ( const Face & rhs ) const;
+    bool operator == ( const Face & rhs ) const;
+};
+
+class FacePair
+{
+public:
+    Face left;
+    Face right;
+public:
+    bool operator < ( const FacePair & rhs ) const;
+    void AddPair( const Face &face1, const Face &face2);
+};
+
+class Transform;
+
+
+class Interface
+{
+public:
+    int zoneid;
+    std::vector<int> zoneList;
+    std::vector<int> global_faceids;
+    std::vector<int> local_faceids;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+    std::vector<double> data_recv;
+    std::vector<double> data_send;
+    std::unordered_map<int, int> global_local_face_map;
+public:
+    std::vector<int> neighbor_donor_zones;
+    std::vector<std::vector<int>> neighbor_donorfaces;
+    std::vector<std::vector<int>> sub_local_faceids;
+    std::vector<int> send_to_zones;
+    std::vector<std::vector<int>> donorfaces_for_send;
+    std::vector<std::vector<int>> donorijk_for_send;
+    std::vector<std::vector<double>> donordata_for_send;
+    std::vector<int> tmp_recv_donor_zones;
+    std::vector<std::vector<int>> tmp_recv_donorfaces;
+public:
+    std::vector<int> recv_donor_zones;
+    std::vector<std::vector<double>> recv_donor_fields;
+public:
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+};
+
+class Field;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+public:
+    static std::map<Face, int> faceMap;
+    static std::map<FacePair, int> facePairMap;
+    static std::vector<FacePair> facePairList;
+    static std::vector<std::set<int>> donor_zone_sets;
+    static std::vector<std::vector<int>> donor_zones;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+public:
+    static void InsertFaceMap( const Face & face );
+    static int InsertFacePairMap( const FacePair & facePair );
+    static void SendGeom( int zone, int donorzone, std::vector<int> & donorfaces );
+    static void ReSendGeomTest( int zone, int zone_to_send, std::vector<int> & donorfaces );
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/heat1d4blocksv1.cgns b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/heat1d4blocksv1.cgns
new file mode 100644
index 00000000..df5ffc5f
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/heat1d4blocksv1.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/main.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/main.cpp
new file mode 100644
index 00000000..fcce6376
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/main.cpp
@@ -0,0 +1,8 @@
+#include "Solver.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/plot.py b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01e/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/CMakeLists.txt
new file mode 100644
index 00000000..d395576a
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/CMakeLists.txt
@@ -0,0 +1,94 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package ( MPI )
+
+message ( STATUS  "MPI_FOUND=${MPI_FOUND}" )
+message ( STATUS  "MPI_CXX_INCLUDE_DIRS=${MPI_CXX_INCLUDE_DIRS}" )
+message ( STATUS  "MPI_LIBRARIES=${MPI_LIBRARIES}" )
+if ( MPI_FOUND )
+	list ( APPEND PRJ_INCLUDE_DIRS ${MPI_CXX_INCLUDE_DIRS} )
+	list ( APPEND PRJ_LIBRARIES ${MPI_LIBRARIES} )
+endif ()
+
+#get_directory_property( my_import_targets DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} IMPORTED_TARGETS )
+#message( STATUS "my_import_targets=${my_import_targets}" )
+
+list ( APPEND PRJ_LIBRARIES MPI::MPI_C )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	Solver.h Solver.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/CgnsGrid.cpp
new file mode 100644
index 00000000..14e34203
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/CgnsGrid.cpp
@@ -0,0 +1,523 @@
+#include "CgnsGrid.h"
+#include "cgnslib.h"
+#include "global.h"
+#include <iostream>
+#include <vector>
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            Grid * grid = new Grid();
+            Global::grids.push_back( grid );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                //std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+
+                coor->DumpCoor();
+                if ( icoord == 0 )
+                {
+                    coor->DumpCoorX( grid->x );
+                }
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+            }
+        }
+    }
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/CgnsGrid.h
new file mode 100644
index 00000000..fddf1db6
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/CgnsGrid.h
@@ -0,0 +1,103 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    int zoneIndex;
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/Field.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/Field.cpp
new file mode 100644
index 00000000..c359a811
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/Field.cpp
@@ -0,0 +1,142 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+
+    std::vector<double> & x = grid->x;
+    this->dx = std::abs( x[ 1 ] - x[ 0 ] );
+    this->dt = dx / 10.0;
+    this->t = 1.0;
+    this->nt = std::round( t / dt );
+
+    double total_time = nt * dt;
+
+    std::cout << "this->dt   = " << this->dt << "\n";
+    std::cout << "this->t    = " << this->t << "\n";
+    std::cout << "this->nt   = " << this->nt << "\n";
+    std::cout << "this->ni   = " << this->ni << "\n";
+    std::cout << "total_time = " << total_time << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        u_e[ i ] = - std::exp( -total_time ) * std::sin( std::numbers::pi * xm ); //theory solution
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+    int kkk = 1;
+}
+
+void Field::Solve( Zone * zone )
+{
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+    }
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        //std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        //region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+        int kkk = 1;
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
+
+void Field::UpdateOldField()
+{
+    for ( int i = 0; i < this->u.size(); ++ i )
+    {
+        this->un[ i ] = this->u[ i ];
+    }
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/Field.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/Field.h
new file mode 100644
index 00000000..084ec9bd
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/Field.h
@@ -0,0 +1,36 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid );
+
+    void Solve( Zone * zone );
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void UpdateOldField();
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/README.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/Solver.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/Solver.cpp
new file mode 100644
index 00000000..97d3fdc6
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/Solver.cpp
@@ -0,0 +1,503 @@
+#include "Solver.h"
+#include <fstream>
+#include <set>
+#include <unordered_map>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    this->InitTopo();
+    this->InitFields();
+    this->SolveMultiZones();
+    this->PostProcess();
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d4blocksv1.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    ReadCgnsGrid( fileName );
+}
+
+void Solver::InitTopo()
+{
+    int nZones = Global::grids.size();
+    Global::donor_zone_sets.resize( nZones );
+    Global::donor_zones.resize( nZones );
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = new Interface();
+        interface->zoneid = iZone;
+        Global::interfaces.push_back( interface );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+        Interface * interface = Global::interfaces[ iZone ];
+
+        int nbc1to1s = zone->bc1to1s.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+        int nInterfaces = interface->zoneList.size();
+        interface->data_recv.resize( nInterfaces );
+        interface->data_send.resize( nInterfaces );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        std::set<int> &donor_zoneSet = Global::donor_zone_sets[ iZone ];
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            donor_zoneSet.insert( donor_zoneid );
+        }
+
+        std::vector<int> &donor_zones = Global::donor_zones[ iZone ];
+        for ( std::set<int>::iterator iter = donor_zoneSet.begin(); iter != donor_zoneSet.end(); ++ iter )
+        {
+            donor_zones.push_back( *iter );
+        }
+
+        interface->neighbor_donor_zones = donor_zones;
+
+        std::unordered_map<int, int> donor_zonelocal;
+
+        for ( int idonor = 0; idonor < donor_zones.size(); ++ idonor )
+        {
+            int donor_zone = donor_zones[ idonor ];
+            donor_zonelocal.insert( std::make_pair( donor_zone, idonor ) );
+        }
+        int index_dim = 1;
+        int ndonors = donor_zones.size();
+        std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+        neighbor_donorfaces.resize( ndonors );
+
+        std::vector<std::vector<int>> & sub_local_faceids = interface->sub_local_faceids;
+        sub_local_faceids.resize( ndonors );
+
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ineighbor = donor_zonelocal[ donor_zoneid ];
+            std::vector<int> &donorfaces = neighbor_donorfaces[ ineighbor ];
+            int global_faceid = interface->global_faceids[ iFace ];
+            donorfaces.push_back( global_faceid );
+            int local_faceid = interface->local_faceids[ iFace ];
+
+            std::vector<int> & sub_local_faces = sub_local_faceids[ ineighbor ];
+            sub_local_faces.push_back( local_faceid );
+        }
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> &neighbor_donor_zones = interface->neighbor_donor_zones;
+        int ndonor_zones = neighbor_donor_zones.size();
+
+        std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donorzone = neighbor_donor_zones[ iNei ];
+            //std::cout << "donorzone = " << donorzone << " donorfaces = ";
+            std::vector<int> & neighbor_donorface = neighbor_donorfaces[ iNei ];
+
+            Global::SendGeom( iZone, donorzone, neighbor_donorface );
+        }
+        int kkk = 1;
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        std::cout << "zone = " << iZone << "\n";
+
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> & send_to_zones = interface->send_to_zones;
+        int nsend_zones = send_to_zones.size();
+    }
+
+    std::cout << "\n";
+
+    int kkk = 1;
+}
+
+void Solver::InitFields()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+    }
+
+    Boundary();
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        int nZones = Global::zones.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Field * field = Global::fields[ iZone ];
+            Zone * zone = Global::zones[ iZone ];
+            zone->zoneIndex = iZone;
+            field->Solve( zone );
+        }
+        Boundary();
+    }
+}
+
+void Solver::Boundary()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+    ExchangeInterfaceField();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->UpdateOldField();
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    int nZones = Global::interfaces.size();
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> & send_to_zones = interface->send_to_zones;
+        int nsend_zones = send_to_zones.size();
+
+        std::vector<std::vector<int>> & donorfaces_for_send = interface->donorfaces_for_send;
+        std::vector<std::vector<int>> & donorijk_for_send = interface->donorijk_for_send;
+        std::vector<std::vector<double>> & donordata_for_send = interface->donordata_for_send;
+
+        Field * field = Global::fields[ iZone ];
+
+        for ( int iSend = 0; iSend < nsend_zones; ++ iSend )
+        {
+            int zone_to_send = send_to_zones[ iSend ];
+            std::vector<int> & donorfaces = donorfaces_for_send[ iSend ];
+            std::vector<int> & donorijks = donorijk_for_send[ iSend ];
+            std::vector<double> & donordatas = donordata_for_send[ iSend ];
+
+            int nface = donorfaces.size();
+            int index_dim = 1;
+            for ( int i = 0; i < nface; ++ i )
+            {
+                int ijkpos = index_dim * i;
+                int i_donor_cell = donorijks[ ijkpos + 0 ];
+                donordatas[ i ] = field->u[ i_donor_cell ];
+            }
+        }
+    }
+    int kkk = 1;
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+
+        std::vector<int> & neighbor_donor_zones = interface->neighbor_donor_zones;
+        int ndonor_zones = neighbor_donor_zones.size();
+
+        //std::vector<std::vector<double>> & recv_donor_fields = interface->recv_donor_fields;
+
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donorzone = neighbor_donor_zones[ iNei ];
+            Interface * donor_interface = Global::interfaces[ donorzone ];
+            int nSize = donor_interface->send_to_zones.size();
+            int ipos = -1;
+            for ( int i = 0; i < nSize; ++ i )
+            {
+                int szone = donor_interface->send_to_zones[ i ];
+                if ( szone == iZone )
+                {
+                    ipos = i;
+                    break;
+                }
+            }
+            std::vector<double> & donordata = donor_interface->donordata_for_send[ ipos ];
+
+            std::vector<int> & neighbor_donorfaces = interface->neighbor_donorfaces[ iNei ];
+            std::vector<int> & sub_local_faceids = interface->sub_local_faceids[ iNei ];
+            for ( int i = 0; i < neighbor_donorfaces.size(); ++ i )
+            {
+                int local_faceid = sub_local_faceids[ i ];
+                double donor_value = donordata[ i ];
+                interface->data_recv[ local_faceid ] = donor_value;
+            }
+        }
+
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+
+            double donor_value = interface->data_recv[ iFace ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::PostProcess()
+{
+    Post post;
+    post.Process();
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    int nZones = Global::grids.size();
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        int ni = grid->x.size();
+        double xmin = grid->x[ 0 ];
+        double xmax = grid->x[ 0 ];
+        int imin = 0;
+        int imax = 0;
+        for ( int i = 0; i < ni; ++ i )
+        {
+            if ( xmin > grid->x[ i ] )
+            {
+                xmin = grid->x[ i ];
+                imin = i;
+            }
+            if ( xmax < grid->x[ i ] )
+            {
+                xmax = grid->x[ i ];
+                imax = i;
+            }
+        }
+        xmin_list.push_back( xmin );
+        xmax_list.push_back( xmax );
+    }
+    std::vector<std::pair<double, int>> pairs;
+    int nSize = xmin_list.size();
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        pairs.push_back( std::make_pair( xmin_list[i], i ) );
+    }
+
+    std::sort( pairs.begin(), pairs.end() );
+
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        this->zoneids.push_back( pairs[i].second );
+    }
+
+    int kkk = 1;
+}
+
+void Post::GatherField()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+        Grid * grid = Global::grids[ zoneid ];
+        Field * field = Global::fields[ zoneid ];
+
+        int ni = grid->x.size();
+
+        int ist = 1;
+        int ied = ni;
+
+        int dir = 1;
+        if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+        if ( dir == 1 )
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ist; i <= ied; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+
+            }
+            else
+            {
+                for ( int i = ist; i <= ied - 1; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+        else
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ied; i >= ist; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+            else
+            {
+                for ( int i = ied; i >= ist + 1; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+    }
+}
+
+void Post::DumpField()
+{
+    int ni_total = this->x.size();
+    std::cout << " DumpField x.size() = " << x.size() << "\n";
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    this->DumpErrorDetails( u_error );
+
+    std::string csvname = "field_final.csv";
+    this->DumpCsvFile( csvname, x, u_e, un, u_error );
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.20f} {:.20f} {:.20f} {:.20f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/Solver.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/Solver.h
new file mode 100644
index 00000000..c50415cf
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/Solver.h
@@ -0,0 +1,41 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+
+class Solver
+{
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveMultiZones();
+public:
+    void Boundary();
+    void ExchangeInterfaceField();
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcess();
+};
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+    std::vector<double> u;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/global.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/global.cpp
new file mode 100644
index 00000000..d96bf9d7
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/global.cpp
@@ -0,0 +1,191 @@
+#include "global.h"
+#include "CgnsGrid.h"
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *> Global::interfaces;
+
+std::map<Face, int> Global::faceMap;
+std::map<FacePair, int> Global::facePairMap;
+std::vector<FacePair> Global::facePairList;
+
+std::vector<std::set<int>> Global::donor_zone_sets;
+std::vector<std::vector<int>> Global::donor_zones;
+
+bool Face::operator < ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return this->zone < rhs.zone;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return this->i < rhs.i;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return this->j < rhs.j;
+    }
+
+    return this->k < rhs.k;
+}
+
+bool Face::operator == ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return false;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return false;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return false;
+    }
+
+    return this->k == rhs.k;
+}
+
+void FacePair::AddPair( const Face & face1, const Face & face2 )
+{
+    if ( face1 < face2 )
+    {
+        this->left = face1;
+        this->right = face2;
+    }
+    else
+    {
+        this->left = face2;
+        this->right = face1;
+    }
+}
+
+bool FacePair::operator < ( const FacePair & rhs ) const
+{
+    if ( this->left == rhs.left || this->left == rhs.right )
+    {
+        return false;
+    }
+
+    return this->left < rhs.left;
+}
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->local_faceids.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        Face face;
+        face.zone = zoneid;
+        face.i = i;
+
+        Global::InsertFaceMap( face );
+
+        int i_donor = index2[ 0 ];
+
+        Face face_donor;
+        face_donor.zone = donor_zoneid;
+        face_donor.i = i_donor;
+
+        Global::InsertFaceMap( face_donor );
+
+        FacePair facePair;
+        facePair.AddPair( face, face_donor );
+
+        Global::facePairList.push_back( facePair );
+        int global_faceid = Global::InsertFacePairMap( facePair );
+        this->global_faceids.push_back( global_faceid );
+
+        this->global_local_face_map.insert( std::make_pair( global_faceid, faceid ) );
+
+        int i_ghost_cell = i + 1;
+        int i_local_donor_cell = i - 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+            i_local_donor_cell = i + 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+        ijk_donors.push_back( i_local_donor_cell );
+
+        icount ++;
+    }
+}
+
+void Global::InsertFaceMap( const Face & face )
+{
+    std::map<Face, int>::iterator iter;
+    iter = Global::faceMap.find( face );
+    if ( iter == Global::faceMap.end() )
+    {
+        int faceid = Global::faceMap.size();
+        Global::faceMap.insert( std::make_pair( face, faceid ) );
+    }
+}
+
+int Global::InsertFacePairMap( const FacePair & facePair )
+{
+    std::map<FacePair, int>::iterator iter;
+    iter = Global::facePairMap.find( facePair );
+    if ( iter == Global::facePairMap.end() )
+    {
+        int facePairId = Global::facePairMap.size();
+        Global::facePairMap.insert( std::make_pair( facePair, facePairId ) );
+        return facePairId;
+    }
+    return iter->second;
+}
+
+void Global::SendGeom( int zone, int donorzone, std::vector<int> & donorfaces )
+{
+    Interface * interface = Global::interfaces[ donorzone ];
+
+    std::vector<int> & send_to_zones = interface->send_to_zones;
+
+    send_to_zones.push_back( zone );
+    interface->donorfaces_for_send.push_back( donorfaces );
+
+    int nface = donorfaces.size();
+    std::vector<int> sub_donorijk;
+    int index_dim = 1;
+    for ( int i = 0; i < nface; ++ i )
+    {
+        int global_faceid = donorfaces[ i ];
+        int local_faceid = interface->global_local_face_map[ global_faceid ];
+        int ijkpos = index_dim * local_faceid;
+        int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+        sub_donorijk.push_back( i_donor_cell );
+        int kkk = 1;
+    }
+
+    interface->donorijk_for_send.push_back( sub_donorijk );
+
+    std::vector<double> sub_donordata( sub_donorijk.size() );
+    interface->donordata_for_send.push_back( sub_donordata );
+}
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/global.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/global.h
new file mode 100644
index 00000000..ce8eef97
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/global.h
@@ -0,0 +1,138 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <unordered_map>
+#include <set>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class Face
+{
+public:
+    int zone = 0;
+    int i = 0;
+    int j = 1;
+    int k = 1;
+public:
+    bool operator < ( const Face & rhs ) const;
+    bool operator == ( const Face & rhs ) const;
+};
+
+class FacePair
+{
+public:
+    Face left;
+    Face right;
+public:
+    bool operator < ( const FacePair & rhs ) const;
+    void AddPair( const Face &face1, const Face &face2);
+};
+
+class Transform;
+
+
+class Interface
+{
+public:
+    int zoneid;
+    std::vector<int> zoneList;
+    std::vector<int> global_faceids;
+    std::vector<int> local_faceids;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+    std::vector<double> data_recv;
+    std::vector<double> data_send;
+    std::unordered_map<int, int> global_local_face_map;
+public:
+    std::vector<int> neighbor_donor_zones;
+    std::vector<std::vector<int>> neighbor_donorfaces;
+    std::vector<std::vector<int>> sub_local_faceids;
+    std::vector<int> send_to_zones;
+    std::vector<std::vector<int>> donorfaces_for_send;
+    std::vector<std::vector<int>> donorijk_for_send;
+    std::vector<std::vector<double>> donordata_for_send;
+public:
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+};
+
+class Field;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+public:
+    static std::map<Face, int> faceMap;
+    static std::map<FacePair, int> facePairMap;
+    static std::vector<FacePair> facePairList;
+    static std::vector<std::set<int>> donor_zone_sets;
+    static std::vector<std::vector<int>> donor_zones;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+public:
+    static void InsertFaceMap( const Face & face );
+    static int InsertFacePairMap( const FacePair & facePair );
+    static void SendGeom( int zone, int donorzone, std::vector<int> & donorfaces );
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/heat1d4blocksv1.cgns b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/heat1d4blocksv1.cgns
new file mode 100644
index 00000000..df5ffc5f
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/heat1d4blocksv1.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/main.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/main.cpp
new file mode 100644
index 00000000..f96606d0
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/main.cpp
@@ -0,0 +1,23 @@
+#include "mpi.h"
+#include "Solver.h"
+
+int main( int argc, char ** argv )
+{
+    int rank, size, len;
+    char version[MPI_MAX_LIBRARY_VERSION_STRING];
+
+    MPI_Init(&argc, &argv);
+    MPI_Comm_rank(MPI_COMM_WORLD, &rank);
+    MPI_Comm_size(MPI_COMM_WORLD, &size);
+    MPI_Get_library_version(version, &len);
+    std::cout << "Hello, world!  I am " << rank << " of " << size
+        << "(" << version << ", " << len << ")" << std::endl;
+    if ( rank == 0 )
+    {
+        Solver solver;
+        solver.Run();
+    }
+
+    MPI_Finalize();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/plot.py b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/01f/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/CMakeLists.txt
new file mode 100644
index 00000000..038616a3
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/CMakeLists.txt
@@ -0,0 +1,97 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package ( MPI )
+
+message ( STATUS  "MPI_FOUND=${MPI_FOUND}" )
+message ( STATUS  "MPI_CXX_INCLUDE_DIRS=${MPI_CXX_INCLUDE_DIRS}" )
+message ( STATUS  "MPI_LIBRARIES=${MPI_LIBRARIES}" )
+if ( MPI_FOUND )
+	list ( APPEND PRJ_INCLUDE_DIRS ${MPI_CXX_INCLUDE_DIRS} )
+	list ( APPEND PRJ_LIBRARIES ${MPI_LIBRARIES} )
+endif ()
+
+#get_directory_property( my_import_targets DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} IMPORTED_TARGETS )
+#message( STATUS "my_import_targets=${my_import_targets}" )
+
+list ( APPEND PRJ_LIBRARIES MPI::MPI_C )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+list ( APPEND PRJ_COMPILE_DEFINITIONS HX_PARALLEL )
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	Parallel.h Parallel.cpp
+	Solver.h Solver.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/CgnsGrid.cpp
new file mode 100644
index 00000000..14e34203
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/CgnsGrid.cpp
@@ -0,0 +1,523 @@
+#include "CgnsGrid.h"
+#include "cgnslib.h"
+#include "global.h"
+#include <iostream>
+#include <vector>
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            Grid * grid = new Grid();
+            Global::grids.push_back( grid );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                //std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+
+                coor->DumpCoor();
+                if ( icoord == 0 )
+                {
+                    coor->DumpCoorX( grid->x );
+                }
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+            }
+        }
+    }
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/CgnsGrid.h
new file mode 100644
index 00000000..fddf1db6
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/CgnsGrid.h
@@ -0,0 +1,103 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    int zoneIndex;
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/Field.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/Field.cpp
new file mode 100644
index 00000000..c359a811
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/Field.cpp
@@ -0,0 +1,142 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+
+    std::vector<double> & x = grid->x;
+    this->dx = std::abs( x[ 1 ] - x[ 0 ] );
+    this->dt = dx / 10.0;
+    this->t = 1.0;
+    this->nt = std::round( t / dt );
+
+    double total_time = nt * dt;
+
+    std::cout << "this->dt   = " << this->dt << "\n";
+    std::cout << "this->t    = " << this->t << "\n";
+    std::cout << "this->nt   = " << this->nt << "\n";
+    std::cout << "this->ni   = " << this->ni << "\n";
+    std::cout << "total_time = " << total_time << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        u_e[ i ] = - std::exp( -total_time ) * std::sin( std::numbers::pi * xm ); //theory solution
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+    int kkk = 1;
+}
+
+void Field::Solve( Zone * zone )
+{
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+    }
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        //std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        //region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+        int kkk = 1;
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
+
+void Field::UpdateOldField()
+{
+    for ( int i = 0; i < this->u.size(); ++ i )
+    {
+        this->un[ i ] = this->u[ i ];
+    }
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/Field.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/Field.h
new file mode 100644
index 00000000..084ec9bd
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/Field.h
@@ -0,0 +1,36 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid );
+
+    void Solve( Zone * zone );
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void UpdateOldField();
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/Parallel.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/Parallel.cpp
new file mode 100644
index 00000000..c4a40b66
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/Parallel.cpp
@@ -0,0 +1,31 @@
+#include "Parallel.h"
+#include <iostream>
+
+int Parallel::pid = 0;
+int Parallel::nProc = 1;
+int Parallel::serverid = 0;
+int Parallel::tag = 0;
+
+void Parallel::Init()
+{
+#ifdef HX_PARALLEL
+    int argc     = 0;
+    char ** argv = 0;
+    MPI_Init( &argc, &argv );
+    MPI_Comm_rank( MPI_COMM_WORLD, &Parallel::pid );
+    MPI_Comm_size( MPI_COMM_WORLD, &Parallel::nProc );
+    int len = -1;
+    char version[ MPI_MAX_LIBRARY_VERSION_STRING ];
+    MPI_Get_library_version( version, &len );
+    std::cout << "Hello, world!  I am " << Parallel::pid << " of " << Parallel::nProc
+        << "(" << version << ", " << len << ")" << std::endl;
+#endif
+}
+
+void Parallel::Finalize()
+{
+#ifdef HX_PARALLEL
+    MPI_Finalize();
+#endif
+}
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/Parallel.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/Parallel.h
new file mode 100644
index 00000000..3e6f50e2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/Parallel.h
@@ -0,0 +1,17 @@
+#pragma once
+#ifdef HX_PARALLEL
+#include "mpi.h"
+#endif
+#include <vector>
+
+class Parallel
+{
+public:
+    static int pid;
+    static int nProc;
+    static int serverid;
+    static int tag;
+public:
+    static void Init();
+    static void Finalize();
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/README.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/Solver.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/Solver.cpp
new file mode 100644
index 00000000..23056f12
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/Solver.cpp
@@ -0,0 +1,518 @@
+#include "Solver.h"
+#include "Parallel.h"
+#include <fstream>
+#include <set>
+#include <unordered_map>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+Solver::Solver()
+{
+    Parallel::Init();
+}
+
+Solver::~Solver()
+{
+    Parallel::Finalize();
+}
+
+
+void Solver::Run()
+{
+    if ( Parallel::pid == Parallel::serverid )
+    {
+        this->ReadGrid();
+        this->InitTopo();
+        this->InitFields();
+        this->SolveMultiZones();
+        this->PostProcess();
+    }
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d4blocksv1.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    ReadCgnsGrid( fileName );
+}
+
+void Solver::InitTopo()
+{
+    int nZones = Global::grids.size();
+    Global::donor_zone_sets.resize( nZones );
+    Global::donor_zones.resize( nZones );
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = new Interface();
+        interface->zoneid = iZone;
+        Global::interfaces.push_back( interface );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+        Interface * interface = Global::interfaces[ iZone ];
+
+        int nbc1to1s = zone->bc1to1s.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+        int nInterfaces = interface->zoneList.size();
+        interface->data_recv.resize( nInterfaces );
+        interface->data_send.resize( nInterfaces );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        std::set<int> &donor_zoneSet = Global::donor_zone_sets[ iZone ];
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            donor_zoneSet.insert( donor_zoneid );
+        }
+
+        std::vector<int> &donor_zones = Global::donor_zones[ iZone ];
+        for ( std::set<int>::iterator iter = donor_zoneSet.begin(); iter != donor_zoneSet.end(); ++ iter )
+        {
+            donor_zones.push_back( *iter );
+        }
+
+        interface->neighbor_donor_zones = donor_zones;
+
+        std::unordered_map<int, int> donor_zonelocal;
+
+        for ( int idonor = 0; idonor < donor_zones.size(); ++ idonor )
+        {
+            int donor_zone = donor_zones[ idonor ];
+            donor_zonelocal.insert( std::make_pair( donor_zone, idonor ) );
+        }
+        int index_dim = 1;
+        int ndonors = donor_zones.size();
+        std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+        neighbor_donorfaces.resize( ndonors );
+
+        std::vector<std::vector<int>> & sub_local_faceids = interface->sub_local_faceids;
+        sub_local_faceids.resize( ndonors );
+
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ineighbor = donor_zonelocal[ donor_zoneid ];
+            std::vector<int> &donorfaces = neighbor_donorfaces[ ineighbor ];
+            int global_faceid = interface->global_faceids[ iFace ];
+            donorfaces.push_back( global_faceid );
+            int local_faceid = interface->local_faceids[ iFace ];
+
+            std::vector<int> & sub_local_faces = sub_local_faceids[ ineighbor ];
+            sub_local_faces.push_back( local_faceid );
+        }
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> &neighbor_donor_zones = interface->neighbor_donor_zones;
+        int ndonor_zones = neighbor_donor_zones.size();
+
+        std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donorzone = neighbor_donor_zones[ iNei ];
+            //std::cout << "donorzone = " << donorzone << " donorfaces = ";
+            std::vector<int> & neighbor_donorface = neighbor_donorfaces[ iNei ];
+
+            Global::SendGeom( iZone, donorzone, neighbor_donorface );
+        }
+        int kkk = 1;
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        std::cout << "zone = " << iZone << "\n";
+
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> & send_to_zones = interface->send_to_zones;
+        int nsend_zones = send_to_zones.size();
+    }
+
+    std::cout << "\n";
+
+    int kkk = 1;
+}
+
+void Solver::InitFields()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+    }
+
+    Boundary();
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        int nZones = Global::zones.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Field * field = Global::fields[ iZone ];
+            Zone * zone = Global::zones[ iZone ];
+            zone->zoneIndex = iZone;
+            field->Solve( zone );
+        }
+        Boundary();
+    }
+}
+
+void Solver::Boundary()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+    ExchangeInterfaceField();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->UpdateOldField();
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    int nZones = Global::interfaces.size();
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> & send_to_zones = interface->send_to_zones;
+        int nsend_zones = send_to_zones.size();
+
+        std::vector<std::vector<int>> & donorfaces_for_send = interface->donorfaces_for_send;
+        std::vector<std::vector<int>> & donorijk_for_send = interface->donorijk_for_send;
+        std::vector<std::vector<double>> & donordata_for_send = interface->donordata_for_send;
+
+        Field * field = Global::fields[ iZone ];
+
+        for ( int iSend = 0; iSend < nsend_zones; ++ iSend )
+        {
+            int zone_to_send = send_to_zones[ iSend ];
+            std::vector<int> & donorfaces = donorfaces_for_send[ iSend ];
+            std::vector<int> & donorijks = donorijk_for_send[ iSend ];
+            std::vector<double> & donordatas = donordata_for_send[ iSend ];
+
+            int nface = donorfaces.size();
+            int index_dim = 1;
+            for ( int i = 0; i < nface; ++ i )
+            {
+                int ijkpos = index_dim * i;
+                int i_donor_cell = donorijks[ ijkpos + 0 ];
+                donordatas[ i ] = field->u[ i_donor_cell ];
+            }
+        }
+    }
+    int kkk = 1;
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+
+        std::vector<int> & neighbor_donor_zones = interface->neighbor_donor_zones;
+        int ndonor_zones = neighbor_donor_zones.size();
+
+        //std::vector<std::vector<double>> & recv_donor_fields = interface->recv_donor_fields;
+
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donorzone = neighbor_donor_zones[ iNei ];
+            Interface * donor_interface = Global::interfaces[ donorzone ];
+            int nSize = donor_interface->send_to_zones.size();
+            int ipos = -1;
+            for ( int i = 0; i < nSize; ++ i )
+            {
+                int szone = donor_interface->send_to_zones[ i ];
+                if ( szone == iZone )
+                {
+                    ipos = i;
+                    break;
+                }
+            }
+            std::vector<double> & donordata = donor_interface->donordata_for_send[ ipos ];
+
+            std::vector<int> & neighbor_donorfaces = interface->neighbor_donorfaces[ iNei ];
+            std::vector<int> & sub_local_faceids = interface->sub_local_faceids[ iNei ];
+            for ( int i = 0; i < neighbor_donorfaces.size(); ++ i )
+            {
+                int local_faceid = sub_local_faceids[ i ];
+                double donor_value = donordata[ i ];
+                interface->data_recv[ local_faceid ] = donor_value;
+            }
+        }
+
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+
+            double donor_value = interface->data_recv[ iFace ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::PostProcess()
+{
+    Post post;
+    post.Process();
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    int nZones = Global::grids.size();
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        int ni = grid->x.size();
+        double xmin = grid->x[ 0 ];
+        double xmax = grid->x[ 0 ];
+        int imin = 0;
+        int imax = 0;
+        for ( int i = 0; i < ni; ++ i )
+        {
+            if ( xmin > grid->x[ i ] )
+            {
+                xmin = grid->x[ i ];
+                imin = i;
+            }
+            if ( xmax < grid->x[ i ] )
+            {
+                xmax = grid->x[ i ];
+                imax = i;
+            }
+        }
+        xmin_list.push_back( xmin );
+        xmax_list.push_back( xmax );
+    }
+    std::vector<std::pair<double, int>> pairs;
+    int nSize = xmin_list.size();
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        pairs.push_back( std::make_pair( xmin_list[i], i ) );
+    }
+
+    std::sort( pairs.begin(), pairs.end() );
+
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        this->zoneids.push_back( pairs[i].second );
+    }
+
+    int kkk = 1;
+}
+
+void Post::GatherField()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+        Grid * grid = Global::grids[ zoneid ];
+        Field * field = Global::fields[ zoneid ];
+
+        int ni = grid->x.size();
+
+        int ist = 1;
+        int ied = ni;
+
+        int dir = 1;
+        if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+        if ( dir == 1 )
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ist; i <= ied; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+
+            }
+            else
+            {
+                for ( int i = ist; i <= ied - 1; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+        else
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ied; i >= ist; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+            else
+            {
+                for ( int i = ied; i >= ist + 1; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+    }
+}
+
+void Post::DumpField()
+{
+    int ni_total = this->x.size();
+    std::cout << " DumpField x.size() = " << x.size() << "\n";
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    this->DumpErrorDetails( u_error );
+
+    std::string csvname = "field_final.csv";
+    this->DumpCsvFile( csvname, x, u_e, un, u_error );
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.20f} {:.20f} {:.20f} {:.20f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/Solver.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/Solver.h
new file mode 100644
index 00000000..d01d3d9c
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/Solver.h
@@ -0,0 +1,44 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+
+class Solver
+{
+public:
+    Solver();
+    ~Solver();
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveMultiZones();
+public:
+    void Boundary();
+    void ExchangeInterfaceField();
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcess();
+};
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+    std::vector<double> u;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/global.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/global.cpp
new file mode 100644
index 00000000..d96bf9d7
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/global.cpp
@@ -0,0 +1,191 @@
+#include "global.h"
+#include "CgnsGrid.h"
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *> Global::interfaces;
+
+std::map<Face, int> Global::faceMap;
+std::map<FacePair, int> Global::facePairMap;
+std::vector<FacePair> Global::facePairList;
+
+std::vector<std::set<int>> Global::donor_zone_sets;
+std::vector<std::vector<int>> Global::donor_zones;
+
+bool Face::operator < ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return this->zone < rhs.zone;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return this->i < rhs.i;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return this->j < rhs.j;
+    }
+
+    return this->k < rhs.k;
+}
+
+bool Face::operator == ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return false;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return false;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return false;
+    }
+
+    return this->k == rhs.k;
+}
+
+void FacePair::AddPair( const Face & face1, const Face & face2 )
+{
+    if ( face1 < face2 )
+    {
+        this->left = face1;
+        this->right = face2;
+    }
+    else
+    {
+        this->left = face2;
+        this->right = face1;
+    }
+}
+
+bool FacePair::operator < ( const FacePair & rhs ) const
+{
+    if ( this->left == rhs.left || this->left == rhs.right )
+    {
+        return false;
+    }
+
+    return this->left < rhs.left;
+}
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->local_faceids.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        Face face;
+        face.zone = zoneid;
+        face.i = i;
+
+        Global::InsertFaceMap( face );
+
+        int i_donor = index2[ 0 ];
+
+        Face face_donor;
+        face_donor.zone = donor_zoneid;
+        face_donor.i = i_donor;
+
+        Global::InsertFaceMap( face_donor );
+
+        FacePair facePair;
+        facePair.AddPair( face, face_donor );
+
+        Global::facePairList.push_back( facePair );
+        int global_faceid = Global::InsertFacePairMap( facePair );
+        this->global_faceids.push_back( global_faceid );
+
+        this->global_local_face_map.insert( std::make_pair( global_faceid, faceid ) );
+
+        int i_ghost_cell = i + 1;
+        int i_local_donor_cell = i - 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+            i_local_donor_cell = i + 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+        ijk_donors.push_back( i_local_donor_cell );
+
+        icount ++;
+    }
+}
+
+void Global::InsertFaceMap( const Face & face )
+{
+    std::map<Face, int>::iterator iter;
+    iter = Global::faceMap.find( face );
+    if ( iter == Global::faceMap.end() )
+    {
+        int faceid = Global::faceMap.size();
+        Global::faceMap.insert( std::make_pair( face, faceid ) );
+    }
+}
+
+int Global::InsertFacePairMap( const FacePair & facePair )
+{
+    std::map<FacePair, int>::iterator iter;
+    iter = Global::facePairMap.find( facePair );
+    if ( iter == Global::facePairMap.end() )
+    {
+        int facePairId = Global::facePairMap.size();
+        Global::facePairMap.insert( std::make_pair( facePair, facePairId ) );
+        return facePairId;
+    }
+    return iter->second;
+}
+
+void Global::SendGeom( int zone, int donorzone, std::vector<int> & donorfaces )
+{
+    Interface * interface = Global::interfaces[ donorzone ];
+
+    std::vector<int> & send_to_zones = interface->send_to_zones;
+
+    send_to_zones.push_back( zone );
+    interface->donorfaces_for_send.push_back( donorfaces );
+
+    int nface = donorfaces.size();
+    std::vector<int> sub_donorijk;
+    int index_dim = 1;
+    for ( int i = 0; i < nface; ++ i )
+    {
+        int global_faceid = donorfaces[ i ];
+        int local_faceid = interface->global_local_face_map[ global_faceid ];
+        int ijkpos = index_dim * local_faceid;
+        int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+        sub_donorijk.push_back( i_donor_cell );
+        int kkk = 1;
+    }
+
+    interface->donorijk_for_send.push_back( sub_donorijk );
+
+    std::vector<double> sub_donordata( sub_donorijk.size() );
+    interface->donordata_for_send.push_back( sub_donordata );
+}
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/global.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/global.h
new file mode 100644
index 00000000..ce8eef97
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/global.h
@@ -0,0 +1,138 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <unordered_map>
+#include <set>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class Face
+{
+public:
+    int zone = 0;
+    int i = 0;
+    int j = 1;
+    int k = 1;
+public:
+    bool operator < ( const Face & rhs ) const;
+    bool operator == ( const Face & rhs ) const;
+};
+
+class FacePair
+{
+public:
+    Face left;
+    Face right;
+public:
+    bool operator < ( const FacePair & rhs ) const;
+    void AddPair( const Face &face1, const Face &face2);
+};
+
+class Transform;
+
+
+class Interface
+{
+public:
+    int zoneid;
+    std::vector<int> zoneList;
+    std::vector<int> global_faceids;
+    std::vector<int> local_faceids;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+    std::vector<double> data_recv;
+    std::vector<double> data_send;
+    std::unordered_map<int, int> global_local_face_map;
+public:
+    std::vector<int> neighbor_donor_zones;
+    std::vector<std::vector<int>> neighbor_donorfaces;
+    std::vector<std::vector<int>> sub_local_faceids;
+    std::vector<int> send_to_zones;
+    std::vector<std::vector<int>> donorfaces_for_send;
+    std::vector<std::vector<int>> donorijk_for_send;
+    std::vector<std::vector<double>> donordata_for_send;
+public:
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+};
+
+class Field;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+public:
+    static std::map<Face, int> faceMap;
+    static std::map<FacePair, int> facePairMap;
+    static std::vector<FacePair> facePairList;
+    static std::vector<std::set<int>> donor_zone_sets;
+    static std::vector<std::vector<int>> donor_zones;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+public:
+    static void InsertFaceMap( const Face & face );
+    static int InsertFacePairMap( const FacePair & facePair );
+    static void SendGeom( int zone, int donorzone, std::vector<int> & donorfaces );
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/heat1d4blocksv1.cgns b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/heat1d4blocksv1.cgns
new file mode 100644
index 00000000..df5ffc5f
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/heat1d4blocksv1.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/main.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/main.cpp
new file mode 100644
index 00000000..df63b7da
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/main.cpp
@@ -0,0 +1,9 @@
+#include "Solver.h"
+#include "Parallel.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/plot.py b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/CMakeLists.txt
new file mode 100644
index 00000000..038616a3
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/CMakeLists.txt
@@ -0,0 +1,97 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package ( MPI )
+
+message ( STATUS  "MPI_FOUND=${MPI_FOUND}" )
+message ( STATUS  "MPI_CXX_INCLUDE_DIRS=${MPI_CXX_INCLUDE_DIRS}" )
+message ( STATUS  "MPI_LIBRARIES=${MPI_LIBRARIES}" )
+if ( MPI_FOUND )
+	list ( APPEND PRJ_INCLUDE_DIRS ${MPI_CXX_INCLUDE_DIRS} )
+	list ( APPEND PRJ_LIBRARIES ${MPI_LIBRARIES} )
+endif ()
+
+#get_directory_property( my_import_targets DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} IMPORTED_TARGETS )
+#message( STATUS "my_import_targets=${my_import_targets}" )
+
+list ( APPEND PRJ_LIBRARIES MPI::MPI_C )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+list ( APPEND PRJ_COMPILE_DEFINITIONS HX_PARALLEL )
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	Parallel.h Parallel.cpp
+	Solver.h Solver.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/CgnsGrid.cpp
new file mode 100644
index 00000000..5cec92ac
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/CgnsGrid.cpp
@@ -0,0 +1,673 @@
+#include "CgnsGrid.h"
+#include "Parallel.h"
+#include "cgnslib.h"
+#include "global.h"
+#include <iostream>
+#include <vector>
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    if ( Parallel::pid == Parallel::serverid )
+    {
+        cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "fileId = " << fileId << "\n";
+    }
+    
+    int nbases = -1;
+    if ( Parallel::pid == Parallel::serverid )
+    {
+        cg_nbases( fileId, &nbases );
+    }
+    MPI_Bcast( &nbases, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "nbases = " << nbases << "\n";
+    
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        if ( Parallel::pid == Parallel::serverid )
+        {
+            cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        }
+
+        MPI_Bcast( &icelldim, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+        MPI_Bcast( &iphysdim, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+
+        int nzones = -1;
+        if ( Parallel::pid == Parallel::serverid )
+        {
+            cg_nzones( fileId, baseId, &nzones );
+        }
+
+        MPI_Bcast( &nzones, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nzones = " << nzones << "\n";
+
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "iZone = " << iZone << "\n";
+
+            int index_dim = -1;
+            if ( Parallel::pid == Parallel::serverid )
+            {
+                cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            }
+            MPI_Bcast( &index_dim, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            if ( Parallel::pid == Parallel::serverid )
+            {
+                cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            }
+
+            MPI_Bcast( zonename, 33, MPI_CHAR, Parallel::serverid, MPI_COMM_WORLD );
+            MPI_Bcast( isize.data(), index_dim * 3, MPI_LONG_LONG, Parallel::serverid, MPI_COMM_WORLD );
+
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "zonename = " << zonename << "\n";
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+
+    if ( Parallel::pid == Parallel::serverid )
+    {
+        cg_close( fileId );
+    }
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            if ( Parallel::pid == Parallel::serverid )
+            {
+                cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            }
+            //MPI_Bcast( &index_dim, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+            HXSendRecvData<int>( &index_dim, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+	    
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "index_dim = " << index_dim << "\n";
+            }
+	    
+            std::vector<cgsize_t> isize( index_dim * 3 );
+            char zonename[ 33 ];
+            if ( Parallel::pid == Parallel::serverid )
+            {
+                cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            }
+	    
+            MPI_Bcast( zonename, 33, MPI_CHAR, Parallel::serverid, MPI_COMM_WORLD );
+            MPI_Bcast( isize.data(), index_dim * 3, MPI_LONG_LONG, Parallel::serverid, MPI_COMM_WORLD );
+	    
+            HXSendRecvData( zonename, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+	    
+            return;
+	    
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "zonename = " << zonename << "\n";
+	    
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+	    
+            std::vector<cgsize_t> irmin( index_dim );
+            std::vector<cgsize_t> irmax( index_dim );
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+	    
+            ZoneType_t zoneType;
+            if ( Parallel::pid == Parallel::serverid )
+            {
+                cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            }
+            MPI_Bcast( &zoneType, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            int ncoords = -1;
+            if ( Parallel::pid == Parallel::serverid )
+            {
+                cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            }
+            MPI_Bcast( &ncoords, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "ncoords = " << ncoords << "\n";
+	    
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                zone->nijk.push_back( isize[ m ] );
+            }
+	    
+            Grid * grid = new Grid();
+            Global::grids.push_back( grid );
+	    
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+	    
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+	    
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                if ( Parallel::pid == Parallel::serverid )
+                {
+                    cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                }
+                MPI_Bcast( coordname, 33, MPI_CHAR, Parallel::serverid, MPI_COMM_WORLD );
+                MPI_Bcast( &dataType, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+	    
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+                if ( Parallel::pid == Parallel::serverid )
+                {
+                    cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+                }
+	    
+                double * pcoor = (double *)coor->coord.data();
+	    
+                MPI_Bcast( pcoor, nNodes, MPI_DOUBLE, Parallel::serverid, MPI_COMM_WORLD );
+	    
+                if ( icoord == 0 )
+                {
+                    grid->x.resize( nNodes );
+                    coor->DumpCoorX( grid->x );
+                }
+            }
+	    
+            int nbocos = -1;
+            if ( Parallel::pid == Parallel::serverid )
+            {
+                cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            }
+            MPI_Bcast( &nbocos, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "nbocos = " << nbocos << "\n";
+	    
+	    
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                if ( Parallel::pid == Parallel::serverid )
+                {
+                    cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                }
+                MPI_Bcast( &location, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+	    
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+	    
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+	    
+                if ( Parallel::pid == Parallel::serverid )
+                {
+                    cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                        &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                }
+                MPI_Bcast( boconame, 33, MPI_CHAR, Parallel::serverid, MPI_COMM_WORLD );
+                MPI_Bcast( &bocotype, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+                MPI_Bcast( &ptset_type, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+                MPI_Bcast( &normalDataType, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+                MPI_Bcast( &npnts, 1, MPI_LONG_LONG, Parallel::serverid, MPI_COMM_WORLD );
+                MPI_Bcast( &normalListSize, 1, MPI_LONG_LONG, Parallel::serverid, MPI_COMM_WORLD );
+                MPI_Bcast( &ndataset, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+                MPI_Bcast( normalIndex.data(), index_dim, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+                zonebc->bcType = bocotype;
+	    
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+	    
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+	    
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+	    
+                if ( Parallel::pid == Parallel::serverid )
+                {
+                    cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                }
+	    
+                MPI_Bcast( pnts.data(), npnts * index_dim, MPI_LONG_LONG, Parallel::serverid, MPI_COMM_WORLD );
+                MPI_Bcast( normalList.data(), nNodes * iphysdim * sizeof( double ), MPI_CHAR, Parallel::serverid, MPI_COMM_WORLD );
+	    
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+	    
+            int n1to1 = -1;
+            if ( Parallel::pid == Parallel::serverid )
+            {
+                cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            }
+            MPI_Bcast( &n1to1, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "n1to1 = " << n1to1 << "\n";
+	    
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+	    
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+	    
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                if ( Parallel::pid == Parallel::serverid )
+                {
+                    cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                }
+                MPI_Bcast( connectname, 33, MPI_CHAR, Parallel::serverid, MPI_COMM_WORLD );
+                MPI_Bcast( donorname, 33, MPI_CHAR, Parallel::serverid, MPI_COMM_WORLD );
+                MPI_Bcast( range.data(), npnts * index_dim, MPI_LONG_LONG, Parallel::serverid, MPI_COMM_WORLD );
+                MPI_Bcast( donor_range.data(), npnts * index_dim, MPI_LONG_LONG, Parallel::serverid, MPI_COMM_WORLD );
+	    
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "donorname = " << donorname << "\n";
+	    
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+	    
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+	    
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+	    
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+	    
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+            }
+        }
+    }   
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/CgnsGrid.h
new file mode 100644
index 00000000..fddf1db6
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/CgnsGrid.h
@@ -0,0 +1,103 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    int zoneIndex;
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/Field.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/Field.cpp
new file mode 100644
index 00000000..c359a811
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/Field.cpp
@@ -0,0 +1,142 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+
+    std::vector<double> & x = grid->x;
+    this->dx = std::abs( x[ 1 ] - x[ 0 ] );
+    this->dt = dx / 10.0;
+    this->t = 1.0;
+    this->nt = std::round( t / dt );
+
+    double total_time = nt * dt;
+
+    std::cout << "this->dt   = " << this->dt << "\n";
+    std::cout << "this->t    = " << this->t << "\n";
+    std::cout << "this->nt   = " << this->nt << "\n";
+    std::cout << "this->ni   = " << this->ni << "\n";
+    std::cout << "total_time = " << total_time << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        u_e[ i ] = - std::exp( -total_time ) * std::sin( std::numbers::pi * xm ); //theory solution
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+    int kkk = 1;
+}
+
+void Field::Solve( Zone * zone )
+{
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+    }
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        //std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        //region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+        int kkk = 1;
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
+
+void Field::UpdateOldField()
+{
+    for ( int i = 0; i < this->u.size(); ++ i )
+    {
+        this->un[ i ] = this->u[ i ];
+    }
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/Field.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/Field.h
new file mode 100644
index 00000000..084ec9bd
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/Field.h
@@ -0,0 +1,36 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid );
+
+    void Solve( Zone * zone );
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void UpdateOldField();
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/Parallel.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/Parallel.cpp
new file mode 100644
index 00000000..c4a40b66
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/Parallel.cpp
@@ -0,0 +1,31 @@
+#include "Parallel.h"
+#include <iostream>
+
+int Parallel::pid = 0;
+int Parallel::nProc = 1;
+int Parallel::serverid = 0;
+int Parallel::tag = 0;
+
+void Parallel::Init()
+{
+#ifdef HX_PARALLEL
+    int argc     = 0;
+    char ** argv = 0;
+    MPI_Init( &argc, &argv );
+    MPI_Comm_rank( MPI_COMM_WORLD, &Parallel::pid );
+    MPI_Comm_size( MPI_COMM_WORLD, &Parallel::nProc );
+    int len = -1;
+    char version[ MPI_MAX_LIBRARY_VERSION_STRING ];
+    MPI_Get_library_version( version, &len );
+    std::cout << "Hello, world!  I am " << Parallel::pid << " of " << Parallel::nProc
+        << "(" << version << ", " << len << ")" << std::endl;
+#endif
+}
+
+void Parallel::Finalize()
+{
+#ifdef HX_PARALLEL
+    MPI_Finalize();
+#endif
+}
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/Parallel.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/Parallel.h
new file mode 100644
index 00000000..3e6f50e2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/Parallel.h
@@ -0,0 +1,17 @@
+#pragma once
+#ifdef HX_PARALLEL
+#include "mpi.h"
+#endif
+#include <vector>
+
+class Parallel
+{
+public:
+    static int pid;
+    static int nProc;
+    static int serverid;
+    static int tag;
+public:
+    static void Init();
+    static void Finalize();
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/README.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/Solver.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/Solver.cpp
new file mode 100644
index 00000000..20d6fc61
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/Solver.cpp
@@ -0,0 +1,519 @@
+#include "Solver.h"
+#include "Parallel.h"
+#include <fstream>
+#include <set>
+#include <unordered_map>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+Solver::Solver()
+{
+    Parallel::Init();
+}
+
+Solver::~Solver()
+{
+    Parallel::Finalize();
+}
+
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    //if ( Parallel::pid == Parallel::serverid )
+    //{
+    //    this->ReadGrid();
+    //    this->InitTopo();
+    //    this->InitFields();
+    //    this->SolveMultiZones();
+    //    this->PostProcess();
+    //}
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d4blocksv1.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    //ReadCgnsGrid( fileName );
+}
+
+void Solver::InitTopo()
+{
+    int nZones = Global::grids.size();
+    Global::donor_zone_sets.resize( nZones );
+    Global::donor_zones.resize( nZones );
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = new Interface();
+        interface->zoneid = iZone;
+        Global::interfaces.push_back( interface );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+        Interface * interface = Global::interfaces[ iZone ];
+
+        int nbc1to1s = zone->bc1to1s.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+        int nInterfaces = interface->zoneList.size();
+        interface->data_recv.resize( nInterfaces );
+        interface->data_send.resize( nInterfaces );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        std::set<int> &donor_zoneSet = Global::donor_zone_sets[ iZone ];
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            donor_zoneSet.insert( donor_zoneid );
+        }
+
+        std::vector<int> &donor_zones = Global::donor_zones[ iZone ];
+        for ( std::set<int>::iterator iter = donor_zoneSet.begin(); iter != donor_zoneSet.end(); ++ iter )
+        {
+            donor_zones.push_back( *iter );
+        }
+
+        interface->neighbor_donor_zones = donor_zones;
+
+        std::unordered_map<int, int> donor_zonelocal;
+
+        for ( int idonor = 0; idonor < donor_zones.size(); ++ idonor )
+        {
+            int donor_zone = donor_zones[ idonor ];
+            donor_zonelocal.insert( std::make_pair( donor_zone, idonor ) );
+        }
+        int index_dim = 1;
+        int ndonors = donor_zones.size();
+        std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+        neighbor_donorfaces.resize( ndonors );
+
+        std::vector<std::vector<int>> & sub_local_faceids = interface->sub_local_faceids;
+        sub_local_faceids.resize( ndonors );
+
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ineighbor = donor_zonelocal[ donor_zoneid ];
+            std::vector<int> &donorfaces = neighbor_donorfaces[ ineighbor ];
+            int global_faceid = interface->global_faceids[ iFace ];
+            donorfaces.push_back( global_faceid );
+            int local_faceid = interface->local_faceids[ iFace ];
+
+            std::vector<int> & sub_local_faces = sub_local_faceids[ ineighbor ];
+            sub_local_faces.push_back( local_faceid );
+        }
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> &neighbor_donor_zones = interface->neighbor_donor_zones;
+        int ndonor_zones = neighbor_donor_zones.size();
+
+        std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donorzone = neighbor_donor_zones[ iNei ];
+            //std::cout << "donorzone = " << donorzone << " donorfaces = ";
+            std::vector<int> & neighbor_donorface = neighbor_donorfaces[ iNei ];
+
+            Global::SendGeom( iZone, donorzone, neighbor_donorface );
+        }
+        int kkk = 1;
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        std::cout << "zone = " << iZone << "\n";
+
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> & send_to_zones = interface->send_to_zones;
+        int nsend_zones = send_to_zones.size();
+    }
+
+    std::cout << "\n";
+
+    int kkk = 1;
+}
+
+void Solver::InitFields()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+    }
+
+    Boundary();
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        int nZones = Global::zones.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Field * field = Global::fields[ iZone ];
+            Zone * zone = Global::zones[ iZone ];
+            zone->zoneIndex = iZone;
+            field->Solve( zone );
+        }
+        Boundary();
+    }
+}
+
+void Solver::Boundary()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+    ExchangeInterfaceField();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->UpdateOldField();
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    int nZones = Global::interfaces.size();
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> & send_to_zones = interface->send_to_zones;
+        int nsend_zones = send_to_zones.size();
+
+        std::vector<std::vector<int>> & donorfaces_for_send = interface->donorfaces_for_send;
+        std::vector<std::vector<int>> & donorijk_for_send = interface->donorijk_for_send;
+        std::vector<std::vector<double>> & donordata_for_send = interface->donordata_for_send;
+
+        Field * field = Global::fields[ iZone ];
+
+        for ( int iSend = 0; iSend < nsend_zones; ++ iSend )
+        {
+            int zone_to_send = send_to_zones[ iSend ];
+            std::vector<int> & donorfaces = donorfaces_for_send[ iSend ];
+            std::vector<int> & donorijks = donorijk_for_send[ iSend ];
+            std::vector<double> & donordatas = donordata_for_send[ iSend ];
+
+            int nface = donorfaces.size();
+            int index_dim = 1;
+            for ( int i = 0; i < nface; ++ i )
+            {
+                int ijkpos = index_dim * i;
+                int i_donor_cell = donorijks[ ijkpos + 0 ];
+                donordatas[ i ] = field->u[ i_donor_cell ];
+            }
+        }
+    }
+    int kkk = 1;
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+
+        std::vector<int> & neighbor_donor_zones = interface->neighbor_donor_zones;
+        int ndonor_zones = neighbor_donor_zones.size();
+
+        //std::vector<std::vector<double>> & recv_donor_fields = interface->recv_donor_fields;
+
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donorzone = neighbor_donor_zones[ iNei ];
+            Interface * donor_interface = Global::interfaces[ donorzone ];
+            int nSize = donor_interface->send_to_zones.size();
+            int ipos = -1;
+            for ( int i = 0; i < nSize; ++ i )
+            {
+                int szone = donor_interface->send_to_zones[ i ];
+                if ( szone == iZone )
+                {
+                    ipos = i;
+                    break;
+                }
+            }
+            std::vector<double> & donordata = donor_interface->donordata_for_send[ ipos ];
+
+            std::vector<int> & neighbor_donorfaces = interface->neighbor_donorfaces[ iNei ];
+            std::vector<int> & sub_local_faceids = interface->sub_local_faceids[ iNei ];
+            for ( int i = 0; i < neighbor_donorfaces.size(); ++ i )
+            {
+                int local_faceid = sub_local_faceids[ i ];
+                double donor_value = donordata[ i ];
+                interface->data_recv[ local_faceid ] = donor_value;
+            }
+        }
+
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+
+            double donor_value = interface->data_recv[ iFace ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::PostProcess()
+{
+    Post post;
+    post.Process();
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    int nZones = Global::grids.size();
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        int ni = grid->x.size();
+        double xmin = grid->x[ 0 ];
+        double xmax = grid->x[ 0 ];
+        int imin = 0;
+        int imax = 0;
+        for ( int i = 0; i < ni; ++ i )
+        {
+            if ( xmin > grid->x[ i ] )
+            {
+                xmin = grid->x[ i ];
+                imin = i;
+            }
+            if ( xmax < grid->x[ i ] )
+            {
+                xmax = grid->x[ i ];
+                imax = i;
+            }
+        }
+        xmin_list.push_back( xmin );
+        xmax_list.push_back( xmax );
+    }
+    std::vector<std::pair<double, int>> pairs;
+    int nSize = xmin_list.size();
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        pairs.push_back( std::make_pair( xmin_list[i], i ) );
+    }
+
+    std::sort( pairs.begin(), pairs.end() );
+
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        this->zoneids.push_back( pairs[i].second );
+    }
+
+    int kkk = 1;
+}
+
+void Post::GatherField()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+        Grid * grid = Global::grids[ zoneid ];
+        Field * field = Global::fields[ zoneid ];
+
+        int ni = grid->x.size();
+
+        int ist = 1;
+        int ied = ni;
+
+        int dir = 1;
+        if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+        if ( dir == 1 )
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ist; i <= ied; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+
+            }
+            else
+            {
+                for ( int i = ist; i <= ied - 1; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+        else
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ied; i >= ist; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+            else
+            {
+                for ( int i = ied; i >= ist + 1; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+    }
+}
+
+void Post::DumpField()
+{
+    int ni_total = this->x.size();
+    std::cout << " DumpField x.size() = " << x.size() << "\n";
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    this->DumpErrorDetails( u_error );
+
+    std::string csvname = "field_final.csv";
+    this->DumpCsvFile( csvname, x, u_e, un, u_error );
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.20f} {:.20f} {:.20f} {:.20f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/Solver.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/Solver.h
new file mode 100644
index 00000000..d01d3d9c
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/Solver.h
@@ -0,0 +1,44 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+
+class Solver
+{
+public:
+    Solver();
+    ~Solver();
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveMultiZones();
+public:
+    void Boundary();
+    void ExchangeInterfaceField();
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcess();
+};
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+    std::vector<double> u;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/global.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/global.cpp
new file mode 100644
index 00000000..d96bf9d7
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/global.cpp
@@ -0,0 +1,191 @@
+#include "global.h"
+#include "CgnsGrid.h"
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *> Global::interfaces;
+
+std::map<Face, int> Global::faceMap;
+std::map<FacePair, int> Global::facePairMap;
+std::vector<FacePair> Global::facePairList;
+
+std::vector<std::set<int>> Global::donor_zone_sets;
+std::vector<std::vector<int>> Global::donor_zones;
+
+bool Face::operator < ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return this->zone < rhs.zone;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return this->i < rhs.i;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return this->j < rhs.j;
+    }
+
+    return this->k < rhs.k;
+}
+
+bool Face::operator == ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return false;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return false;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return false;
+    }
+
+    return this->k == rhs.k;
+}
+
+void FacePair::AddPair( const Face & face1, const Face & face2 )
+{
+    if ( face1 < face2 )
+    {
+        this->left = face1;
+        this->right = face2;
+    }
+    else
+    {
+        this->left = face2;
+        this->right = face1;
+    }
+}
+
+bool FacePair::operator < ( const FacePair & rhs ) const
+{
+    if ( this->left == rhs.left || this->left == rhs.right )
+    {
+        return false;
+    }
+
+    return this->left < rhs.left;
+}
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->local_faceids.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        Face face;
+        face.zone = zoneid;
+        face.i = i;
+
+        Global::InsertFaceMap( face );
+
+        int i_donor = index2[ 0 ];
+
+        Face face_donor;
+        face_donor.zone = donor_zoneid;
+        face_donor.i = i_donor;
+
+        Global::InsertFaceMap( face_donor );
+
+        FacePair facePair;
+        facePair.AddPair( face, face_donor );
+
+        Global::facePairList.push_back( facePair );
+        int global_faceid = Global::InsertFacePairMap( facePair );
+        this->global_faceids.push_back( global_faceid );
+
+        this->global_local_face_map.insert( std::make_pair( global_faceid, faceid ) );
+
+        int i_ghost_cell = i + 1;
+        int i_local_donor_cell = i - 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+            i_local_donor_cell = i + 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+        ijk_donors.push_back( i_local_donor_cell );
+
+        icount ++;
+    }
+}
+
+void Global::InsertFaceMap( const Face & face )
+{
+    std::map<Face, int>::iterator iter;
+    iter = Global::faceMap.find( face );
+    if ( iter == Global::faceMap.end() )
+    {
+        int faceid = Global::faceMap.size();
+        Global::faceMap.insert( std::make_pair( face, faceid ) );
+    }
+}
+
+int Global::InsertFacePairMap( const FacePair & facePair )
+{
+    std::map<FacePair, int>::iterator iter;
+    iter = Global::facePairMap.find( facePair );
+    if ( iter == Global::facePairMap.end() )
+    {
+        int facePairId = Global::facePairMap.size();
+        Global::facePairMap.insert( std::make_pair( facePair, facePairId ) );
+        return facePairId;
+    }
+    return iter->second;
+}
+
+void Global::SendGeom( int zone, int donorzone, std::vector<int> & donorfaces )
+{
+    Interface * interface = Global::interfaces[ donorzone ];
+
+    std::vector<int> & send_to_zones = interface->send_to_zones;
+
+    send_to_zones.push_back( zone );
+    interface->donorfaces_for_send.push_back( donorfaces );
+
+    int nface = donorfaces.size();
+    std::vector<int> sub_donorijk;
+    int index_dim = 1;
+    for ( int i = 0; i < nface; ++ i )
+    {
+        int global_faceid = donorfaces[ i ];
+        int local_faceid = interface->global_local_face_map[ global_faceid ];
+        int ijkpos = index_dim * local_faceid;
+        int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+        sub_donorijk.push_back( i_donor_cell );
+        int kkk = 1;
+    }
+
+    interface->donorijk_for_send.push_back( sub_donorijk );
+
+    std::vector<double> sub_donordata( sub_donorijk.size() );
+    interface->donordata_for_send.push_back( sub_donordata );
+}
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/global.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/global.h
new file mode 100644
index 00000000..ce8eef97
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/global.h
@@ -0,0 +1,138 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <unordered_map>
+#include <set>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class Face
+{
+public:
+    int zone = 0;
+    int i = 0;
+    int j = 1;
+    int k = 1;
+public:
+    bool operator < ( const Face & rhs ) const;
+    bool operator == ( const Face & rhs ) const;
+};
+
+class FacePair
+{
+public:
+    Face left;
+    Face right;
+public:
+    bool operator < ( const FacePair & rhs ) const;
+    void AddPair( const Face &face1, const Face &face2);
+};
+
+class Transform;
+
+
+class Interface
+{
+public:
+    int zoneid;
+    std::vector<int> zoneList;
+    std::vector<int> global_faceids;
+    std::vector<int> local_faceids;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+    std::vector<double> data_recv;
+    std::vector<double> data_send;
+    std::unordered_map<int, int> global_local_face_map;
+public:
+    std::vector<int> neighbor_donor_zones;
+    std::vector<std::vector<int>> neighbor_donorfaces;
+    std::vector<std::vector<int>> sub_local_faceids;
+    std::vector<int> send_to_zones;
+    std::vector<std::vector<int>> donorfaces_for_send;
+    std::vector<std::vector<int>> donorijk_for_send;
+    std::vector<std::vector<double>> donordata_for_send;
+public:
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+};
+
+class Field;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+public:
+    static std::map<Face, int> faceMap;
+    static std::map<FacePair, int> facePairMap;
+    static std::vector<FacePair> facePairList;
+    static std::vector<std::set<int>> donor_zone_sets;
+    static std::vector<std::vector<int>> donor_zones;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+public:
+    static void InsertFaceMap( const Face & face );
+    static int InsertFacePairMap( const FacePair & facePair );
+    static void SendGeom( int zone, int donorzone, std::vector<int> & donorfaces );
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/heat1d4blocksv1.cgns b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/heat1d4blocksv1.cgns
new file mode 100644
index 00000000..df5ffc5f
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/heat1d4blocksv1.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/main.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/main.cpp
new file mode 100644
index 00000000..df63b7da
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/main.cpp
@@ -0,0 +1,9 @@
+#include "Solver.h"
+#include "Parallel.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/plot.py b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02a/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/CMakeLists.txt
new file mode 100644
index 00000000..038616a3
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/CMakeLists.txt
@@ -0,0 +1,97 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package ( MPI )
+
+message ( STATUS  "MPI_FOUND=${MPI_FOUND}" )
+message ( STATUS  "MPI_CXX_INCLUDE_DIRS=${MPI_CXX_INCLUDE_DIRS}" )
+message ( STATUS  "MPI_LIBRARIES=${MPI_LIBRARIES}" )
+if ( MPI_FOUND )
+	list ( APPEND PRJ_INCLUDE_DIRS ${MPI_CXX_INCLUDE_DIRS} )
+	list ( APPEND PRJ_LIBRARIES ${MPI_LIBRARIES} )
+endif ()
+
+#get_directory_property( my_import_targets DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} IMPORTED_TARGETS )
+#message( STATUS "my_import_targets=${my_import_targets}" )
+
+list ( APPEND PRJ_LIBRARIES MPI::MPI_C )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+list ( APPEND PRJ_COMPILE_DEFINITIONS HX_PARALLEL )
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	Parallel.h Parallel.cpp
+	Solver.h Solver.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/CgnsGrid.cpp
new file mode 100644
index 00000000..8341e8d4
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/CgnsGrid.cpp
@@ -0,0 +1,687 @@
+#include "CgnsGrid.h"
+#include "Parallel.h"
+#include "cgnslib.h"
+#include "global.h"
+#include <iostream>
+#include <vector>
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    if ( Parallel::pid == Parallel::serverid )
+    {
+        cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "fileId = " << fileId << "\n";
+    }
+    
+    int nbases = -1;
+    if ( Parallel::pid == Parallel::serverid )
+    {
+        cg_nbases( fileId, &nbases );
+    }
+    MPI_Bcast( &nbases, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "nbases = " << nbases << "\n";
+    
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        if ( Parallel::pid == Parallel::serverid )
+        {
+            cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        }
+
+        MPI_Bcast( &icelldim, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+        MPI_Bcast( &iphysdim, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+
+        int nzones = -1;
+        if ( Parallel::pid == Parallel::serverid )
+        {
+            cg_nzones( fileId, baseId, &nzones );
+        }
+
+        MPI_Bcast( &nzones, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nzones = " << nzones << "\n";
+
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "iZone = " << iZone << "\n";
+
+            int index_dim = -1;
+            if ( Parallel::pid == Parallel::serverid )
+            {
+                cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            }
+            MPI_Bcast( &index_dim, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            if ( Parallel::pid == Parallel::serverid )
+            {
+                cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            }
+
+            MPI_Bcast( zonename, 33, MPI_CHAR, Parallel::serverid, MPI_COMM_WORLD );
+            MPI_Bcast( isize.data(), index_dim * 3, MPI_LONG_LONG, Parallel::serverid, MPI_COMM_WORLD );
+
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "zonename = " << zonename << "\n";
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+
+    if ( Parallel::pid == Parallel::serverid )
+    {
+        cg_close( fileId );
+    }
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    if ( Parallel::pid == Parallel::serverid )
+    {
+        cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+        std::cout << "fileId = " << fileId << "\n";
+    }
+    
+    int nbases = -1;
+    if ( Parallel::pid == Parallel::serverid )
+    {
+        cg_nbases( fileId, &nbases );
+    }
+    MPI_Bcast( &nbases, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        if ( Parallel::pid == Parallel::serverid )
+        {
+            cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        }
+        MPI_Bcast( &icelldim, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+        MPI_Bcast( &iphysdim, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+
+        int nzones = -1;
+        if ( Parallel::pid == Parallel::serverid )
+        {
+            cg_nzones( fileId, baseId, &nzones );
+        }
+        MPI_Bcast( &nzones, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nzones = " << nzones << "\n";
+
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            if ( Parallel::pid == Parallel::serverid )
+            {
+                cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            }
+            MPI_Bcast( &index_dim, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            if ( Parallel::pid == Parallel::serverid )
+            {
+                cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            }
+
+            MPI_Bcast( zonename, 33, MPI_CHAR, Parallel::serverid, MPI_COMM_WORLD );
+            MPI_Bcast( isize.data(), index_dim * 3, MPI_LONG_LONG, Parallel::serverid, MPI_COMM_WORLD );
+
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "zonename = " << zonename << "\n";
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin( index_dim );
+            std::vector<cgsize_t> irmax( index_dim );
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            if ( Parallel::pid == Parallel::serverid )
+            {
+                cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            }
+            MPI_Bcast( &zoneType, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            int ncoords = -1;
+            if ( Parallel::pid == Parallel::serverid )
+            {
+                cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            }
+            MPI_Bcast( &ncoords, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                zone->nijk.push_back( isize[ m ] );
+            }
+
+            Grid * grid = new Grid();
+            Global::grids.push_back( grid );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                if ( Parallel::pid == Parallel::serverid )
+                {
+                    cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                }
+                MPI_Bcast( coordname, 33, MPI_CHAR, Parallel::serverid, MPI_COMM_WORLD );
+                MPI_Bcast( &dataType, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+                if ( Parallel::pid == Parallel::serverid )
+                {
+                    cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+                }
+
+                double * pcoor = (double *)coor->coord.data();
+
+                MPI_Bcast( pcoor, nNodes, MPI_DOUBLE, Parallel::serverid, MPI_COMM_WORLD );
+
+                if ( icoord == 0 )
+                {
+                    grid->x.resize( nNodes );
+                    coor->DumpCoorX( grid->x );
+                }
+            }
+
+            int nbocos = -1;
+            if ( Parallel::pid == Parallel::serverid )
+            {
+                cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            }
+            MPI_Bcast( &nbocos, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "nbocos = " << nbocos << "\n";
+
+
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                if ( Parallel::pid == Parallel::serverid )
+                {
+                    cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                }
+                MPI_Bcast( &location, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                if ( Parallel::pid == Parallel::serverid )
+                {
+                    cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                        &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                }
+                MPI_Bcast( boconame, 33, MPI_CHAR, Parallel::serverid, MPI_COMM_WORLD );
+                MPI_Bcast( &bocotype, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+                MPI_Bcast( &ptset_type, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+                MPI_Bcast( &normalDataType, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+                MPI_Bcast( &npnts, 1, MPI_LONG_LONG, Parallel::serverid, MPI_COMM_WORLD );
+                MPI_Bcast( &normalListSize, 1, MPI_LONG_LONG, Parallel::serverid, MPI_COMM_WORLD );
+                MPI_Bcast( &ndataset, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+                MPI_Bcast( normalIndex.data(), index_dim, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+                zonebc->bcType = bocotype;
+
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+
+                if ( Parallel::pid == Parallel::serverid )
+                {
+                    cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                }
+
+                MPI_Bcast( pnts.data(), npnts * index_dim, MPI_LONG_LONG, Parallel::serverid, MPI_COMM_WORLD );
+                MPI_Bcast( normalList.data(), nNodes * iphysdim * sizeof( double ), MPI_CHAR, Parallel::serverid, MPI_COMM_WORLD );
+
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+
+            int n1to1 = -1;
+            if ( Parallel::pid == Parallel::serverid )
+            {
+                cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            }
+            MPI_Bcast( &n1to1, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "n1to1 = " << n1to1 << "\n";
+
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                if ( Parallel::pid == Parallel::serverid )
+                {
+                    cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                }
+                MPI_Bcast( connectname, 33, MPI_CHAR, Parallel::serverid, MPI_COMM_WORLD );
+                MPI_Bcast( donorname, 33, MPI_CHAR, Parallel::serverid, MPI_COMM_WORLD );
+                MPI_Bcast( range.data(), npnts * index_dim, MPI_LONG_LONG, Parallel::serverid, MPI_COMM_WORLD );
+                MPI_Bcast( donor_range.data(), npnts * index_dim, MPI_LONG_LONG, Parallel::serverid, MPI_COMM_WORLD );
+
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+            }
+        }
+    }
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/CgnsGrid.h
new file mode 100644
index 00000000..fddf1db6
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/CgnsGrid.h
@@ -0,0 +1,103 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    int zoneIndex;
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/Field.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/Field.cpp
new file mode 100644
index 00000000..c359a811
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/Field.cpp
@@ -0,0 +1,142 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+
+    std::vector<double> & x = grid->x;
+    this->dx = std::abs( x[ 1 ] - x[ 0 ] );
+    this->dt = dx / 10.0;
+    this->t = 1.0;
+    this->nt = std::round( t / dt );
+
+    double total_time = nt * dt;
+
+    std::cout << "this->dt   = " << this->dt << "\n";
+    std::cout << "this->t    = " << this->t << "\n";
+    std::cout << "this->nt   = " << this->nt << "\n";
+    std::cout << "this->ni   = " << this->ni << "\n";
+    std::cout << "total_time = " << total_time << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        u_e[ i ] = - std::exp( -total_time ) * std::sin( std::numbers::pi * xm ); //theory solution
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+    int kkk = 1;
+}
+
+void Field::Solve( Zone * zone )
+{
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+    }
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        //std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        //region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+        int kkk = 1;
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
+
+void Field::UpdateOldField()
+{
+    for ( int i = 0; i < this->u.size(); ++ i )
+    {
+        this->un[ i ] = this->u[ i ];
+    }
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/Field.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/Field.h
new file mode 100644
index 00000000..084ec9bd
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/Field.h
@@ -0,0 +1,36 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid );
+
+    void Solve( Zone * zone );
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void UpdateOldField();
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/Parallel.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/Parallel.cpp
new file mode 100644
index 00000000..c4a40b66
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/Parallel.cpp
@@ -0,0 +1,31 @@
+#include "Parallel.h"
+#include <iostream>
+
+int Parallel::pid = 0;
+int Parallel::nProc = 1;
+int Parallel::serverid = 0;
+int Parallel::tag = 0;
+
+void Parallel::Init()
+{
+#ifdef HX_PARALLEL
+    int argc     = 0;
+    char ** argv = 0;
+    MPI_Init( &argc, &argv );
+    MPI_Comm_rank( MPI_COMM_WORLD, &Parallel::pid );
+    MPI_Comm_size( MPI_COMM_WORLD, &Parallel::nProc );
+    int len = -1;
+    char version[ MPI_MAX_LIBRARY_VERSION_STRING ];
+    MPI_Get_library_version( version, &len );
+    std::cout << "Hello, world!  I am " << Parallel::pid << " of " << Parallel::nProc
+        << "(" << version << ", " << len << ")" << std::endl;
+#endif
+}
+
+void Parallel::Finalize()
+{
+#ifdef HX_PARALLEL
+    MPI_Finalize();
+#endif
+}
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/Parallel.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/Parallel.h
new file mode 100644
index 00000000..3e6f50e2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/Parallel.h
@@ -0,0 +1,17 @@
+#pragma once
+#ifdef HX_PARALLEL
+#include "mpi.h"
+#endif
+#include <vector>
+
+class Parallel
+{
+public:
+    static int pid;
+    static int nProc;
+    static int serverid;
+    static int tag;
+public:
+    static void Init();
+    static void Finalize();
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/README.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/Solver.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/Solver.cpp
new file mode 100644
index 00000000..be1a9053
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/Solver.cpp
@@ -0,0 +1,518 @@
+#include "Solver.h"
+#include "Parallel.h"
+#include <fstream>
+#include <set>
+#include <unordered_map>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+Solver::Solver()
+{
+    Parallel::Init();
+}
+
+Solver::~Solver()
+{
+    Parallel::Finalize();
+}
+
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    //if ( Parallel::pid == Parallel::serverid )
+    //{
+    //    this->ReadGrid();
+    //    this->InitTopo();
+    //    this->InitFields();
+    //    this->SolveMultiZones();
+    //    this->PostProcess();
+    //}
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d4blocksv1.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    ReadCgnsGrid( fileName );
+}
+
+void Solver::InitTopo()
+{
+    int nZones = Global::grids.size();
+    Global::donor_zone_sets.resize( nZones );
+    Global::donor_zones.resize( nZones );
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = new Interface();
+        interface->zoneid = iZone;
+        Global::interfaces.push_back( interface );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+        Interface * interface = Global::interfaces[ iZone ];
+
+        int nbc1to1s = zone->bc1to1s.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+        int nInterfaces = interface->zoneList.size();
+        interface->data_recv.resize( nInterfaces );
+        interface->data_send.resize( nInterfaces );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        std::set<int> &donor_zoneSet = Global::donor_zone_sets[ iZone ];
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            donor_zoneSet.insert( donor_zoneid );
+        }
+
+        std::vector<int> &donor_zones = Global::donor_zones[ iZone ];
+        for ( std::set<int>::iterator iter = donor_zoneSet.begin(); iter != donor_zoneSet.end(); ++ iter )
+        {
+            donor_zones.push_back( *iter );
+        }
+
+        interface->neighbor_donor_zones = donor_zones;
+
+        std::unordered_map<int, int> donor_zonelocal;
+
+        for ( int idonor = 0; idonor < donor_zones.size(); ++ idonor )
+        {
+            int donor_zone = donor_zones[ idonor ];
+            donor_zonelocal.insert( std::make_pair( donor_zone, idonor ) );
+        }
+        int index_dim = 1;
+        int ndonors = donor_zones.size();
+        std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+        neighbor_donorfaces.resize( ndonors );
+
+        std::vector<std::vector<int>> & sub_local_faceids = interface->sub_local_faceids;
+        sub_local_faceids.resize( ndonors );
+
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ineighbor = donor_zonelocal[ donor_zoneid ];
+            std::vector<int> &donorfaces = neighbor_donorfaces[ ineighbor ];
+            int global_faceid = interface->global_faceids[ iFace ];
+            donorfaces.push_back( global_faceid );
+            int local_faceid = interface->local_faceids[ iFace ];
+
+            std::vector<int> & sub_local_faces = sub_local_faceids[ ineighbor ];
+            sub_local_faces.push_back( local_faceid );
+        }
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> &neighbor_donor_zones = interface->neighbor_donor_zones;
+        int ndonor_zones = neighbor_donor_zones.size();
+
+        std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donorzone = neighbor_donor_zones[ iNei ];
+            std::vector<int> & neighbor_donorface = neighbor_donorfaces[ iNei ];
+
+            Global::SendGeom( iZone, donorzone, neighbor_donorface );
+        }
+        int kkk = 1;
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        std::cout << "zone = " << iZone << "\n";
+
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> & send_to_zones = interface->send_to_zones;
+        int nsend_zones = send_to_zones.size();
+    }
+
+    std::cout << "\n";
+
+    int kkk = 1;
+}
+
+void Solver::InitFields()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+    }
+
+    Boundary();
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        int nZones = Global::zones.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Field * field = Global::fields[ iZone ];
+            Zone * zone = Global::zones[ iZone ];
+            zone->zoneIndex = iZone;
+            field->Solve( zone );
+        }
+        Boundary();
+    }
+}
+
+void Solver::Boundary()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+    ExchangeInterfaceField();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->UpdateOldField();
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    int nZones = Global::interfaces.size();
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> & send_to_zones = interface->send_to_zones;
+        int nsend_zones = send_to_zones.size();
+
+        std::vector<std::vector<int>> & donorfaces_for_send = interface->donorfaces_for_send;
+        std::vector<std::vector<int>> & donorijk_for_send = interface->donorijk_for_send;
+        std::vector<std::vector<double>> & donordata_for_send = interface->donordata_for_send;
+
+        Field * field = Global::fields[ iZone ];
+
+        for ( int iSend = 0; iSend < nsend_zones; ++ iSend )
+        {
+            int zone_to_send = send_to_zones[ iSend ];
+            std::vector<int> & donorfaces = donorfaces_for_send[ iSend ];
+            std::vector<int> & donorijks = donorijk_for_send[ iSend ];
+            std::vector<double> & donordatas = donordata_for_send[ iSend ];
+
+            int nface = donorfaces.size();
+            int index_dim = 1;
+            for ( int i = 0; i < nface; ++ i )
+            {
+                int ijkpos = index_dim * i;
+                int i_donor_cell = donorijks[ ijkpos + 0 ];
+                donordatas[ i ] = field->u[ i_donor_cell ];
+            }
+        }
+    }
+    int kkk = 1;
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+
+        std::vector<int> & neighbor_donor_zones = interface->neighbor_donor_zones;
+        int ndonor_zones = neighbor_donor_zones.size();
+
+        //std::vector<std::vector<double>> & recv_donor_fields = interface->recv_donor_fields;
+
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donorzone = neighbor_donor_zones[ iNei ];
+            Interface * donor_interface = Global::interfaces[ donorzone ];
+            int nSize = donor_interface->send_to_zones.size();
+            int ipos = -1;
+            for ( int i = 0; i < nSize; ++ i )
+            {
+                int szone = donor_interface->send_to_zones[ i ];
+                if ( szone == iZone )
+                {
+                    ipos = i;
+                    break;
+                }
+            }
+            std::vector<double> & donordata = donor_interface->donordata_for_send[ ipos ];
+
+            std::vector<int> & neighbor_donorfaces = interface->neighbor_donorfaces[ iNei ];
+            std::vector<int> & sub_local_faceids = interface->sub_local_faceids[ iNei ];
+            for ( int i = 0; i < neighbor_donorfaces.size(); ++ i )
+            {
+                int local_faceid = sub_local_faceids[ i ];
+                double donor_value = donordata[ i ];
+                interface->data_recv[ local_faceid ] = donor_value;
+            }
+        }
+
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+
+            double donor_value = interface->data_recv[ iFace ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::PostProcess()
+{
+    Post post;
+    post.Process();
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    int nZones = Global::grids.size();
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        int ni = grid->x.size();
+        double xmin = grid->x[ 0 ];
+        double xmax = grid->x[ 0 ];
+        int imin = 0;
+        int imax = 0;
+        for ( int i = 0; i < ni; ++ i )
+        {
+            if ( xmin > grid->x[ i ] )
+            {
+                xmin = grid->x[ i ];
+                imin = i;
+            }
+            if ( xmax < grid->x[ i ] )
+            {
+                xmax = grid->x[ i ];
+                imax = i;
+            }
+        }
+        xmin_list.push_back( xmin );
+        xmax_list.push_back( xmax );
+    }
+    std::vector<std::pair<double, int>> pairs;
+    int nSize = xmin_list.size();
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        pairs.push_back( std::make_pair( xmin_list[i], i ) );
+    }
+
+    std::sort( pairs.begin(), pairs.end() );
+
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        this->zoneids.push_back( pairs[i].second );
+    }
+
+    int kkk = 1;
+}
+
+void Post::GatherField()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+        Grid * grid = Global::grids[ zoneid ];
+        Field * field = Global::fields[ zoneid ];
+
+        int ni = grid->x.size();
+
+        int ist = 1;
+        int ied = ni;
+
+        int dir = 1;
+        if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+        if ( dir == 1 )
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ist; i <= ied; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+
+            }
+            else
+            {
+                for ( int i = ist; i <= ied - 1; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+        else
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ied; i >= ist; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+            else
+            {
+                for ( int i = ied; i >= ist + 1; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+    }
+}
+
+void Post::DumpField()
+{
+    int ni_total = this->x.size();
+    std::cout << " DumpField x.size() = " << x.size() << "\n";
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    this->DumpErrorDetails( u_error );
+
+    std::string csvname = "field_final.csv";
+    this->DumpCsvFile( csvname, x, u_e, un, u_error );
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.20f} {:.20f} {:.20f} {:.20f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/Solver.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/Solver.h
new file mode 100644
index 00000000..d01d3d9c
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/Solver.h
@@ -0,0 +1,44 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+
+class Solver
+{
+public:
+    Solver();
+    ~Solver();
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveMultiZones();
+public:
+    void Boundary();
+    void ExchangeInterfaceField();
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcess();
+};
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+    std::vector<double> u;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/global.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/global.cpp
new file mode 100644
index 00000000..d96bf9d7
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/global.cpp
@@ -0,0 +1,191 @@
+#include "global.h"
+#include "CgnsGrid.h"
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *> Global::interfaces;
+
+std::map<Face, int> Global::faceMap;
+std::map<FacePair, int> Global::facePairMap;
+std::vector<FacePair> Global::facePairList;
+
+std::vector<std::set<int>> Global::donor_zone_sets;
+std::vector<std::vector<int>> Global::donor_zones;
+
+bool Face::operator < ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return this->zone < rhs.zone;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return this->i < rhs.i;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return this->j < rhs.j;
+    }
+
+    return this->k < rhs.k;
+}
+
+bool Face::operator == ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return false;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return false;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return false;
+    }
+
+    return this->k == rhs.k;
+}
+
+void FacePair::AddPair( const Face & face1, const Face & face2 )
+{
+    if ( face1 < face2 )
+    {
+        this->left = face1;
+        this->right = face2;
+    }
+    else
+    {
+        this->left = face2;
+        this->right = face1;
+    }
+}
+
+bool FacePair::operator < ( const FacePair & rhs ) const
+{
+    if ( this->left == rhs.left || this->left == rhs.right )
+    {
+        return false;
+    }
+
+    return this->left < rhs.left;
+}
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->local_faceids.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        Face face;
+        face.zone = zoneid;
+        face.i = i;
+
+        Global::InsertFaceMap( face );
+
+        int i_donor = index2[ 0 ];
+
+        Face face_donor;
+        face_donor.zone = donor_zoneid;
+        face_donor.i = i_donor;
+
+        Global::InsertFaceMap( face_donor );
+
+        FacePair facePair;
+        facePair.AddPair( face, face_donor );
+
+        Global::facePairList.push_back( facePair );
+        int global_faceid = Global::InsertFacePairMap( facePair );
+        this->global_faceids.push_back( global_faceid );
+
+        this->global_local_face_map.insert( std::make_pair( global_faceid, faceid ) );
+
+        int i_ghost_cell = i + 1;
+        int i_local_donor_cell = i - 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+            i_local_donor_cell = i + 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+        ijk_donors.push_back( i_local_donor_cell );
+
+        icount ++;
+    }
+}
+
+void Global::InsertFaceMap( const Face & face )
+{
+    std::map<Face, int>::iterator iter;
+    iter = Global::faceMap.find( face );
+    if ( iter == Global::faceMap.end() )
+    {
+        int faceid = Global::faceMap.size();
+        Global::faceMap.insert( std::make_pair( face, faceid ) );
+    }
+}
+
+int Global::InsertFacePairMap( const FacePair & facePair )
+{
+    std::map<FacePair, int>::iterator iter;
+    iter = Global::facePairMap.find( facePair );
+    if ( iter == Global::facePairMap.end() )
+    {
+        int facePairId = Global::facePairMap.size();
+        Global::facePairMap.insert( std::make_pair( facePair, facePairId ) );
+        return facePairId;
+    }
+    return iter->second;
+}
+
+void Global::SendGeom( int zone, int donorzone, std::vector<int> & donorfaces )
+{
+    Interface * interface = Global::interfaces[ donorzone ];
+
+    std::vector<int> & send_to_zones = interface->send_to_zones;
+
+    send_to_zones.push_back( zone );
+    interface->donorfaces_for_send.push_back( donorfaces );
+
+    int nface = donorfaces.size();
+    std::vector<int> sub_donorijk;
+    int index_dim = 1;
+    for ( int i = 0; i < nface; ++ i )
+    {
+        int global_faceid = donorfaces[ i ];
+        int local_faceid = interface->global_local_face_map[ global_faceid ];
+        int ijkpos = index_dim * local_faceid;
+        int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+        sub_donorijk.push_back( i_donor_cell );
+        int kkk = 1;
+    }
+
+    interface->donorijk_for_send.push_back( sub_donorijk );
+
+    std::vector<double> sub_donordata( sub_donorijk.size() );
+    interface->donordata_for_send.push_back( sub_donordata );
+}
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/global.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/global.h
new file mode 100644
index 00000000..ce8eef97
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/global.h
@@ -0,0 +1,138 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <unordered_map>
+#include <set>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class Face
+{
+public:
+    int zone = 0;
+    int i = 0;
+    int j = 1;
+    int k = 1;
+public:
+    bool operator < ( const Face & rhs ) const;
+    bool operator == ( const Face & rhs ) const;
+};
+
+class FacePair
+{
+public:
+    Face left;
+    Face right;
+public:
+    bool operator < ( const FacePair & rhs ) const;
+    void AddPair( const Face &face1, const Face &face2);
+};
+
+class Transform;
+
+
+class Interface
+{
+public:
+    int zoneid;
+    std::vector<int> zoneList;
+    std::vector<int> global_faceids;
+    std::vector<int> local_faceids;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+    std::vector<double> data_recv;
+    std::vector<double> data_send;
+    std::unordered_map<int, int> global_local_face_map;
+public:
+    std::vector<int> neighbor_donor_zones;
+    std::vector<std::vector<int>> neighbor_donorfaces;
+    std::vector<std::vector<int>> sub_local_faceids;
+    std::vector<int> send_to_zones;
+    std::vector<std::vector<int>> donorfaces_for_send;
+    std::vector<std::vector<int>> donorijk_for_send;
+    std::vector<std::vector<double>> donordata_for_send;
+public:
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+};
+
+class Field;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+public:
+    static std::map<Face, int> faceMap;
+    static std::map<FacePair, int> facePairMap;
+    static std::vector<FacePair> facePairList;
+    static std::vector<std::set<int>> donor_zone_sets;
+    static std::vector<std::vector<int>> donor_zones;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+public:
+    static void InsertFaceMap( const Face & face );
+    static int InsertFacePairMap( const FacePair & facePair );
+    static void SendGeom( int zone, int donorzone, std::vector<int> & donorfaces );
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/heat1d4blocksv1.cgns b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/heat1d4blocksv1.cgns
new file mode 100644
index 00000000..df5ffc5f
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/heat1d4blocksv1.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/main.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/main.cpp
new file mode 100644
index 00000000..df63b7da
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/main.cpp
@@ -0,0 +1,9 @@
+#include "Solver.h"
+#include "Parallel.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/plot.py b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02b/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/CMakeLists.txt
new file mode 100644
index 00000000..9e834b72
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/CMakeLists.txt
@@ -0,0 +1,99 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package ( MPI )
+
+message ( STATUS  "MPI_FOUND=${MPI_FOUND}" )
+message ( STATUS  "MPI_CXX_INCLUDE_DIRS=${MPI_CXX_INCLUDE_DIRS}" )
+message ( STATUS  "MPI_LIBRARIES=${MPI_LIBRARIES}" )
+if ( MPI_FOUND )
+	list ( APPEND PRJ_INCLUDE_DIRS ${MPI_CXX_INCLUDE_DIRS} )
+	list ( APPEND PRJ_LIBRARIES ${MPI_LIBRARIES} )
+endif ()
+
+#get_directory_property( my_import_targets DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} IMPORTED_TARGETS )
+#message( STATUS "my_import_targets=${my_import_targets}" )
+
+list ( APPEND PRJ_LIBRARIES MPI::MPI_C )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+list ( APPEND PRJ_COMPILE_DEFINITIONS HX_PARALLEL )
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	LogFile.h LogFile.cpp
+	Parallel.h Parallel.cpp
+	Solver.h Solver.cpp
+	ZoneState.h ZoneState.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/CgnsGrid.cpp
new file mode 100644
index 00000000..de8b8efa
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/CgnsGrid.cpp
@@ -0,0 +1,733 @@
+#include "CgnsGrid.h"
+#include "Parallel.h"
+#include "cgnslib.h"
+#include "global.h"
+#include "ZoneState.h"
+#include <iostream>
+#include <vector>
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    if ( Parallel::pid == Parallel::serverid )
+    {
+        cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "fileId = " << fileId << "\n";
+    }
+    
+    int nbases = -1;
+    if ( Parallel::pid == Parallel::serverid )
+    {
+        cg_nbases( fileId, &nbases );
+    }
+    MPI_Bcast( &nbases, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "nbases = " << nbases << "\n";
+    
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        if ( Parallel::pid == Parallel::serverid )
+        {
+            cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        }
+
+        MPI_Bcast( &icelldim, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+        MPI_Bcast( &iphysdim, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+
+        int nzones = -1;
+        if ( Parallel::pid == Parallel::serverid )
+        {
+            cg_nzones( fileId, baseId, &nzones );
+        }
+
+        MPI_Bcast( &nzones, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+
+        ZoneState::nZones = nzones;
+        ZoneState::pids.resize( nzones );
+
+        if ( Parallel::nProc == 1 )
+        {
+            for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+            {
+                ZoneState::pids[ iZone ] = 0;
+            }
+        }
+        else
+        {
+            for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+            {
+                ZoneState::pids[ iZone ] = iZone;
+            }
+        }
+
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nzones = " << nzones << "\n";
+
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "iZone = " << iZone << "\n";
+
+            int index_dim = -1;
+            if ( Parallel::pid == Parallel::serverid )
+            {
+                cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            }
+            MPI_Bcast( &index_dim, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            if ( Parallel::pid == Parallel::serverid )
+            {
+                cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            }
+
+            MPI_Bcast( zonename, 33, MPI_CHAR, Parallel::serverid, MPI_COMM_WORLD );
+            MPI_Bcast( isize.data(), index_dim * 3, MPI_LONG_LONG, Parallel::serverid, MPI_COMM_WORLD );
+
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "zonename = " << zonename << "\n";
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+
+    if ( Parallel::pid == Parallel::serverid )
+    {
+        cg_close( fileId );
+    }
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    if ( Parallel::pid == Parallel::serverid )
+    {
+        cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+        std::cout << "fileId = " << fileId << "\n";
+    }
+    
+    int nbases = -1;
+    if ( Parallel::pid == Parallel::serverid )
+    {
+        cg_nbases( fileId, &nbases );
+    }
+    MPI_Bcast( &nbases, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        if ( Parallel::pid == Parallel::serverid )
+        {
+            cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        }
+        MPI_Bcast( &icelldim, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+        MPI_Bcast( &iphysdim, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+
+        int nzones = -1;
+        if ( Parallel::pid == Parallel::serverid )
+        {
+            cg_nzones( fileId, baseId, &nzones );
+        }
+        MPI_Bcast( &nzones, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nzones = " << nzones << "\n";
+
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            if ( Parallel::pid == Parallel::serverid )
+            {
+                cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            }
+            //MPI_Bcast( &index_dim, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+            HXSendRecvData<int>( &index_dim, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "index_dim = " << index_dim << "\n";
+            }
+        }
+        return;
+
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            if ( Parallel::pid == Parallel::serverid )
+            {
+                cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            }
+            //MPI_Bcast( &index_dim, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+            HXSendRecvData<int>( &index_dim, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "index_dim = " << index_dim << "\n";
+            }
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+            char zonename[ 33 ];
+            if ( Parallel::pid == Parallel::serverid )
+            {
+                cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            }
+
+            MPI_Bcast( zonename, 33, MPI_CHAR, Parallel::serverid, MPI_COMM_WORLD );
+            MPI_Bcast( isize.data(), index_dim * 3, MPI_LONG_LONG, Parallel::serverid, MPI_COMM_WORLD );
+
+            HXSendRecvData( zonename, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            return;
+
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "zonename = " << zonename << "\n";
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin( index_dim );
+            std::vector<cgsize_t> irmax( index_dim );
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            if ( Parallel::pid == Parallel::serverid )
+            {
+                cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            }
+            MPI_Bcast( &zoneType, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            int ncoords = -1;
+            if ( Parallel::pid == Parallel::serverid )
+            {
+                cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            }
+            MPI_Bcast( &ncoords, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                zone->nijk.push_back( isize[ m ] );
+            }
+
+            Grid * grid = new Grid();
+            Global::grids.push_back( grid );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                if ( Parallel::pid == Parallel::serverid )
+                {
+                    cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                }
+                MPI_Bcast( coordname, 33, MPI_CHAR, Parallel::serverid, MPI_COMM_WORLD );
+                MPI_Bcast( &dataType, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+                if ( Parallel::pid == Parallel::serverid )
+                {
+                    cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+                }
+
+                double * pcoor = (double *)coor->coord.data();
+
+                MPI_Bcast( pcoor, nNodes, MPI_DOUBLE, Parallel::serverid, MPI_COMM_WORLD );
+
+                if ( icoord == 0 )
+                {
+                    grid->x.resize( nNodes );
+                    coor->DumpCoorX( grid->x );
+                }
+            }
+
+            int nbocos = -1;
+            if ( Parallel::pid == Parallel::serverid )
+            {
+                cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            }
+            MPI_Bcast( &nbocos, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "nbocos = " << nbocos << "\n";
+
+
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                if ( Parallel::pid == Parallel::serverid )
+                {
+                    cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                }
+                MPI_Bcast( &location, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                if ( Parallel::pid == Parallel::serverid )
+                {
+                    cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                        &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                }
+                MPI_Bcast( boconame, 33, MPI_CHAR, Parallel::serverid, MPI_COMM_WORLD );
+                MPI_Bcast( &bocotype, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+                MPI_Bcast( &ptset_type, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+                MPI_Bcast( &normalDataType, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+                MPI_Bcast( &npnts, 1, MPI_LONG_LONG, Parallel::serverid, MPI_COMM_WORLD );
+                MPI_Bcast( &normalListSize, 1, MPI_LONG_LONG, Parallel::serverid, MPI_COMM_WORLD );
+                MPI_Bcast( &ndataset, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+                MPI_Bcast( normalIndex.data(), index_dim, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+                zonebc->bcType = bocotype;
+
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+
+                if ( Parallel::pid == Parallel::serverid )
+                {
+                    cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                }
+
+                MPI_Bcast( pnts.data(), npnts * index_dim, MPI_LONG_LONG, Parallel::serverid, MPI_COMM_WORLD );
+                MPI_Bcast( normalList.data(), nNodes * iphysdim * sizeof( double ), MPI_CHAR, Parallel::serverid, MPI_COMM_WORLD );
+
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+
+            int n1to1 = -1;
+            if ( Parallel::pid == Parallel::serverid )
+            {
+                cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            }
+            MPI_Bcast( &n1to1, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "n1to1 = " << n1to1 << "\n";
+
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                if ( Parallel::pid == Parallel::serverid )
+                {
+                    cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                }
+                MPI_Bcast( connectname, 33, MPI_CHAR, Parallel::serverid, MPI_COMM_WORLD );
+                MPI_Bcast( donorname, 33, MPI_CHAR, Parallel::serverid, MPI_COMM_WORLD );
+                MPI_Bcast( range.data(), npnts * index_dim, MPI_LONG_LONG, Parallel::serverid, MPI_COMM_WORLD );
+                MPI_Bcast( donor_range.data(), npnts * index_dim, MPI_LONG_LONG, Parallel::serverid, MPI_COMM_WORLD );
+
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+            }
+        }
+    }
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/CgnsGrid.h
new file mode 100644
index 00000000..fddf1db6
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/CgnsGrid.h
@@ -0,0 +1,103 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    int zoneIndex;
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/Field.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/Field.cpp
new file mode 100644
index 00000000..c359a811
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/Field.cpp
@@ -0,0 +1,142 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+
+    std::vector<double> & x = grid->x;
+    this->dx = std::abs( x[ 1 ] - x[ 0 ] );
+    this->dt = dx / 10.0;
+    this->t = 1.0;
+    this->nt = std::round( t / dt );
+
+    double total_time = nt * dt;
+
+    std::cout << "this->dt   = " << this->dt << "\n";
+    std::cout << "this->t    = " << this->t << "\n";
+    std::cout << "this->nt   = " << this->nt << "\n";
+    std::cout << "this->ni   = " << this->ni << "\n";
+    std::cout << "total_time = " << total_time << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        u_e[ i ] = - std::exp( -total_time ) * std::sin( std::numbers::pi * xm ); //theory solution
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+    int kkk = 1;
+}
+
+void Field::Solve( Zone * zone )
+{
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+    }
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        //std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        //region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+        int kkk = 1;
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
+
+void Field::UpdateOldField()
+{
+    for ( int i = 0; i < this->u.size(); ++ i )
+    {
+        this->un[ i ] = this->u[ i ];
+    }
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/Field.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/Field.h
new file mode 100644
index 00000000..084ec9bd
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/Field.h
@@ -0,0 +1,36 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid );
+
+    void Solve( Zone * zone );
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void UpdateOldField();
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/LogFile.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/LogFile.cpp
new file mode 100644
index 00000000..08ccd453
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/LogFile.cpp
@@ -0,0 +1,138 @@
+#include "LogFile.h"
+#include "Parallel.h"
+#include <sstream>
+#include <iostream>
+
+#ifdef _WINDOWS
+#include <windows.h>
+#include <direct.h>
+#include <io.h>
+#else
+#include <sys/stat.h>
+#include <unistd.h>
+#endif
+
+LogFile logFile;
+
+class OStream : public std::ostringstream
+{
+public:
+    OStream() {}
+    ~OStream() {}
+public:
+    void ClearAll()
+    {
+        this->clear();
+        this->str("");
+    }
+};
+
+OStream StrIO;
+std::string GetPrjDirName( const std::string & fileName );
+bool DirExist( const std::string & dirName );
+void MakeDir( const std::string & dirName );
+
+std::string GetPrjDirName( const std::string & fileName )
+{
+    size_t pos = fileName.find_last_of("\\/");
+    if ( std::string::npos == pos )
+    {
+        return "";
+    }
+    else
+    {
+        return fileName.substr( 0, pos );
+    }
+}
+
+bool DirExist( const std::string & dirName )
+{
+#ifdef _WINDOWS
+    bool flag = ( _access( dirName.c_str(), 0 ) == 0 );
+    return flag;
+#else
+    bool flag = ( access( dirName.c_str(), 0 ) == 0 );
+    return flag;
+#endif
+}
+
+void MakeDir( const std::string & dirName )
+{
+    int flag;
+#ifdef _WINDOWS
+    flag = _mkdir( dirName.c_str() );
+#else
+    flag = mkdir( dirName.c_str(), S_IRWXU );
+#endif
+    if ( flag == 0 )
+    {
+        std::cout << dirName << " directory has been created successfully !\n";
+    }
+}
+
+void CreateDirIfNeeded( std::string & prjFileName )
+{
+    std::string prj_dir = GetPrjDirName( prjFileName );
+
+    if ( ! DirExist( prj_dir ) )
+    {
+        MakeDir( prj_dir );
+    }
+}
+
+
+void OpenLogFile( int logFileIndex, std::fstream & file )
+{
+    static int ifReWrite = 0;
+
+    StrIO.ClearAll();
+    StrIO << "log/log" << logFileIndex << ".log";
+    std::string fileName = StrIO.str();
+
+    std::ios_base::openmode openMode;
+
+    if ( ifReWrite == 0 )
+    {
+        CreateDirIfNeeded( fileName );
+
+        openMode = std::ios_base::out | std::ios_base::trunc;
+
+        ifReWrite = 1;
+    }
+    else
+    {
+        openMode = std::ios_base::out | std::ios_base::app;
+    }
+
+    file.open( fileName.c_str(), openMode );
+    if ( ! file )
+    {
+        std::cout << "could not open " << fileName << std::endl;
+        exit( 0 );
+    }
+}
+
+void CloseLogFile( std::fstream & file )
+{
+    file.close();
+    file.clear();
+}
+
+LogFile::LogFile()
+{
+}
+
+LogFile::~LogFile()
+{
+}
+
+void LogFile::Open()
+{
+    int pid = Parallel::pid;
+    OpenLogFile( pid, this->my_fstream );
+}
+
+void LogFile::Close()
+{
+    CloseLogFile( this->my_fstream );
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/LogFile.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/LogFile.h
new file mode 100644
index 00000000..00e775ab
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/LogFile.h
@@ -0,0 +1,27 @@
+#pragma once
+#include <fstream>
+
+void OpenLogFile( int logFileIndex, std::fstream & file );
+void CloseLogFile( std::fstream & file );
+class LogFile;
+extern LogFile logFile;
+
+class LogFile
+{
+public:
+    LogFile();
+    ~LogFile();
+    std::fstream my_fstream;
+public:
+    void Open();
+    void Close();
+};
+
+template< typename T >
+LogFile & operator << ( LogFile & f, const T & value )
+{
+    f.Open();
+    f.my_fstream << value;
+    f.Close();
+    return f;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/Parallel.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/Parallel.cpp
new file mode 100644
index 00000000..fa42ac8d
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/Parallel.cpp
@@ -0,0 +1,49 @@
+#include "Parallel.h"
+#include <iostream>
+
+int Parallel::pid = 0;
+int Parallel::nProc = 1;
+int Parallel::serverid = 0;
+int Parallel::tag = 0;
+
+void Parallel::Init()
+{
+#ifdef HX_PARALLEL
+    int argc     = 0;
+    char ** argv = 0;
+    MPI_Init( &argc, &argv );
+    MPI_Comm_rank( MPI_COMM_WORLD, &Parallel::pid );
+    MPI_Comm_size( MPI_COMM_WORLD, &Parallel::nProc );
+    int len = -1;
+    char version[ MPI_MAX_LIBRARY_VERSION_STRING ];
+    MPI_Get_library_version( version, &len );
+    std::cout << "Hello, world!  I am " << Parallel::pid << " of " << Parallel::nProc
+        << "(" << version << ", " << len << ")" << std::endl;
+#endif
+}
+
+void Parallel::Finalize()
+{
+#ifdef HX_PARALLEL
+    MPI_Finalize();
+#endif
+}
+
+void HXSendChar( void * data, int size, int pid, int tag )
+{
+#ifdef HX_PARALLEL
+    if ( size <= 0 ) return;
+    MPI_Send( data, size, MPI_CHAR, pid, tag, MPI_COMM_WORLD );
+#endif
+}
+
+void HXRecvChar( void * data, int size, int pid, int tag )
+{
+#ifdef HX_PARALLEL
+    if ( size <= 0 ) return;
+
+    MPI_Status status;
+    MPI_Recv( data, size, MPI_CHAR, pid, tag, MPI_COMM_WORLD, & status );
+#endif
+}
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/Parallel.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/Parallel.h
new file mode 100644
index 00000000..34ff06a6
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/Parallel.h
@@ -0,0 +1,46 @@
+#pragma once
+#ifdef HX_PARALLEL
+#include "mpi.h"
+#endif
+#include <vector>
+#include "LogFile.h"
+
+class Parallel
+{
+public:
+    static int pid;
+    static int nProc;
+    static int serverid;
+    static int tag;
+public:
+    static void Init();
+    static void Finalize();
+};
+
+void HXSendChar( void * data, int size, int pid, int tag );
+void HXRecvChar( void * data, int size, int pid, int tag );
+
+template< typename T >
+void HXSendRecvData( T * field, int nElement, int send_pid, int recv_pid, int tag = 0 )
+{
+    logFile << " send_pid = " << send_pid << "\n";
+    logFile << " recv_pid = " << recv_pid << "\n";
+    logFile << " Parallel::pid = " << Parallel::pid << "\n";
+
+    if ( send_pid == recv_pid ) return;
+
+    if ( nElement <= 0 ) return;
+
+    int buffer_size = nElement * sizeof( T );
+
+    logFile << " buffer_size = " << buffer_size << "\n";
+
+    if ( Parallel::pid == send_pid )
+    {
+        HXSendChar( field, buffer_size, recv_pid, tag );
+    }
+    else if ( Parallel::pid == recv_pid )
+    {
+        HXRecvChar( field, buffer_size, send_pid, tag );
+    }
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/README.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/Solver.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/Solver.cpp
new file mode 100644
index 00000000..a2d6783e
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/Solver.cpp
@@ -0,0 +1,516 @@
+#include "Solver.h"
+#include "Parallel.h"
+#include <fstream>
+#include <set>
+#include <unordered_map>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+Solver::Solver()
+{
+    Parallel::Init();
+}
+
+Solver::~Solver()
+{
+    Parallel::Finalize();
+}
+
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    //if ( Parallel::pid == Parallel::serverid )
+    //{
+    //    this->ReadGrid();
+    //    this->InitTopo();
+    //    this->InitFields();
+    //    this->SolveMultiZones();
+    //    this->PostProcess();
+    //}
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d4blocksv1.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    ReadCgnsGrid( fileName );
+}
+
+void Solver::InitTopo()
+{
+    int nZones = Global::grids.size();
+    Global::donor_zone_sets.resize( nZones );
+    Global::donor_zones.resize( nZones );
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = new Interface();
+        interface->zoneid = iZone;
+        Global::interfaces.push_back( interface );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+        Interface * interface = Global::interfaces[ iZone ];
+
+        int nbc1to1s = zone->bc1to1s.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+        int nInterfaces = interface->zoneList.size();
+        interface->data_recv.resize( nInterfaces );
+        interface->data_send.resize( nInterfaces );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        std::set<int> &donor_zoneSet = Global::donor_zone_sets[ iZone ];
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            donor_zoneSet.insert( donor_zoneid );
+        }
+
+        std::vector<int> &donor_zones = Global::donor_zones[ iZone ];
+        for ( std::set<int>::iterator iter = donor_zoneSet.begin(); iter != donor_zoneSet.end(); ++ iter )
+        {
+            donor_zones.push_back( *iter );
+        }
+
+        interface->neighbor_donor_zones = donor_zones;
+
+        std::unordered_map<int, int> donor_zonelocal;
+
+        for ( int idonor = 0; idonor < donor_zones.size(); ++ idonor )
+        {
+            int donor_zone = donor_zones[ idonor ];
+            donor_zonelocal.insert( std::make_pair( donor_zone, idonor ) );
+        }
+        int index_dim = 1;
+        int ndonors = donor_zones.size();
+        std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+        neighbor_donorfaces.resize( ndonors );
+
+        std::vector<std::vector<int>> & sub_local_faceids = interface->sub_local_faceids;
+        sub_local_faceids.resize( ndonors );
+
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ineighbor = donor_zonelocal[ donor_zoneid ];
+            std::vector<int> &donorfaces = neighbor_donorfaces[ ineighbor ];
+            int global_faceid = interface->global_faceids[ iFace ];
+            donorfaces.push_back( global_faceid );
+            int local_faceid = interface->local_faceids[ iFace ];
+
+            std::vector<int> & sub_local_faces = sub_local_faceids[ ineighbor ];
+            sub_local_faces.push_back( local_faceid );
+        }
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> &neighbor_donor_zones = interface->neighbor_donor_zones;
+        int ndonor_zones = neighbor_donor_zones.size();
+
+        std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donorzone = neighbor_donor_zones[ iNei ];
+            std::vector<int> & neighbor_donorface = neighbor_donorfaces[ iNei ];
+
+            Global::SendGeom( iZone, donorzone, neighbor_donorface );
+        }
+        int kkk = 1;
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        std::cout << "zone = " << iZone << "\n";
+
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> & send_to_zones = interface->send_to_zones;
+        int nsend_zones = send_to_zones.size();
+    }
+
+    std::cout << "\n";
+}
+
+void Solver::InitFields()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+    }
+
+    Boundary();
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        int nZones = Global::zones.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Field * field = Global::fields[ iZone ];
+            Zone * zone = Global::zones[ iZone ];
+            zone->zoneIndex = iZone;
+            field->Solve( zone );
+        }
+        Boundary();
+    }
+}
+
+void Solver::Boundary()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+    ExchangeInterfaceField();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->UpdateOldField();
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    int nZones = Global::interfaces.size();
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> & send_to_zones = interface->send_to_zones;
+        int nsend_zones = send_to_zones.size();
+
+        std::vector<std::vector<int>> & donorfaces_for_send = interface->donorfaces_for_send;
+        std::vector<std::vector<int>> & donorijk_for_send = interface->donorijk_for_send;
+        std::vector<std::vector<double>> & donordata_for_send = interface->donordata_for_send;
+
+        Field * field = Global::fields[ iZone ];
+
+        for ( int iSend = 0; iSend < nsend_zones; ++ iSend )
+        {
+            int zone_to_send = send_to_zones[ iSend ];
+            std::vector<int> & donorfaces = donorfaces_for_send[ iSend ];
+            std::vector<int> & donorijks = donorijk_for_send[ iSend ];
+            std::vector<double> & donordatas = donordata_for_send[ iSend ];
+
+            int nface = donorfaces.size();
+            int index_dim = 1;
+            for ( int i = 0; i < nface; ++ i )
+            {
+                int ijkpos = index_dim * i;
+                int i_donor_cell = donorijks[ ijkpos + 0 ];
+                donordatas[ i ] = field->u[ i_donor_cell ];
+            }
+        }
+    }
+    int kkk = 1;
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+
+        std::vector<int> & neighbor_donor_zones = interface->neighbor_donor_zones;
+        int ndonor_zones = neighbor_donor_zones.size();
+
+        //std::vector<std::vector<double>> & recv_donor_fields = interface->recv_donor_fields;
+
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donorzone = neighbor_donor_zones[ iNei ];
+            Interface * donor_interface = Global::interfaces[ donorzone ];
+            int nSize = donor_interface->send_to_zones.size();
+            int ipos = -1;
+            for ( int i = 0; i < nSize; ++ i )
+            {
+                int szone = donor_interface->send_to_zones[ i ];
+                if ( szone == iZone )
+                {
+                    ipos = i;
+                    break;
+                }
+            }
+            std::vector<double> & donordata = donor_interface->donordata_for_send[ ipos ];
+
+            std::vector<int> & neighbor_donorfaces = interface->neighbor_donorfaces[ iNei ];
+            std::vector<int> & sub_local_faceids = interface->sub_local_faceids[ iNei ];
+            for ( int i = 0; i < neighbor_donorfaces.size(); ++ i )
+            {
+                int local_faceid = sub_local_faceids[ i ];
+                double donor_value = donordata[ i ];
+                interface->data_recv[ local_faceid ] = donor_value;
+            }
+        }
+
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+
+            double donor_value = interface->data_recv[ iFace ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::PostProcess()
+{
+    Post post;
+    post.Process();
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    int nZones = Global::grids.size();
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        int ni = grid->x.size();
+        double xmin = grid->x[ 0 ];
+        double xmax = grid->x[ 0 ];
+        int imin = 0;
+        int imax = 0;
+        for ( int i = 0; i < ni; ++ i )
+        {
+            if ( xmin > grid->x[ i ] )
+            {
+                xmin = grid->x[ i ];
+                imin = i;
+            }
+            if ( xmax < grid->x[ i ] )
+            {
+                xmax = grid->x[ i ];
+                imax = i;
+            }
+        }
+        xmin_list.push_back( xmin );
+        xmax_list.push_back( xmax );
+    }
+    std::vector<std::pair<double, int>> pairs;
+    int nSize = xmin_list.size();
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        pairs.push_back( std::make_pair( xmin_list[i], i ) );
+    }
+
+    std::sort( pairs.begin(), pairs.end() );
+
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        this->zoneids.push_back( pairs[i].second );
+    }
+
+    int kkk = 1;
+}
+
+void Post::GatherField()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+        Grid * grid = Global::grids[ zoneid ];
+        Field * field = Global::fields[ zoneid ];
+
+        int ni = grid->x.size();
+
+        int ist = 1;
+        int ied = ni;
+
+        int dir = 1;
+        if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+        if ( dir == 1 )
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ist; i <= ied; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+
+            }
+            else
+            {
+                for ( int i = ist; i <= ied - 1; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+        else
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ied; i >= ist; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+            else
+            {
+                for ( int i = ied; i >= ist + 1; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+    }
+}
+
+void Post::DumpField()
+{
+    int ni_total = this->x.size();
+    std::cout << " DumpField x.size() = " << x.size() << "\n";
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    this->DumpErrorDetails( u_error );
+
+    std::string csvname = "field_final.csv";
+    this->DumpCsvFile( csvname, x, u_e, un, u_error );
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.20f} {:.20f} {:.20f} {:.20f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/Solver.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/Solver.h
new file mode 100644
index 00000000..d01d3d9c
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/Solver.h
@@ -0,0 +1,44 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+
+class Solver
+{
+public:
+    Solver();
+    ~Solver();
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveMultiZones();
+public:
+    void Boundary();
+    void ExchangeInterfaceField();
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcess();
+};
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+    std::vector<double> u;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/ZoneState.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/ZoneState.cpp
new file mode 100644
index 00000000..528305fe
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/ZoneState.cpp
@@ -0,0 +1,15 @@
+#include "ZoneState.h"
+#include "Parallel.h"
+
+int ZoneState::nZones = 0;
+std::vector<int> ZoneState::pids;
+
+bool ZoneState::IsValid( int zoneid )
+{
+    return ZoneState::pids[ zoneid ] == Parallel::pid;
+}
+
+int ZoneState::GetProcID( int zoneid )
+{
+    return ZoneState::pids[ zoneid ];
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/ZoneState.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/ZoneState.h
new file mode 100644
index 00000000..8d1863b7
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/ZoneState.h
@@ -0,0 +1,13 @@
+#pragma once
+#include <vector>
+
+class ZoneState
+{
+public:
+    static int nZones;
+    static int zone_id;
+    static std::vector<int> pids;
+public:
+    static bool IsValid( int zoneid );
+    static int GetProcID( int zoneid );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/global.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/global.cpp
new file mode 100644
index 00000000..d96bf9d7
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/global.cpp
@@ -0,0 +1,191 @@
+#include "global.h"
+#include "CgnsGrid.h"
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *> Global::interfaces;
+
+std::map<Face, int> Global::faceMap;
+std::map<FacePair, int> Global::facePairMap;
+std::vector<FacePair> Global::facePairList;
+
+std::vector<std::set<int>> Global::donor_zone_sets;
+std::vector<std::vector<int>> Global::donor_zones;
+
+bool Face::operator < ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return this->zone < rhs.zone;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return this->i < rhs.i;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return this->j < rhs.j;
+    }
+
+    return this->k < rhs.k;
+}
+
+bool Face::operator == ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return false;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return false;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return false;
+    }
+
+    return this->k == rhs.k;
+}
+
+void FacePair::AddPair( const Face & face1, const Face & face2 )
+{
+    if ( face1 < face2 )
+    {
+        this->left = face1;
+        this->right = face2;
+    }
+    else
+    {
+        this->left = face2;
+        this->right = face1;
+    }
+}
+
+bool FacePair::operator < ( const FacePair & rhs ) const
+{
+    if ( this->left == rhs.left || this->left == rhs.right )
+    {
+        return false;
+    }
+
+    return this->left < rhs.left;
+}
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->local_faceids.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        Face face;
+        face.zone = zoneid;
+        face.i = i;
+
+        Global::InsertFaceMap( face );
+
+        int i_donor = index2[ 0 ];
+
+        Face face_donor;
+        face_donor.zone = donor_zoneid;
+        face_donor.i = i_donor;
+
+        Global::InsertFaceMap( face_donor );
+
+        FacePair facePair;
+        facePair.AddPair( face, face_donor );
+
+        Global::facePairList.push_back( facePair );
+        int global_faceid = Global::InsertFacePairMap( facePair );
+        this->global_faceids.push_back( global_faceid );
+
+        this->global_local_face_map.insert( std::make_pair( global_faceid, faceid ) );
+
+        int i_ghost_cell = i + 1;
+        int i_local_donor_cell = i - 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+            i_local_donor_cell = i + 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+        ijk_donors.push_back( i_local_donor_cell );
+
+        icount ++;
+    }
+}
+
+void Global::InsertFaceMap( const Face & face )
+{
+    std::map<Face, int>::iterator iter;
+    iter = Global::faceMap.find( face );
+    if ( iter == Global::faceMap.end() )
+    {
+        int faceid = Global::faceMap.size();
+        Global::faceMap.insert( std::make_pair( face, faceid ) );
+    }
+}
+
+int Global::InsertFacePairMap( const FacePair & facePair )
+{
+    std::map<FacePair, int>::iterator iter;
+    iter = Global::facePairMap.find( facePair );
+    if ( iter == Global::facePairMap.end() )
+    {
+        int facePairId = Global::facePairMap.size();
+        Global::facePairMap.insert( std::make_pair( facePair, facePairId ) );
+        return facePairId;
+    }
+    return iter->second;
+}
+
+void Global::SendGeom( int zone, int donorzone, std::vector<int> & donorfaces )
+{
+    Interface * interface = Global::interfaces[ donorzone ];
+
+    std::vector<int> & send_to_zones = interface->send_to_zones;
+
+    send_to_zones.push_back( zone );
+    interface->donorfaces_for_send.push_back( donorfaces );
+
+    int nface = donorfaces.size();
+    std::vector<int> sub_donorijk;
+    int index_dim = 1;
+    for ( int i = 0; i < nface; ++ i )
+    {
+        int global_faceid = donorfaces[ i ];
+        int local_faceid = interface->global_local_face_map[ global_faceid ];
+        int ijkpos = index_dim * local_faceid;
+        int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+        sub_donorijk.push_back( i_donor_cell );
+        int kkk = 1;
+    }
+
+    interface->donorijk_for_send.push_back( sub_donorijk );
+
+    std::vector<double> sub_donordata( sub_donorijk.size() );
+    interface->donordata_for_send.push_back( sub_donordata );
+}
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/global.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/global.h
new file mode 100644
index 00000000..ce8eef97
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/global.h
@@ -0,0 +1,138 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <unordered_map>
+#include <set>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class Face
+{
+public:
+    int zone = 0;
+    int i = 0;
+    int j = 1;
+    int k = 1;
+public:
+    bool operator < ( const Face & rhs ) const;
+    bool operator == ( const Face & rhs ) const;
+};
+
+class FacePair
+{
+public:
+    Face left;
+    Face right;
+public:
+    bool operator < ( const FacePair & rhs ) const;
+    void AddPair( const Face &face1, const Face &face2);
+};
+
+class Transform;
+
+
+class Interface
+{
+public:
+    int zoneid;
+    std::vector<int> zoneList;
+    std::vector<int> global_faceids;
+    std::vector<int> local_faceids;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+    std::vector<double> data_recv;
+    std::vector<double> data_send;
+    std::unordered_map<int, int> global_local_face_map;
+public:
+    std::vector<int> neighbor_donor_zones;
+    std::vector<std::vector<int>> neighbor_donorfaces;
+    std::vector<std::vector<int>> sub_local_faceids;
+    std::vector<int> send_to_zones;
+    std::vector<std::vector<int>> donorfaces_for_send;
+    std::vector<std::vector<int>> donorijk_for_send;
+    std::vector<std::vector<double>> donordata_for_send;
+public:
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+};
+
+class Field;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+public:
+    static std::map<Face, int> faceMap;
+    static std::map<FacePair, int> facePairMap;
+    static std::vector<FacePair> facePairList;
+    static std::vector<std::set<int>> donor_zone_sets;
+    static std::vector<std::vector<int>> donor_zones;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+public:
+    static void InsertFaceMap( const Face & face );
+    static int InsertFacePairMap( const FacePair & facePair );
+    static void SendGeom( int zone, int donorzone, std::vector<int> & donorfaces );
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/heat1d4blocksv1.cgns b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/heat1d4blocksv1.cgns
new file mode 100644
index 00000000..df5ffc5f
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/heat1d4blocksv1.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/main.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/main.cpp
new file mode 100644
index 00000000..df63b7da
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/main.cpp
@@ -0,0 +1,9 @@
+#include "Solver.h"
+#include "Parallel.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/plot.py b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02c/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/CMakeLists.txt
new file mode 100644
index 00000000..9e834b72
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/CMakeLists.txt
@@ -0,0 +1,99 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package ( MPI )
+
+message ( STATUS  "MPI_FOUND=${MPI_FOUND}" )
+message ( STATUS  "MPI_CXX_INCLUDE_DIRS=${MPI_CXX_INCLUDE_DIRS}" )
+message ( STATUS  "MPI_LIBRARIES=${MPI_LIBRARIES}" )
+if ( MPI_FOUND )
+	list ( APPEND PRJ_INCLUDE_DIRS ${MPI_CXX_INCLUDE_DIRS} )
+	list ( APPEND PRJ_LIBRARIES ${MPI_LIBRARIES} )
+endif ()
+
+#get_directory_property( my_import_targets DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} IMPORTED_TARGETS )
+#message( STATUS "my_import_targets=${my_import_targets}" )
+
+list ( APPEND PRJ_LIBRARIES MPI::MPI_C )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+list ( APPEND PRJ_COMPILE_DEFINITIONS HX_PARALLEL )
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	LogFile.h LogFile.cpp
+	Parallel.h Parallel.cpp
+	Solver.h Solver.cpp
+	ZoneState.h ZoneState.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/CgnsGrid.cpp
new file mode 100644
index 00000000..c9f72fa3
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/CgnsGrid.cpp
@@ -0,0 +1,859 @@
+#include "CgnsGrid.h"
+#include "Parallel.h"
+#include "cgnslib.h"
+#include "global.h"
+#include "ZoneState.h"
+#include <iostream>
+#include <vector>
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    if ( Parallel::pid == Parallel::serverid )
+    {
+        cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "fileId = " << fileId << "\n";
+    }
+    
+    int nbases = -1;
+    if ( Parallel::pid == Parallel::serverid )
+    {
+        cg_nbases( fileId, &nbases );
+    }
+    MPI_Bcast( &nbases, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "nbases = " << nbases << "\n";
+    
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        if ( Parallel::pid == Parallel::serverid )
+        {
+            cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        }
+
+        MPI_Bcast( &icelldim, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+        MPI_Bcast( &iphysdim, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+
+        int nzones = -1;
+        if ( Parallel::pid == Parallel::serverid )
+        {
+            cg_nzones( fileId, baseId, &nzones );
+        }
+
+        MPI_Bcast( &nzones, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+
+        ZoneState::nZones = nzones;
+        ZoneState::pids.resize( nzones );
+
+        if ( Parallel::nProc == 1 )
+        {
+            for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+            {
+                ZoneState::pids[ iZone ] = 0;
+            }
+        }
+        else
+        {
+            for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+            {
+                ZoneState::pids[ iZone ] = iZone;
+            }
+        }
+
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nzones = " << nzones << "\n";
+
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "iZone = " << iZone << "\n";
+
+            int index_dim = -1;
+            if ( Parallel::pid == Parallel::serverid )
+            {
+                cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            }
+            MPI_Bcast( &index_dim, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            if ( Parallel::pid == Parallel::serverid )
+            {
+                cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            }
+
+            MPI_Bcast( zonename, 33, MPI_CHAR, Parallel::serverid, MPI_COMM_WORLD );
+            MPI_Bcast( isize.data(), index_dim * 3, MPI_LONG_LONG, Parallel::serverid, MPI_COMM_WORLD );
+
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "zonename = " << zonename << "\n";
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+
+    if ( Parallel::pid == Parallel::serverid )
+    {
+        cg_close( fileId );
+    }
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    if ( Parallel::pid == Parallel::serverid )
+    {
+        cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+        std::cout << "fileId = " << fileId << "\n";
+    }
+    
+    int nbases = -1;
+    if ( Parallel::pid == Parallel::serverid )
+    {
+        cg_nbases( fileId, &nbases );
+    }
+    MPI_Bcast( &nbases, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        if ( Parallel::pid == Parallel::serverid )
+        {
+            cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        }
+        MPI_Bcast( &icelldim, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+        MPI_Bcast( &iphysdim, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+
+        int nzones = -1;
+        if ( Parallel::pid == Parallel::serverid )
+        {
+            cg_nzones( fileId, baseId, &nzones );
+        }
+        MPI_Bcast( &nzones, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nzones = " << nzones << "\n";
+
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            if ( Parallel::pid == Parallel::serverid )
+            {
+                cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            }
+            HXSendRecvData<int>( &index_dim, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "index_dim = " << index_dim << "\n";
+            }
+
+            //std::vector<cgsize_t> isize( index_dim * 3 );
+            std::vector<cgsize_t> isize;
+            char zonename[ 33 ];
+            if ( Parallel::pid == Parallel::serverid )
+            {
+                isize.resize( index_dim * 3 );
+                cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            }
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                isize.resize( index_dim * 3 );
+            }
+
+            //MPI_Bcast( zonename, 33, MPI_CHAR, Parallel::serverid, MPI_COMM_WORLD );
+            //MPI_Bcast( isize.data(), index_dim * 3, MPI_LONG_LONG, Parallel::serverid, MPI_COMM_WORLD );
+
+            HXSendRecvData( zonename, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+            HXSendRecvData( isize.data(), index_dim * 3, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "zonename = " << zonename << "\n";
+
+                for ( int i = 0; i < isize.size(); ++ i )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+                }
+            }
+
+            std::vector<cgsize_t> irmin;
+            std::vector<cgsize_t> irmax;
+            int nNodes = 1;
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                irmin.resize( index_dim );
+                irmax.resize( index_dim );
+                for ( int m = 0; m < index_dim; ++ m )
+                {
+                    /* lower range index */
+                    irmin[ m ] = 1;
+                    /* upper range index of vertices */
+                    irmax[ m ] = isize[ m ];
+                    nNodes *= irmax[ m ];
+                }
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "nNodes = " << nNodes << "\n";
+            }
+
+            ZoneType_t zoneType;
+            if ( Parallel::pid == Parallel::serverid )
+            {
+                cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            }
+            HXSendRecvData( &zoneType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            }
+
+            Zone * zone = nullptr;
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                zone = new Zone();
+                Global::zones.push_back( zone );
+                for ( int m = 0; m < index_dim; ++ m )
+                {
+                    zone->nijk.push_back( isize[ m ] );
+                }
+            }
+
+            Grid * grid = nullptr;
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                grid = new Grid();
+                Global::grids.push_back( grid );
+            }
+
+            BaseZone baseZone;
+
+            int gZoneId = -1;
+            if ( Parallel::IsServer() )
+            {
+                baseZone.zone_name = zonename;
+                gZoneId = Global::zone_names.FindBaseZone( baseZone );
+            }
+
+            HXSendRecvData( &gZoneId, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "gZoneId = " << gZoneId << "\n";
+            }
+
+            int ncoords = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            }
+            HXSendRecvData( &ncoords, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "ncoords = " << ncoords << "\n";
+            }
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                if ( Parallel::IsServer() )
+                {
+                    cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                }
+                HXSendRecvData( coordname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &dataType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "coordname = " << coordname << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                }
+
+                std::vector<char> coord;
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    coord.resize( nNodes * sizeof( double ) );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coord.data() );
+                }
+
+                HXSendRecvData( coord.data(), coord.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                Coor * coor = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    coor = new Coor();
+                    zone->coors.push_back( coor );
+                    coor->coorname = coordname;
+                    coor->nNodes = nNodes;
+                    coor->coord = coord;
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    coor->DumpCoor();
+
+                    if ( icoord == 0 )
+                    {
+                        grid->x.resize( nNodes );
+                        coor->DumpCoorX( grid->x );
+                    }
+                }
+            }
+
+            int nbocos = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            }
+            HXSendRecvData( &nbocos, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "nbocos = " << nbocos << "\n";
+            }
+
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                if ( Parallel::IsServer() )
+                {
+                    cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                }
+                HXSendRecvData( &location, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+                }
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                //std::vector<int> normalIndex( index_dim, -1 );
+                std::vector<int> normalIndex;
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+                if ( Parallel::IsServer() )
+                {
+                    normalIndex.resize( index_dim );
+                    cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                        &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                }
+
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    normalIndex.resize( index_dim );
+                }
+                
+                HXSendRecvData( boconame, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &bocotype, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &ptset_type, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &npnts, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &normalDataType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &normalListSize, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( normalIndex.data(), index_dim, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &ndataset, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "npnts = " << npnts << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalListSize = " << normalListSize << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalIndex = ";
+                    for ( int i = 0; i < index_dim; ++ i )
+                    {
+                        std::cout << normalIndex[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "ndataset = " << ndataset << "\n";
+                }
+
+                std::vector<char> normalList;
+                std::vector<cgsize_t> pnts;
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    if ( normalDataType == DataTypeNull )
+                    {
+                        normalList.resize( sizeof( int ) );
+                    }
+                    else
+                    {
+                        int nSize = nNodes * index_dim * sizeof( double );
+                        normalList.resize( nSize );
+                    }
+                    pnts.resize( npnts * index_dim );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                }
+
+                HXSendRecvData( pnts.data(), npnts * index_dim, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "pnts = ";
+                    for ( int i = 0; i < pnts.size(); ++ i )
+                    {
+                        std::cout << pnts[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                }
+                HXSendRecvData( normalList.data(), normalList.size(), Parallel::serverid, ZoneState::GetProcID(iZone));
+
+                ZoneBc * zonebc = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    zonebc = new ZoneBc();
+                    zone->bccos.push_back( zonebc );
+                    zonebc->bcType = bocotype;
+                    for ( int i = 0; i < pnts.size(); ++ i )
+                    {
+                        zonebc->pnts.push_back( pnts[ i ] );
+                    }
+                }
+            }
+            int n1to1 = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            }
+
+            HXSendRecvData( &n1to1, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "n1to1 = " << n1to1 << "\n";
+            }
+
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                //ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                //zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range;
+                std::vector<cgsize_t> donor_range;
+                std::vector<int> transform;
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    range.resize( npnts * index_dim );
+                    donor_range.resize( npnts * index_dim );
+                    transform.resize( index_dim );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                }
+
+                HXSendRecvData( connectname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( donorname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( range.data(), range.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( donor_range.data(), donor_range.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( transform.data(), transform.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "connectname = " << connectname << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "donorname = " << donorname << "\n";
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "range = ";
+                    for ( int i = 0; i < range.size(); ++ i )
+                    {
+                        std::cout << range[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "donor_range = ";
+                    for ( int i = 0; i < donor_range.size(); ++ i )
+                    {
+                        std::cout << donor_range[ i ] << " ";
+                    }
+                    std::cout << "\n";
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "transform = ";
+                    for ( int i = 0; i < transform.size(); ++ i )
+                    {
+                        std::cout << transform[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                }
+
+                int gDonorZoneId = -1;
+                if ( Parallel::IsServer() )
+                {
+                    BaseZone baseZoneDonor;
+                    baseZoneDonor.zone_name = donorname;
+
+                    gDonorZoneId = Global::zone_names.FindBaseZone( baseZoneDonor );
+                }
+
+                HXSendRecvData( &gDonorZoneId, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                ZoneBc1To1 * zonebc_1to1 = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    zonebc_1to1 = new ZoneBc1To1();
+                    zone->bc1to1s.push_back( zonebc_1to1 );
+                    zonebc_1to1->zoneid = gZoneId;
+                    zonebc_1to1->transform = transform;
+                    zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                    for ( int i = 0; i < range.size(); ++ i )
+                    {
+                        zonebc_1to1->pnts.push_back( range[ i ] );
+                        zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                    }
+                }
+            }
+        }
+    }
+
+    {
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "Global::zones.size() = " << Global::zones.size() << "\n";
+    }
+
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/CgnsGrid.h
new file mode 100644
index 00000000..fddf1db6
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/CgnsGrid.h
@@ -0,0 +1,103 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    int zoneIndex;
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/Field.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/Field.cpp
new file mode 100644
index 00000000..c359a811
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/Field.cpp
@@ -0,0 +1,142 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+
+    std::vector<double> & x = grid->x;
+    this->dx = std::abs( x[ 1 ] - x[ 0 ] );
+    this->dt = dx / 10.0;
+    this->t = 1.0;
+    this->nt = std::round( t / dt );
+
+    double total_time = nt * dt;
+
+    std::cout << "this->dt   = " << this->dt << "\n";
+    std::cout << "this->t    = " << this->t << "\n";
+    std::cout << "this->nt   = " << this->nt << "\n";
+    std::cout << "this->ni   = " << this->ni << "\n";
+    std::cout << "total_time = " << total_time << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        u_e[ i ] = - std::exp( -total_time ) * std::sin( std::numbers::pi * xm ); //theory solution
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+    int kkk = 1;
+}
+
+void Field::Solve( Zone * zone )
+{
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+    }
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        //std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        //region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+        int kkk = 1;
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
+
+void Field::UpdateOldField()
+{
+    for ( int i = 0; i < this->u.size(); ++ i )
+    {
+        this->un[ i ] = this->u[ i ];
+    }
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/Field.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/Field.h
new file mode 100644
index 00000000..084ec9bd
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/Field.h
@@ -0,0 +1,36 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid );
+
+    void Solve( Zone * zone );
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void UpdateOldField();
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/LogFile.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/LogFile.cpp
new file mode 100644
index 00000000..08ccd453
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/LogFile.cpp
@@ -0,0 +1,138 @@
+#include "LogFile.h"
+#include "Parallel.h"
+#include <sstream>
+#include <iostream>
+
+#ifdef _WINDOWS
+#include <windows.h>
+#include <direct.h>
+#include <io.h>
+#else
+#include <sys/stat.h>
+#include <unistd.h>
+#endif
+
+LogFile logFile;
+
+class OStream : public std::ostringstream
+{
+public:
+    OStream() {}
+    ~OStream() {}
+public:
+    void ClearAll()
+    {
+        this->clear();
+        this->str("");
+    }
+};
+
+OStream StrIO;
+std::string GetPrjDirName( const std::string & fileName );
+bool DirExist( const std::string & dirName );
+void MakeDir( const std::string & dirName );
+
+std::string GetPrjDirName( const std::string & fileName )
+{
+    size_t pos = fileName.find_last_of("\\/");
+    if ( std::string::npos == pos )
+    {
+        return "";
+    }
+    else
+    {
+        return fileName.substr( 0, pos );
+    }
+}
+
+bool DirExist( const std::string & dirName )
+{
+#ifdef _WINDOWS
+    bool flag = ( _access( dirName.c_str(), 0 ) == 0 );
+    return flag;
+#else
+    bool flag = ( access( dirName.c_str(), 0 ) == 0 );
+    return flag;
+#endif
+}
+
+void MakeDir( const std::string & dirName )
+{
+    int flag;
+#ifdef _WINDOWS
+    flag = _mkdir( dirName.c_str() );
+#else
+    flag = mkdir( dirName.c_str(), S_IRWXU );
+#endif
+    if ( flag == 0 )
+    {
+        std::cout << dirName << " directory has been created successfully !\n";
+    }
+}
+
+void CreateDirIfNeeded( std::string & prjFileName )
+{
+    std::string prj_dir = GetPrjDirName( prjFileName );
+
+    if ( ! DirExist( prj_dir ) )
+    {
+        MakeDir( prj_dir );
+    }
+}
+
+
+void OpenLogFile( int logFileIndex, std::fstream & file )
+{
+    static int ifReWrite = 0;
+
+    StrIO.ClearAll();
+    StrIO << "log/log" << logFileIndex << ".log";
+    std::string fileName = StrIO.str();
+
+    std::ios_base::openmode openMode;
+
+    if ( ifReWrite == 0 )
+    {
+        CreateDirIfNeeded( fileName );
+
+        openMode = std::ios_base::out | std::ios_base::trunc;
+
+        ifReWrite = 1;
+    }
+    else
+    {
+        openMode = std::ios_base::out | std::ios_base::app;
+    }
+
+    file.open( fileName.c_str(), openMode );
+    if ( ! file )
+    {
+        std::cout << "could not open " << fileName << std::endl;
+        exit( 0 );
+    }
+}
+
+void CloseLogFile( std::fstream & file )
+{
+    file.close();
+    file.clear();
+}
+
+LogFile::LogFile()
+{
+}
+
+LogFile::~LogFile()
+{
+}
+
+void LogFile::Open()
+{
+    int pid = Parallel::pid;
+    OpenLogFile( pid, this->my_fstream );
+}
+
+void LogFile::Close()
+{
+    CloseLogFile( this->my_fstream );
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/LogFile.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/LogFile.h
new file mode 100644
index 00000000..00e775ab
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/LogFile.h
@@ -0,0 +1,27 @@
+#pragma once
+#include <fstream>
+
+void OpenLogFile( int logFileIndex, std::fstream & file );
+void CloseLogFile( std::fstream & file );
+class LogFile;
+extern LogFile logFile;
+
+class LogFile
+{
+public:
+    LogFile();
+    ~LogFile();
+    std::fstream my_fstream;
+public:
+    void Open();
+    void Close();
+};
+
+template< typename T >
+LogFile & operator << ( LogFile & f, const T & value )
+{
+    f.Open();
+    f.my_fstream << value;
+    f.Close();
+    return f;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/Parallel.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/Parallel.cpp
new file mode 100644
index 00000000..0bce1a60
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/Parallel.cpp
@@ -0,0 +1,54 @@
+#include "Parallel.h"
+#include <iostream>
+
+int Parallel::pid = 0;
+int Parallel::nProc = 1;
+int Parallel::serverid = 0;
+int Parallel::tag = 0;
+
+void Parallel::Init()
+{
+#ifdef HX_PARALLEL
+    int argc     = 0;
+    char ** argv = 0;
+    MPI_Init( &argc, &argv );
+    MPI_Comm_rank( MPI_COMM_WORLD, &Parallel::pid );
+    MPI_Comm_size( MPI_COMM_WORLD, &Parallel::nProc );
+    int len = -1;
+    char version[ MPI_MAX_LIBRARY_VERSION_STRING ];
+    MPI_Get_library_version( version, &len );
+    std::cout << "Hello, world!  I am " << Parallel::pid << " of " << Parallel::nProc
+        << "(" << version << ", " << len << ")" << std::endl;
+#endif
+}
+
+void Parallel::Finalize()
+{
+#ifdef HX_PARALLEL
+    MPI_Finalize();
+#endif
+}
+
+bool Parallel::IsServer()
+{
+    return Parallel::pid == Parallel::serverid;
+}
+
+void HXSendChar( void * data, int size, int pid, int tag )
+{
+#ifdef HX_PARALLEL
+    if ( size <= 0 ) return;
+    MPI_Send( data, size, MPI_CHAR, pid, tag, MPI_COMM_WORLD );
+#endif
+}
+
+void HXRecvChar( void * data, int size, int pid, int tag )
+{
+#ifdef HX_PARALLEL
+    if ( size <= 0 ) return;
+
+    MPI_Status status;
+    MPI_Recv( data, size, MPI_CHAR, pid, tag, MPI_COMM_WORLD, & status );
+#endif
+}
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/Parallel.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/Parallel.h
new file mode 100644
index 00000000..f42746a7
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/Parallel.h
@@ -0,0 +1,48 @@
+#pragma once
+#ifdef HX_PARALLEL
+#include "mpi.h"
+#endif
+#include <vector>
+#include "LogFile.h"
+
+class Parallel
+{
+public:
+    static int pid;
+    static int nProc;
+    static int serverid;
+    static int tag;
+public:
+    static void Init();
+    static void Finalize();
+public:
+    static bool IsServer();
+};
+
+void HXSendChar( void * data, int size, int pid, int tag );
+void HXRecvChar( void * data, int size, int pid, int tag );
+
+template< typename T >
+void HXSendRecvData( T * field, int nElement, int send_pid, int recv_pid, int tag = 0 )
+{
+    logFile << " send_pid = " << send_pid << "\n";
+    logFile << " recv_pid = " << recv_pid << "\n";
+    logFile << " Parallel::pid = " << Parallel::pid << "\n";
+
+    if ( send_pid == recv_pid ) return;
+
+    if ( nElement <= 0 ) return;
+
+    int buffer_size = nElement * sizeof( T );
+
+    logFile << "nElement = " << nElement << " buffer_size = " << buffer_size << "\n";
+
+    if ( Parallel::pid == send_pid )
+    {
+        HXSendChar( field, buffer_size, recv_pid, tag );
+    }
+    else if ( Parallel::pid == recv_pid )
+    {
+        HXRecvChar( field, buffer_size, send_pid, tag );
+    }
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/README.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/Solver.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/Solver.cpp
new file mode 100644
index 00000000..a2d6783e
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/Solver.cpp
@@ -0,0 +1,516 @@
+#include "Solver.h"
+#include "Parallel.h"
+#include <fstream>
+#include <set>
+#include <unordered_map>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+Solver::Solver()
+{
+    Parallel::Init();
+}
+
+Solver::~Solver()
+{
+    Parallel::Finalize();
+}
+
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    //if ( Parallel::pid == Parallel::serverid )
+    //{
+    //    this->ReadGrid();
+    //    this->InitTopo();
+    //    this->InitFields();
+    //    this->SolveMultiZones();
+    //    this->PostProcess();
+    //}
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d4blocksv1.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    ReadCgnsGrid( fileName );
+}
+
+void Solver::InitTopo()
+{
+    int nZones = Global::grids.size();
+    Global::donor_zone_sets.resize( nZones );
+    Global::donor_zones.resize( nZones );
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = new Interface();
+        interface->zoneid = iZone;
+        Global::interfaces.push_back( interface );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+        Interface * interface = Global::interfaces[ iZone ];
+
+        int nbc1to1s = zone->bc1to1s.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+        int nInterfaces = interface->zoneList.size();
+        interface->data_recv.resize( nInterfaces );
+        interface->data_send.resize( nInterfaces );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        std::set<int> &donor_zoneSet = Global::donor_zone_sets[ iZone ];
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            donor_zoneSet.insert( donor_zoneid );
+        }
+
+        std::vector<int> &donor_zones = Global::donor_zones[ iZone ];
+        for ( std::set<int>::iterator iter = donor_zoneSet.begin(); iter != donor_zoneSet.end(); ++ iter )
+        {
+            donor_zones.push_back( *iter );
+        }
+
+        interface->neighbor_donor_zones = donor_zones;
+
+        std::unordered_map<int, int> donor_zonelocal;
+
+        for ( int idonor = 0; idonor < donor_zones.size(); ++ idonor )
+        {
+            int donor_zone = donor_zones[ idonor ];
+            donor_zonelocal.insert( std::make_pair( donor_zone, idonor ) );
+        }
+        int index_dim = 1;
+        int ndonors = donor_zones.size();
+        std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+        neighbor_donorfaces.resize( ndonors );
+
+        std::vector<std::vector<int>> & sub_local_faceids = interface->sub_local_faceids;
+        sub_local_faceids.resize( ndonors );
+
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ineighbor = donor_zonelocal[ donor_zoneid ];
+            std::vector<int> &donorfaces = neighbor_donorfaces[ ineighbor ];
+            int global_faceid = interface->global_faceids[ iFace ];
+            donorfaces.push_back( global_faceid );
+            int local_faceid = interface->local_faceids[ iFace ];
+
+            std::vector<int> & sub_local_faces = sub_local_faceids[ ineighbor ];
+            sub_local_faces.push_back( local_faceid );
+        }
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> &neighbor_donor_zones = interface->neighbor_donor_zones;
+        int ndonor_zones = neighbor_donor_zones.size();
+
+        std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donorzone = neighbor_donor_zones[ iNei ];
+            std::vector<int> & neighbor_donorface = neighbor_donorfaces[ iNei ];
+
+            Global::SendGeom( iZone, donorzone, neighbor_donorface );
+        }
+        int kkk = 1;
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        std::cout << "zone = " << iZone << "\n";
+
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> & send_to_zones = interface->send_to_zones;
+        int nsend_zones = send_to_zones.size();
+    }
+
+    std::cout << "\n";
+}
+
+void Solver::InitFields()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+    }
+
+    Boundary();
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        int nZones = Global::zones.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Field * field = Global::fields[ iZone ];
+            Zone * zone = Global::zones[ iZone ];
+            zone->zoneIndex = iZone;
+            field->Solve( zone );
+        }
+        Boundary();
+    }
+}
+
+void Solver::Boundary()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+    ExchangeInterfaceField();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->UpdateOldField();
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    int nZones = Global::interfaces.size();
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> & send_to_zones = interface->send_to_zones;
+        int nsend_zones = send_to_zones.size();
+
+        std::vector<std::vector<int>> & donorfaces_for_send = interface->donorfaces_for_send;
+        std::vector<std::vector<int>> & donorijk_for_send = interface->donorijk_for_send;
+        std::vector<std::vector<double>> & donordata_for_send = interface->donordata_for_send;
+
+        Field * field = Global::fields[ iZone ];
+
+        for ( int iSend = 0; iSend < nsend_zones; ++ iSend )
+        {
+            int zone_to_send = send_to_zones[ iSend ];
+            std::vector<int> & donorfaces = donorfaces_for_send[ iSend ];
+            std::vector<int> & donorijks = donorijk_for_send[ iSend ];
+            std::vector<double> & donordatas = donordata_for_send[ iSend ];
+
+            int nface = donorfaces.size();
+            int index_dim = 1;
+            for ( int i = 0; i < nface; ++ i )
+            {
+                int ijkpos = index_dim * i;
+                int i_donor_cell = donorijks[ ijkpos + 0 ];
+                donordatas[ i ] = field->u[ i_donor_cell ];
+            }
+        }
+    }
+    int kkk = 1;
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+
+        std::vector<int> & neighbor_donor_zones = interface->neighbor_donor_zones;
+        int ndonor_zones = neighbor_donor_zones.size();
+
+        //std::vector<std::vector<double>> & recv_donor_fields = interface->recv_donor_fields;
+
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donorzone = neighbor_donor_zones[ iNei ];
+            Interface * donor_interface = Global::interfaces[ donorzone ];
+            int nSize = donor_interface->send_to_zones.size();
+            int ipos = -1;
+            for ( int i = 0; i < nSize; ++ i )
+            {
+                int szone = donor_interface->send_to_zones[ i ];
+                if ( szone == iZone )
+                {
+                    ipos = i;
+                    break;
+                }
+            }
+            std::vector<double> & donordata = donor_interface->donordata_for_send[ ipos ];
+
+            std::vector<int> & neighbor_donorfaces = interface->neighbor_donorfaces[ iNei ];
+            std::vector<int> & sub_local_faceids = interface->sub_local_faceids[ iNei ];
+            for ( int i = 0; i < neighbor_donorfaces.size(); ++ i )
+            {
+                int local_faceid = sub_local_faceids[ i ];
+                double donor_value = donordata[ i ];
+                interface->data_recv[ local_faceid ] = donor_value;
+            }
+        }
+
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+
+            double donor_value = interface->data_recv[ iFace ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::PostProcess()
+{
+    Post post;
+    post.Process();
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    int nZones = Global::grids.size();
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        int ni = grid->x.size();
+        double xmin = grid->x[ 0 ];
+        double xmax = grid->x[ 0 ];
+        int imin = 0;
+        int imax = 0;
+        for ( int i = 0; i < ni; ++ i )
+        {
+            if ( xmin > grid->x[ i ] )
+            {
+                xmin = grid->x[ i ];
+                imin = i;
+            }
+            if ( xmax < grid->x[ i ] )
+            {
+                xmax = grid->x[ i ];
+                imax = i;
+            }
+        }
+        xmin_list.push_back( xmin );
+        xmax_list.push_back( xmax );
+    }
+    std::vector<std::pair<double, int>> pairs;
+    int nSize = xmin_list.size();
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        pairs.push_back( std::make_pair( xmin_list[i], i ) );
+    }
+
+    std::sort( pairs.begin(), pairs.end() );
+
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        this->zoneids.push_back( pairs[i].second );
+    }
+
+    int kkk = 1;
+}
+
+void Post::GatherField()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+        Grid * grid = Global::grids[ zoneid ];
+        Field * field = Global::fields[ zoneid ];
+
+        int ni = grid->x.size();
+
+        int ist = 1;
+        int ied = ni;
+
+        int dir = 1;
+        if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+        if ( dir == 1 )
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ist; i <= ied; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+
+            }
+            else
+            {
+                for ( int i = ist; i <= ied - 1; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+        else
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ied; i >= ist; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+            else
+            {
+                for ( int i = ied; i >= ist + 1; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+    }
+}
+
+void Post::DumpField()
+{
+    int ni_total = this->x.size();
+    std::cout << " DumpField x.size() = " << x.size() << "\n";
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    this->DumpErrorDetails( u_error );
+
+    std::string csvname = "field_final.csv";
+    this->DumpCsvFile( csvname, x, u_e, un, u_error );
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.20f} {:.20f} {:.20f} {:.20f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/Solver.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/Solver.h
new file mode 100644
index 00000000..d01d3d9c
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/Solver.h
@@ -0,0 +1,44 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+
+class Solver
+{
+public:
+    Solver();
+    ~Solver();
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveMultiZones();
+public:
+    void Boundary();
+    void ExchangeInterfaceField();
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcess();
+};
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+    std::vector<double> u;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/ZoneState.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/ZoneState.cpp
new file mode 100644
index 00000000..528305fe
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/ZoneState.cpp
@@ -0,0 +1,15 @@
+#include "ZoneState.h"
+#include "Parallel.h"
+
+int ZoneState::nZones = 0;
+std::vector<int> ZoneState::pids;
+
+bool ZoneState::IsValid( int zoneid )
+{
+    return ZoneState::pids[ zoneid ] == Parallel::pid;
+}
+
+int ZoneState::GetProcID( int zoneid )
+{
+    return ZoneState::pids[ zoneid ];
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/ZoneState.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/ZoneState.h
new file mode 100644
index 00000000..8d1863b7
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/ZoneState.h
@@ -0,0 +1,13 @@
+#pragma once
+#include <vector>
+
+class ZoneState
+{
+public:
+    static int nZones;
+    static int zone_id;
+    static std::vector<int> pids;
+public:
+    static bool IsValid( int zoneid );
+    static int GetProcID( int zoneid );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/global.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/global.cpp
new file mode 100644
index 00000000..d96bf9d7
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/global.cpp
@@ -0,0 +1,191 @@
+#include "global.h"
+#include "CgnsGrid.h"
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *> Global::interfaces;
+
+std::map<Face, int> Global::faceMap;
+std::map<FacePair, int> Global::facePairMap;
+std::vector<FacePair> Global::facePairList;
+
+std::vector<std::set<int>> Global::donor_zone_sets;
+std::vector<std::vector<int>> Global::donor_zones;
+
+bool Face::operator < ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return this->zone < rhs.zone;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return this->i < rhs.i;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return this->j < rhs.j;
+    }
+
+    return this->k < rhs.k;
+}
+
+bool Face::operator == ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return false;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return false;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return false;
+    }
+
+    return this->k == rhs.k;
+}
+
+void FacePair::AddPair( const Face & face1, const Face & face2 )
+{
+    if ( face1 < face2 )
+    {
+        this->left = face1;
+        this->right = face2;
+    }
+    else
+    {
+        this->left = face2;
+        this->right = face1;
+    }
+}
+
+bool FacePair::operator < ( const FacePair & rhs ) const
+{
+    if ( this->left == rhs.left || this->left == rhs.right )
+    {
+        return false;
+    }
+
+    return this->left < rhs.left;
+}
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->local_faceids.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        Face face;
+        face.zone = zoneid;
+        face.i = i;
+
+        Global::InsertFaceMap( face );
+
+        int i_donor = index2[ 0 ];
+
+        Face face_donor;
+        face_donor.zone = donor_zoneid;
+        face_donor.i = i_donor;
+
+        Global::InsertFaceMap( face_donor );
+
+        FacePair facePair;
+        facePair.AddPair( face, face_donor );
+
+        Global::facePairList.push_back( facePair );
+        int global_faceid = Global::InsertFacePairMap( facePair );
+        this->global_faceids.push_back( global_faceid );
+
+        this->global_local_face_map.insert( std::make_pair( global_faceid, faceid ) );
+
+        int i_ghost_cell = i + 1;
+        int i_local_donor_cell = i - 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+            i_local_donor_cell = i + 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+        ijk_donors.push_back( i_local_donor_cell );
+
+        icount ++;
+    }
+}
+
+void Global::InsertFaceMap( const Face & face )
+{
+    std::map<Face, int>::iterator iter;
+    iter = Global::faceMap.find( face );
+    if ( iter == Global::faceMap.end() )
+    {
+        int faceid = Global::faceMap.size();
+        Global::faceMap.insert( std::make_pair( face, faceid ) );
+    }
+}
+
+int Global::InsertFacePairMap( const FacePair & facePair )
+{
+    std::map<FacePair, int>::iterator iter;
+    iter = Global::facePairMap.find( facePair );
+    if ( iter == Global::facePairMap.end() )
+    {
+        int facePairId = Global::facePairMap.size();
+        Global::facePairMap.insert( std::make_pair( facePair, facePairId ) );
+        return facePairId;
+    }
+    return iter->second;
+}
+
+void Global::SendGeom( int zone, int donorzone, std::vector<int> & donorfaces )
+{
+    Interface * interface = Global::interfaces[ donorzone ];
+
+    std::vector<int> & send_to_zones = interface->send_to_zones;
+
+    send_to_zones.push_back( zone );
+    interface->donorfaces_for_send.push_back( donorfaces );
+
+    int nface = donorfaces.size();
+    std::vector<int> sub_donorijk;
+    int index_dim = 1;
+    for ( int i = 0; i < nface; ++ i )
+    {
+        int global_faceid = donorfaces[ i ];
+        int local_faceid = interface->global_local_face_map[ global_faceid ];
+        int ijkpos = index_dim * local_faceid;
+        int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+        sub_donorijk.push_back( i_donor_cell );
+        int kkk = 1;
+    }
+
+    interface->donorijk_for_send.push_back( sub_donorijk );
+
+    std::vector<double> sub_donordata( sub_donorijk.size() );
+    interface->donordata_for_send.push_back( sub_donordata );
+}
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/global.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/global.h
new file mode 100644
index 00000000..ce8eef97
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/global.h
@@ -0,0 +1,138 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <unordered_map>
+#include <set>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class Face
+{
+public:
+    int zone = 0;
+    int i = 0;
+    int j = 1;
+    int k = 1;
+public:
+    bool operator < ( const Face & rhs ) const;
+    bool operator == ( const Face & rhs ) const;
+};
+
+class FacePair
+{
+public:
+    Face left;
+    Face right;
+public:
+    bool operator < ( const FacePair & rhs ) const;
+    void AddPair( const Face &face1, const Face &face2);
+};
+
+class Transform;
+
+
+class Interface
+{
+public:
+    int zoneid;
+    std::vector<int> zoneList;
+    std::vector<int> global_faceids;
+    std::vector<int> local_faceids;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+    std::vector<double> data_recv;
+    std::vector<double> data_send;
+    std::unordered_map<int, int> global_local_face_map;
+public:
+    std::vector<int> neighbor_donor_zones;
+    std::vector<std::vector<int>> neighbor_donorfaces;
+    std::vector<std::vector<int>> sub_local_faceids;
+    std::vector<int> send_to_zones;
+    std::vector<std::vector<int>> donorfaces_for_send;
+    std::vector<std::vector<int>> donorijk_for_send;
+    std::vector<std::vector<double>> donordata_for_send;
+public:
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+};
+
+class Field;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+public:
+    static std::map<Face, int> faceMap;
+    static std::map<FacePair, int> facePairMap;
+    static std::vector<FacePair> facePairList;
+    static std::vector<std::set<int>> donor_zone_sets;
+    static std::vector<std::vector<int>> donor_zones;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+public:
+    static void InsertFaceMap( const Face & face );
+    static int InsertFacePairMap( const FacePair & facePair );
+    static void SendGeom( int zone, int donorzone, std::vector<int> & donorfaces );
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/heat1d4blocksv1.cgns b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/heat1d4blocksv1.cgns
new file mode 100644
index 00000000..df5ffc5f
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/heat1d4blocksv1.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/main.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/main.cpp
new file mode 100644
index 00000000..df63b7da
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/main.cpp
@@ -0,0 +1,9 @@
+#include "Solver.h"
+#include "Parallel.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/plot.py b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02d/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/CMakeLists.txt
new file mode 100644
index 00000000..9e834b72
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/CMakeLists.txt
@@ -0,0 +1,99 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package ( MPI )
+
+message ( STATUS  "MPI_FOUND=${MPI_FOUND}" )
+message ( STATUS  "MPI_CXX_INCLUDE_DIRS=${MPI_CXX_INCLUDE_DIRS}" )
+message ( STATUS  "MPI_LIBRARIES=${MPI_LIBRARIES}" )
+if ( MPI_FOUND )
+	list ( APPEND PRJ_INCLUDE_DIRS ${MPI_CXX_INCLUDE_DIRS} )
+	list ( APPEND PRJ_LIBRARIES ${MPI_LIBRARIES} )
+endif ()
+
+#get_directory_property( my_import_targets DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} IMPORTED_TARGETS )
+#message( STATUS "my_import_targets=${my_import_targets}" )
+
+list ( APPEND PRJ_LIBRARIES MPI::MPI_C )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+list ( APPEND PRJ_COMPILE_DEFINITIONS HX_PARALLEL )
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	LogFile.h LogFile.cpp
+	Parallel.h Parallel.cpp
+	Solver.h Solver.cpp
+	ZoneState.h ZoneState.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/CgnsGrid.cpp
new file mode 100644
index 00000000..8e47482e
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/CgnsGrid.cpp
@@ -0,0 +1,854 @@
+#include "CgnsGrid.h"
+#include "Parallel.h"
+#include "cgnslib.h"
+#include "global.h"
+#include "ZoneState.h"
+#include <iostream>
+#include <vector>
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "fileId = " << fileId << "\n";
+    }
+    
+    int nbases = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_nbases( fileId, &nbases );
+    }
+    MPI_Bcast( &nbases, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "nbases = " << nbases << "\n";
+    
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        }
+
+        MPI_Bcast( &icelldim, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+        MPI_Bcast( &iphysdim, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+
+        int nzones = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_nzones( fileId, baseId, &nzones );
+        }
+
+        MPI_Bcast( &nzones, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+
+        ZoneState::nZones = nzones;
+        ZoneState::pids.resize( nzones );
+
+        if ( Parallel::nProc == 1 )
+        {
+            for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+            {
+                ZoneState::pids[ iZone ] = 0;
+            }
+        }
+        else
+        {
+            for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+            {
+                ZoneState::pids[ iZone ] = iZone;
+            }
+        }
+
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nzones = " << nzones << "\n";
+
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "iZone = " << iZone << "\n";
+
+            int index_dim = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            }
+            MPI_Bcast( &index_dim, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            if ( Parallel::IsServer() )
+            {
+                cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            }
+
+            MPI_Bcast( zonename, 33, MPI_CHAR, Parallel::serverid, MPI_COMM_WORLD );
+            MPI_Bcast( isize.data(), index_dim * 3, MPI_LONG_LONG, Parallel::serverid, MPI_COMM_WORLD );
+
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "zonename = " << zonename << "\n";
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+
+    if ( Parallel::IsServer() )
+    {
+        cg_close( fileId );
+    }
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+        std::cout << "fileId = " << fileId << "\n";
+    }
+    
+    int nbases = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_nbases( fileId, &nbases );
+    }
+    MPI_Bcast( &nbases, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        }
+        MPI_Bcast( &icelldim, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+        MPI_Bcast( &iphysdim, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+
+        int nzones = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_nzones( fileId, baseId, &nzones );
+        }
+        MPI_Bcast( &nzones, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nzones = " << nzones << "\n";
+
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            }
+            HXSendRecvData<int>( &index_dim, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "index_dim = " << index_dim << "\n";
+            }
+
+            std::vector<cgsize_t> isize;
+            char zonename[ 33 ];
+            if ( Parallel::IsServer() )
+            {
+                isize.resize( index_dim * 3 );
+                cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            }
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                isize.resize( index_dim * 3 );
+            }
+
+            HXSendRecvData( zonename, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+            HXSendRecvData( isize.data(), index_dim * 3, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "zonename = " << zonename << "\n";
+
+                for ( int i = 0; i < isize.size(); ++ i )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+                }
+            }
+
+            std::vector<cgsize_t> irmin;
+            std::vector<cgsize_t> irmax;
+            int nNodes = 1;
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                irmin.resize( index_dim );
+                irmax.resize( index_dim );
+                for ( int m = 0; m < index_dim; ++ m )
+                {
+                    /* lower range index */
+                    irmin[ m ] = 1;
+                    /* upper range index of vertices */
+                    irmax[ m ] = isize[ m ];
+                    nNodes *= irmax[ m ];
+                }
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "nNodes = " << nNodes << "\n";
+            }
+
+            ZoneType_t zoneType;
+            if ( Parallel::IsServer() )
+            {
+                cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            }
+            HXSendRecvData( &zoneType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            }
+
+            Zone * zone = nullptr;
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                zone = new Zone();
+                Global::zones.push_back( zone );
+                LocalZone::global_zoneids.push_back( iZone );
+                LocalZone::nZones = LocalZone::global_zoneids.size();
+                for ( int m = 0; m < index_dim; ++ m )
+                {
+                    zone->nijk.push_back( isize[ m ] );
+                }
+            }
+
+            Grid * grid = nullptr;
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                grid = new Grid();
+                Global::grids.push_back( grid );
+            }
+
+            BaseZone baseZone;
+
+            int gZoneId = -1;
+            if ( Parallel::IsServer() )
+            {
+                baseZone.zone_name = zonename;
+                gZoneId = Global::zone_names.FindBaseZone( baseZone );
+            }
+
+            HXSendRecvData( &gZoneId, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "gZoneId = " << gZoneId << "\n";
+            }
+
+            int ncoords = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            }
+            HXSendRecvData( &ncoords, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "ncoords = " << ncoords << "\n";
+            }
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                if ( Parallel::IsServer() )
+                {
+                    cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                }
+                HXSendRecvData( coordname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &dataType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "coordname = " << coordname << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                }
+
+                std::vector<char> coord;
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    coord.resize( nNodes * sizeof( double ) );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coord.data() );
+                }
+
+                HXSendRecvData( coord.data(), coord.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                Coor * coor = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    coor = new Coor();
+                    zone->coors.push_back( coor );
+                    coor->coorname = coordname;
+                    coor->nNodes = nNodes;
+                    coor->coord = coord;
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    coor->DumpCoor();
+
+                    if ( icoord == 0 )
+                    {
+                        grid->x.resize( nNodes );
+                        coor->DumpCoorX( grid->x );
+                    }
+                }
+            }
+
+            int nbocos = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            }
+            HXSendRecvData( &nbocos, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "nbocos = " << nbocos << "\n";
+            }
+
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                if ( Parallel::IsServer() )
+                {
+                    cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                }
+                HXSendRecvData( &location, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+                }
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                //std::vector<int> normalIndex( index_dim, -1 );
+                std::vector<int> normalIndex;
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+                if ( Parallel::IsServer() )
+                {
+                    normalIndex.resize( index_dim );
+                    cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                        &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                }
+
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    normalIndex.resize( index_dim );
+                }
+                
+                HXSendRecvData( boconame, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &bocotype, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &ptset_type, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &npnts, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &normalDataType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &normalListSize, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( normalIndex.data(), index_dim, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &ndataset, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "npnts = " << npnts << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalListSize = " << normalListSize << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalIndex = ";
+                    for ( int i = 0; i < index_dim; ++ i )
+                    {
+                        std::cout << normalIndex[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "ndataset = " << ndataset << "\n";
+                }
+
+                std::vector<char> normalList;
+                std::vector<cgsize_t> pnts;
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    if ( normalDataType == DataTypeNull )
+                    {
+                        normalList.resize( sizeof( int ) );
+                    }
+                    else
+                    {
+                        int nSize = nNodes * index_dim * sizeof( double );
+                        normalList.resize( nSize );
+                    }
+                    pnts.resize( npnts * index_dim );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                }
+
+                HXSendRecvData( pnts.data(), npnts * index_dim, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "pnts = ";
+                    for ( int i = 0; i < pnts.size(); ++ i )
+                    {
+                        std::cout << pnts[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                }
+                HXSendRecvData( normalList.data(), normalList.size(), Parallel::serverid, ZoneState::GetProcID(iZone));
+
+                ZoneBc * zonebc = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    zonebc = new ZoneBc();
+                    zone->bccos.push_back( zonebc );
+                    zonebc->bcType = bocotype;
+                    for ( int i = 0; i < pnts.size(); ++ i )
+                    {
+                        zonebc->pnts.push_back( pnts[ i ] );
+                    }
+                }
+            }
+            int n1to1 = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            }
+
+            HXSendRecvData( &n1to1, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "n1to1 = " << n1to1 << "\n";
+            }
+
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range;
+                std::vector<cgsize_t> donor_range;
+                std::vector<int> transform;
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    range.resize( npnts * index_dim );
+                    donor_range.resize( npnts * index_dim );
+                    transform.resize( index_dim );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                }
+
+                HXSendRecvData( connectname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( donorname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( range.data(), range.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( donor_range.data(), donor_range.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( transform.data(), transform.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "connectname = " << connectname << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "donorname = " << donorname << "\n";
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "range = ";
+                    for ( int i = 0; i < range.size(); ++ i )
+                    {
+                        std::cout << range[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "donor_range = ";
+                    for ( int i = 0; i < donor_range.size(); ++ i )
+                    {
+                        std::cout << donor_range[ i ] << " ";
+                    }
+                    std::cout << "\n";
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "transform = ";
+                    for ( int i = 0; i < transform.size(); ++ i )
+                    {
+                        std::cout << transform[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                }
+
+                int gDonorZoneId = -1;
+                if ( Parallel::IsServer() )
+                {
+                    BaseZone baseZoneDonor;
+                    baseZoneDonor.zone_name = donorname;
+
+                    gDonorZoneId = Global::zone_names.FindBaseZone( baseZoneDonor );
+                }
+
+                HXSendRecvData( &gDonorZoneId, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                ZoneBc1To1 * zonebc_1to1 = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    zonebc_1to1 = new ZoneBc1To1();
+                    zone->bc1to1s.push_back( zonebc_1to1 );
+                    zonebc_1to1->zoneid = gZoneId;
+                    zonebc_1to1->transform = transform;
+                    zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                    for ( int i = 0; i < range.size(); ++ i )
+                    {
+                        zonebc_1to1->pnts.push_back( range[ i ] );
+                        zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                    }
+                }
+            }
+        }
+    }
+
+    {
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "Global::zones.size() = " << Global::zones.size() << "\n";
+    }
+
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/CgnsGrid.h
new file mode 100644
index 00000000..fddf1db6
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/CgnsGrid.h
@@ -0,0 +1,103 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    int zoneIndex;
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/Field.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/Field.cpp
new file mode 100644
index 00000000..c359a811
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/Field.cpp
@@ -0,0 +1,142 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+
+    std::vector<double> & x = grid->x;
+    this->dx = std::abs( x[ 1 ] - x[ 0 ] );
+    this->dt = dx / 10.0;
+    this->t = 1.0;
+    this->nt = std::round( t / dt );
+
+    double total_time = nt * dt;
+
+    std::cout << "this->dt   = " << this->dt << "\n";
+    std::cout << "this->t    = " << this->t << "\n";
+    std::cout << "this->nt   = " << this->nt << "\n";
+    std::cout << "this->ni   = " << this->ni << "\n";
+    std::cout << "total_time = " << total_time << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        u_e[ i ] = - std::exp( -total_time ) * std::sin( std::numbers::pi * xm ); //theory solution
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+    int kkk = 1;
+}
+
+void Field::Solve( Zone * zone )
+{
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+    }
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        //std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        //region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+        int kkk = 1;
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
+
+void Field::UpdateOldField()
+{
+    for ( int i = 0; i < this->u.size(); ++ i )
+    {
+        this->un[ i ] = this->u[ i ];
+    }
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/Field.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/Field.h
new file mode 100644
index 00000000..084ec9bd
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/Field.h
@@ -0,0 +1,36 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid );
+
+    void Solve( Zone * zone );
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void UpdateOldField();
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/LogFile.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/LogFile.cpp
new file mode 100644
index 00000000..08ccd453
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/LogFile.cpp
@@ -0,0 +1,138 @@
+#include "LogFile.h"
+#include "Parallel.h"
+#include <sstream>
+#include <iostream>
+
+#ifdef _WINDOWS
+#include <windows.h>
+#include <direct.h>
+#include <io.h>
+#else
+#include <sys/stat.h>
+#include <unistd.h>
+#endif
+
+LogFile logFile;
+
+class OStream : public std::ostringstream
+{
+public:
+    OStream() {}
+    ~OStream() {}
+public:
+    void ClearAll()
+    {
+        this->clear();
+        this->str("");
+    }
+};
+
+OStream StrIO;
+std::string GetPrjDirName( const std::string & fileName );
+bool DirExist( const std::string & dirName );
+void MakeDir( const std::string & dirName );
+
+std::string GetPrjDirName( const std::string & fileName )
+{
+    size_t pos = fileName.find_last_of("\\/");
+    if ( std::string::npos == pos )
+    {
+        return "";
+    }
+    else
+    {
+        return fileName.substr( 0, pos );
+    }
+}
+
+bool DirExist( const std::string & dirName )
+{
+#ifdef _WINDOWS
+    bool flag = ( _access( dirName.c_str(), 0 ) == 0 );
+    return flag;
+#else
+    bool flag = ( access( dirName.c_str(), 0 ) == 0 );
+    return flag;
+#endif
+}
+
+void MakeDir( const std::string & dirName )
+{
+    int flag;
+#ifdef _WINDOWS
+    flag = _mkdir( dirName.c_str() );
+#else
+    flag = mkdir( dirName.c_str(), S_IRWXU );
+#endif
+    if ( flag == 0 )
+    {
+        std::cout << dirName << " directory has been created successfully !\n";
+    }
+}
+
+void CreateDirIfNeeded( std::string & prjFileName )
+{
+    std::string prj_dir = GetPrjDirName( prjFileName );
+
+    if ( ! DirExist( prj_dir ) )
+    {
+        MakeDir( prj_dir );
+    }
+}
+
+
+void OpenLogFile( int logFileIndex, std::fstream & file )
+{
+    static int ifReWrite = 0;
+
+    StrIO.ClearAll();
+    StrIO << "log/log" << logFileIndex << ".log";
+    std::string fileName = StrIO.str();
+
+    std::ios_base::openmode openMode;
+
+    if ( ifReWrite == 0 )
+    {
+        CreateDirIfNeeded( fileName );
+
+        openMode = std::ios_base::out | std::ios_base::trunc;
+
+        ifReWrite = 1;
+    }
+    else
+    {
+        openMode = std::ios_base::out | std::ios_base::app;
+    }
+
+    file.open( fileName.c_str(), openMode );
+    if ( ! file )
+    {
+        std::cout << "could not open " << fileName << std::endl;
+        exit( 0 );
+    }
+}
+
+void CloseLogFile( std::fstream & file )
+{
+    file.close();
+    file.clear();
+}
+
+LogFile::LogFile()
+{
+}
+
+LogFile::~LogFile()
+{
+}
+
+void LogFile::Open()
+{
+    int pid = Parallel::pid;
+    OpenLogFile( pid, this->my_fstream );
+}
+
+void LogFile::Close()
+{
+    CloseLogFile( this->my_fstream );
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/LogFile.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/LogFile.h
new file mode 100644
index 00000000..00e775ab
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/LogFile.h
@@ -0,0 +1,27 @@
+#pragma once
+#include <fstream>
+
+void OpenLogFile( int logFileIndex, std::fstream & file );
+void CloseLogFile( std::fstream & file );
+class LogFile;
+extern LogFile logFile;
+
+class LogFile
+{
+public:
+    LogFile();
+    ~LogFile();
+    std::fstream my_fstream;
+public:
+    void Open();
+    void Close();
+};
+
+template< typename T >
+LogFile & operator << ( LogFile & f, const T & value )
+{
+    f.Open();
+    f.my_fstream << value;
+    f.Close();
+    return f;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/Parallel.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/Parallel.cpp
new file mode 100644
index 00000000..0bce1a60
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/Parallel.cpp
@@ -0,0 +1,54 @@
+#include "Parallel.h"
+#include <iostream>
+
+int Parallel::pid = 0;
+int Parallel::nProc = 1;
+int Parallel::serverid = 0;
+int Parallel::tag = 0;
+
+void Parallel::Init()
+{
+#ifdef HX_PARALLEL
+    int argc     = 0;
+    char ** argv = 0;
+    MPI_Init( &argc, &argv );
+    MPI_Comm_rank( MPI_COMM_WORLD, &Parallel::pid );
+    MPI_Comm_size( MPI_COMM_WORLD, &Parallel::nProc );
+    int len = -1;
+    char version[ MPI_MAX_LIBRARY_VERSION_STRING ];
+    MPI_Get_library_version( version, &len );
+    std::cout << "Hello, world!  I am " << Parallel::pid << " of " << Parallel::nProc
+        << "(" << version << ", " << len << ")" << std::endl;
+#endif
+}
+
+void Parallel::Finalize()
+{
+#ifdef HX_PARALLEL
+    MPI_Finalize();
+#endif
+}
+
+bool Parallel::IsServer()
+{
+    return Parallel::pid == Parallel::serverid;
+}
+
+void HXSendChar( void * data, int size, int pid, int tag )
+{
+#ifdef HX_PARALLEL
+    if ( size <= 0 ) return;
+    MPI_Send( data, size, MPI_CHAR, pid, tag, MPI_COMM_WORLD );
+#endif
+}
+
+void HXRecvChar( void * data, int size, int pid, int tag )
+{
+#ifdef HX_PARALLEL
+    if ( size <= 0 ) return;
+
+    MPI_Status status;
+    MPI_Recv( data, size, MPI_CHAR, pid, tag, MPI_COMM_WORLD, & status );
+#endif
+}
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/Parallel.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/Parallel.h
new file mode 100644
index 00000000..17045502
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/Parallel.h
@@ -0,0 +1,48 @@
+#pragma once
+#ifdef HX_PARALLEL
+#include "mpi.h"
+#endif
+#include <vector>
+#include "LogFile.h"
+
+class Parallel
+{
+public:
+    static int pid;
+    static int nProc;
+    static int serverid;
+    static int tag;
+public:
+    static void Init();
+    static void Finalize();
+public:
+    static bool IsServer();
+};
+
+void HXSendChar( void * data, int size, int pid, int tag );
+void HXRecvChar( void * data, int size, int pid, int tag );
+
+template< typename T >
+void HXSendRecvData( T * field, int nElement, int send_pid, int recv_pid, int tag = 0 )
+{
+    //logFile << " send_pid = " << send_pid << "\n";
+    //logFile << " recv_pid = " << recv_pid << "\n";
+    //logFile << " Parallel::pid = " << Parallel::pid << "\n";
+
+    if ( send_pid == recv_pid ) return;
+
+    if ( nElement <= 0 ) return;
+
+    int buffer_size = nElement * sizeof( T );
+
+    //logFile << "nElement = " << nElement << " buffer_size = " << buffer_size << "\n";
+
+    if ( Parallel::pid == send_pid )
+    {
+        HXSendChar( field, buffer_size, recv_pid, tag );
+    }
+    else if ( Parallel::pid == recv_pid )
+    {
+        HXRecvChar( field, buffer_size, send_pid, tag );
+    }
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/README.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/Solver.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/Solver.cpp
new file mode 100644
index 00000000..164d23c7
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/Solver.cpp
@@ -0,0 +1,556 @@
+#include "Solver.h"
+#include "Parallel.h"
+#include "ZoneState.h"
+#include <fstream>
+#include <set>
+#include <unordered_map>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+Solver::Solver()
+{
+    Parallel::Init();
+}
+
+Solver::~Solver()
+{
+    Parallel::Finalize();
+}
+
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    this->InitTopo();
+    this->InitFields();
+    //if ( Parallel::pid == Parallel::serverid )
+    //{
+        this->SolveMultiZones();
+        this->PostProcess();
+    //}
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d4blocksv1.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    ReadCgnsGrid( fileName );
+}
+
+void Solver::InitTopo()
+{
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "Solver::InitTopo() " << "\n";
+
+    Global::donor_zone_sets.resize( LocalZone::nZones );
+    Global::donor_zones.resize( LocalZone::nZones );
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        int global_zoneid = LocalZone::global_zoneids[ iZone ];
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "iZone = " << iZone << " global_zoneid = " << global_zoneid << "\n";
+
+        Interface * interface = new Interface();
+        interface->zoneid = iZone;
+        Global::interfaces.push_back( interface );
+    }
+
+    //for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    //{
+    //    Zone * zone = Global::zones[ iZone ];
+
+    //    Interface * interface = Global::interfaces[ iZone ];
+
+    //    int nbc1to1s = zone->bc1to1s.size();
+    //    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    //    std::cout <<  "nbc1to1s = " << nbc1to1s << "\n";
+
+    //    for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+    //    {
+    //        ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+    //        int zoneid = bc1to1->zoneid;
+    //        int donor_zoneid = bc1to1->donor_zoneid;
+    //        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    //        std::cout << "zoneid = " << zoneid << " donor_zoneid = " << donor_zoneid << "\n";
+
+    //        Region region;
+    //        region.SetRegion( bc1to1->pnts );
+
+    //        Region donor_region;
+    //        donor_region.SetRegion( bc1to1->donor_pnts );
+
+    //        Transform transform;
+    //        transform.begin1 = region.start;
+    //        transform.begin2 = donor_region.start;
+    //        transform.transform = bc1to1->transform;
+    //        transform.Init();
+
+    //        interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+    //    }
+    //}
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+        
+        Interface * interface = Global::interfaces[ iZone ];
+
+        int nbc1to1s = zone->bc1to1s.size();
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout <<  "nbc1to1s = " << nbc1to1s << "\n";
+
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "zoneid = " << zoneid << " donor_zoneid = " << donor_zoneid << "\n";
+
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+        int nInterfaces = interface->zoneList.size();
+        interface->data_recv.resize( nInterfaces );
+        interface->data_send.resize( nInterfaces );
+    }
+
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        if ( ! ZoneState::IsValid( iZone ) ) continue;
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        std::set<int> &donor_zoneSet = Global::donor_zone_sets[ iZone ];
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            donor_zoneSet.insert( donor_zoneid );
+        }
+
+        std::vector<int> &donor_zones = Global::donor_zones[ iZone ];
+        for ( std::set<int>::iterator iter = donor_zoneSet.begin(); iter != donor_zoneSet.end(); ++ iter )
+        {
+            donor_zones.push_back( *iter );
+        }
+
+        interface->neighbor_donor_zones = donor_zones;
+
+        std::unordered_map<int, int> donor_zonelocal;
+
+        for ( int idonor = 0; idonor < donor_zones.size(); ++ idonor )
+        {
+            int donor_zone = donor_zones[ idonor ];
+            donor_zonelocal.insert( std::make_pair( donor_zone, idonor ) );
+        }
+        int index_dim = 1;
+        int ndonors = donor_zones.size();
+        std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+        neighbor_donorfaces.resize( ndonors );
+
+        std::vector<std::vector<int>> & sub_local_faceids = interface->sub_local_faceids;
+        sub_local_faceids.resize( ndonors );
+
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ineighbor = donor_zonelocal[ donor_zoneid ];
+            std::vector<int> &donorfaces = neighbor_donorfaces[ ineighbor ];
+            int global_faceid = interface->global_faceids[ iFace ];
+            donorfaces.push_back( global_faceid );
+            int local_faceid = interface->local_faceids[ iFace ];
+
+            std::vector<int> & sub_local_faces = sub_local_faceids[ ineighbor ];
+            sub_local_faces.push_back( local_faceid );
+        }
+    }
+
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        if ( ! ZoneState::IsValid( iZone ) ) continue;
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> &neighbor_donor_zones = interface->neighbor_donor_zones;
+        int ndonor_zones = neighbor_donor_zones.size();
+
+        std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donorzone = neighbor_donor_zones[ iNei ];
+            std::vector<int> & neighbor_donorface = neighbor_donorfaces[ iNei ];
+
+            Global::SendGeom( iZone, donorzone, neighbor_donorface );
+        }
+        int kkk = 1;
+    }
+}
+
+void Solver::InitFields()
+{
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "Solver::InitFields() ZoneState::nZones = " << ZoneState::nZones <<  "\n";
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        if ( ! ZoneState::IsValid( iZone ) ) continue;
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        if ( ! ZoneState::IsValid( iZone ) ) continue;
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+    }
+
+    Boundary();
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        int nZones = Global::zones.size();
+        for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+        {
+            if ( ! ZoneState::IsValid( iZone ) ) continue;
+            Field * field = Global::fields[ iZone ];
+            Zone * zone = Global::zones[ iZone ];
+            zone->zoneIndex = iZone;
+            field->Solve( zone );
+        }
+        Boundary();
+    }
+}
+
+void Solver::Boundary()
+{
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        if ( ! ZoneState::IsValid( iZone ) ) continue;
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+    ExchangeInterfaceField();
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        if ( ! ZoneState::IsValid( iZone ) ) continue;
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->UpdateOldField();
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> & send_to_zones = interface->send_to_zones;
+        int nsend_zones = send_to_zones.size();
+
+        std::vector<std::vector<int>> & donorfaces_for_send = interface->donorfaces_for_send;
+        std::vector<std::vector<int>> & donorijk_for_send = interface->donorijk_for_send;
+        std::vector<std::vector<double>> & donordata_for_send = interface->donordata_for_send;
+
+        Field * field = Global::fields[ iZone ];
+
+        for ( int iSend = 0; iSend < nsend_zones; ++ iSend )
+        {
+            int zone_to_send = send_to_zones[ iSend ];
+            std::vector<int> & donorfaces = donorfaces_for_send[ iSend ];
+            std::vector<int> & donorijks = donorijk_for_send[ iSend ];
+            std::vector<double> & donordatas = donordata_for_send[ iSend ];
+
+            int nface = donorfaces.size();
+            int index_dim = 1;
+            for ( int i = 0; i < nface; ++ i )
+            {
+                int ijkpos = index_dim * i;
+                int i_donor_cell = donorijks[ ijkpos + 0 ];
+                donordatas[ i ] = field->u[ i_donor_cell ];
+            }
+        }
+    }
+    int kkk = 1;
+
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+
+        std::vector<int> & neighbor_donor_zones = interface->neighbor_donor_zones;
+        int ndonor_zones = neighbor_donor_zones.size();
+
+        //std::vector<std::vector<double>> & recv_donor_fields = interface->recv_donor_fields;
+
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donorzone = neighbor_donor_zones[ iNei ];
+            Interface * donor_interface = Global::interfaces[ donorzone ];
+            int nSize = donor_interface->send_to_zones.size();
+            int ipos = -1;
+            for ( int i = 0; i < nSize; ++ i )
+            {
+                int szone = donor_interface->send_to_zones[ i ];
+                if ( szone == iZone )
+                {
+                    ipos = i;
+                    break;
+                }
+            }
+            std::vector<double> & donordata = donor_interface->donordata_for_send[ ipos ];
+
+            std::vector<int> & neighbor_donorfaces = interface->neighbor_donorfaces[ iNei ];
+            std::vector<int> & sub_local_faceids = interface->sub_local_faceids[ iNei ];
+            for ( int i = 0; i < neighbor_donorfaces.size(); ++ i )
+            {
+                int local_faceid = sub_local_faceids[ i ];
+                double donor_value = donordata[ i ];
+                interface->data_recv[ local_faceid ] = donor_value;
+            }
+        }
+
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+
+            double donor_value = interface->data_recv[ iFace ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::PostProcess()
+{
+    Post post;
+    post.Process();
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    int nZones = Global::grids.size();
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        int ni = grid->x.size();
+        double xmin = grid->x[ 0 ];
+        double xmax = grid->x[ 0 ];
+        int imin = 0;
+        int imax = 0;
+        for ( int i = 0; i < ni; ++ i )
+        {
+            if ( xmin > grid->x[ i ] )
+            {
+                xmin = grid->x[ i ];
+                imin = i;
+            }
+            if ( xmax < grid->x[ i ] )
+            {
+                xmax = grid->x[ i ];
+                imax = i;
+            }
+        }
+        xmin_list.push_back( xmin );
+        xmax_list.push_back( xmax );
+    }
+    std::vector<std::pair<double, int>> pairs;
+    int nSize = xmin_list.size();
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        pairs.push_back( std::make_pair( xmin_list[i], i ) );
+    }
+
+    std::sort( pairs.begin(), pairs.end() );
+
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        this->zoneids.push_back( pairs[i].second );
+    }
+
+    int kkk = 1;
+}
+
+void Post::GatherField()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+        Grid * grid = Global::grids[ zoneid ];
+        Field * field = Global::fields[ zoneid ];
+
+        int ni = grid->x.size();
+
+        int ist = 1;
+        int ied = ni;
+
+        int dir = 1;
+        if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+        if ( dir == 1 )
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ist; i <= ied; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+
+            }
+            else
+            {
+                for ( int i = ist; i <= ied - 1; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+        else
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ied; i >= ist; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+            else
+            {
+                for ( int i = ied; i >= ist + 1; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+    }
+}
+
+void Post::DumpField()
+{
+    int ni_total = this->x.size();
+    std::cout << " DumpField x.size() = " << x.size() << "\n";
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    this->DumpErrorDetails( u_error );
+
+    std::string csvname = "field_final.csv";
+    this->DumpCsvFile( csvname, x, u_e, un, u_error );
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.20f} {:.20f} {:.20f} {:.20f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/Solver.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/Solver.h
new file mode 100644
index 00000000..d01d3d9c
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/Solver.h
@@ -0,0 +1,44 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+
+class Solver
+{
+public:
+    Solver();
+    ~Solver();
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveMultiZones();
+public:
+    void Boundary();
+    void ExchangeInterfaceField();
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcess();
+};
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+    std::vector<double> u;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/ZoneState.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/ZoneState.cpp
new file mode 100644
index 00000000..bdafab8c
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/ZoneState.cpp
@@ -0,0 +1,19 @@
+#include "ZoneState.h"
+#include "Parallel.h"
+
+int ZoneState::nZones = 0;
+std::vector<int> ZoneState::pids;
+
+bool ZoneState::IsValid( int zoneid )
+{
+    return ZoneState::pids[ zoneid ] == Parallel::pid;
+}
+
+int ZoneState::GetProcID( int zoneid )
+{
+    return ZoneState::pids[ zoneid ];
+}
+
+int LocalZone::nZones = 0;
+std::vector<int> LocalZone::global_zoneids;
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/ZoneState.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/ZoneState.h
new file mode 100644
index 00000000..35f9a1e8
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/ZoneState.h
@@ -0,0 +1,20 @@
+#pragma once
+#include <vector>
+
+class ZoneState
+{
+public:
+    static int nZones;
+    static int zone_id;
+    static std::vector<int> pids;
+public:
+    static bool IsValid( int zoneid );
+    static int GetProcID( int zoneid );
+};
+
+class LocalZone
+{
+public:
+    static int nZones;
+    static std::vector<int> global_zoneids;
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/global.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/global.cpp
new file mode 100644
index 00000000..6d725629
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/global.cpp
@@ -0,0 +1,241 @@
+#include "global.h"
+#include "CgnsGrid.h"
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *> Global::interfaces;
+
+std::map<Face, int> Global::faceMap;
+std::map<FacePair, int> Global::facePairMap;
+std::vector<FacePair> Global::facePairList;
+
+std::vector<std::set<int>> Global::donor_zone_sets;
+std::vector<std::vector<int>> Global::donor_zones;
+
+bool Face::operator < ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return this->zone < rhs.zone;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return this->i < rhs.i;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return this->j < rhs.j;
+    }
+
+    return this->k < rhs.k;
+}
+
+bool Face::operator == ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return false;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return false;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return false;
+    }
+
+    return this->k == rhs.k;
+}
+
+void FacePair::AddPair( const Face & face1, const Face & face2 )
+{
+    if ( face1 < face2 )
+    {
+        this->left = face1;
+        this->right = face2;
+    }
+    else
+    {
+        this->left = face2;
+        this->right = face1;
+    }
+}
+
+bool FacePair::operator < ( const FacePair & rhs ) const
+{
+    if ( this->left == rhs.left || this->left == rhs.right )
+    {
+        return false;
+    }
+
+    return this->left < rhs.left;
+}
+
+void Interface::CalcInterfaceOld( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->local_faceids.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        Face face;
+        face.zone = zoneid;
+        face.i = i;
+
+        Global::InsertFaceMap( face );
+
+        int i_donor = index2[ 0 ];
+
+        Face face_donor;
+        face_donor.zone = donor_zoneid;
+        face_donor.i = i_donor;
+
+        Global::InsertFaceMap( face_donor );
+
+        FacePair facePair;
+        facePair.AddPair( face, face_donor );
+
+        Global::facePairList.push_back( facePair );
+        int global_faceid = Global::InsertFacePairMap( facePair );
+        this->global_faceids.push_back( global_faceid );
+
+        this->global_local_face_map.insert( std::make_pair( global_faceid, faceid ) );
+
+        int i_ghost_cell = i + 1;
+        int i_local_donor_cell = i - 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+            i_local_donor_cell = i + 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+        ijk_donors.push_back( i_local_donor_cell );
+
+        icount ++;
+    }
+}
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->local_faceids.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        Face face;
+        face.zone = zoneid;
+        face.i = i;
+
+        int i_donor = index2[ 0 ];
+
+        Face face_donor;
+        face_donor.zone = donor_zoneid;
+        face_donor.i = i_donor;
+
+        FacePair facePair;
+        facePair.AddPair( face, face_donor );
+
+        Global::facePairList.push_back( facePair );
+        int global_faceid = Global::InsertFacePairMap( facePair );
+        this->global_faceids.push_back( global_faceid );
+
+        this->global_local_face_map.insert( std::make_pair( global_faceid, faceid ) );
+
+        int i_ghost_cell = i + 1;
+        int i_local_donor_cell = i - 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+            i_local_donor_cell = i + 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+        ijk_donors.push_back( i_local_donor_cell );
+
+        icount ++;
+    }
+}
+
+void Global::InsertFaceMap( const Face & face )
+{
+    std::map<Face, int>::iterator iter;
+    iter = Global::faceMap.find( face );
+    if ( iter == Global::faceMap.end() )
+    {
+        int faceid = Global::faceMap.size();
+        Global::faceMap.insert( std::make_pair( face, faceid ) );
+    }
+}
+
+int Global::InsertFacePairMap( const FacePair & facePair )
+{
+    std::map<FacePair, int>::iterator iter;
+    iter = Global::facePairMap.find( facePair );
+    if ( iter == Global::facePairMap.end() )
+    {
+        int facePairId = Global::facePairMap.size();
+        Global::facePairMap.insert( std::make_pair( facePair, facePairId ) );
+        return facePairId;
+    }
+    return iter->second;
+}
+
+void Global::SendGeom( int zone, int donorzone, std::vector<int> & donorfaces )
+{
+    Interface * interface = Global::interfaces[ donorzone ];
+
+    std::vector<int> & send_to_zones = interface->send_to_zones;
+
+    send_to_zones.push_back( zone );
+    interface->donorfaces_for_send.push_back( donorfaces );
+
+    int nface = donorfaces.size();
+    std::vector<int> sub_donorijk;
+    int index_dim = 1;
+    for ( int i = 0; i < nface; ++ i )
+    {
+        int global_faceid = donorfaces[ i ];
+        int local_faceid = interface->global_local_face_map[ global_faceid ];
+        int ijkpos = index_dim * local_faceid;
+        int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+        sub_donorijk.push_back( i_donor_cell );
+        int kkk = 1;
+    }
+
+    interface->donorijk_for_send.push_back( sub_donorijk );
+
+    std::vector<double> sub_donordata( sub_donorijk.size() );
+    interface->donordata_for_send.push_back( sub_donordata );
+}
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/global.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/global.h
new file mode 100644
index 00000000..1600c81e
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/global.h
@@ -0,0 +1,139 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <unordered_map>
+#include <set>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class Face
+{
+public:
+    int zone = 0;
+    int i = 0;
+    int j = 1;
+    int k = 1;
+public:
+    bool operator < ( const Face & rhs ) const;
+    bool operator == ( const Face & rhs ) const;
+};
+
+class FacePair
+{
+public:
+    Face left;
+    Face right;
+public:
+    bool operator < ( const FacePair & rhs ) const;
+    void AddPair( const Face &face1, const Face &face2);
+};
+
+class Transform;
+
+
+class Interface
+{
+public:
+    int zoneid;
+    std::vector<int> zoneList;
+    std::vector<int> global_faceids;
+    std::vector<int> local_faceids;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+    std::vector<double> data_recv;
+    std::vector<double> data_send;
+    std::unordered_map<int, int> global_local_face_map;
+public:
+    std::vector<int> neighbor_donor_zones;
+    std::vector<std::vector<int>> neighbor_donorfaces;
+    std::vector<std::vector<int>> sub_local_faceids;
+    std::vector<int> send_to_zones;
+    std::vector<std::vector<int>> donorfaces_for_send;
+    std::vector<std::vector<int>> donorijk_for_send;
+    std::vector<std::vector<double>> donordata_for_send;
+public:
+    void CalcInterfaceOld( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+};
+
+class Field;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+public:
+    static std::map<Face, int> faceMap;
+    static std::map<FacePair, int> facePairMap;
+    static std::vector<FacePair> facePairList;
+    static std::vector<std::set<int>> donor_zone_sets;
+    static std::vector<std::vector<int>> donor_zones;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+public:
+    static void InsertFaceMap( const Face & face );
+    static int InsertFacePairMap( const FacePair & facePair );
+    static void SendGeom( int zone, int donorzone, std::vector<int> & donorfaces );
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/heat1d4blocksv1.cgns b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/heat1d4blocksv1.cgns
new file mode 100644
index 00000000..df5ffc5f
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/heat1d4blocksv1.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/main.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/main.cpp
new file mode 100644
index 00000000..df63b7da
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/main.cpp
@@ -0,0 +1,9 @@
+#include "Solver.h"
+#include "Parallel.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/plot.py b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02e/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/CMakeLists.txt
new file mode 100644
index 00000000..9e834b72
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/CMakeLists.txt
@@ -0,0 +1,99 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package ( MPI )
+
+message ( STATUS  "MPI_FOUND=${MPI_FOUND}" )
+message ( STATUS  "MPI_CXX_INCLUDE_DIRS=${MPI_CXX_INCLUDE_DIRS}" )
+message ( STATUS  "MPI_LIBRARIES=${MPI_LIBRARIES}" )
+if ( MPI_FOUND )
+	list ( APPEND PRJ_INCLUDE_DIRS ${MPI_CXX_INCLUDE_DIRS} )
+	list ( APPEND PRJ_LIBRARIES ${MPI_LIBRARIES} )
+endif ()
+
+#get_directory_property( my_import_targets DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} IMPORTED_TARGETS )
+#message( STATUS "my_import_targets=${my_import_targets}" )
+
+list ( APPEND PRJ_LIBRARIES MPI::MPI_C )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+list ( APPEND PRJ_COMPILE_DEFINITIONS HX_PARALLEL )
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	LogFile.h LogFile.cpp
+	Parallel.h Parallel.cpp
+	Solver.h Solver.cpp
+	ZoneState.h ZoneState.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/CgnsGrid.cpp
new file mode 100644
index 00000000..4af275c7
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/CgnsGrid.cpp
@@ -0,0 +1,855 @@
+#include "CgnsGrid.h"
+#include "Parallel.h"
+#include "cgnslib.h"
+#include "global.h"
+#include "ZoneState.h"
+#include <iostream>
+#include <vector>
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "fileId = " << fileId << "\n";
+    }
+    
+    int nbases = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_nbases( fileId, &nbases );
+    }
+    HXBcastData( &nbases, 1, Parallel::serverid );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "nbases = " << nbases << "\n";
+    
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        }
+
+        HXBcastData( &icelldim, 1, Parallel::serverid );
+        HXBcastData( &iphysdim, 1, Parallel::serverid );
+
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+
+        int nzones = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_nzones( fileId, baseId, &nzones );
+        }
+
+        HXBcastData( &nzones, 1, Parallel::serverid );
+
+        ZoneState::nZones = nzones;
+        ZoneState::pids.resize( nzones );
+
+        if ( Parallel::nProc == 1 )
+        {
+            for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+            {
+                ZoneState::pids[ iZone ] = 0;
+            }
+        }
+        else
+        {
+            for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+            {
+                ZoneState::pids[ iZone ] = iZone;
+            }
+        }
+
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nzones = " << nzones << "\n";
+
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "iZone = " << iZone << "\n";
+
+            int index_dim = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            }
+            HXBcastData( &index_dim, 1, Parallel::serverid );
+
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            if ( Parallel::IsServer() )
+            {
+                cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            }
+
+            HXBcastData( zonename, 33, Parallel::serverid );
+            HXBcastData( isize.data(), isize.size(), Parallel::serverid);
+
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "zonename = " << zonename << "\n";
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+
+    if ( Parallel::IsServer() )
+    {
+        cg_close( fileId );
+    }
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+        std::cout << "fileId = " << fileId << "\n";
+    }
+    
+    int nbases = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_nbases( fileId, &nbases );
+    }
+    MPI_Bcast( &nbases, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        }
+
+        HXBcastData( &icelldim, 1, Parallel::serverid );
+        HXBcastData( &iphysdim, 1, Parallel::serverid );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+
+        int nzones = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_nzones( fileId, baseId, &nzones );
+        }
+        HXBcastData( &nzones, 1, Parallel::serverid );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nzones = " << nzones << "\n";
+
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            }
+            HXSendRecvData<int>( &index_dim, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "index_dim = " << index_dim << "\n";
+            }
+
+            std::vector<cgsize_t> isize;
+            char zonename[ 33 ];
+            if ( Parallel::IsServer() )
+            {
+                isize.resize( index_dim * 3 );
+                cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            }
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                isize.resize( index_dim * 3 );
+            }
+
+            HXSendRecvData( zonename, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+            HXSendRecvData( isize.data(), index_dim * 3, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "zonename = " << zonename << "\n";
+
+                for ( int i = 0; i < isize.size(); ++ i )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+                }
+            }
+
+            std::vector<cgsize_t> irmin;
+            std::vector<cgsize_t> irmax;
+            int nNodes = 1;
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                irmin.resize( index_dim );
+                irmax.resize( index_dim );
+                for ( int m = 0; m < index_dim; ++ m )
+                {
+                    /* lower range index */
+                    irmin[ m ] = 1;
+                    /* upper range index of vertices */
+                    irmax[ m ] = isize[ m ];
+                    nNodes *= irmax[ m ];
+                }
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "nNodes = " << nNodes << "\n";
+            }
+
+            ZoneType_t zoneType;
+            if ( Parallel::IsServer() )
+            {
+                cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            }
+            HXSendRecvData( &zoneType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            }
+
+            Zone * zone = nullptr;
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                zone = new Zone();
+                Global::zones.push_back( zone );
+                LocalZone::global_zoneids.push_back( iZone );
+                LocalZone::nZones = LocalZone::global_zoneids.size();
+                for ( int m = 0; m < index_dim; ++ m )
+                {
+                    zone->nijk.push_back( isize[ m ] );
+                }
+            }
+
+            Grid * grid = nullptr;
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                grid = new Grid();
+                Global::grids.push_back( grid );
+            }
+
+            BaseZone baseZone;
+
+            int gZoneId = -1;
+            if ( Parallel::IsServer() )
+            {
+                baseZone.zone_name = zonename;
+                gZoneId = Global::zone_names.FindBaseZone( baseZone );
+            }
+
+            HXSendRecvData( &gZoneId, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "gZoneId = " << gZoneId << "\n";
+            }
+
+            int ncoords = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            }
+            HXSendRecvData( &ncoords, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "ncoords = " << ncoords << "\n";
+            }
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                if ( Parallel::IsServer() )
+                {
+                    cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                }
+                HXSendRecvData( coordname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &dataType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "coordname = " << coordname << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                }
+
+                std::vector<char> coord;
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    coord.resize( nNodes * sizeof( double ) );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coord.data() );
+                }
+
+                HXSendRecvData( coord.data(), coord.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                Coor * coor = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    coor = new Coor();
+                    zone->coors.push_back( coor );
+                    coor->coorname = coordname;
+                    coor->nNodes = nNodes;
+                    coor->coord = coord;
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    coor->DumpCoor();
+
+                    if ( icoord == 0 )
+                    {
+                        grid->x.resize( nNodes );
+                        coor->DumpCoorX( grid->x );
+                    }
+                }
+            }
+
+            int nbocos = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            }
+            HXSendRecvData( &nbocos, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "nbocos = " << nbocos << "\n";
+            }
+
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                if ( Parallel::IsServer() )
+                {
+                    cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                }
+                HXSendRecvData( &location, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+                }
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                //std::vector<int> normalIndex( index_dim, -1 );
+                std::vector<int> normalIndex;
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+                if ( Parallel::IsServer() )
+                {
+                    normalIndex.resize( index_dim );
+                    cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                        &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                }
+
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    normalIndex.resize( index_dim );
+                }
+                
+                HXSendRecvData( boconame, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &bocotype, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &ptset_type, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &npnts, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &normalDataType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &normalListSize, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( normalIndex.data(), index_dim, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &ndataset, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "npnts = " << npnts << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalListSize = " << normalListSize << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalIndex = ";
+                    for ( int i = 0; i < index_dim; ++ i )
+                    {
+                        std::cout << normalIndex[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "ndataset = " << ndataset << "\n";
+                }
+
+                std::vector<char> normalList;
+                std::vector<cgsize_t> pnts;
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    if ( normalDataType == DataTypeNull )
+                    {
+                        normalList.resize( sizeof( int ) );
+                    }
+                    else
+                    {
+                        int nSize = nNodes * index_dim * sizeof( double );
+                        normalList.resize( nSize );
+                    }
+                    pnts.resize( npnts * index_dim );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                }
+
+                HXSendRecvData( pnts.data(), npnts * index_dim, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "pnts = ";
+                    for ( int i = 0; i < pnts.size(); ++ i )
+                    {
+                        std::cout << pnts[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                }
+                HXSendRecvData( normalList.data(), normalList.size(), Parallel::serverid, ZoneState::GetProcID(iZone));
+
+                ZoneBc * zonebc = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    zonebc = new ZoneBc();
+                    zone->bccos.push_back( zonebc );
+                    zonebc->bcType = bocotype;
+                    for ( int i = 0; i < pnts.size(); ++ i )
+                    {
+                        zonebc->pnts.push_back( pnts[ i ] );
+                    }
+                }
+            }
+            int n1to1 = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            }
+
+            HXSendRecvData( &n1to1, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "n1to1 = " << n1to1 << "\n";
+            }
+
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range;
+                std::vector<cgsize_t> donor_range;
+                std::vector<int> transform;
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    range.resize( npnts * index_dim );
+                    donor_range.resize( npnts * index_dim );
+                    transform.resize( index_dim );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                }
+
+                HXSendRecvData( connectname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( donorname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( range.data(), range.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( donor_range.data(), donor_range.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( transform.data(), transform.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "connectname = " << connectname << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "donorname = " << donorname << "\n";
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "range = ";
+                    for ( int i = 0; i < range.size(); ++ i )
+                    {
+                        std::cout << range[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "donor_range = ";
+                    for ( int i = 0; i < donor_range.size(); ++ i )
+                    {
+                        std::cout << donor_range[ i ] << " ";
+                    }
+                    std::cout << "\n";
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "transform = ";
+                    for ( int i = 0; i < transform.size(); ++ i )
+                    {
+                        std::cout << transform[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                }
+
+                int gDonorZoneId = -1;
+                if ( Parallel::IsServer() )
+                {
+                    BaseZone baseZoneDonor;
+                    baseZoneDonor.zone_name = donorname;
+
+                    gDonorZoneId = Global::zone_names.FindBaseZone( baseZoneDonor );
+                }
+
+                HXSendRecvData( &gDonorZoneId, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                ZoneBc1To1 * zonebc_1to1 = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    zonebc_1to1 = new ZoneBc1To1();
+                    zone->bc1to1s.push_back( zonebc_1to1 );
+                    zonebc_1to1->zoneid = gZoneId;
+                    zonebc_1to1->transform = transform;
+                    zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                    for ( int i = 0; i < range.size(); ++ i )
+                    {
+                        zonebc_1to1->pnts.push_back( range[ i ] );
+                        zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                    }
+                }
+            }
+        }
+    }
+
+    {
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "Global::zones.size() = " << Global::zones.size() << "\n";
+    }
+
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/CgnsGrid.h
new file mode 100644
index 00000000..fddf1db6
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/CgnsGrid.h
@@ -0,0 +1,103 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    int zoneIndex;
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/Field.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/Field.cpp
new file mode 100644
index 00000000..c359a811
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/Field.cpp
@@ -0,0 +1,142 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+
+    std::vector<double> & x = grid->x;
+    this->dx = std::abs( x[ 1 ] - x[ 0 ] );
+    this->dt = dx / 10.0;
+    this->t = 1.0;
+    this->nt = std::round( t / dt );
+
+    double total_time = nt * dt;
+
+    std::cout << "this->dt   = " << this->dt << "\n";
+    std::cout << "this->t    = " << this->t << "\n";
+    std::cout << "this->nt   = " << this->nt << "\n";
+    std::cout << "this->ni   = " << this->ni << "\n";
+    std::cout << "total_time = " << total_time << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        u_e[ i ] = - std::exp( -total_time ) * std::sin( std::numbers::pi * xm ); //theory solution
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+    int kkk = 1;
+}
+
+void Field::Solve( Zone * zone )
+{
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+    }
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        //std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        //region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+        int kkk = 1;
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
+
+void Field::UpdateOldField()
+{
+    for ( int i = 0; i < this->u.size(); ++ i )
+    {
+        this->un[ i ] = this->u[ i ];
+    }
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/Field.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/Field.h
new file mode 100644
index 00000000..084ec9bd
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/Field.h
@@ -0,0 +1,36 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid );
+
+    void Solve( Zone * zone );
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void UpdateOldField();
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/LogFile.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/LogFile.cpp
new file mode 100644
index 00000000..08ccd453
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/LogFile.cpp
@@ -0,0 +1,138 @@
+#include "LogFile.h"
+#include "Parallel.h"
+#include <sstream>
+#include <iostream>
+
+#ifdef _WINDOWS
+#include <windows.h>
+#include <direct.h>
+#include <io.h>
+#else
+#include <sys/stat.h>
+#include <unistd.h>
+#endif
+
+LogFile logFile;
+
+class OStream : public std::ostringstream
+{
+public:
+    OStream() {}
+    ~OStream() {}
+public:
+    void ClearAll()
+    {
+        this->clear();
+        this->str("");
+    }
+};
+
+OStream StrIO;
+std::string GetPrjDirName( const std::string & fileName );
+bool DirExist( const std::string & dirName );
+void MakeDir( const std::string & dirName );
+
+std::string GetPrjDirName( const std::string & fileName )
+{
+    size_t pos = fileName.find_last_of("\\/");
+    if ( std::string::npos == pos )
+    {
+        return "";
+    }
+    else
+    {
+        return fileName.substr( 0, pos );
+    }
+}
+
+bool DirExist( const std::string & dirName )
+{
+#ifdef _WINDOWS
+    bool flag = ( _access( dirName.c_str(), 0 ) == 0 );
+    return flag;
+#else
+    bool flag = ( access( dirName.c_str(), 0 ) == 0 );
+    return flag;
+#endif
+}
+
+void MakeDir( const std::string & dirName )
+{
+    int flag;
+#ifdef _WINDOWS
+    flag = _mkdir( dirName.c_str() );
+#else
+    flag = mkdir( dirName.c_str(), S_IRWXU );
+#endif
+    if ( flag == 0 )
+    {
+        std::cout << dirName << " directory has been created successfully !\n";
+    }
+}
+
+void CreateDirIfNeeded( std::string & prjFileName )
+{
+    std::string prj_dir = GetPrjDirName( prjFileName );
+
+    if ( ! DirExist( prj_dir ) )
+    {
+        MakeDir( prj_dir );
+    }
+}
+
+
+void OpenLogFile( int logFileIndex, std::fstream & file )
+{
+    static int ifReWrite = 0;
+
+    StrIO.ClearAll();
+    StrIO << "log/log" << logFileIndex << ".log";
+    std::string fileName = StrIO.str();
+
+    std::ios_base::openmode openMode;
+
+    if ( ifReWrite == 0 )
+    {
+        CreateDirIfNeeded( fileName );
+
+        openMode = std::ios_base::out | std::ios_base::trunc;
+
+        ifReWrite = 1;
+    }
+    else
+    {
+        openMode = std::ios_base::out | std::ios_base::app;
+    }
+
+    file.open( fileName.c_str(), openMode );
+    if ( ! file )
+    {
+        std::cout << "could not open " << fileName << std::endl;
+        exit( 0 );
+    }
+}
+
+void CloseLogFile( std::fstream & file )
+{
+    file.close();
+    file.clear();
+}
+
+LogFile::LogFile()
+{
+}
+
+LogFile::~LogFile()
+{
+}
+
+void LogFile::Open()
+{
+    int pid = Parallel::pid;
+    OpenLogFile( pid, this->my_fstream );
+}
+
+void LogFile::Close()
+{
+    CloseLogFile( this->my_fstream );
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/LogFile.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/LogFile.h
new file mode 100644
index 00000000..00e775ab
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/LogFile.h
@@ -0,0 +1,27 @@
+#pragma once
+#include <fstream>
+
+void OpenLogFile( int logFileIndex, std::fstream & file );
+void CloseLogFile( std::fstream & file );
+class LogFile;
+extern LogFile logFile;
+
+class LogFile
+{
+public:
+    LogFile();
+    ~LogFile();
+    std::fstream my_fstream;
+public:
+    void Open();
+    void Close();
+};
+
+template< typename T >
+LogFile & operator << ( LogFile & f, const T & value )
+{
+    f.Open();
+    f.my_fstream << value;
+    f.Close();
+    return f;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/Parallel.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/Parallel.cpp
new file mode 100644
index 00000000..0bce1a60
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/Parallel.cpp
@@ -0,0 +1,54 @@
+#include "Parallel.h"
+#include <iostream>
+
+int Parallel::pid = 0;
+int Parallel::nProc = 1;
+int Parallel::serverid = 0;
+int Parallel::tag = 0;
+
+void Parallel::Init()
+{
+#ifdef HX_PARALLEL
+    int argc     = 0;
+    char ** argv = 0;
+    MPI_Init( &argc, &argv );
+    MPI_Comm_rank( MPI_COMM_WORLD, &Parallel::pid );
+    MPI_Comm_size( MPI_COMM_WORLD, &Parallel::nProc );
+    int len = -1;
+    char version[ MPI_MAX_LIBRARY_VERSION_STRING ];
+    MPI_Get_library_version( version, &len );
+    std::cout << "Hello, world!  I am " << Parallel::pid << " of " << Parallel::nProc
+        << "(" << version << ", " << len << ")" << std::endl;
+#endif
+}
+
+void Parallel::Finalize()
+{
+#ifdef HX_PARALLEL
+    MPI_Finalize();
+#endif
+}
+
+bool Parallel::IsServer()
+{
+    return Parallel::pid == Parallel::serverid;
+}
+
+void HXSendChar( void * data, int size, int pid, int tag )
+{
+#ifdef HX_PARALLEL
+    if ( size <= 0 ) return;
+    MPI_Send( data, size, MPI_CHAR, pid, tag, MPI_COMM_WORLD );
+#endif
+}
+
+void HXRecvChar( void * data, int size, int pid, int tag )
+{
+#ifdef HX_PARALLEL
+    if ( size <= 0 ) return;
+
+    MPI_Status status;
+    MPI_Recv( data, size, MPI_CHAR, pid, tag, MPI_COMM_WORLD, & status );
+#endif
+}
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/Parallel.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/Parallel.h
new file mode 100644
index 00000000..2a9267d8
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/Parallel.h
@@ -0,0 +1,58 @@
+#pragma once
+#ifdef HX_PARALLEL
+#include "mpi.h"
+#endif
+#include <vector>
+#include "LogFile.h"
+
+class Parallel
+{
+public:
+    static int pid;
+    static int nProc;
+    static int serverid;
+    static int tag;
+public:
+    static void Init();
+    static void Finalize();
+public:
+    static bool IsServer();
+};
+
+void HXSendChar( void * data, int size, int pid, int tag );
+void HXRecvChar( void * data, int size, int pid, int tag );
+
+template< typename T >
+void HXSendRecvData( T * field, int nElement, int send_pid, int recv_pid, int tag = 0 )
+{
+    //logFile << " send_pid = " << send_pid << "\n";
+    //logFile << " recv_pid = " << recv_pid << "\n";
+    //logFile << " Parallel::pid = " << Parallel::pid << "\n";
+
+    if ( send_pid == recv_pid ) return;
+
+    if ( nElement <= 0 ) return;
+
+    int buffer_size = nElement * sizeof( T );
+
+    //logFile << "nElement = " << nElement << " buffer_size = " << buffer_size << "\n";
+
+    if ( Parallel::pid == send_pid )
+    {
+        HXSendChar( field, buffer_size, recv_pid, tag );
+    }
+    else if ( Parallel::pid == recv_pid )
+    {
+        HXRecvChar( field, buffer_size, send_pid, tag );
+    }
+}
+
+template< typename T >
+void HXBcastData( T * field, int nElement, int send_pid )
+{
+    if ( nElement <= 0 ) return;
+    int buffer_size = nElement * sizeof( T );
+#ifdef HX_PARALLEL
+    MPI_Bcast( field, buffer_size, MPI_CHAR, send_pid, MPI_COMM_WORLD );
+#endif
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/README.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/Solver.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/Solver.cpp
new file mode 100644
index 00000000..daa75a5e
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/Solver.cpp
@@ -0,0 +1,573 @@
+#include "Solver.h"
+#include "Parallel.h"
+#include "ZoneState.h"
+#include "global.h"
+#include <fstream>
+#include <set>
+#include <unordered_map>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+Solver::Solver()
+{
+    Parallel::Init();
+}
+
+Solver::~Solver()
+{
+    Parallel::Finalize();
+}
+
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    this->InitTopo();
+    this->InitFields();
+    ////if ( Parallel::pid == Parallel::serverid )
+    ////{
+        this->SolveMultiZones();
+        this->PostProcess();
+    ////}
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d4blocksv1.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    ReadCgnsGrid( fileName );
+}
+
+void Solver::InitTopo()
+{
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "Solver::InitTopo() " << "\n";
+
+    Global::donor_zone_sets.resize( LocalZone::nZones );
+    Global::donor_zones.resize( LocalZone::nZones );
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        int global_zoneid = LocalZone::global_zoneids[ iZone ];
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "iZone = " << iZone << " global_zoneid = " << global_zoneid << "\n";
+
+        Interface * interface = new Interface();
+        interface->zoneid = iZone;
+        Global::interfaces.push_back( interface );
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+
+        int nbc1to1s = zone->bc1to1s.size();
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout <<  "nbc1to1s = " << nbc1to1s << "\n";
+
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "zoneid = " << zoneid << " donor_zoneid = " << donor_zoneid << "\n";
+
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+        int nInterfaces = interface->zoneList.size();
+        interface->data_recv.resize( nInterfaces );
+        interface->data_send.resize( nInterfaces );
+    }
+
+    for ( int iProc = 0; iProc < Parallel::nProc; ++ iProc )
+    {
+        int nSize = -1;
+        if ( iProc == Parallel::pid )
+        {
+            nSize = Global::facePairList.size();
+        }
+        HXBcastData( &nSize, 1, iProc );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nSize = " << nSize << "\n";
+        std::vector<FacePair> tmp;
+        if ( iProc == Parallel::pid )
+        {
+            tmp = Global::facePairList;
+        }
+        else
+        {
+            tmp.resize( nSize );
+        }
+
+        HXBcastData( tmp.data(), tmp.size(), iProc );
+        Global::AddFacePairList( Global::mpi_facePairList, tmp );
+    }
+
+    for ( int i = 0; i < Global::mpi_facePairList.size(); ++ i )
+    {
+        FacePair &facePair = Global::mpi_facePairList[ i ];
+        Global::InsertFacePairMap( facePair );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        facePair.Print();
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterfaces = interface->local_faceids.size();
+        for ( int iInterface = 0; iInterface < nInterfaces; ++ iInterface )
+        {
+            int local_faceid = interface->local_faceids[ iInterface ];
+            int proc_global_faceid = interface->proc_global_faceids[ iInterface ];
+            FacePair & facePair = Global::facePairList[ proc_global_faceid ];
+            int global_faceid = Global::InsertFacePairMap( facePair );
+            interface->global_faceids.push_back( global_faceid );
+            interface->global_local_face_map.insert( std::make_pair( global_faceid, local_faceid ) );
+        }
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        std::set<int> &donor_zoneSet = Global::donor_zone_sets[ iZone ];
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            donor_zoneSet.insert( donor_zoneid );
+        }
+
+        std::vector<int> &donor_zones = Global::donor_zones[ iZone ];
+        for ( std::set<int>::iterator iter = donor_zoneSet.begin(); iter != donor_zoneSet.end(); ++ iter )
+        {
+            donor_zones.push_back( *iter );
+        }
+
+        interface->neighbor_donor_zones = donor_zones;
+
+        std::unordered_map<int, int> donor_zonelocal;
+
+        for ( int idonor = 0; idonor < donor_zones.size(); ++ idonor )
+        {
+            int donor_zone = donor_zones[ idonor ];
+            donor_zonelocal.insert( std::make_pair( donor_zone, idonor ) );
+        }
+        int ndonors = donor_zones.size();
+        std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+        neighbor_donorfaces.resize( ndonors );
+
+        std::vector<std::vector<int>> & sub_local_faceids = interface->sub_local_faceids;
+        sub_local_faceids.resize( ndonors );
+
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ineighbor = donor_zonelocal[ donor_zoneid ];
+            std::vector<int> &donorfaces = neighbor_donorfaces[ ineighbor ];
+            int global_faceid = interface->global_faceids[ iFace ];
+            donorfaces.push_back( global_faceid );
+            int local_faceid = interface->local_faceids[ iFace ];
+
+            std::vector<int> & sub_local_faces = sub_local_faceids[ ineighbor ];
+            sub_local_faces.push_back( local_faceid );
+        }
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> &neighbor_donor_zones = interface->neighbor_donor_zones;
+        int ndonor_zones = neighbor_donor_zones.size();
+
+        std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donorzone = neighbor_donor_zones[ iNei ];
+            std::vector<int> & neighbor_donorface = neighbor_donorfaces[ iNei ];
+
+            Interface * interface = Global::interfaces[ donorzone ];
+            interface->SendGeom( iZone, neighbor_donorface );
+
+            //Global::SendGeom( iZone, donorzone, neighbor_donorface );
+        }
+        int kkk = 1;
+    }
+    return;
+}
+
+void Solver::InitFields()
+{
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "Solver::InitFields() ZoneState::nZones = " << ZoneState::nZones <<  "\n";
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        if ( ! ZoneState::IsValid( iZone ) ) continue;
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        if ( ! ZoneState::IsValid( iZone ) ) continue;
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+    }
+
+    Boundary();
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        int nZones = Global::zones.size();
+        for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+        {
+            if ( ! ZoneState::IsValid( iZone ) ) continue;
+            Field * field = Global::fields[ iZone ];
+            Zone * zone = Global::zones[ iZone ];
+            zone->zoneIndex = iZone;
+            field->Solve( zone );
+        }
+        Boundary();
+    }
+}
+
+void Solver::Boundary()
+{
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        if ( ! ZoneState::IsValid( iZone ) ) continue;
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+    ExchangeInterfaceField();
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        if ( ! ZoneState::IsValid( iZone ) ) continue;
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->UpdateOldField();
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> & send_to_zones = interface->send_to_zones;
+        int nsend_zones = send_to_zones.size();
+
+        std::vector<std::vector<int>> & donorfaces_for_send = interface->donorfaces_for_send;
+        std::vector<std::vector<int>> & donorijk_for_send = interface->donorijk_for_send;
+        std::vector<std::vector<double>> & donordata_for_send = interface->donordata_for_send;
+
+        Field * field = Global::fields[ iZone ];
+
+        for ( int iSend = 0; iSend < nsend_zones; ++ iSend )
+        {
+            int zone_to_send = send_to_zones[ iSend ];
+            std::vector<int> & donorfaces = donorfaces_for_send[ iSend ];
+            std::vector<int> & donorijks = donorijk_for_send[ iSend ];
+            std::vector<double> & donordatas = donordata_for_send[ iSend ];
+
+            int nface = donorfaces.size();
+            int index_dim = 1;
+            for ( int i = 0; i < nface; ++ i )
+            {
+                int ijkpos = index_dim * i;
+                int i_donor_cell = donorijks[ ijkpos + 0 ];
+                donordatas[ i ] = field->u[ i_donor_cell ];
+            }
+        }
+    }
+    int kkk = 1;
+
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+
+        std::vector<int> & neighbor_donor_zones = interface->neighbor_donor_zones;
+        int ndonor_zones = neighbor_donor_zones.size();
+
+        //std::vector<std::vector<double>> & recv_donor_fields = interface->recv_donor_fields;
+
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donorzone = neighbor_donor_zones[ iNei ];
+            Interface * donor_interface = Global::interfaces[ donorzone ];
+            int nSize = donor_interface->send_to_zones.size();
+            int ipos = -1;
+            for ( int i = 0; i < nSize; ++ i )
+            {
+                int szone = donor_interface->send_to_zones[ i ];
+                if ( szone == iZone )
+                {
+                    ipos = i;
+                    break;
+                }
+            }
+            std::vector<double> & donordata = donor_interface->donordata_for_send[ ipos ];
+
+            std::vector<int> & neighbor_donorfaces = interface->neighbor_donorfaces[ iNei ];
+            std::vector<int> & sub_local_faceids = interface->sub_local_faceids[ iNei ];
+            for ( int i = 0; i < neighbor_donorfaces.size(); ++ i )
+            {
+                int local_faceid = sub_local_faceids[ i ];
+                double donor_value = donordata[ i ];
+                interface->data_recv[ local_faceid ] = donor_value;
+            }
+        }
+
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+
+            double donor_value = interface->data_recv[ iFace ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::PostProcess()
+{
+    Post post;
+    post.Process();
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    int nZones = Global::grids.size();
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        int ni = grid->x.size();
+        double xmin = grid->x[ 0 ];
+        double xmax = grid->x[ 0 ];
+        int imin = 0;
+        int imax = 0;
+        for ( int i = 0; i < ni; ++ i )
+        {
+            if ( xmin > grid->x[ i ] )
+            {
+                xmin = grid->x[ i ];
+                imin = i;
+            }
+            if ( xmax < grid->x[ i ] )
+            {
+                xmax = grid->x[ i ];
+                imax = i;
+            }
+        }
+        xmin_list.push_back( xmin );
+        xmax_list.push_back( xmax );
+    }
+    std::vector<std::pair<double, int>> pairs;
+    int nSize = xmin_list.size();
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        pairs.push_back( std::make_pair( xmin_list[i], i ) );
+    }
+
+    std::sort( pairs.begin(), pairs.end() );
+
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        this->zoneids.push_back( pairs[i].second );
+    }
+
+    int kkk = 1;
+}
+
+void Post::GatherField()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+        Grid * grid = Global::grids[ zoneid ];
+        Field * field = Global::fields[ zoneid ];
+
+        int ni = grid->x.size();
+
+        int ist = 1;
+        int ied = ni;
+
+        int dir = 1;
+        if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+        if ( dir == 1 )
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ist; i <= ied; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+
+            }
+            else
+            {
+                for ( int i = ist; i <= ied - 1; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+        else
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ied; i >= ist; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+            else
+            {
+                for ( int i = ied; i >= ist + 1; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+    }
+}
+
+void Post::DumpField()
+{
+    int ni_total = this->x.size();
+    std::cout << " DumpField x.size() = " << x.size() << "\n";
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    this->DumpErrorDetails( u_error );
+
+    std::string csvname = "field_final.csv";
+    this->DumpCsvFile( csvname, x, u_e, un, u_error );
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.20f} {:.20f} {:.20f} {:.20f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/Solver.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/Solver.h
new file mode 100644
index 00000000..d01d3d9c
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/Solver.h
@@ -0,0 +1,44 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+
+class Solver
+{
+public:
+    Solver();
+    ~Solver();
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveMultiZones();
+public:
+    void Boundary();
+    void ExchangeInterfaceField();
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcess();
+};
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+    std::vector<double> u;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/ZoneState.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/ZoneState.cpp
new file mode 100644
index 00000000..bdafab8c
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/ZoneState.cpp
@@ -0,0 +1,19 @@
+#include "ZoneState.h"
+#include "Parallel.h"
+
+int ZoneState::nZones = 0;
+std::vector<int> ZoneState::pids;
+
+bool ZoneState::IsValid( int zoneid )
+{
+    return ZoneState::pids[ zoneid ] == Parallel::pid;
+}
+
+int ZoneState::GetProcID( int zoneid )
+{
+    return ZoneState::pids[ zoneid ];
+}
+
+int LocalZone::nZones = 0;
+std::vector<int> LocalZone::global_zoneids;
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/ZoneState.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/ZoneState.h
new file mode 100644
index 00000000..35f9a1e8
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/ZoneState.h
@@ -0,0 +1,20 @@
+#pragma once
+#include <vector>
+
+class ZoneState
+{
+public:
+    static int nZones;
+    static int zone_id;
+    static std::vector<int> pids;
+public:
+    static bool IsValid( int zoneid );
+    static int GetProcID( int zoneid );
+};
+
+class LocalZone
+{
+public:
+    static int nZones;
+    static std::vector<int> global_zoneids;
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/global.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/global.cpp
new file mode 100644
index 00000000..991f0df0
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/global.cpp
@@ -0,0 +1,291 @@
+#include "global.h"
+#include "CgnsGrid.h"
+#include <iostream>
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *> Global::interfaces;
+
+std::map<Face, int> Global::faceMap;
+std::map<FacePair, int> Global::facePairMap;
+std::vector<FacePair> Global::facePairList;
+std::vector<FacePair> Global::mpi_facePairList;
+
+std::vector<std::set<int>> Global::donor_zone_sets;
+std::vector<std::vector<int>> Global::donor_zones;
+
+bool Face::operator < ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return this->zone < rhs.zone;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return this->i < rhs.i;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return this->j < rhs.j;
+    }
+
+    return this->k < rhs.k;
+}
+
+bool Face::operator == ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return false;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return false;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return false;
+    }
+
+    return this->k == rhs.k;
+}
+
+void Face::Print()
+{
+    std::cout << "(" << this->zone << "," << this->i << ")";
+}
+
+void FacePair::AddPair( const Face & face1, const Face & face2 )
+{
+    if ( face1 < face2 )
+    {
+        this->left = face1;
+        this->right = face2;
+    }
+    else
+    {
+        this->left = face2;
+        this->right = face1;
+    }
+}
+
+bool FacePair::operator < ( const FacePair & rhs ) const
+{
+    if ( this->left == rhs.left || this->left == rhs.right )
+    {
+        return false;
+    }
+
+    return this->left < rhs.left;
+}
+
+void FacePair::Print()
+{
+    this->left.Print();
+    std::cout << " ";
+    this->right.Print();
+    std::cout << "\n";
+}
+
+void Interface::CalcInterfaceOld( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->local_faceids.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        Face face;
+        face.zone = zoneid;
+        face.i = i;
+
+        Global::InsertFaceMap( face );
+
+        int i_donor = index2[ 0 ];
+
+        Face face_donor;
+        face_donor.zone = donor_zoneid;
+        face_donor.i = i_donor;
+
+        Global::InsertFaceMap( face_donor );
+
+        FacePair facePair;
+        facePair.AddPair( face, face_donor );
+
+        Global::facePairList.push_back( facePair );
+        int global_faceid = Global::InsertFacePairMap( facePair );
+        this->global_faceids.push_back( global_faceid );
+
+        this->global_local_face_map.insert( std::make_pair( global_faceid, faceid ) );
+
+        int i_ghost_cell = i + 1;
+        int i_local_donor_cell = i - 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+            i_local_donor_cell = i + 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+        ijk_donors.push_back( i_local_donor_cell );
+
+        icount ++;
+    }
+}
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->local_faceids.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        Face face;
+        face.zone = zoneid;
+        face.i = i;
+
+        int i_donor = index2[ 0 ];
+
+        Face face_donor;
+        face_donor.zone = donor_zoneid;
+        face_donor.i = i_donor;
+
+        FacePair facePair;
+        facePair.AddPair( face, face_donor );
+
+        Global::facePairList.push_back( facePair );
+        int nSize = Global::facePairList.size();
+        this->proc_global_faceids.push_back( nSize - 1 );
+
+        int i_ghost_cell = i + 1;
+        int i_local_donor_cell = i - 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+            i_local_donor_cell = i + 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+        ijk_donors.push_back( i_local_donor_cell );
+
+        icount ++;
+    }
+}
+
+void Interface::SendGeom( int zone, std::vector<int> & donorfaces )
+{
+    //Interface * interface = Global::interfaces[ donorzone ];
+    Interface * interface = this;
+
+    std::vector<int> & send_to_zones = interface->send_to_zones;
+
+    send_to_zones.push_back( zone );
+    interface->donorfaces_for_send.push_back( donorfaces );
+
+    int nface = donorfaces.size();
+    std::vector<int> sub_donorijk;
+    int index_dim = 1;
+    for ( int i = 0; i < nface; ++ i )
+    {
+        int global_faceid = donorfaces[ i ];
+        int local_faceid = interface->global_local_face_map[ global_faceid ];
+        int ijkpos = index_dim * local_faceid;
+        int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+        sub_donorijk.push_back( i_donor_cell );
+        int kkk = 1;
+    }
+
+    interface->donorijk_for_send.push_back( sub_donorijk );
+
+    std::vector<double> sub_donordata( sub_donorijk.size() );
+    interface->donordata_for_send.push_back( sub_donordata );
+}
+
+void Global::InsertFaceMap( const Face & face )
+{
+    std::map<Face, int>::iterator iter;
+    iter = Global::faceMap.find( face );
+    if ( iter == Global::faceMap.end() )
+    {
+        int faceid = Global::faceMap.size();
+        Global::faceMap.insert( std::make_pair( face, faceid ) );
+    }
+}
+
+int Global::InsertFacePairMap( const FacePair & facePair )
+{
+    std::map<FacePair, int>::iterator iter;
+    iter = Global::facePairMap.find( facePair );
+    if ( iter == Global::facePairMap.end() )
+    {
+        int facePairId = Global::facePairMap.size();
+        Global::facePairMap.insert( std::make_pair( facePair, facePairId ) );
+        return facePairId;
+    }
+    return iter->second;
+}
+
+void Global::SendGeom( int zone, int donorzone, std::vector<int> & donorfaces )
+{
+    Interface * interface = Global::interfaces[ donorzone ];
+
+    std::vector<int> & send_to_zones = interface->send_to_zones;
+
+    send_to_zones.push_back( zone );
+    interface->donorfaces_for_send.push_back( donorfaces );
+
+    int nface = donorfaces.size();
+    std::vector<int> sub_donorijk;
+    int index_dim = 1;
+    for ( int i = 0; i < nface; ++ i )
+    {
+        int global_faceid = donorfaces[ i ];
+        int local_faceid = interface->global_local_face_map[ global_faceid ];
+        int ijkpos = index_dim * local_faceid;
+        int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+        sub_donorijk.push_back( i_donor_cell );
+        int kkk = 1;
+    }
+
+    interface->donorijk_for_send.push_back( sub_donorijk );
+
+    std::vector<double> sub_donordata( sub_donorijk.size() );
+    interface->donordata_for_send.push_back( sub_donordata );
+}
+
+void Global::AddFacePairList( std::vector<FacePair> & a, std::vector<FacePair> & b )
+{
+    for ( int i = 0; i < b.size(); ++ i )
+    {
+        a.push_back( b[ i ] );
+    }
+}
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/global.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/global.h
new file mode 100644
index 00000000..fa3f5c92
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/global.h
@@ -0,0 +1,148 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <unordered_map>
+#include <set>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class Face
+{
+public:
+    int zone = 0;
+    int i = 0;
+    int j = 1;
+    int k = 1;
+public:
+    bool operator < ( const Face & rhs ) const;
+    bool operator == ( const Face & rhs ) const;
+public:
+    void Print();
+};
+
+class FacePair
+{
+public:
+    Face left;
+    Face right;
+public:
+    bool operator < ( const FacePair & rhs ) const;
+    void AddPair( const Face &face1, const Face &face2);
+public:
+    void Print();
+};
+
+class Transform;
+
+
+class Interface
+{
+public:
+    int zoneid;
+    std::vector<int> zoneList;
+    std::vector<int> global_faceids;
+    std::vector<int> mpi_global_faceids;
+    std::vector<int> proc_global_faceids;
+    std::vector<int> local_faceids;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+    std::vector<double> data_recv;
+    std::vector<double> data_send;
+    std::unordered_map<int, int> global_local_face_map;
+public:
+    std::vector<int> neighbor_donor_zones;
+    std::vector<std::vector<int>> neighbor_donorfaces;
+    std::vector<std::vector<int>> sub_local_faceids;
+    std::vector<int> send_to_zones;
+    std::vector<std::vector<int>> donorfaces_for_send;
+    std::vector<std::vector<int>> donorijk_for_send;
+    std::vector<std::vector<double>> donordata_for_send;
+public:
+    void CalcInterfaceOld( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+    void SendGeom( int zone, std::vector<int> & donorfaces );
+};
+
+class Field;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+public:
+    static std::map<Face, int> faceMap;
+    static std::map<FacePair, int> facePairMap;
+    static std::vector<FacePair> facePairList;
+    static std::vector<FacePair> mpi_facePairList;
+    static std::vector<std::set<int>> donor_zone_sets;
+    static std::vector<std::vector<int>> donor_zones;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+public:
+    static void InsertFaceMap( const Face & face );
+    static int InsertFacePairMap( const FacePair & facePair );
+    static void SendGeom( int zone, int donorzone, std::vector<int> & donorfaces );
+    static void AddFacePairList( std::vector<FacePair> & a, std::vector<FacePair> & b );
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/heat1d4blocksv1.cgns b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/heat1d4blocksv1.cgns
new file mode 100644
index 00000000..df5ffc5f
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/heat1d4blocksv1.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/main.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/main.cpp
new file mode 100644
index 00000000..df63b7da
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/main.cpp
@@ -0,0 +1,9 @@
+#include "Solver.h"
+#include "Parallel.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/plot.py b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02f/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/CMakeLists.txt
new file mode 100644
index 00000000..9e834b72
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/CMakeLists.txt
@@ -0,0 +1,99 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package ( MPI )
+
+message ( STATUS  "MPI_FOUND=${MPI_FOUND}" )
+message ( STATUS  "MPI_CXX_INCLUDE_DIRS=${MPI_CXX_INCLUDE_DIRS}" )
+message ( STATUS  "MPI_LIBRARIES=${MPI_LIBRARIES}" )
+if ( MPI_FOUND )
+	list ( APPEND PRJ_INCLUDE_DIRS ${MPI_CXX_INCLUDE_DIRS} )
+	list ( APPEND PRJ_LIBRARIES ${MPI_LIBRARIES} )
+endif ()
+
+#get_directory_property( my_import_targets DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} IMPORTED_TARGETS )
+#message( STATUS "my_import_targets=${my_import_targets}" )
+
+list ( APPEND PRJ_LIBRARIES MPI::MPI_C )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+list ( APPEND PRJ_COMPILE_DEFINITIONS HX_PARALLEL )
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	LogFile.h LogFile.cpp
+	Parallel.h Parallel.cpp
+	Solver.h Solver.cpp
+	ZoneState.h ZoneState.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/CgnsGrid.cpp
new file mode 100644
index 00000000..566675e2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/CgnsGrid.cpp
@@ -0,0 +1,858 @@
+#include "CgnsGrid.h"
+#include "Parallel.h"
+#include "cgnslib.h"
+#include "global.h"
+#include "ZoneState.h"
+#include <iostream>
+#include <vector>
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "fileId = " << fileId << "\n";
+    }
+    
+    int nbases = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_nbases( fileId, &nbases );
+    }
+    HXBcastData( &nbases, 1, Parallel::serverid );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "nbases = " << nbases << "\n";
+    
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        }
+
+        HXBcastData( &icelldim, 1, Parallel::serverid );
+        HXBcastData( &iphysdim, 1, Parallel::serverid );
+
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+
+        int nzones = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_nzones( fileId, baseId, &nzones );
+        }
+
+        HXBcastData( &nzones, 1, Parallel::serverid );
+
+        ZoneState::nZones = nzones;
+        ZoneState::pids.resize( nzones );
+        ZoneState::g2lzoneids.resize( nzones );
+
+        if ( Parallel::nProc == 1 )
+        {
+            for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+            {
+                ZoneState::pids[ iZone ] = 0;
+                ZoneState::g2lzoneids[ iZone ] = iZone;
+            }
+        }
+        else
+        {
+            for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+            {
+                ZoneState::pids[ iZone ] = iZone;
+                ZoneState::g2lzoneids[ iZone ] = 0;
+            }
+        }
+
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nzones = " << nzones << "\n";
+
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "iZone = " << iZone << "\n";
+
+            int index_dim = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            }
+            HXBcastData( &index_dim, 1, Parallel::serverid );
+
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            if ( Parallel::IsServer() )
+            {
+                cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            }
+
+            HXBcastData( zonename, 33, Parallel::serverid );
+            HXBcastData( isize.data(), isize.size(), Parallel::serverid);
+
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "zonename = " << zonename << "\n";
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+
+    if ( Parallel::IsServer() )
+    {
+        cg_close( fileId );
+    }
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+        std::cout << "fileId = " << fileId << "\n";
+    }
+    
+    int nbases = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_nbases( fileId, &nbases );
+    }
+    MPI_Bcast( &nbases, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        }
+
+        HXBcastData( &icelldim, 1, Parallel::serverid );
+        HXBcastData( &iphysdim, 1, Parallel::serverid );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+
+        int nzones = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_nzones( fileId, baseId, &nzones );
+        }
+        HXBcastData( &nzones, 1, Parallel::serverid );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nzones = " << nzones << "\n";
+
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            }
+            HXSendRecvData<int>( &index_dim, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "index_dim = " << index_dim << "\n";
+            }
+
+            std::vector<cgsize_t> isize;
+            char zonename[ 33 ];
+            if ( Parallel::IsServer() )
+            {
+                isize.resize( index_dim * 3 );
+                cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            }
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                isize.resize( index_dim * 3 );
+            }
+
+            HXSendRecvData( zonename, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+            HXSendRecvData( isize.data(), index_dim * 3, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "zonename = " << zonename << "\n";
+
+                for ( int i = 0; i < isize.size(); ++ i )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+                }
+            }
+
+            std::vector<cgsize_t> irmin;
+            std::vector<cgsize_t> irmax;
+            int nNodes = 1;
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                irmin.resize( index_dim );
+                irmax.resize( index_dim );
+                for ( int m = 0; m < index_dim; ++ m )
+                {
+                    /* lower range index */
+                    irmin[ m ] = 1;
+                    /* upper range index of vertices */
+                    irmax[ m ] = isize[ m ];
+                    nNodes *= irmax[ m ];
+                }
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "nNodes = " << nNodes << "\n";
+            }
+
+            ZoneType_t zoneType;
+            if ( Parallel::IsServer() )
+            {
+                cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            }
+            HXSendRecvData( &zoneType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            }
+
+            Zone * zone = nullptr;
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                zone = new Zone();
+                Global::zones.push_back( zone );
+                LocalZone::global_zoneids.push_back( iZone );
+                LocalZone::nZones = LocalZone::global_zoneids.size();
+                for ( int m = 0; m < index_dim; ++ m )
+                {
+                    zone->nijk.push_back( isize[ m ] );
+                }
+            }
+
+            Grid * grid = nullptr;
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                grid = new Grid();
+                Global::grids.push_back( grid );
+            }
+
+            BaseZone baseZone;
+
+            int gZoneId = -1;
+            if ( Parallel::IsServer() )
+            {
+                baseZone.zone_name = zonename;
+                gZoneId = Global::zone_names.FindBaseZone( baseZone );
+            }
+
+            HXSendRecvData( &gZoneId, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "gZoneId = " << gZoneId << "\n";
+            }
+
+            int ncoords = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            }
+            HXSendRecvData( &ncoords, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "ncoords = " << ncoords << "\n";
+            }
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                if ( Parallel::IsServer() )
+                {
+                    cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                }
+                HXSendRecvData( coordname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &dataType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "coordname = " << coordname << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                }
+
+                std::vector<char> coord;
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    coord.resize( nNodes * sizeof( double ) );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coord.data() );
+                }
+
+                HXSendRecvData( coord.data(), coord.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                Coor * coor = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    coor = new Coor();
+                    zone->coors.push_back( coor );
+                    coor->coorname = coordname;
+                    coor->nNodes = nNodes;
+                    coor->coord = coord;
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    coor->DumpCoor();
+
+                    if ( icoord == 0 )
+                    {
+                        grid->x.resize( nNodes );
+                        coor->DumpCoorX( grid->x );
+                    }
+                }
+            }
+
+            int nbocos = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            }
+            HXSendRecvData( &nbocos, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "nbocos = " << nbocos << "\n";
+            }
+
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                if ( Parallel::IsServer() )
+                {
+                    cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                }
+                HXSendRecvData( &location, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+                }
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                //std::vector<int> normalIndex( index_dim, -1 );
+                std::vector<int> normalIndex;
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+                if ( Parallel::IsServer() )
+                {
+                    normalIndex.resize( index_dim );
+                    cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                        &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                }
+
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    normalIndex.resize( index_dim );
+                }
+                
+                HXSendRecvData( boconame, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &bocotype, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &ptset_type, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &npnts, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &normalDataType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &normalListSize, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( normalIndex.data(), index_dim, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &ndataset, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "npnts = " << npnts << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalListSize = " << normalListSize << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalIndex = ";
+                    for ( int i = 0; i < index_dim; ++ i )
+                    {
+                        std::cout << normalIndex[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "ndataset = " << ndataset << "\n";
+                }
+
+                std::vector<char> normalList;
+                std::vector<cgsize_t> pnts;
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    if ( normalDataType == DataTypeNull )
+                    {
+                        normalList.resize( sizeof( int ) );
+                    }
+                    else
+                    {
+                        int nSize = nNodes * index_dim * sizeof( double );
+                        normalList.resize( nSize );
+                    }
+                    pnts.resize( npnts * index_dim );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                }
+
+                HXSendRecvData( pnts.data(), npnts * index_dim, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "pnts = ";
+                    for ( int i = 0; i < pnts.size(); ++ i )
+                    {
+                        std::cout << pnts[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                }
+                HXSendRecvData( normalList.data(), normalList.size(), Parallel::serverid, ZoneState::GetProcID(iZone));
+
+                ZoneBc * zonebc = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    zonebc = new ZoneBc();
+                    zone->bccos.push_back( zonebc );
+                    zonebc->bcType = bocotype;
+                    for ( int i = 0; i < pnts.size(); ++ i )
+                    {
+                        zonebc->pnts.push_back( pnts[ i ] );
+                    }
+                }
+            }
+            int n1to1 = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            }
+
+            HXSendRecvData( &n1to1, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "n1to1 = " << n1to1 << "\n";
+            }
+
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range;
+                std::vector<cgsize_t> donor_range;
+                std::vector<int> transform;
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    range.resize( npnts * index_dim );
+                    donor_range.resize( npnts * index_dim );
+                    transform.resize( index_dim );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                }
+
+                HXSendRecvData( connectname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( donorname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( range.data(), range.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( donor_range.data(), donor_range.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( transform.data(), transform.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "connectname = " << connectname << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "donorname = " << donorname << "\n";
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "range = ";
+                    for ( int i = 0; i < range.size(); ++ i )
+                    {
+                        std::cout << range[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "donor_range = ";
+                    for ( int i = 0; i < donor_range.size(); ++ i )
+                    {
+                        std::cout << donor_range[ i ] << " ";
+                    }
+                    std::cout << "\n";
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "transform = ";
+                    for ( int i = 0; i < transform.size(); ++ i )
+                    {
+                        std::cout << transform[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                }
+
+                int gDonorZoneId = -1;
+                if ( Parallel::IsServer() )
+                {
+                    BaseZone baseZoneDonor;
+                    baseZoneDonor.zone_name = donorname;
+
+                    gDonorZoneId = Global::zone_names.FindBaseZone( baseZoneDonor );
+                }
+
+                HXSendRecvData( &gDonorZoneId, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                ZoneBc1To1 * zonebc_1to1 = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    zonebc_1to1 = new ZoneBc1To1();
+                    zone->bc1to1s.push_back( zonebc_1to1 );
+                    zonebc_1to1->zoneid = gZoneId;
+                    zonebc_1to1->transform = transform;
+                    zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                    for ( int i = 0; i < range.size(); ++ i )
+                    {
+                        zonebc_1to1->pnts.push_back( range[ i ] );
+                        zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                    }
+                }
+            }
+        }
+    }
+
+    {
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "Global::zones.size() = " << Global::zones.size() << "\n";
+    }
+
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/CgnsGrid.h
new file mode 100644
index 00000000..fddf1db6
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/CgnsGrid.h
@@ -0,0 +1,103 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    int zoneIndex;
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/Field.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/Field.cpp
new file mode 100644
index 00000000..c359a811
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/Field.cpp
@@ -0,0 +1,142 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+
+    std::vector<double> & x = grid->x;
+    this->dx = std::abs( x[ 1 ] - x[ 0 ] );
+    this->dt = dx / 10.0;
+    this->t = 1.0;
+    this->nt = std::round( t / dt );
+
+    double total_time = nt * dt;
+
+    std::cout << "this->dt   = " << this->dt << "\n";
+    std::cout << "this->t    = " << this->t << "\n";
+    std::cout << "this->nt   = " << this->nt << "\n";
+    std::cout << "this->ni   = " << this->ni << "\n";
+    std::cout << "total_time = " << total_time << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        u_e[ i ] = - std::exp( -total_time ) * std::sin( std::numbers::pi * xm ); //theory solution
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+    int kkk = 1;
+}
+
+void Field::Solve( Zone * zone )
+{
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+    }
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        //std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        //region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+        int kkk = 1;
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
+
+void Field::UpdateOldField()
+{
+    for ( int i = 0; i < this->u.size(); ++ i )
+    {
+        this->un[ i ] = this->u[ i ];
+    }
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/Field.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/Field.h
new file mode 100644
index 00000000..084ec9bd
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/Field.h
@@ -0,0 +1,36 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid );
+
+    void Solve( Zone * zone );
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void UpdateOldField();
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/LogFile.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/LogFile.cpp
new file mode 100644
index 00000000..08ccd453
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/LogFile.cpp
@@ -0,0 +1,138 @@
+#include "LogFile.h"
+#include "Parallel.h"
+#include <sstream>
+#include <iostream>
+
+#ifdef _WINDOWS
+#include <windows.h>
+#include <direct.h>
+#include <io.h>
+#else
+#include <sys/stat.h>
+#include <unistd.h>
+#endif
+
+LogFile logFile;
+
+class OStream : public std::ostringstream
+{
+public:
+    OStream() {}
+    ~OStream() {}
+public:
+    void ClearAll()
+    {
+        this->clear();
+        this->str("");
+    }
+};
+
+OStream StrIO;
+std::string GetPrjDirName( const std::string & fileName );
+bool DirExist( const std::string & dirName );
+void MakeDir( const std::string & dirName );
+
+std::string GetPrjDirName( const std::string & fileName )
+{
+    size_t pos = fileName.find_last_of("\\/");
+    if ( std::string::npos == pos )
+    {
+        return "";
+    }
+    else
+    {
+        return fileName.substr( 0, pos );
+    }
+}
+
+bool DirExist( const std::string & dirName )
+{
+#ifdef _WINDOWS
+    bool flag = ( _access( dirName.c_str(), 0 ) == 0 );
+    return flag;
+#else
+    bool flag = ( access( dirName.c_str(), 0 ) == 0 );
+    return flag;
+#endif
+}
+
+void MakeDir( const std::string & dirName )
+{
+    int flag;
+#ifdef _WINDOWS
+    flag = _mkdir( dirName.c_str() );
+#else
+    flag = mkdir( dirName.c_str(), S_IRWXU );
+#endif
+    if ( flag == 0 )
+    {
+        std::cout << dirName << " directory has been created successfully !\n";
+    }
+}
+
+void CreateDirIfNeeded( std::string & prjFileName )
+{
+    std::string prj_dir = GetPrjDirName( prjFileName );
+
+    if ( ! DirExist( prj_dir ) )
+    {
+        MakeDir( prj_dir );
+    }
+}
+
+
+void OpenLogFile( int logFileIndex, std::fstream & file )
+{
+    static int ifReWrite = 0;
+
+    StrIO.ClearAll();
+    StrIO << "log/log" << logFileIndex << ".log";
+    std::string fileName = StrIO.str();
+
+    std::ios_base::openmode openMode;
+
+    if ( ifReWrite == 0 )
+    {
+        CreateDirIfNeeded( fileName );
+
+        openMode = std::ios_base::out | std::ios_base::trunc;
+
+        ifReWrite = 1;
+    }
+    else
+    {
+        openMode = std::ios_base::out | std::ios_base::app;
+    }
+
+    file.open( fileName.c_str(), openMode );
+    if ( ! file )
+    {
+        std::cout << "could not open " << fileName << std::endl;
+        exit( 0 );
+    }
+}
+
+void CloseLogFile( std::fstream & file )
+{
+    file.close();
+    file.clear();
+}
+
+LogFile::LogFile()
+{
+}
+
+LogFile::~LogFile()
+{
+}
+
+void LogFile::Open()
+{
+    int pid = Parallel::pid;
+    OpenLogFile( pid, this->my_fstream );
+}
+
+void LogFile::Close()
+{
+    CloseLogFile( this->my_fstream );
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/LogFile.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/LogFile.h
new file mode 100644
index 00000000..00e775ab
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/LogFile.h
@@ -0,0 +1,27 @@
+#pragma once
+#include <fstream>
+
+void OpenLogFile( int logFileIndex, std::fstream & file );
+void CloseLogFile( std::fstream & file );
+class LogFile;
+extern LogFile logFile;
+
+class LogFile
+{
+public:
+    LogFile();
+    ~LogFile();
+    std::fstream my_fstream;
+public:
+    void Open();
+    void Close();
+};
+
+template< typename T >
+LogFile & operator << ( LogFile & f, const T & value )
+{
+    f.Open();
+    f.my_fstream << value;
+    f.Close();
+    return f;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/Parallel.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/Parallel.cpp
new file mode 100644
index 00000000..0bce1a60
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/Parallel.cpp
@@ -0,0 +1,54 @@
+#include "Parallel.h"
+#include <iostream>
+
+int Parallel::pid = 0;
+int Parallel::nProc = 1;
+int Parallel::serverid = 0;
+int Parallel::tag = 0;
+
+void Parallel::Init()
+{
+#ifdef HX_PARALLEL
+    int argc     = 0;
+    char ** argv = 0;
+    MPI_Init( &argc, &argv );
+    MPI_Comm_rank( MPI_COMM_WORLD, &Parallel::pid );
+    MPI_Comm_size( MPI_COMM_WORLD, &Parallel::nProc );
+    int len = -1;
+    char version[ MPI_MAX_LIBRARY_VERSION_STRING ];
+    MPI_Get_library_version( version, &len );
+    std::cout << "Hello, world!  I am " << Parallel::pid << " of " << Parallel::nProc
+        << "(" << version << ", " << len << ")" << std::endl;
+#endif
+}
+
+void Parallel::Finalize()
+{
+#ifdef HX_PARALLEL
+    MPI_Finalize();
+#endif
+}
+
+bool Parallel::IsServer()
+{
+    return Parallel::pid == Parallel::serverid;
+}
+
+void HXSendChar( void * data, int size, int pid, int tag )
+{
+#ifdef HX_PARALLEL
+    if ( size <= 0 ) return;
+    MPI_Send( data, size, MPI_CHAR, pid, tag, MPI_COMM_WORLD );
+#endif
+}
+
+void HXRecvChar( void * data, int size, int pid, int tag )
+{
+#ifdef HX_PARALLEL
+    if ( size <= 0 ) return;
+
+    MPI_Status status;
+    MPI_Recv( data, size, MPI_CHAR, pid, tag, MPI_COMM_WORLD, & status );
+#endif
+}
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/Parallel.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/Parallel.h
new file mode 100644
index 00000000..2a9267d8
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/Parallel.h
@@ -0,0 +1,58 @@
+#pragma once
+#ifdef HX_PARALLEL
+#include "mpi.h"
+#endif
+#include <vector>
+#include "LogFile.h"
+
+class Parallel
+{
+public:
+    static int pid;
+    static int nProc;
+    static int serverid;
+    static int tag;
+public:
+    static void Init();
+    static void Finalize();
+public:
+    static bool IsServer();
+};
+
+void HXSendChar( void * data, int size, int pid, int tag );
+void HXRecvChar( void * data, int size, int pid, int tag );
+
+template< typename T >
+void HXSendRecvData( T * field, int nElement, int send_pid, int recv_pid, int tag = 0 )
+{
+    //logFile << " send_pid = " << send_pid << "\n";
+    //logFile << " recv_pid = " << recv_pid << "\n";
+    //logFile << " Parallel::pid = " << Parallel::pid << "\n";
+
+    if ( send_pid == recv_pid ) return;
+
+    if ( nElement <= 0 ) return;
+
+    int buffer_size = nElement * sizeof( T );
+
+    //logFile << "nElement = " << nElement << " buffer_size = " << buffer_size << "\n";
+
+    if ( Parallel::pid == send_pid )
+    {
+        HXSendChar( field, buffer_size, recv_pid, tag );
+    }
+    else if ( Parallel::pid == recv_pid )
+    {
+        HXRecvChar( field, buffer_size, send_pid, tag );
+    }
+}
+
+template< typename T >
+void HXBcastData( T * field, int nElement, int send_pid )
+{
+    if ( nElement <= 0 ) return;
+    int buffer_size = nElement * sizeof( T );
+#ifdef HX_PARALLEL
+    MPI_Bcast( field, buffer_size, MPI_CHAR, send_pid, MPI_COMM_WORLD );
+#endif
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/README.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/Solver.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/Solver.cpp
new file mode 100644
index 00000000..d07b92bf
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/Solver.cpp
@@ -0,0 +1,581 @@
+#include "Solver.h"
+#include "Parallel.h"
+#include "ZoneState.h"
+#include "global.h"
+#include <fstream>
+#include <set>
+#include <unordered_map>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+Solver::Solver()
+{
+    Parallel::Init();
+}
+
+Solver::~Solver()
+{
+    Parallel::Finalize();
+}
+
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    this->InitTopo();
+    this->InitFields();
+    if ( Parallel::pid == Parallel::serverid )
+    {
+        this->SolveMultiZones();
+        this->PostProcess();
+    }
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d4blocksv1.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    ReadCgnsGrid( fileName );
+}
+
+void Solver::InitTopo()
+{
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "Solver::InitTopo() " << "\n";
+
+    Global::donor_zone_sets.resize( LocalZone::nZones );
+    Global::donor_zones.resize( LocalZone::nZones );
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        int global_zoneid = LocalZone::global_zoneids[ iZone ];
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "iZone = " << iZone << " global_zoneid = " << global_zoneid << "\n";
+
+        Interface * interface = new Interface();
+        interface->zoneid = iZone;
+        Global::interfaces.push_back( interface );
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+
+        int nbc1to1s = zone->bc1to1s.size();
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout <<  "nbc1to1s = " << nbc1to1s << "\n";
+
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "zoneid = " << zoneid << " donor_zoneid = " << donor_zoneid << "\n";
+
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+        int nInterfaces = interface->zoneList.size();
+        interface->data_recv.resize( nInterfaces );
+        interface->data_send.resize( nInterfaces );
+    }
+
+    for ( int iProc = 0; iProc < Parallel::nProc; ++ iProc )
+    {
+        int nSize = -1;
+        if ( iProc == Parallel::pid )
+        {
+            nSize = Global::facePairList.size();
+        }
+        HXBcastData( &nSize, 1, iProc );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nSize = " << nSize << "\n";
+        std::vector<FacePair> tmp;
+        if ( iProc == Parallel::pid )
+        {
+            tmp = Global::facePairList;
+        }
+        else
+        {
+            tmp.resize( nSize );
+        }
+
+        HXBcastData( tmp.data(), tmp.size(), iProc );
+        Global::AddFacePairList( Global::mpi_facePairList, tmp );
+    }
+
+    for ( int i = 0; i < Global::mpi_facePairList.size(); ++ i )
+    {
+        FacePair &facePair = Global::mpi_facePairList[ i ];
+        Global::InsertFacePairMap( facePair );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        facePair.Print();
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterfaces = interface->local_faceids.size();
+        for ( int iInterface = 0; iInterface < nInterfaces; ++ iInterface )
+        {
+            int local_faceid = interface->local_faceids[ iInterface ];
+            int proc_global_faceid = interface->proc_global_faceids[ iInterface ];
+            FacePair & facePair = Global::facePairList[ proc_global_faceid ];
+            int global_faceid = Global::InsertFacePairMap( facePair );
+            interface->global_faceids.push_back( global_faceid );
+            interface->global_local_face_map.insert( std::make_pair( global_faceid, local_faceid ) );
+        }
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        std::set<int> &donor_zoneSet = Global::donor_zone_sets[ iZone ];
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            donor_zoneSet.insert( donor_zoneid );
+        }
+
+        std::vector<int> &donor_zones = Global::donor_zones[ iZone ];
+        for ( std::set<int>::iterator iter = donor_zoneSet.begin(); iter != donor_zoneSet.end(); ++ iter )
+        {
+            donor_zones.push_back( *iter );
+        }
+
+        interface->neighbor_donor_zones = donor_zones;
+
+        std::unordered_map<int, int> donor_zonelocal;
+
+        for ( int idonor = 0; idonor < donor_zones.size(); ++ idonor )
+        {
+            int donor_zone = donor_zones[ idonor ];
+            donor_zonelocal.insert( std::make_pair( donor_zone, idonor ) );
+        }
+        int ndonors = donor_zones.size();
+        std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+        neighbor_donorfaces.resize( ndonors );
+
+        std::vector<std::vector<int>> & sub_local_faceids = interface->sub_local_faceids;
+        sub_local_faceids.resize( ndonors );
+
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ineighbor = donor_zonelocal[ donor_zoneid ];
+            std::vector<int> &donorfaces = neighbor_donorfaces[ ineighbor ];
+            int global_faceid = interface->global_faceids[ iFace ];
+            donorfaces.push_back( global_faceid );
+            int local_faceid = interface->local_faceids[ iFace ];
+
+            std::vector<int> & sub_local_faces = sub_local_faceids[ ineighbor ];
+            sub_local_faces.push_back( local_faceid );
+        }
+    }
+
+    Global::interfaceTopo.InitNeighborInfo();
+    Global::interfaceTopo.SwapNeighborInfo();
+
+    int kkk = 1;
+}
+
+void Solver::InitFields()
+{
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "Solver::InitFields() ZoneState::nZones = " << ZoneState::nZones <<  "\n";
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+    }
+
+    Boundary();
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+        {
+            Field * field = Global::fields[ iZone ];
+            Zone * zone = Global::zones[ iZone ];
+            zone->zoneIndex = iZone;
+            field->Solve( zone );
+        }
+        Boundary();
+    }
+}
+
+void Solver::Boundary()
+{
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+    ExchangeInterfaceField();
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->UpdateOldField();
+    }
+}
+
+void Solver::UploadInterfaceField()
+{
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> & send_to_zones = interface->send_to_zones;
+        int nsend_zones = send_to_zones.size();
+
+        std::vector<std::vector<int>> & donorfaces_for_send = interface->donorfaces_for_send;
+        std::vector<std::vector<int>> & donorijk_for_send = interface->donorijk_for_send;
+        std::vector<std::vector<double>> & donordata_for_send = interface->donordata_for_send;
+
+        Field * field = Global::fields[ iZone ];
+
+        for ( int iSend = 0; iSend < nsend_zones; ++ iSend )
+        {
+            int zone_to_send = send_to_zones[ iSend ];
+            std::vector<int> & donorfaces = donorfaces_for_send[ iSend ];
+            std::vector<int> & donorijks = donorijk_for_send[ iSend ];
+            std::vector<double> & donordatas = donordata_for_send[ iSend ];
+
+            int nface = donorfaces.size();
+            int index_dim = 1;
+            for ( int i = 0; i < nface; ++ i )
+            {
+                int ijkpos = index_dim * i;
+                int i_donor_cell = donorijks[ ijkpos + 0 ];
+                donordatas[ i ] = field->u[ i_donor_cell ];
+            }
+        }
+    }
+}
+
+void Solver::UpdateInterfaceField()
+{
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        int ndonor_zones = Global::interfaceTopo.linkmap[ iZone ].size();
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donor_zone = Global::interfaceTopo.linkmap[ iZone ][ iNei ];
+            int send_pid = ZoneState::pids[ iZone ];
+            int recv_pid = ZoneState::pids[ donor_zone ];
+            int nsend = -1;
+            std::vector<double> donordata;
+            if ( Parallel::pid == send_pid )
+            {
+                int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+                Interface * interface = Global::interfaces[ local_zoneid ];
+                donordata = interface->donordata_for_send[ iNei ];
+                nsend = donordata.size();
+            }
+            HXSendRecvData( &nsend, 1, send_pid, recv_pid );
+
+            if ( Parallel::pid == recv_pid )
+            {
+                donordata.resize( nsend );
+            }
+            HXSendRecvData( donordata.data(), donordata.size(), send_pid, recv_pid );
+            if ( Parallel::pid == recv_pid )
+            {
+                int local_donor_zoneid = ZoneState::g2lzoneids[ donor_zone ];
+                Interface * donor_interface = Global::interfaces[ local_donor_zoneid ];
+                int nSize = donor_interface->neighbor_donor_zones.size();
+                int ipos = -1;
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    int nei_zone = donor_interface->neighbor_donor_zones[ i ];
+                    if ( nei_zone == iZone )
+                    {
+                        ipos = i;
+                        break;
+                    }
+                }
+
+                std::vector<int> & neighbor_donorfaces = donor_interface->neighbor_donorfaces[ ipos ];
+                std::vector<int> & sub_local_faceids = donor_interface->sub_local_faceids[ ipos ];
+                for ( int i = 0; i < neighbor_donorfaces.size(); ++ i )
+                {
+                    int local_faceid = sub_local_faceids[ i ];
+                    double donor_value = donordata[ i ];
+                    donor_interface->data_recv[ local_faceid ] = donor_value;
+                }
+            }
+        }
+    }
+}
+
+void Solver::DownloadInterfaceField()
+{
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+        Field * field = Global::fields[ iZone ];
+
+        int nInterFaces = interface->data_recv.size();
+
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+
+            double donor_value = interface->data_recv[ iFace ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    this->UploadInterfaceField();
+    this->UpdateInterfaceField();
+    this->DownloadInterfaceField();
+}
+
+void Solver::PostProcess()
+{
+    Post post;
+    post.Process();
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    int nZones = Global::grids.size();
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        int ni = grid->x.size();
+        double xmin = grid->x[ 0 ];
+        double xmax = grid->x[ 0 ];
+        int imin = 0;
+        int imax = 0;
+        for ( int i = 0; i < ni; ++ i )
+        {
+            if ( xmin > grid->x[ i ] )
+            {
+                xmin = grid->x[ i ];
+                imin = i;
+            }
+            if ( xmax < grid->x[ i ] )
+            {
+                xmax = grid->x[ i ];
+                imax = i;
+            }
+        }
+        xmin_list.push_back( xmin );
+        xmax_list.push_back( xmax );
+    }
+    std::vector<std::pair<double, int>> pairs;
+    int nSize = xmin_list.size();
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        pairs.push_back( std::make_pair( xmin_list[i], i ) );
+    }
+
+    std::sort( pairs.begin(), pairs.end() );
+
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        this->zoneids.push_back( pairs[i].second );
+    }
+
+    int kkk = 1;
+}
+
+void Post::GatherField()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+        Grid * grid = Global::grids[ zoneid ];
+        Field * field = Global::fields[ zoneid ];
+
+        int ni = grid->x.size();
+
+        int ist = 1;
+        int ied = ni;
+
+        int dir = 1;
+        if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+        if ( dir == 1 )
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ist; i <= ied; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+
+            }
+            else
+            {
+                for ( int i = ist; i <= ied - 1; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+        else
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ied; i >= ist; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+            else
+            {
+                for ( int i = ied; i >= ist + 1; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+    }
+}
+
+void Post::DumpField()
+{
+    int ni_total = this->x.size();
+    std::cout << " DumpField x.size() = " << x.size() << "\n";
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    this->DumpErrorDetails( u_error );
+
+    std::string csvname = "field_final.csv";
+    this->DumpCsvFile( csvname, x, u_e, un, u_error );
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.20f} {:.20f} {:.20f} {:.20f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/Solver.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/Solver.h
new file mode 100644
index 00000000..a7799d19
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/Solver.h
@@ -0,0 +1,47 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+
+class Solver
+{
+public:
+    Solver();
+    ~Solver();
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveMultiZones();
+public:
+    void Boundary();
+    void UploadInterfaceField();
+    void UpdateInterfaceField();
+    void DownloadInterfaceField();
+    void ExchangeInterfaceField();
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcess();
+};
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+    std::vector<double> u;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/ZoneState.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/ZoneState.cpp
new file mode 100644
index 00000000..ff810849
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/ZoneState.cpp
@@ -0,0 +1,20 @@
+#include "ZoneState.h"
+#include "Parallel.h"
+
+int ZoneState::nZones = 0;
+std::vector<int> ZoneState::pids;
+std::vector<int> ZoneState::g2lzoneids;
+
+bool ZoneState::IsValid( int zoneid )
+{
+    return ZoneState::pids[ zoneid ] == Parallel::pid;
+}
+
+int ZoneState::GetProcID( int zoneid )
+{
+    return ZoneState::pids[ zoneid ];
+}
+
+int LocalZone::nZones = 0;
+std::vector<int> LocalZone::global_zoneids;
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/ZoneState.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/ZoneState.h
new file mode 100644
index 00000000..1096d632
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/ZoneState.h
@@ -0,0 +1,21 @@
+#pragma once
+#include <vector>
+
+class ZoneState
+{
+public:
+    static int nZones;
+    static int zone_id;
+    static std::vector<int> pids;
+    static std::vector<int> g2lzoneids; //global zone id to local zone id
+public:
+    static bool IsValid( int zoneid );
+    static int GetProcID( int zoneid );
+};
+
+class LocalZone
+{
+public:
+    static int nZones;
+    static std::vector<int> global_zoneids;
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/global.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/global.cpp
new file mode 100644
index 00000000..8562907f
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/global.cpp
@@ -0,0 +1,301 @@
+#include "global.h"
+#include "CgnsGrid.h"
+#include "ZoneState.h"
+#include "Parallel.h"
+#include <iostream>
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *> Global::interfaces;
+
+std::map<Face, int> Global::faceMap;
+std::map<FacePair, int> Global::facePairMap;
+std::vector<FacePair> Global::facePairList;
+std::vector<FacePair> Global::mpi_facePairList;
+
+std::vector<std::set<int>> Global::donor_zone_sets;
+std::vector<std::vector<int>> Global::donor_zones;
+
+InterfaceTopo Global::interfaceTopo;
+
+bool Face::operator < ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return this->zone < rhs.zone;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return this->i < rhs.i;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return this->j < rhs.j;
+    }
+
+    return this->k < rhs.k;
+}
+
+bool Face::operator == ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return false;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return false;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return false;
+    }
+
+    return this->k == rhs.k;
+}
+
+void Face::Print()
+{
+    std::cout << "(" << this->zone << "," << this->i << ")";
+}
+
+void FacePair::AddPair( const Face & face1, const Face & face2 )
+{
+    if ( face1 < face2 )
+    {
+        this->left = face1;
+        this->right = face2;
+    }
+    else
+    {
+        this->left = face2;
+        this->right = face1;
+    }
+}
+
+bool FacePair::operator < ( const FacePair & rhs ) const
+{
+    if ( this->left == rhs.left || this->left == rhs.right )
+    {
+        return false;
+    }
+
+    return this->left < rhs.left;
+}
+
+void FacePair::Print()
+{
+    this->left.Print();
+    std::cout << " ";
+    this->right.Print();
+    std::cout << "\n";
+}
+
+void InterfaceTopo::InitNeighborInfo()
+{
+    this->linkmap.resize( ZoneState::nZones );
+
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        if ( ! ZoneState::IsValid( iZone ) ) continue;
+
+        int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+
+        Interface * interface = Global::interfaces[ local_zoneid ];
+
+        std::vector<int> & t = this->linkmap[ iZone ];
+        t = interface->neighbor_donor_zones;
+    }
+}
+
+void InterfaceTopo::SwapNeighborInfo()
+{
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        int pid = ZoneState::pids[ iZone ];
+
+        std::vector<int> & donor_zones = this->linkmap[ iZone ];
+        int nNeighbor = donor_zones.size();
+
+        HXBcastData( &nNeighbor, 1, pid );
+
+        donor_zones.resize( nNeighbor );
+
+        HXBcastData( donor_zones.data(), donor_zones.size(), pid );
+    }
+
+    this->SwapNeighborDonorfaces();
+}
+
+void InterfaceTopo::SwapNeighborDonorfaces()
+{
+    int gl = 0;
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        int send_pid = ZoneState::pids[ iZone ];
+
+        std::vector<int> & donor_zones = this->linkmap[ iZone ];
+        int ndonor_zones = donor_zones.size();
+
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donor_zone = donor_zones[ iNei ];
+            int recv_pid = ZoneState::pids[ donor_zone ];
+            int nInterFaces = 0;
+            std::vector<int> donorfaces;
+
+            if ( Parallel::pid == send_pid )
+            {
+                int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+
+                Interface * interface = Global::interfaces[ local_zoneid ];
+
+                std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+
+                std::vector<int> & neighbor_donorface = neighbor_donorfaces[ iNei ];
+
+                nInterFaces = neighbor_donorface.size();
+
+                donorfaces = neighbor_donorface;
+            }
+
+            HXSendRecvData( &nInterFaces, 1, send_pid, recv_pid );
+
+            if ( Parallel::pid == recv_pid && send_pid != recv_pid )
+            {
+                donorfaces.resize( nInterFaces );
+            }
+
+            HXSendRecvData( donorfaces.data(), donorfaces.size(), send_pid, recv_pid );
+
+            if ( Parallel::pid == recv_pid )
+            {
+                int local_donor_zoneid = ZoneState::g2lzoneids[ donor_zone ];
+                Interface * interface_recv = Global::interfaces[ local_donor_zoneid ];
+                interface_recv->SendGeom( iZone, donorfaces );
+            }
+        }
+    }
+}
+
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->local_faceids.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        Face face;
+        face.zone = zoneid;
+        face.i = i;
+
+        int i_donor = index2[ 0 ];
+
+        Face face_donor;
+        face_donor.zone = donor_zoneid;
+        face_donor.i = i_donor;
+
+        FacePair facePair;
+        facePair.AddPair( face, face_donor );
+
+        Global::facePairList.push_back( facePair );
+        int nSize = Global::facePairList.size();
+        this->proc_global_faceids.push_back( nSize - 1 );
+
+        int i_ghost_cell = i + 1;
+        int i_local_donor_cell = i - 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+            i_local_donor_cell = i + 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+        ijk_donors.push_back( i_local_donor_cell );
+
+        icount ++;
+    }
+}
+
+void Interface::SendGeom( int zone, std::vector<int> & donorfaces )
+{
+    //Interface * interface = Global::interfaces[ donorzone ];
+    Interface * interface = this;
+
+    std::vector<int> & send_to_zones = interface->send_to_zones;
+
+    send_to_zones.push_back( zone );
+    interface->donorfaces_for_send.push_back( donorfaces );
+
+    int nface = donorfaces.size();
+    std::vector<int> sub_donorijk;
+    int index_dim = 1;
+    for ( int i = 0; i < nface; ++ i )
+    {
+        int global_faceid = donorfaces[ i ];
+        int local_faceid = interface->global_local_face_map[ global_faceid ];
+        int ijkpos = index_dim * local_faceid;
+        int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+        sub_donorijk.push_back( i_donor_cell );
+        int kkk = 1;
+    }
+
+    interface->donorijk_for_send.push_back( sub_donorijk );
+
+    std::vector<double> sub_donordata( sub_donorijk.size() );
+    interface->donordata_for_send.push_back( sub_donordata );
+}
+
+void Global::InsertFaceMap( const Face & face )
+{
+    std::map<Face, int>::iterator iter;
+    iter = Global::faceMap.find( face );
+    if ( iter == Global::faceMap.end() )
+    {
+        int faceid = Global::faceMap.size();
+        Global::faceMap.insert( std::make_pair( face, faceid ) );
+    }
+}
+
+int Global::InsertFacePairMap( const FacePair & facePair )
+{
+    std::map<FacePair, int>::iterator iter;
+    iter = Global::facePairMap.find( facePair );
+    if ( iter == Global::facePairMap.end() )
+    {
+        int facePairId = Global::facePairMap.size();
+        Global::facePairMap.insert( std::make_pair( facePair, facePairId ) );
+        return facePairId;
+    }
+    return iter->second;
+}
+
+void Global::AddFacePairList( std::vector<FacePair> & a, std::vector<FacePair> & b )
+{
+    for ( int i = 0; i < b.size(); ++ i )
+    {
+        a.push_back( b[ i ] );
+    }
+}
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/global.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/global.h
new file mode 100644
index 00000000..933cec05
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/global.h
@@ -0,0 +1,157 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <unordered_map>
+#include <set>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class Face
+{
+public:
+    int zone = 0;
+    int i = 0;
+    int j = 1;
+    int k = 1;
+public:
+    bool operator < ( const Face & rhs ) const;
+    bool operator == ( const Face & rhs ) const;
+public:
+    void Print();
+};
+
+class FacePair
+{
+public:
+    Face left;
+    Face right;
+public:
+    bool operator < ( const FacePair & rhs ) const;
+    void AddPair( const Face &face1, const Face &face2);
+public:
+    void Print();
+};
+
+class Transform;
+
+class InterfaceTopo
+{
+public:
+    std::vector<std::vector<int>> linkmap;
+public:
+    void InitNeighborInfo();
+    void SwapNeighborInfo();
+    void SwapNeighborDonorfaces();
+};
+
+
+class Interface
+{
+public:
+    int zoneid;
+    std::vector<int> zoneList;
+    std::vector<int> global_faceids;
+    std::vector<int> mpi_global_faceids;
+    std::vector<int> proc_global_faceids;
+    std::vector<int> local_faceids;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+    std::vector<double> data_recv;
+    std::vector<double> data_send;
+    std::unordered_map<int, int> global_local_face_map;
+public:
+    std::vector<int> neighbor_donor_zones;
+    std::vector<std::vector<int>> neighbor_donorfaces;
+    std::vector<std::vector<int>> sub_local_faceids;
+    std::vector<int> send_to_zones;
+    std::vector<std::vector<int>> donorfaces_for_send;
+    std::vector<std::vector<int>> donorijk_for_send;
+    std::vector<std::vector<double>> donordata_for_send;
+public:
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+    void SendGeom( int zone, std::vector<int> & donorfaces );
+};
+
+class Field;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+public:
+    static std::map<Face, int> faceMap;
+    static std::map<FacePair, int> facePairMap;
+    static std::vector<FacePair> facePairList;
+    static std::vector<FacePair> mpi_facePairList;
+    static std::vector<std::set<int>> donor_zone_sets;
+    static std::vector<std::vector<int>> donor_zones;
+    static InterfaceTopo interfaceTopo;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+public:
+    static void InsertFaceMap( const Face & face );
+    static int InsertFacePairMap( const FacePair & facePair );
+    static void AddFacePairList( std::vector<FacePair> & a, std::vector<FacePair> & b );
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/heat1d4blocksv1.cgns b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/heat1d4blocksv1.cgns
new file mode 100644
index 00000000..df5ffc5f
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/heat1d4blocksv1.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/main.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/main.cpp
new file mode 100644
index 00000000..df63b7da
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/main.cpp
@@ -0,0 +1,9 @@
+#include "Solver.h"
+#include "Parallel.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/plot.py b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02g/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/CMakeLists.txt
new file mode 100644
index 00000000..9e834b72
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/CMakeLists.txt
@@ -0,0 +1,99 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package ( MPI )
+
+message ( STATUS  "MPI_FOUND=${MPI_FOUND}" )
+message ( STATUS  "MPI_CXX_INCLUDE_DIRS=${MPI_CXX_INCLUDE_DIRS}" )
+message ( STATUS  "MPI_LIBRARIES=${MPI_LIBRARIES}" )
+if ( MPI_FOUND )
+	list ( APPEND PRJ_INCLUDE_DIRS ${MPI_CXX_INCLUDE_DIRS} )
+	list ( APPEND PRJ_LIBRARIES ${MPI_LIBRARIES} )
+endif ()
+
+#get_directory_property( my_import_targets DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} IMPORTED_TARGETS )
+#message( STATUS "my_import_targets=${my_import_targets}" )
+
+list ( APPEND PRJ_LIBRARIES MPI::MPI_C )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+list ( APPEND PRJ_COMPILE_DEFINITIONS HX_PARALLEL )
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	LogFile.h LogFile.cpp
+	Parallel.h Parallel.cpp
+	Solver.h Solver.cpp
+	ZoneState.h ZoneState.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/CgnsGrid.cpp
new file mode 100644
index 00000000..4baf036f
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/CgnsGrid.cpp
@@ -0,0 +1,858 @@
+#include "CgnsGrid.h"
+#include "Parallel.h"
+#include "cgnslib.h"
+#include "global.h"
+#include "ZoneState.h"
+#include <iostream>
+#include <vector>
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "fileId = " << fileId << "\n";
+    }
+    
+    int nbases = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_nbases( fileId, &nbases );
+    }
+    HXBcastData( &nbases, 1, Parallel::serverid );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "nbases = " << nbases << "\n";
+    
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        }
+
+        HXBcastData( &icelldim, 1, Parallel::serverid );
+        HXBcastData( &iphysdim, 1, Parallel::serverid );
+
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+
+        int nzones = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_nzones( fileId, baseId, &nzones );
+        }
+
+        HXBcastData( &nzones, 1, Parallel::serverid );
+
+        ZoneState::nZones = nzones;
+        ZoneState::pids.resize( nzones );
+        ZoneState::g2lzoneids.resize( nzones );
+
+        if ( Parallel::nProc == 1 )
+        {
+            for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+            {
+                ZoneState::pids[ iZone ] = 0;
+                ZoneState::g2lzoneids[ iZone ] = iZone;
+            }
+        }
+        else
+        {
+            for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+            {
+                ZoneState::pids[ iZone ] = iZone;
+                ZoneState::g2lzoneids[ iZone ] = 0;
+            }
+        }
+
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nzones = " << nzones << "\n";
+
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "iZone = " << iZone << "\n";
+
+            int index_dim = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            }
+            HXBcastData( &index_dim, 1, Parallel::serverid );
+
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            if ( Parallel::IsServer() )
+            {
+                cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            }
+
+            HXBcastData( zonename, 33, Parallel::serverid );
+            HXBcastData( isize.data(), isize.size(), Parallel::serverid);
+
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "zonename = " << zonename << "\n";
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+
+    if ( Parallel::IsServer() )
+    {
+        cg_close( fileId );
+    }
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+        std::cout << "fileId = " << fileId << "\n";
+    }
+    
+    int nbases = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_nbases( fileId, &nbases );
+    }
+    MPI_Bcast( &nbases, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        }
+
+        HXBcastData( &icelldim, 1, Parallel::serverid );
+        HXBcastData( &iphysdim, 1, Parallel::serverid );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+
+        int nzones = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_nzones( fileId, baseId, &nzones );
+        }
+        HXBcastData( &nzones, 1, Parallel::serverid );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nzones = " << nzones << "\n";
+
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            }
+            HXSendRecvData( &index_dim, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "index_dim = " << index_dim << "\n";
+            }
+
+            std::vector<cgsize_t> isize;
+            char zonename[ 33 ];
+            if ( Parallel::IsServer() )
+            {
+                isize.resize( index_dim * 3 );
+                cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            }
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                isize.resize( index_dim * 3 );
+            }
+
+            HXSendRecvData( zonename, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+            HXSendRecvData( isize.data(), index_dim * 3, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "zonename = " << zonename << "\n";
+
+                for ( int i = 0; i < isize.size(); ++ i )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+                }
+            }
+
+            std::vector<cgsize_t> irmin;
+            std::vector<cgsize_t> irmax;
+            int nNodes = 1;
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                irmin.resize( index_dim );
+                irmax.resize( index_dim );
+                for ( int m = 0; m < index_dim; ++ m )
+                {
+                    /* lower range index */
+                    irmin[ m ] = 1;
+                    /* upper range index of vertices */
+                    irmax[ m ] = isize[ m ];
+                    nNodes *= irmax[ m ];
+                }
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "nNodes = " << nNodes << "\n";
+            }
+
+            ZoneType_t zoneType;
+            if ( Parallel::IsServer() )
+            {
+                cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            }
+            HXSendRecvData( &zoneType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            }
+
+            Zone * zone = nullptr;
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                zone = new Zone();
+                Global::zones.push_back( zone );
+                LocalZone::global_zoneids.push_back( iZone );
+                LocalZone::nZones = LocalZone::global_zoneids.size();
+                for ( int m = 0; m < index_dim; ++ m )
+                {
+                    zone->nijk.push_back( isize[ m ] );
+                }
+            }
+
+            Grid * grid = nullptr;
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                grid = new Grid();
+                Global::grids.push_back( grid );
+            }
+
+            BaseZone baseZone;
+
+            int gZoneId = -1;
+            if ( Parallel::IsServer() )
+            {
+                baseZone.zone_name = zonename;
+                gZoneId = Global::zone_names.FindBaseZone( baseZone );
+            }
+
+            HXSendRecvData( &gZoneId, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "gZoneId = " << gZoneId << "\n";
+            }
+
+            int ncoords = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            }
+            HXSendRecvData( &ncoords, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "ncoords = " << ncoords << "\n";
+            }
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                if ( Parallel::IsServer() )
+                {
+                    cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                }
+                HXSendRecvData( coordname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &dataType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "coordname = " << coordname << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                }
+
+                std::vector<char> coord;
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    coord.resize( nNodes * sizeof( double ) );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coord.data() );
+                }
+
+                HXSendRecvData( coord.data(), coord.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                Coor * coor = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    coor = new Coor();
+                    zone->coors.push_back( coor );
+                    coor->coorname = coordname;
+                    coor->nNodes = nNodes;
+                    coor->coord = coord;
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    coor->DumpCoor();
+
+                    if ( icoord == 0 )
+                    {
+                        grid->x.resize( nNodes );
+                        coor->DumpCoorX( grid->x );
+                    }
+                }
+            }
+
+            int nbocos = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            }
+            HXSendRecvData( &nbocos, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "nbocos = " << nbocos << "\n";
+            }
+
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                if ( Parallel::IsServer() )
+                {
+                    cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                }
+                HXSendRecvData( &location, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+                }
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                //std::vector<int> normalIndex( index_dim, -1 );
+                std::vector<int> normalIndex;
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+                if ( Parallel::IsServer() )
+                {
+                    normalIndex.resize( index_dim );
+                    cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                        &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                }
+
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    normalIndex.resize( index_dim );
+                }
+                
+                HXSendRecvData( boconame, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &bocotype, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &ptset_type, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &npnts, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &normalDataType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &normalListSize, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( normalIndex.data(), index_dim, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &ndataset, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "npnts = " << npnts << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalListSize = " << normalListSize << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalIndex = ";
+                    for ( int i = 0; i < index_dim; ++ i )
+                    {
+                        std::cout << normalIndex[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "ndataset = " << ndataset << "\n";
+                }
+
+                std::vector<char> normalList;
+                std::vector<cgsize_t> pnts;
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    if ( normalDataType == DataTypeNull )
+                    {
+                        normalList.resize( sizeof( int ) );
+                    }
+                    else
+                    {
+                        int nSize = nNodes * index_dim * sizeof( double );
+                        normalList.resize( nSize );
+                    }
+                    pnts.resize( npnts * index_dim );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                }
+
+                HXSendRecvData( pnts.data(), npnts * index_dim, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "pnts = ";
+                    for ( int i = 0; i < pnts.size(); ++ i )
+                    {
+                        std::cout << pnts[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                }
+                HXSendRecvData( normalList.data(), normalList.size(), Parallel::serverid, ZoneState::GetProcID(iZone));
+
+                ZoneBc * zonebc = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    zonebc = new ZoneBc();
+                    zone->bccos.push_back( zonebc );
+                    zonebc->bcType = bocotype;
+                    for ( int i = 0; i < pnts.size(); ++ i )
+                    {
+                        zonebc->pnts.push_back( pnts[ i ] );
+                    }
+                }
+            }
+            int n1to1 = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            }
+
+            HXSendRecvData( &n1to1, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "n1to1 = " << n1to1 << "\n";
+            }
+
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range;
+                std::vector<cgsize_t> donor_range;
+                std::vector<int> transform;
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    range.resize( npnts * index_dim );
+                    donor_range.resize( npnts * index_dim );
+                    transform.resize( index_dim );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                }
+
+                HXSendRecvData( connectname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( donorname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( range.data(), range.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( donor_range.data(), donor_range.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( transform.data(), transform.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "connectname = " << connectname << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "donorname = " << donorname << "\n";
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "range = ";
+                    for ( int i = 0; i < range.size(); ++ i )
+                    {
+                        std::cout << range[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "donor_range = ";
+                    for ( int i = 0; i < donor_range.size(); ++ i )
+                    {
+                        std::cout << donor_range[ i ] << " ";
+                    }
+                    std::cout << "\n";
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "transform = ";
+                    for ( int i = 0; i < transform.size(); ++ i )
+                    {
+                        std::cout << transform[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                }
+
+                int gDonorZoneId = -1;
+                if ( Parallel::IsServer() )
+                {
+                    BaseZone baseZoneDonor;
+                    baseZoneDonor.zone_name = donorname;
+
+                    gDonorZoneId = Global::zone_names.FindBaseZone( baseZoneDonor );
+                }
+
+                HXSendRecvData( &gDonorZoneId, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                ZoneBc1To1 * zonebc_1to1 = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    zonebc_1to1 = new ZoneBc1To1();
+                    zone->bc1to1s.push_back( zonebc_1to1 );
+                    zonebc_1to1->zoneid = gZoneId;
+                    zonebc_1to1->transform = transform;
+                    zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                    for ( int i = 0; i < range.size(); ++ i )
+                    {
+                        zonebc_1to1->pnts.push_back( range[ i ] );
+                        zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                    }
+                }
+            }
+        }
+    }
+
+    {
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "Global::zones.size() = " << Global::zones.size() << "\n";
+    }
+
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/CgnsGrid.h
new file mode 100644
index 00000000..fddf1db6
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/CgnsGrid.h
@@ -0,0 +1,103 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    int zoneIndex;
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/Field.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/Field.cpp
new file mode 100644
index 00000000..718f1385
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/Field.cpp
@@ -0,0 +1,143 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+
+    std::vector<double> & x = grid->x;
+    this->dx = std::abs( x[ 1 ] - x[ 0 ] );
+    this->dt = dx / 10.0;
+    this->t = 1.0;
+    this->nt = std::round( t / dt );
+    this->nt = 1;
+
+    double total_time = nt * dt;
+
+    std::cout << "this->dt   = " << this->dt << "\n";
+    std::cout << "this->t    = " << this->t << "\n";
+    std::cout << "this->nt   = " << this->nt << "\n";
+    std::cout << "this->ni   = " << this->ni << "\n";
+    std::cout << "total_time = " << total_time << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        u_e[ i ] = - std::exp( -total_time ) * std::sin( std::numbers::pi * xm ); //theory solution
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+    int kkk = 1;
+}
+
+void Field::Solve( Zone * zone )
+{
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+    }
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        //std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        //region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+        int kkk = 1;
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
+
+void Field::UpdateOldField()
+{
+    for ( int i = 0; i < this->u.size(); ++ i )
+    {
+        this->un[ i ] = this->u[ i ];
+    }
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/Field.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/Field.h
new file mode 100644
index 00000000..084ec9bd
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/Field.h
@@ -0,0 +1,36 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid );
+
+    void Solve( Zone * zone );
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void UpdateOldField();
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/LogFile.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/LogFile.cpp
new file mode 100644
index 00000000..08ccd453
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/LogFile.cpp
@@ -0,0 +1,138 @@
+#include "LogFile.h"
+#include "Parallel.h"
+#include <sstream>
+#include <iostream>
+
+#ifdef _WINDOWS
+#include <windows.h>
+#include <direct.h>
+#include <io.h>
+#else
+#include <sys/stat.h>
+#include <unistd.h>
+#endif
+
+LogFile logFile;
+
+class OStream : public std::ostringstream
+{
+public:
+    OStream() {}
+    ~OStream() {}
+public:
+    void ClearAll()
+    {
+        this->clear();
+        this->str("");
+    }
+};
+
+OStream StrIO;
+std::string GetPrjDirName( const std::string & fileName );
+bool DirExist( const std::string & dirName );
+void MakeDir( const std::string & dirName );
+
+std::string GetPrjDirName( const std::string & fileName )
+{
+    size_t pos = fileName.find_last_of("\\/");
+    if ( std::string::npos == pos )
+    {
+        return "";
+    }
+    else
+    {
+        return fileName.substr( 0, pos );
+    }
+}
+
+bool DirExist( const std::string & dirName )
+{
+#ifdef _WINDOWS
+    bool flag = ( _access( dirName.c_str(), 0 ) == 0 );
+    return flag;
+#else
+    bool flag = ( access( dirName.c_str(), 0 ) == 0 );
+    return flag;
+#endif
+}
+
+void MakeDir( const std::string & dirName )
+{
+    int flag;
+#ifdef _WINDOWS
+    flag = _mkdir( dirName.c_str() );
+#else
+    flag = mkdir( dirName.c_str(), S_IRWXU );
+#endif
+    if ( flag == 0 )
+    {
+        std::cout << dirName << " directory has been created successfully !\n";
+    }
+}
+
+void CreateDirIfNeeded( std::string & prjFileName )
+{
+    std::string prj_dir = GetPrjDirName( prjFileName );
+
+    if ( ! DirExist( prj_dir ) )
+    {
+        MakeDir( prj_dir );
+    }
+}
+
+
+void OpenLogFile( int logFileIndex, std::fstream & file )
+{
+    static int ifReWrite = 0;
+
+    StrIO.ClearAll();
+    StrIO << "log/log" << logFileIndex << ".log";
+    std::string fileName = StrIO.str();
+
+    std::ios_base::openmode openMode;
+
+    if ( ifReWrite == 0 )
+    {
+        CreateDirIfNeeded( fileName );
+
+        openMode = std::ios_base::out | std::ios_base::trunc;
+
+        ifReWrite = 1;
+    }
+    else
+    {
+        openMode = std::ios_base::out | std::ios_base::app;
+    }
+
+    file.open( fileName.c_str(), openMode );
+    if ( ! file )
+    {
+        std::cout << "could not open " << fileName << std::endl;
+        exit( 0 );
+    }
+}
+
+void CloseLogFile( std::fstream & file )
+{
+    file.close();
+    file.clear();
+}
+
+LogFile::LogFile()
+{
+}
+
+LogFile::~LogFile()
+{
+}
+
+void LogFile::Open()
+{
+    int pid = Parallel::pid;
+    OpenLogFile( pid, this->my_fstream );
+}
+
+void LogFile::Close()
+{
+    CloseLogFile( this->my_fstream );
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/LogFile.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/LogFile.h
new file mode 100644
index 00000000..00e775ab
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/LogFile.h
@@ -0,0 +1,27 @@
+#pragma once
+#include <fstream>
+
+void OpenLogFile( int logFileIndex, std::fstream & file );
+void CloseLogFile( std::fstream & file );
+class LogFile;
+extern LogFile logFile;
+
+class LogFile
+{
+public:
+    LogFile();
+    ~LogFile();
+    std::fstream my_fstream;
+public:
+    void Open();
+    void Close();
+};
+
+template< typename T >
+LogFile & operator << ( LogFile & f, const T & value )
+{
+    f.Open();
+    f.my_fstream << value;
+    f.Close();
+    return f;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/Parallel.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/Parallel.cpp
new file mode 100644
index 00000000..0bce1a60
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/Parallel.cpp
@@ -0,0 +1,54 @@
+#include "Parallel.h"
+#include <iostream>
+
+int Parallel::pid = 0;
+int Parallel::nProc = 1;
+int Parallel::serverid = 0;
+int Parallel::tag = 0;
+
+void Parallel::Init()
+{
+#ifdef HX_PARALLEL
+    int argc     = 0;
+    char ** argv = 0;
+    MPI_Init( &argc, &argv );
+    MPI_Comm_rank( MPI_COMM_WORLD, &Parallel::pid );
+    MPI_Comm_size( MPI_COMM_WORLD, &Parallel::nProc );
+    int len = -1;
+    char version[ MPI_MAX_LIBRARY_VERSION_STRING ];
+    MPI_Get_library_version( version, &len );
+    std::cout << "Hello, world!  I am " << Parallel::pid << " of " << Parallel::nProc
+        << "(" << version << ", " << len << ")" << std::endl;
+#endif
+}
+
+void Parallel::Finalize()
+{
+#ifdef HX_PARALLEL
+    MPI_Finalize();
+#endif
+}
+
+bool Parallel::IsServer()
+{
+    return Parallel::pid == Parallel::serverid;
+}
+
+void HXSendChar( void * data, int size, int pid, int tag )
+{
+#ifdef HX_PARALLEL
+    if ( size <= 0 ) return;
+    MPI_Send( data, size, MPI_CHAR, pid, tag, MPI_COMM_WORLD );
+#endif
+}
+
+void HXRecvChar( void * data, int size, int pid, int tag )
+{
+#ifdef HX_PARALLEL
+    if ( size <= 0 ) return;
+
+    MPI_Status status;
+    MPI_Recv( data, size, MPI_CHAR, pid, tag, MPI_COMM_WORLD, & status );
+#endif
+}
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/Parallel.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/Parallel.h
new file mode 100644
index 00000000..880a71cb
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/Parallel.h
@@ -0,0 +1,78 @@
+#pragma once
+#ifdef HX_PARALLEL
+#include "mpi.h"
+#endif
+#include <vector>
+#include "LogFile.h"
+
+class Parallel
+{
+public:
+    static int pid;
+    static int nProc;
+    static int serverid;
+    static int tag;
+public:
+    static void Init();
+    static void Finalize();
+public:
+    static bool IsServer();
+};
+
+void HXSendChar( void * data, int size, int pid, int tag );
+void HXRecvChar( void * data, int size, int pid, int tag );
+
+template< typename T >
+void HXSendData( T * field, int nElement, int recv_pid, int tag  );
+
+template< typename T >
+void HXRecvData( T * field, int nElement, int send_pid, int tag );
+
+template< typename T >
+void HXSendData( T * field, int nElement, int recv_pid, int tag = 0 )
+{
+    if ( nElement <= 0 ) return;
+
+    int buffer_size = nElement * sizeof( T );
+
+    HXSendChar( field, buffer_size, recv_pid, tag );
+}
+
+template< typename T >
+void HXRecvData( T * field, int nElement, int send_pid, int tag = 0 )
+{
+    if ( nElement <= 0 ) return;
+
+    int buffer_size = nElement * sizeof( T );
+
+    HXRecvChar( field, buffer_size, send_pid, tag );
+}
+
+template< typename T >
+void HXSendRecvData( T * field, int nElement, int send_pid, int recv_pid, int tag = 0 )
+{
+    if ( send_pid == recv_pid ) return;
+
+    if ( nElement <= 0 ) return;
+
+    int buffer_size = nElement * sizeof( T );
+
+    if ( Parallel::pid == send_pid )
+    {
+        HXSendChar( field, buffer_size, recv_pid, tag );
+    }
+    else if ( Parallel::pid == recv_pid )
+    {
+        HXRecvChar( field, buffer_size, send_pid, tag );
+    }
+}
+
+template< typename T >
+void HXBcastData( T * field, int nElement, int send_pid )
+{
+    if ( nElement <= 0 ) return;
+    int buffer_size = nElement * sizeof( T );
+#ifdef HX_PARALLEL
+    MPI_Bcast( field, buffer_size, MPI_CHAR, send_pid, MPI_COMM_WORLD );
+#endif
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/README.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/Solver.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/Solver.cpp
new file mode 100644
index 00000000..8a355cc7
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/Solver.cpp
@@ -0,0 +1,752 @@
+#include "Solver.h"
+#include "Parallel.h"
+#include "ZoneState.h"
+#include "global.h"
+#include <fstream>
+#include <set>
+#include <unordered_map>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+Solver::Solver()
+{
+    Parallel::Init();
+}
+
+Solver::~Solver()
+{
+    Parallel::Finalize();
+}
+
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    this->InitTopo();
+    this->InitFields();
+    this->SolveMultiZones();
+    this->PostProcess();
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d4blocksv1.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    ReadCgnsGrid( fileName );
+}
+
+void Solver::InitTopo()
+{
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "Solver::InitTopo() " << "\n";
+
+    Global::donor_zone_sets.resize( LocalZone::nZones );
+    Global::donor_zones.resize( LocalZone::nZones );
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        int global_zoneid = LocalZone::global_zoneids[ iZone ];
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "iZone = " << iZone << " global_zoneid = " << global_zoneid << "\n";
+
+        Interface * interface = new Interface();
+        interface->zoneid = iZone;
+        Global::interfaces.push_back( interface );
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+
+        int nbc1to1s = zone->bc1to1s.size();
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout <<  "nbc1to1s = " << nbc1to1s << "\n";
+
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "zoneid = " << zoneid << " donor_zoneid = " << donor_zoneid << "\n";
+
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+        int nInterfaces = interface->zoneList.size();
+        interface->data_recv.resize( nInterfaces );
+        interface->data_send.resize( nInterfaces );
+    }
+
+    for ( int iProc = 0; iProc < Parallel::nProc; ++ iProc )
+    {
+        int nSize = -1;
+        if ( iProc == Parallel::pid )
+        {
+            nSize = Global::facePairList.size();
+        }
+        HXBcastData( &nSize, 1, iProc );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nSize = " << nSize << "\n";
+        std::vector<FacePair> tmp;
+        if ( iProc == Parallel::pid )
+        {
+            tmp = Global::facePairList;
+        }
+        else
+        {
+            tmp.resize( nSize );
+        }
+
+        HXBcastData( tmp.data(), tmp.size(), iProc );
+        Global::AddFacePairList( Global::mpi_facePairList, tmp );
+    }
+
+    for ( int i = 0; i < Global::mpi_facePairList.size(); ++ i )
+    {
+        FacePair &facePair = Global::mpi_facePairList[ i ];
+        Global::InsertFacePairMap( facePair );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        facePair.Print();
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterfaces = interface->local_faceids.size();
+        for ( int iInterface = 0; iInterface < nInterfaces; ++ iInterface )
+        {
+            int local_faceid = interface->local_faceids[ iInterface ];
+            int proc_global_faceid = interface->proc_global_faceids[ iInterface ];
+            FacePair & facePair = Global::facePairList[ proc_global_faceid ];
+            int global_faceid = Global::InsertFacePairMap( facePair );
+            interface->global_faceids.push_back( global_faceid );
+            interface->global_local_face_map.insert( std::make_pair( global_faceid, local_faceid ) );
+        }
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        std::set<int> &donor_zoneSet = Global::donor_zone_sets[ iZone ];
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            donor_zoneSet.insert( donor_zoneid );
+        }
+
+        std::vector<int> &donor_zones = Global::donor_zones[ iZone ];
+        for ( std::set<int>::iterator iter = donor_zoneSet.begin(); iter != donor_zoneSet.end(); ++ iter )
+        {
+            donor_zones.push_back( *iter );
+        }
+
+        interface->neighbor_donor_zones = donor_zones;
+
+        std::unordered_map<int, int> donor_zonelocal;
+
+        for ( int idonor = 0; idonor < donor_zones.size(); ++ idonor )
+        {
+            int donor_zone = donor_zones[ idonor ];
+            donor_zonelocal.insert( std::make_pair( donor_zone, idonor ) );
+        }
+        int ndonors = donor_zones.size();
+        std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+        neighbor_donorfaces.resize( ndonors );
+
+        std::vector<std::vector<int>> & sub_local_faceids = interface->sub_local_faceids;
+        sub_local_faceids.resize( ndonors );
+
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ineighbor = donor_zonelocal[ donor_zoneid ];
+            std::vector<int> &donorfaces = neighbor_donorfaces[ ineighbor ];
+            int global_faceid = interface->global_faceids[ iFace ];
+            donorfaces.push_back( global_faceid );
+            int local_faceid = interface->local_faceids[ iFace ];
+
+            std::vector<int> & sub_local_faces = sub_local_faceids[ ineighbor ];
+            sub_local_faces.push_back( local_faceid );
+        }
+    }
+
+    Global::interfaceTopo.InitNeighborInfo();
+    Global::interfaceTopo.SwapNeighborInfo();
+
+    int kkk = 1;
+}
+
+void Solver::InitFields()
+{
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "Solver::InitFields() ZoneState::nZones = " << ZoneState::nZones <<  "\n";
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+    }
+
+    Boundary();
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+        {
+            Field * field = Global::fields[ iZone ];
+            Zone * zone = Global::zones[ iZone ];
+            zone->zoneIndex = iZone;
+            field->Solve( zone );
+        }
+        Boundary();
+    }
+}
+
+void Solver::Boundary()
+{
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+    ExchangeInterfaceField();
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->UpdateOldField();
+    }
+}
+
+void Solver::UploadInterfaceField()
+{
+    logFile << "UploadInterfaceField\n";
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        logFile << "ilocal zone = " << iZone << " global zone = " << LocalZone::global_zoneids[ iZone ] << "\n";
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> & send_to_zones = interface->send_to_zones;
+        int nsend_zones = send_to_zones.size();
+
+        logFile << "nsend_zones = " << nsend_zones << "\n";
+
+        std::vector<std::vector<int>> & donorfaces_for_send = interface->donorfaces_for_send;
+        std::vector<std::vector<int>> & donorijk_for_send = interface->donorijk_for_send;
+        std::vector<std::vector<double>> & donordata_for_send = interface->donordata_for_send;
+
+        Field * field = Global::fields[ iZone ];
+
+        for ( int iSend = 0; iSend < nsend_zones; ++ iSend )
+        {
+            int zone_to_send = send_to_zones[ iSend ];
+            std::vector<int> & donorfaces = donorfaces_for_send[ iSend ];
+            std::vector<int> & donorijks = donorijk_for_send[ iSend ];
+            std::vector<double> & donordatas = donordata_for_send[ iSend ];
+
+            logFile << "iSend = " << iSend << " zone_to_send " << zone_to_send << "\n";
+            logFile << "donorfaces = ";
+            for ( int i = 0; i < donorfaces.size(); ++ i )
+            {
+                logFile << donorfaces[ i ] << " ";
+            }
+            logFile << "\n";
+            logFile << "donordatas = ";
+            for ( int i = 0; i < donordatas.size(); ++ i )
+            {
+                logFile << donordatas[ i ] << " ";
+            }
+            logFile << "\n";
+
+            int nface = donorfaces.size();
+            int index_dim = 1;
+            for ( int i = 0; i < nface; ++ i )
+            {
+                int ijkpos = index_dim * i;
+                int i_donor_cell = donorijks[ ijkpos + 0 ];
+                logFile << "i = " << i << " nface " << nface << " i_donor_cell = " << i_donor_cell << "\n";
+                donordatas[ i ] = field->u[ i_donor_cell ];
+            }
+
+            logFile << "donordatas after = ";
+            for ( int i = 0; i < donordatas.size(); ++ i )
+            {
+                logFile << donordatas[ i ] << " ";
+            }
+            logFile << "\n";
+        }
+    }
+}
+
+void Solver::UpdateInterfaceField()
+{
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        logFile << "UpdateInterfaceField iZone = " << iZone << "\n";
+        int ndonor_zones = Global::interfaceTopo.linkmap[ iZone ].size();
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donor_zone = Global::interfaceTopo.linkmap[ iZone ][ iNei ];
+            int send_pid = ZoneState::pids[ iZone ];
+            int recv_pid = ZoneState::pids[ donor_zone ];
+            logFile << "iZone = " << iZone << " donor_zone = " << donor_zone << "\n";
+            logFile << "send_pid = " << send_pid << " recv_pid = " << recv_pid << "\n";
+            int nsend = -1;
+            std::vector<double> donordata;
+            std::vector<int> donorface;
+            if ( Parallel::pid != send_pid && Parallel::pid != recv_pid ) continue;
+            if ( Parallel::pid == send_pid )
+            {
+                int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+                Interface * interface = Global::interfaces[ local_zoneid ];
+                donordata = interface->donordata_for_send[ iNei ];
+                donorface = interface->donorfaces_for_send[ iNei ];
+                nsend = donordata.size();
+            }
+            HXSendRecvData( &nsend, 1, send_pid, recv_pid );
+
+            logFile << "nsend = " << nsend << "\n";
+
+            if ( Parallel::pid == recv_pid )
+            {
+                donordata.resize( nsend );
+                donorface.resize( nsend );
+            }
+            HXSendRecvData( donordata.data(), donordata.size(), send_pid, recv_pid );
+            HXSendRecvData( donorface.data(), donorface.size(), send_pid, recv_pid );
+            logFile << "donordata = ";
+            for ( int i = 0; i < donordata.size(); ++ i )
+            {
+                logFile << donordata[ i ] << " ";
+            }
+            logFile << "\n";
+            logFile << "donorface = ";
+            for ( int i = 0; i < donorface.size(); ++ i )
+            {
+                logFile << donorface[ i ] << " ";
+            }
+            logFile << "\n";
+
+            if ( Parallel::pid == recv_pid )
+            {
+                int local_donor_zoneid = ZoneState::g2lzoneids[ donor_zone ];
+                Interface * donor_interface = Global::interfaces[ local_donor_zoneid ];
+                int nSize = donor_interface->neighbor_donor_zones.size();
+                int ipos = -1;
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    int nei_zone = donor_interface->neighbor_donor_zones[ i ];
+                    if ( nei_zone == iZone )
+                    {
+                        ipos = i;
+                        break;
+                    }
+                }
+
+                std::vector<int> & neighbor_donorfaces = donor_interface->neighbor_donorfaces[ ipos ];
+                std::vector<int> & sub_local_faceids = donor_interface->sub_local_faceids[ ipos ];
+                for ( int i = 0; i < neighbor_donorfaces.size(); ++ i )
+                {
+                    int local_faceid = sub_local_faceids[ i ];
+                    double donor_value = donordata[ i ];
+                    donor_interface->data_recv[ local_faceid ] = donor_value;
+                }
+            }
+        }
+    }
+}
+
+void Solver::DownloadInterfaceField()
+{
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+        Field * field = Global::fields[ iZone ];
+
+        logFile << "DownloadInterfaceField\n";
+        logFile << "LocalZone::nZones = " << LocalZone::nZones << "\n";
+        logFile << "iZone = " << iZone << " LocalZone::global_zoneids[iZone] = " << LocalZone::global_zoneids[ iZone ] << "\n";
+
+        logFile << "field->u[ 1 ] = " <<field->u[ 1 ] << "\n";
+        logFile << "field->u[ 21 ] = " <<field->u[ 21 ] << "\n";
+
+        int nInterFaces = interface->data_recv.size();
+
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+
+            double donor_value = interface->data_recv[ iFace ];
+            logFile << "donor_value = " << donor_value << "\n";
+            logFile << "i_ghost_cell = " << i_ghost_cell << "\n";
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    this->UploadInterfaceField();
+    this->UpdateInterfaceField();
+    this->DownloadInterfaceField();
+}
+
+void Solver::PostProcess()
+{
+    Post post;
+    post.Process();
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        if ( !ZoneState::IsValid( iZone ) && !Parallel::IsServer() ) continue;
+
+        double xmin = 0.0;
+        double xmax = 0.0;
+
+        if ( ZoneState::IsValid( iZone ) )
+        {
+            int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+            Grid * grid = Global::grids[ local_zoneid ];
+            int ni = grid->x.size();
+            xmin = grid->x[ 0 ];
+            xmax = grid->x[ 0 ];
+            int imin = 0;
+            int imax = 0;
+            for ( int i = 0; i < ni; ++ i )
+            {
+                if ( xmin > grid->x[ i ] )
+                {
+                    xmin = grid->x[ i ];
+                    imin = i;
+                }
+                if ( xmax < grid->x[ i ] )
+                {
+                    xmax = grid->x[ i ];
+                    imax = i;
+                }
+            }
+        }
+
+        HXSendRecvData( &xmin, 1, ZoneState::pids[ iZone ], Parallel::serverid );
+        HXSendRecvData( &xmax, 1, ZoneState::pids[ iZone ], Parallel::serverid );
+
+        if ( Parallel::IsServer() )
+        {
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "xmin = " << xmin << "\n";
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "xmax = " << xmax << "\n";
+        }
+
+        if ( Parallel::IsServer() )
+        {
+            xmin_list.push_back( xmin );
+            xmax_list.push_back( xmax );
+        }
+    }
+
+    if ( Parallel::IsServer() )
+    {
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        for ( int i = 0; i < xmin_list.size(); ++ i )
+        {
+            std::cout << "(" << xmin_list[ i ] << "," << xmax_list[ i ] << ") ";
+        }
+        std::cout << "\n";
+    }
+
+    if ( Parallel::IsServer() )
+    {
+        std::vector<std::pair<double, int>> pairs;
+        int nSize = xmin_list.size();
+        for ( int i = 0; i < nSize; ++ i )
+        {
+            pairs.push_back( std::make_pair( xmin_list[ i ], i ) );
+        }
+
+        std::sort( pairs.begin(), pairs.end() );
+
+        for ( int i = 0; i < nSize; ++ i )
+        {
+            this->zoneids.push_back( pairs[ i ].second );
+        }
+    }
+
+    int kkk = 1;
+}
+
+bool IsLastZone( int iZone );
+bool IsLastZone( int iZone )
+{
+    return iZone == ZoneState::nZones - 1;
+}
+
+void Post::AddVector( std::vector<double> & a, std::vector<double> & b )
+{
+    for ( int i = 0; i < b.size(); ++ i )
+    {
+        a.push_back( b[ i ] );
+    }
+}
+
+void Post::GatherField()
+{
+    logFile << "Post::GatherField  1 \n";
+    this->zoneids.resize( ZoneState::nZones );
+    HXBcastData( this->zoneids.data(), this->zoneids.size(), Parallel::serverid );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "Post::GatherField() this->zoneids = \n";
+    for ( int i = 0; i < this->zoneids.size(); ++ i )
+    {
+        std::cout << this->zoneids[ i ] << " ";
+    }
+    std::cout << "\n";
+
+    logFile << "Post::GatherField  2 \n";
+
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+        logFile << "iZone = " << iZone << " zoneid = " << zoneid << "\n";
+        logFile << "ZoneState::pids[ iZone ] = " << ZoneState::pids[ iZone ] << "\n";
+
+        if ( !ZoneState::IsValid( zoneid ) && !Parallel::IsServer() ) continue;
+
+        int nSize = -1;
+        logFile << "nSize = " << nSize << "\n";
+        std::vector<double> local_x;
+        std::vector<double> local_u_e;
+        std::vector<double> local_un;
+        std::vector<double> local_u;
+
+        logFile << "Parallel::pid = " << Parallel::pid << " ZoneState::pids[ zoneid ] = " << ZoneState::pids[ zoneid ] << "\n";
+
+        if ( Parallel::pid == ZoneState::pids[ zoneid ] )
+        {
+            int local_zoneid = ZoneState::g2lzoneids[ zoneid ];
+            Grid * grid = Global::grids[ local_zoneid ];
+            Field * field = Global::fields[ local_zoneid ];
+            int ni = grid->x.size();
+
+            int ist = 1;
+            int ied = ni;
+
+            int dir = 1;
+            if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+            if ( dir == 1 )
+            {
+                if ( IsLastZone( iZone ) )
+                {
+                    for ( int i = ist; i <= ied; ++ i )
+                    {
+                        double xm = grid->x[ i - ist ];
+                        local_x.push_back( xm );
+                        local_u_e.push_back( field->u_e[ i ] );
+                        local_un.push_back( field->un[ i ] );
+                        local_u.push_back( field->u[ i ] );
+                    }
+                }
+                else
+                {
+                    for ( int i = ist; i <= ied - 1; ++ i )
+                    {
+                        double xm = grid->x[ i - ist ];
+                        local_x.push_back( xm );
+                        local_u_e.push_back( field->u_e[ i ] );
+                        local_un.push_back( field->un[ i ] );
+                        local_u.push_back( field->u[ i ] );
+                    }
+                }
+            }
+            else
+            {
+                if ( IsLastZone( iZone ) )
+                {
+                    for ( int i = ied; i >= ist; -- i )
+                    {
+                        double xm = grid->x[ i - ist ];
+                        local_x.push_back( xm );
+                        local_u_e.push_back( field->u_e[ i ] );
+                        local_un.push_back( field->un[ i ] );
+                        local_u.push_back( field->u[ i ] );
+                    }
+                }
+                else
+                {
+                    for ( int i = ied; i >= ist + 1; -- i )
+                    {
+                        double xm = grid->x[ i - ist ];
+                        local_x.push_back( xm );
+                        local_u_e.push_back( field->u_e[ i ] );
+                        local_un.push_back( field->un[ i ] );
+                        local_u.push_back( field->u[ i ] );
+                    }
+                }
+            }
+            nSize = local_x.size();
+        }
+
+        logFile << "Parallel::pid = " << Parallel::pid << "\n";
+        logFile << "ZoneState::pids[ zoneid ] = " << ZoneState::pids[ zoneid ] << "\n";
+        logFile << "Parallel::serverid = " << Parallel::serverid << "\n";
+
+        int send_pid = ZoneState::pids[ zoneid ];
+        logFile << "send_pid = " << send_pid << "\n";
+
+        HXSendRecvData( &nSize, 1, send_pid, Parallel::serverid );
+
+        logFile << "nSize = " << nSize << "\n";
+
+        if ( Parallel::IsServer() )
+        {
+            local_x.resize( nSize );
+            local_u_e.resize( nSize );
+            local_un.resize( nSize );
+            local_u.resize( nSize );
+        }
+
+        HXSendRecvData( local_x.data(), local_x.size(), send_pid, Parallel::serverid );
+        HXSendRecvData( local_u_e.data(), local_u_e.size(), send_pid, Parallel::serverid );
+        HXSendRecvData( local_un.data(), local_un.size(), send_pid, Parallel::serverid );
+        HXSendRecvData( local_u.data(), local_u.size(), send_pid, Parallel::serverid );
+
+        if ( Parallel::IsServer() )
+        {
+            this->AddVector( this->x, local_x );
+            this->AddVector( this->u_e, local_u_e );
+            this->AddVector( this->un, local_un );
+            this->AddVector( this->u, local_u );
+        }
+    }
+
+    logFile << "Post::GatherField  3 \n";
+}
+
+void Post::DumpField()
+{
+    if ( !Parallel::IsServer() ) return;
+    int ni_total = this->x.size();
+    std::cout << " DumpField x.size() = " << x.size() << "\n";
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    this->DumpErrorDetails( u_error );
+
+    std::string csvname = "field_final.csv";
+    this->DumpCsvFile( csvname, x, u_e, un, u_error );
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.20f} {:.20f} {:.20f} {:.20f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/Solver.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/Solver.h
new file mode 100644
index 00000000..9914c1d7
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/Solver.h
@@ -0,0 +1,49 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+
+class Solver
+{
+public:
+    Solver();
+    ~Solver();
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveMultiZones();
+public:
+    void Boundary();
+    void UploadInterfaceField();
+    void UpdateInterfaceField();
+    void DownloadInterfaceField();
+    void ExchangeInterfaceField();
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcess();
+};
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+    std::vector<double> u;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+public:
+    void AddVector( std::vector<double> & a, std::vector<double> & b );
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/ZoneState.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/ZoneState.cpp
new file mode 100644
index 00000000..ff810849
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/ZoneState.cpp
@@ -0,0 +1,20 @@
+#include "ZoneState.h"
+#include "Parallel.h"
+
+int ZoneState::nZones = 0;
+std::vector<int> ZoneState::pids;
+std::vector<int> ZoneState::g2lzoneids;
+
+bool ZoneState::IsValid( int zoneid )
+{
+    return ZoneState::pids[ zoneid ] == Parallel::pid;
+}
+
+int ZoneState::GetProcID( int zoneid )
+{
+    return ZoneState::pids[ zoneid ];
+}
+
+int LocalZone::nZones = 0;
+std::vector<int> LocalZone::global_zoneids;
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/ZoneState.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/ZoneState.h
new file mode 100644
index 00000000..1096d632
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/ZoneState.h
@@ -0,0 +1,21 @@
+#pragma once
+#include <vector>
+
+class ZoneState
+{
+public:
+    static int nZones;
+    static int zone_id;
+    static std::vector<int> pids;
+    static std::vector<int> g2lzoneids; //global zone id to local zone id
+public:
+    static bool IsValid( int zoneid );
+    static int GetProcID( int zoneid );
+};
+
+class LocalZone
+{
+public:
+    static int nZones;
+    static std::vector<int> global_zoneids;
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/global.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/global.cpp
new file mode 100644
index 00000000..8562907f
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/global.cpp
@@ -0,0 +1,301 @@
+#include "global.h"
+#include "CgnsGrid.h"
+#include "ZoneState.h"
+#include "Parallel.h"
+#include <iostream>
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *> Global::interfaces;
+
+std::map<Face, int> Global::faceMap;
+std::map<FacePair, int> Global::facePairMap;
+std::vector<FacePair> Global::facePairList;
+std::vector<FacePair> Global::mpi_facePairList;
+
+std::vector<std::set<int>> Global::donor_zone_sets;
+std::vector<std::vector<int>> Global::donor_zones;
+
+InterfaceTopo Global::interfaceTopo;
+
+bool Face::operator < ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return this->zone < rhs.zone;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return this->i < rhs.i;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return this->j < rhs.j;
+    }
+
+    return this->k < rhs.k;
+}
+
+bool Face::operator == ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return false;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return false;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return false;
+    }
+
+    return this->k == rhs.k;
+}
+
+void Face::Print()
+{
+    std::cout << "(" << this->zone << "," << this->i << ")";
+}
+
+void FacePair::AddPair( const Face & face1, const Face & face2 )
+{
+    if ( face1 < face2 )
+    {
+        this->left = face1;
+        this->right = face2;
+    }
+    else
+    {
+        this->left = face2;
+        this->right = face1;
+    }
+}
+
+bool FacePair::operator < ( const FacePair & rhs ) const
+{
+    if ( this->left == rhs.left || this->left == rhs.right )
+    {
+        return false;
+    }
+
+    return this->left < rhs.left;
+}
+
+void FacePair::Print()
+{
+    this->left.Print();
+    std::cout << " ";
+    this->right.Print();
+    std::cout << "\n";
+}
+
+void InterfaceTopo::InitNeighborInfo()
+{
+    this->linkmap.resize( ZoneState::nZones );
+
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        if ( ! ZoneState::IsValid( iZone ) ) continue;
+
+        int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+
+        Interface * interface = Global::interfaces[ local_zoneid ];
+
+        std::vector<int> & t = this->linkmap[ iZone ];
+        t = interface->neighbor_donor_zones;
+    }
+}
+
+void InterfaceTopo::SwapNeighborInfo()
+{
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        int pid = ZoneState::pids[ iZone ];
+
+        std::vector<int> & donor_zones = this->linkmap[ iZone ];
+        int nNeighbor = donor_zones.size();
+
+        HXBcastData( &nNeighbor, 1, pid );
+
+        donor_zones.resize( nNeighbor );
+
+        HXBcastData( donor_zones.data(), donor_zones.size(), pid );
+    }
+
+    this->SwapNeighborDonorfaces();
+}
+
+void InterfaceTopo::SwapNeighborDonorfaces()
+{
+    int gl = 0;
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        int send_pid = ZoneState::pids[ iZone ];
+
+        std::vector<int> & donor_zones = this->linkmap[ iZone ];
+        int ndonor_zones = donor_zones.size();
+
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donor_zone = donor_zones[ iNei ];
+            int recv_pid = ZoneState::pids[ donor_zone ];
+            int nInterFaces = 0;
+            std::vector<int> donorfaces;
+
+            if ( Parallel::pid == send_pid )
+            {
+                int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+
+                Interface * interface = Global::interfaces[ local_zoneid ];
+
+                std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+
+                std::vector<int> & neighbor_donorface = neighbor_donorfaces[ iNei ];
+
+                nInterFaces = neighbor_donorface.size();
+
+                donorfaces = neighbor_donorface;
+            }
+
+            HXSendRecvData( &nInterFaces, 1, send_pid, recv_pid );
+
+            if ( Parallel::pid == recv_pid && send_pid != recv_pid )
+            {
+                donorfaces.resize( nInterFaces );
+            }
+
+            HXSendRecvData( donorfaces.data(), donorfaces.size(), send_pid, recv_pid );
+
+            if ( Parallel::pid == recv_pid )
+            {
+                int local_donor_zoneid = ZoneState::g2lzoneids[ donor_zone ];
+                Interface * interface_recv = Global::interfaces[ local_donor_zoneid ];
+                interface_recv->SendGeom( iZone, donorfaces );
+            }
+        }
+    }
+}
+
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->local_faceids.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        Face face;
+        face.zone = zoneid;
+        face.i = i;
+
+        int i_donor = index2[ 0 ];
+
+        Face face_donor;
+        face_donor.zone = donor_zoneid;
+        face_donor.i = i_donor;
+
+        FacePair facePair;
+        facePair.AddPair( face, face_donor );
+
+        Global::facePairList.push_back( facePair );
+        int nSize = Global::facePairList.size();
+        this->proc_global_faceids.push_back( nSize - 1 );
+
+        int i_ghost_cell = i + 1;
+        int i_local_donor_cell = i - 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+            i_local_donor_cell = i + 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+        ijk_donors.push_back( i_local_donor_cell );
+
+        icount ++;
+    }
+}
+
+void Interface::SendGeom( int zone, std::vector<int> & donorfaces )
+{
+    //Interface * interface = Global::interfaces[ donorzone ];
+    Interface * interface = this;
+
+    std::vector<int> & send_to_zones = interface->send_to_zones;
+
+    send_to_zones.push_back( zone );
+    interface->donorfaces_for_send.push_back( donorfaces );
+
+    int nface = donorfaces.size();
+    std::vector<int> sub_donorijk;
+    int index_dim = 1;
+    for ( int i = 0; i < nface; ++ i )
+    {
+        int global_faceid = donorfaces[ i ];
+        int local_faceid = interface->global_local_face_map[ global_faceid ];
+        int ijkpos = index_dim * local_faceid;
+        int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+        sub_donorijk.push_back( i_donor_cell );
+        int kkk = 1;
+    }
+
+    interface->donorijk_for_send.push_back( sub_donorijk );
+
+    std::vector<double> sub_donordata( sub_donorijk.size() );
+    interface->donordata_for_send.push_back( sub_donordata );
+}
+
+void Global::InsertFaceMap( const Face & face )
+{
+    std::map<Face, int>::iterator iter;
+    iter = Global::faceMap.find( face );
+    if ( iter == Global::faceMap.end() )
+    {
+        int faceid = Global::faceMap.size();
+        Global::faceMap.insert( std::make_pair( face, faceid ) );
+    }
+}
+
+int Global::InsertFacePairMap( const FacePair & facePair )
+{
+    std::map<FacePair, int>::iterator iter;
+    iter = Global::facePairMap.find( facePair );
+    if ( iter == Global::facePairMap.end() )
+    {
+        int facePairId = Global::facePairMap.size();
+        Global::facePairMap.insert( std::make_pair( facePair, facePairId ) );
+        return facePairId;
+    }
+    return iter->second;
+}
+
+void Global::AddFacePairList( std::vector<FacePair> & a, std::vector<FacePair> & b )
+{
+    for ( int i = 0; i < b.size(); ++ i )
+    {
+        a.push_back( b[ i ] );
+    }
+}
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/global.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/global.h
new file mode 100644
index 00000000..933cec05
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/global.h
@@ -0,0 +1,157 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <unordered_map>
+#include <set>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class Face
+{
+public:
+    int zone = 0;
+    int i = 0;
+    int j = 1;
+    int k = 1;
+public:
+    bool operator < ( const Face & rhs ) const;
+    bool operator == ( const Face & rhs ) const;
+public:
+    void Print();
+};
+
+class FacePair
+{
+public:
+    Face left;
+    Face right;
+public:
+    bool operator < ( const FacePair & rhs ) const;
+    void AddPair( const Face &face1, const Face &face2);
+public:
+    void Print();
+};
+
+class Transform;
+
+class InterfaceTopo
+{
+public:
+    std::vector<std::vector<int>> linkmap;
+public:
+    void InitNeighborInfo();
+    void SwapNeighborInfo();
+    void SwapNeighborDonorfaces();
+};
+
+
+class Interface
+{
+public:
+    int zoneid;
+    std::vector<int> zoneList;
+    std::vector<int> global_faceids;
+    std::vector<int> mpi_global_faceids;
+    std::vector<int> proc_global_faceids;
+    std::vector<int> local_faceids;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+    std::vector<double> data_recv;
+    std::vector<double> data_send;
+    std::unordered_map<int, int> global_local_face_map;
+public:
+    std::vector<int> neighbor_donor_zones;
+    std::vector<std::vector<int>> neighbor_donorfaces;
+    std::vector<std::vector<int>> sub_local_faceids;
+    std::vector<int> send_to_zones;
+    std::vector<std::vector<int>> donorfaces_for_send;
+    std::vector<std::vector<int>> donorijk_for_send;
+    std::vector<std::vector<double>> donordata_for_send;
+public:
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+    void SendGeom( int zone, std::vector<int> & donorfaces );
+};
+
+class Field;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+public:
+    static std::map<Face, int> faceMap;
+    static std::map<FacePair, int> facePairMap;
+    static std::vector<FacePair> facePairList;
+    static std::vector<FacePair> mpi_facePairList;
+    static std::vector<std::set<int>> donor_zone_sets;
+    static std::vector<std::vector<int>> donor_zones;
+    static InterfaceTopo interfaceTopo;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+public:
+    static void InsertFaceMap( const Face & face );
+    static int InsertFacePairMap( const FacePair & facePair );
+    static void AddFacePairList( std::vector<FacePair> & a, std::vector<FacePair> & b );
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/heat1d4blocksv1.cgns b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/heat1d4blocksv1.cgns
new file mode 100644
index 00000000..df5ffc5f
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/heat1d4blocksv1.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/main.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/main.cpp
new file mode 100644
index 00000000..df63b7da
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/main.cpp
@@ -0,0 +1,9 @@
+#include "Solver.h"
+#include "Parallel.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/plot.py b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02h/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/CMakeLists.txt
new file mode 100644
index 00000000..9e834b72
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/CMakeLists.txt
@@ -0,0 +1,99 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package ( MPI )
+
+message ( STATUS  "MPI_FOUND=${MPI_FOUND}" )
+message ( STATUS  "MPI_CXX_INCLUDE_DIRS=${MPI_CXX_INCLUDE_DIRS}" )
+message ( STATUS  "MPI_LIBRARIES=${MPI_LIBRARIES}" )
+if ( MPI_FOUND )
+	list ( APPEND PRJ_INCLUDE_DIRS ${MPI_CXX_INCLUDE_DIRS} )
+	list ( APPEND PRJ_LIBRARIES ${MPI_LIBRARIES} )
+endif ()
+
+#get_directory_property( my_import_targets DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} IMPORTED_TARGETS )
+#message( STATUS "my_import_targets=${my_import_targets}" )
+
+list ( APPEND PRJ_LIBRARIES MPI::MPI_C )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+list ( APPEND PRJ_COMPILE_DEFINITIONS HX_PARALLEL )
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	LogFile.h LogFile.cpp
+	Parallel.h Parallel.cpp
+	Solver.h Solver.cpp
+	ZoneState.h ZoneState.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/CgnsGrid.cpp
new file mode 100644
index 00000000..4baf036f
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/CgnsGrid.cpp
@@ -0,0 +1,858 @@
+#include "CgnsGrid.h"
+#include "Parallel.h"
+#include "cgnslib.h"
+#include "global.h"
+#include "ZoneState.h"
+#include <iostream>
+#include <vector>
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "fileId = " << fileId << "\n";
+    }
+    
+    int nbases = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_nbases( fileId, &nbases );
+    }
+    HXBcastData( &nbases, 1, Parallel::serverid );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "nbases = " << nbases << "\n";
+    
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        }
+
+        HXBcastData( &icelldim, 1, Parallel::serverid );
+        HXBcastData( &iphysdim, 1, Parallel::serverid );
+
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+
+        int nzones = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_nzones( fileId, baseId, &nzones );
+        }
+
+        HXBcastData( &nzones, 1, Parallel::serverid );
+
+        ZoneState::nZones = nzones;
+        ZoneState::pids.resize( nzones );
+        ZoneState::g2lzoneids.resize( nzones );
+
+        if ( Parallel::nProc == 1 )
+        {
+            for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+            {
+                ZoneState::pids[ iZone ] = 0;
+                ZoneState::g2lzoneids[ iZone ] = iZone;
+            }
+        }
+        else
+        {
+            for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+            {
+                ZoneState::pids[ iZone ] = iZone;
+                ZoneState::g2lzoneids[ iZone ] = 0;
+            }
+        }
+
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nzones = " << nzones << "\n";
+
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "iZone = " << iZone << "\n";
+
+            int index_dim = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            }
+            HXBcastData( &index_dim, 1, Parallel::serverid );
+
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            if ( Parallel::IsServer() )
+            {
+                cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            }
+
+            HXBcastData( zonename, 33, Parallel::serverid );
+            HXBcastData( isize.data(), isize.size(), Parallel::serverid);
+
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "zonename = " << zonename << "\n";
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+
+    if ( Parallel::IsServer() )
+    {
+        cg_close( fileId );
+    }
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+        std::cout << "fileId = " << fileId << "\n";
+    }
+    
+    int nbases = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_nbases( fileId, &nbases );
+    }
+    MPI_Bcast( &nbases, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        }
+
+        HXBcastData( &icelldim, 1, Parallel::serverid );
+        HXBcastData( &iphysdim, 1, Parallel::serverid );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+
+        int nzones = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_nzones( fileId, baseId, &nzones );
+        }
+        HXBcastData( &nzones, 1, Parallel::serverid );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nzones = " << nzones << "\n";
+
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            }
+            HXSendRecvData( &index_dim, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "index_dim = " << index_dim << "\n";
+            }
+
+            std::vector<cgsize_t> isize;
+            char zonename[ 33 ];
+            if ( Parallel::IsServer() )
+            {
+                isize.resize( index_dim * 3 );
+                cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            }
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                isize.resize( index_dim * 3 );
+            }
+
+            HXSendRecvData( zonename, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+            HXSendRecvData( isize.data(), index_dim * 3, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "zonename = " << zonename << "\n";
+
+                for ( int i = 0; i < isize.size(); ++ i )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+                }
+            }
+
+            std::vector<cgsize_t> irmin;
+            std::vector<cgsize_t> irmax;
+            int nNodes = 1;
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                irmin.resize( index_dim );
+                irmax.resize( index_dim );
+                for ( int m = 0; m < index_dim; ++ m )
+                {
+                    /* lower range index */
+                    irmin[ m ] = 1;
+                    /* upper range index of vertices */
+                    irmax[ m ] = isize[ m ];
+                    nNodes *= irmax[ m ];
+                }
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "nNodes = " << nNodes << "\n";
+            }
+
+            ZoneType_t zoneType;
+            if ( Parallel::IsServer() )
+            {
+                cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            }
+            HXSendRecvData( &zoneType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            }
+
+            Zone * zone = nullptr;
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                zone = new Zone();
+                Global::zones.push_back( zone );
+                LocalZone::global_zoneids.push_back( iZone );
+                LocalZone::nZones = LocalZone::global_zoneids.size();
+                for ( int m = 0; m < index_dim; ++ m )
+                {
+                    zone->nijk.push_back( isize[ m ] );
+                }
+            }
+
+            Grid * grid = nullptr;
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                grid = new Grid();
+                Global::grids.push_back( grid );
+            }
+
+            BaseZone baseZone;
+
+            int gZoneId = -1;
+            if ( Parallel::IsServer() )
+            {
+                baseZone.zone_name = zonename;
+                gZoneId = Global::zone_names.FindBaseZone( baseZone );
+            }
+
+            HXSendRecvData( &gZoneId, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "gZoneId = " << gZoneId << "\n";
+            }
+
+            int ncoords = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            }
+            HXSendRecvData( &ncoords, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "ncoords = " << ncoords << "\n";
+            }
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                if ( Parallel::IsServer() )
+                {
+                    cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                }
+                HXSendRecvData( coordname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &dataType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "coordname = " << coordname << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                }
+
+                std::vector<char> coord;
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    coord.resize( nNodes * sizeof( double ) );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coord.data() );
+                }
+
+                HXSendRecvData( coord.data(), coord.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                Coor * coor = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    coor = new Coor();
+                    zone->coors.push_back( coor );
+                    coor->coorname = coordname;
+                    coor->nNodes = nNodes;
+                    coor->coord = coord;
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    coor->DumpCoor();
+
+                    if ( icoord == 0 )
+                    {
+                        grid->x.resize( nNodes );
+                        coor->DumpCoorX( grid->x );
+                    }
+                }
+            }
+
+            int nbocos = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            }
+            HXSendRecvData( &nbocos, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "nbocos = " << nbocos << "\n";
+            }
+
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                if ( Parallel::IsServer() )
+                {
+                    cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                }
+                HXSendRecvData( &location, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+                }
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                //std::vector<int> normalIndex( index_dim, -1 );
+                std::vector<int> normalIndex;
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+                if ( Parallel::IsServer() )
+                {
+                    normalIndex.resize( index_dim );
+                    cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                        &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                }
+
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    normalIndex.resize( index_dim );
+                }
+                
+                HXSendRecvData( boconame, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &bocotype, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &ptset_type, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &npnts, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &normalDataType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &normalListSize, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( normalIndex.data(), index_dim, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &ndataset, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "npnts = " << npnts << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalListSize = " << normalListSize << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalIndex = ";
+                    for ( int i = 0; i < index_dim; ++ i )
+                    {
+                        std::cout << normalIndex[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "ndataset = " << ndataset << "\n";
+                }
+
+                std::vector<char> normalList;
+                std::vector<cgsize_t> pnts;
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    if ( normalDataType == DataTypeNull )
+                    {
+                        normalList.resize( sizeof( int ) );
+                    }
+                    else
+                    {
+                        int nSize = nNodes * index_dim * sizeof( double );
+                        normalList.resize( nSize );
+                    }
+                    pnts.resize( npnts * index_dim );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                }
+
+                HXSendRecvData( pnts.data(), npnts * index_dim, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "pnts = ";
+                    for ( int i = 0; i < pnts.size(); ++ i )
+                    {
+                        std::cout << pnts[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                }
+                HXSendRecvData( normalList.data(), normalList.size(), Parallel::serverid, ZoneState::GetProcID(iZone));
+
+                ZoneBc * zonebc = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    zonebc = new ZoneBc();
+                    zone->bccos.push_back( zonebc );
+                    zonebc->bcType = bocotype;
+                    for ( int i = 0; i < pnts.size(); ++ i )
+                    {
+                        zonebc->pnts.push_back( pnts[ i ] );
+                    }
+                }
+            }
+            int n1to1 = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            }
+
+            HXSendRecvData( &n1to1, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "n1to1 = " << n1to1 << "\n";
+            }
+
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range;
+                std::vector<cgsize_t> donor_range;
+                std::vector<int> transform;
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    range.resize( npnts * index_dim );
+                    donor_range.resize( npnts * index_dim );
+                    transform.resize( index_dim );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                }
+
+                HXSendRecvData( connectname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( donorname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( range.data(), range.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( donor_range.data(), donor_range.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( transform.data(), transform.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "connectname = " << connectname << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "donorname = " << donorname << "\n";
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "range = ";
+                    for ( int i = 0; i < range.size(); ++ i )
+                    {
+                        std::cout << range[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "donor_range = ";
+                    for ( int i = 0; i < donor_range.size(); ++ i )
+                    {
+                        std::cout << donor_range[ i ] << " ";
+                    }
+                    std::cout << "\n";
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "transform = ";
+                    for ( int i = 0; i < transform.size(); ++ i )
+                    {
+                        std::cout << transform[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                }
+
+                int gDonorZoneId = -1;
+                if ( Parallel::IsServer() )
+                {
+                    BaseZone baseZoneDonor;
+                    baseZoneDonor.zone_name = donorname;
+
+                    gDonorZoneId = Global::zone_names.FindBaseZone( baseZoneDonor );
+                }
+
+                HXSendRecvData( &gDonorZoneId, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                ZoneBc1To1 * zonebc_1to1 = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    zonebc_1to1 = new ZoneBc1To1();
+                    zone->bc1to1s.push_back( zonebc_1to1 );
+                    zonebc_1to1->zoneid = gZoneId;
+                    zonebc_1to1->transform = transform;
+                    zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                    for ( int i = 0; i < range.size(); ++ i )
+                    {
+                        zonebc_1to1->pnts.push_back( range[ i ] );
+                        zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                    }
+                }
+            }
+        }
+    }
+
+    {
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "Global::zones.size() = " << Global::zones.size() << "\n";
+    }
+
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/CgnsGrid.h
new file mode 100644
index 00000000..fddf1db6
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/CgnsGrid.h
@@ -0,0 +1,103 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    int zoneIndex;
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/Field.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/Field.cpp
new file mode 100644
index 00000000..c359a811
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/Field.cpp
@@ -0,0 +1,142 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+
+    std::vector<double> & x = grid->x;
+    this->dx = std::abs( x[ 1 ] - x[ 0 ] );
+    this->dt = dx / 10.0;
+    this->t = 1.0;
+    this->nt = std::round( t / dt );
+
+    double total_time = nt * dt;
+
+    std::cout << "this->dt   = " << this->dt << "\n";
+    std::cout << "this->t    = " << this->t << "\n";
+    std::cout << "this->nt   = " << this->nt << "\n";
+    std::cout << "this->ni   = " << this->ni << "\n";
+    std::cout << "total_time = " << total_time << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        u_e[ i ] = - std::exp( -total_time ) * std::sin( std::numbers::pi * xm ); //theory solution
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+    int kkk = 1;
+}
+
+void Field::Solve( Zone * zone )
+{
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+    }
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        //std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        //region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+        int kkk = 1;
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
+
+void Field::UpdateOldField()
+{
+    for ( int i = 0; i < this->u.size(); ++ i )
+    {
+        this->un[ i ] = this->u[ i ];
+    }
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/Field.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/Field.h
new file mode 100644
index 00000000..084ec9bd
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/Field.h
@@ -0,0 +1,36 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid );
+
+    void Solve( Zone * zone );
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void UpdateOldField();
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/LogFile.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/LogFile.cpp
new file mode 100644
index 00000000..08ccd453
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/LogFile.cpp
@@ -0,0 +1,138 @@
+#include "LogFile.h"
+#include "Parallel.h"
+#include <sstream>
+#include <iostream>
+
+#ifdef _WINDOWS
+#include <windows.h>
+#include <direct.h>
+#include <io.h>
+#else
+#include <sys/stat.h>
+#include <unistd.h>
+#endif
+
+LogFile logFile;
+
+class OStream : public std::ostringstream
+{
+public:
+    OStream() {}
+    ~OStream() {}
+public:
+    void ClearAll()
+    {
+        this->clear();
+        this->str("");
+    }
+};
+
+OStream StrIO;
+std::string GetPrjDirName( const std::string & fileName );
+bool DirExist( const std::string & dirName );
+void MakeDir( const std::string & dirName );
+
+std::string GetPrjDirName( const std::string & fileName )
+{
+    size_t pos = fileName.find_last_of("\\/");
+    if ( std::string::npos == pos )
+    {
+        return "";
+    }
+    else
+    {
+        return fileName.substr( 0, pos );
+    }
+}
+
+bool DirExist( const std::string & dirName )
+{
+#ifdef _WINDOWS
+    bool flag = ( _access( dirName.c_str(), 0 ) == 0 );
+    return flag;
+#else
+    bool flag = ( access( dirName.c_str(), 0 ) == 0 );
+    return flag;
+#endif
+}
+
+void MakeDir( const std::string & dirName )
+{
+    int flag;
+#ifdef _WINDOWS
+    flag = _mkdir( dirName.c_str() );
+#else
+    flag = mkdir( dirName.c_str(), S_IRWXU );
+#endif
+    if ( flag == 0 )
+    {
+        std::cout << dirName << " directory has been created successfully !\n";
+    }
+}
+
+void CreateDirIfNeeded( std::string & prjFileName )
+{
+    std::string prj_dir = GetPrjDirName( prjFileName );
+
+    if ( ! DirExist( prj_dir ) )
+    {
+        MakeDir( prj_dir );
+    }
+}
+
+
+void OpenLogFile( int logFileIndex, std::fstream & file )
+{
+    static int ifReWrite = 0;
+
+    StrIO.ClearAll();
+    StrIO << "log/log" << logFileIndex << ".log";
+    std::string fileName = StrIO.str();
+
+    std::ios_base::openmode openMode;
+
+    if ( ifReWrite == 0 )
+    {
+        CreateDirIfNeeded( fileName );
+
+        openMode = std::ios_base::out | std::ios_base::trunc;
+
+        ifReWrite = 1;
+    }
+    else
+    {
+        openMode = std::ios_base::out | std::ios_base::app;
+    }
+
+    file.open( fileName.c_str(), openMode );
+    if ( ! file )
+    {
+        std::cout << "could not open " << fileName << std::endl;
+        exit( 0 );
+    }
+}
+
+void CloseLogFile( std::fstream & file )
+{
+    file.close();
+    file.clear();
+}
+
+LogFile::LogFile()
+{
+}
+
+LogFile::~LogFile()
+{
+}
+
+void LogFile::Open()
+{
+    int pid = Parallel::pid;
+    OpenLogFile( pid, this->my_fstream );
+}
+
+void LogFile::Close()
+{
+    CloseLogFile( this->my_fstream );
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/LogFile.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/LogFile.h
new file mode 100644
index 00000000..00e775ab
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/LogFile.h
@@ -0,0 +1,27 @@
+#pragma once
+#include <fstream>
+
+void OpenLogFile( int logFileIndex, std::fstream & file );
+void CloseLogFile( std::fstream & file );
+class LogFile;
+extern LogFile logFile;
+
+class LogFile
+{
+public:
+    LogFile();
+    ~LogFile();
+    std::fstream my_fstream;
+public:
+    void Open();
+    void Close();
+};
+
+template< typename T >
+LogFile & operator << ( LogFile & f, const T & value )
+{
+    f.Open();
+    f.my_fstream << value;
+    f.Close();
+    return f;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/Parallel.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/Parallel.cpp
new file mode 100644
index 00000000..0bce1a60
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/Parallel.cpp
@@ -0,0 +1,54 @@
+#include "Parallel.h"
+#include <iostream>
+
+int Parallel::pid = 0;
+int Parallel::nProc = 1;
+int Parallel::serverid = 0;
+int Parallel::tag = 0;
+
+void Parallel::Init()
+{
+#ifdef HX_PARALLEL
+    int argc     = 0;
+    char ** argv = 0;
+    MPI_Init( &argc, &argv );
+    MPI_Comm_rank( MPI_COMM_WORLD, &Parallel::pid );
+    MPI_Comm_size( MPI_COMM_WORLD, &Parallel::nProc );
+    int len = -1;
+    char version[ MPI_MAX_LIBRARY_VERSION_STRING ];
+    MPI_Get_library_version( version, &len );
+    std::cout << "Hello, world!  I am " << Parallel::pid << " of " << Parallel::nProc
+        << "(" << version << ", " << len << ")" << std::endl;
+#endif
+}
+
+void Parallel::Finalize()
+{
+#ifdef HX_PARALLEL
+    MPI_Finalize();
+#endif
+}
+
+bool Parallel::IsServer()
+{
+    return Parallel::pid == Parallel::serverid;
+}
+
+void HXSendChar( void * data, int size, int pid, int tag )
+{
+#ifdef HX_PARALLEL
+    if ( size <= 0 ) return;
+    MPI_Send( data, size, MPI_CHAR, pid, tag, MPI_COMM_WORLD );
+#endif
+}
+
+void HXRecvChar( void * data, int size, int pid, int tag )
+{
+#ifdef HX_PARALLEL
+    if ( size <= 0 ) return;
+
+    MPI_Status status;
+    MPI_Recv( data, size, MPI_CHAR, pid, tag, MPI_COMM_WORLD, & status );
+#endif
+}
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/Parallel.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/Parallel.h
new file mode 100644
index 00000000..880a71cb
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/Parallel.h
@@ -0,0 +1,78 @@
+#pragma once
+#ifdef HX_PARALLEL
+#include "mpi.h"
+#endif
+#include <vector>
+#include "LogFile.h"
+
+class Parallel
+{
+public:
+    static int pid;
+    static int nProc;
+    static int serverid;
+    static int tag;
+public:
+    static void Init();
+    static void Finalize();
+public:
+    static bool IsServer();
+};
+
+void HXSendChar( void * data, int size, int pid, int tag );
+void HXRecvChar( void * data, int size, int pid, int tag );
+
+template< typename T >
+void HXSendData( T * field, int nElement, int recv_pid, int tag  );
+
+template< typename T >
+void HXRecvData( T * field, int nElement, int send_pid, int tag );
+
+template< typename T >
+void HXSendData( T * field, int nElement, int recv_pid, int tag = 0 )
+{
+    if ( nElement <= 0 ) return;
+
+    int buffer_size = nElement * sizeof( T );
+
+    HXSendChar( field, buffer_size, recv_pid, tag );
+}
+
+template< typename T >
+void HXRecvData( T * field, int nElement, int send_pid, int tag = 0 )
+{
+    if ( nElement <= 0 ) return;
+
+    int buffer_size = nElement * sizeof( T );
+
+    HXRecvChar( field, buffer_size, send_pid, tag );
+}
+
+template< typename T >
+void HXSendRecvData( T * field, int nElement, int send_pid, int recv_pid, int tag = 0 )
+{
+    if ( send_pid == recv_pid ) return;
+
+    if ( nElement <= 0 ) return;
+
+    int buffer_size = nElement * sizeof( T );
+
+    if ( Parallel::pid == send_pid )
+    {
+        HXSendChar( field, buffer_size, recv_pid, tag );
+    }
+    else if ( Parallel::pid == recv_pid )
+    {
+        HXRecvChar( field, buffer_size, send_pid, tag );
+    }
+}
+
+template< typename T >
+void HXBcastData( T * field, int nElement, int send_pid )
+{
+    if ( nElement <= 0 ) return;
+    int buffer_size = nElement * sizeof( T );
+#ifdef HX_PARALLEL
+    MPI_Bcast( field, buffer_size, MPI_CHAR, send_pid, MPI_COMM_WORLD );
+#endif
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/README.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/Solver.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/Solver.cpp
new file mode 100644
index 00000000..e5f99802
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/Solver.cpp
@@ -0,0 +1,763 @@
+#include "Solver.h"
+#include "Parallel.h"
+#include "ZoneState.h"
+#include "global.h"
+#include <fstream>
+#include <set>
+#include <unordered_map>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+Solver::Solver()
+{
+    Parallel::Init();
+}
+
+Solver::~Solver()
+{
+    Parallel::Finalize();
+}
+
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    this->InitTopo();
+    this->InitFields();
+    this->SolveMultiZones();
+    this->PostProcess();
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d4blocksv1.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    ReadCgnsGrid( fileName );
+}
+
+void Solver::InitTopo()
+{
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "Solver::InitTopo() " << "\n";
+
+    //logFile << "Solver::InitTopo()\n";
+
+    Global::donor_zone_sets.resize( LocalZone::nZones );
+    Global::donor_zones.resize( LocalZone::nZones );
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        int global_zoneid = LocalZone::global_zoneids[ iZone ];
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "iZone = " << iZone << " global_zoneid = " << global_zoneid << "\n";
+
+        Interface * interface = new Interface();
+        interface->zoneid = global_zoneid;
+        Global::interfaces.push_back( interface );
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+        Interface * interface = Global::interfaces[ iZone ];
+        //logFile << "iZone = " << iZone << " LocalZone::global_zoneids[iZone] = " << LocalZone::global_zoneids[ iZone ] << "\n";
+
+        int nbc1to1s = zone->bc1to1s.size();
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout <<  "nbc1to1s = " << nbc1to1s << "\n";
+
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "zoneid = " << zoneid << " donor_zoneid = " << donor_zoneid << "\n";
+
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+        int nInterfaces = interface->zoneList.size();
+        interface->data_recv.resize( nInterfaces );
+        interface->data_send.resize( nInterfaces );
+    }
+
+    for ( int iProc = 0; iProc < Parallel::nProc; ++ iProc )
+    {
+        int nSize = -1;
+        if ( iProc == Parallel::pid )
+        {
+            nSize = Global::facePairList.size();
+        }
+        HXBcastData( &nSize, 1, iProc );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nSize = " << nSize << "\n";
+        std::vector<FacePair> tmp;
+        if ( iProc == Parallel::pid )
+        {
+            tmp = Global::facePairList;
+        }
+        else
+        {
+            tmp.resize( nSize );
+        }
+
+        HXBcastData( tmp.data(), tmp.size(), iProc );
+        Global::AddFacePairList( Global::mpi_facePairList, tmp );
+    }
+
+    for ( int i = 0; i < Global::mpi_facePairList.size(); ++ i )
+    {
+        FacePair &facePair = Global::mpi_facePairList[ i ];
+        Global::InsertFacePairMap( facePair );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        facePair.Print();
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterfaces = interface->local_faceids.size();
+        for ( int iInterface = 0; iInterface < nInterfaces; ++ iInterface )
+        {
+            int local_faceid = interface->local_faceids[ iInterface ];
+            int proc_global_faceid = interface->proc_global_faceids[ iInterface ];
+            FacePair & facePair = Global::facePairList[ proc_global_faceid ];
+            int global_faceid = Global::InsertFacePairMap( facePair );
+            interface->global_faceids.push_back( global_faceid );
+            interface->global_local_face_map.insert( std::make_pair( global_faceid, local_faceid ) );
+        }
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        std::set<int> &donor_zoneSet = Global::donor_zone_sets[ iZone ];
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            donor_zoneSet.insert( donor_zoneid );
+        }
+
+        std::vector<int> &donor_zones = Global::donor_zones[ iZone ];
+        for ( std::set<int>::iterator iter = donor_zoneSet.begin(); iter != donor_zoneSet.end(); ++ iter )
+        {
+            donor_zones.push_back( *iter );
+        }
+
+        interface->neighbor_donor_zones = donor_zones;
+
+        std::unordered_map<int, int> donor_zonelocal;
+
+        for ( int idonor = 0; idonor < donor_zones.size(); ++ idonor )
+        {
+            int donor_zone = donor_zones[ idonor ];
+            donor_zonelocal.insert( std::make_pair( donor_zone, idonor ) );
+        }
+        int ndonors = donor_zones.size();
+        std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+        neighbor_donorfaces.resize( ndonors );
+
+        std::vector<std::vector<int>> & sub_local_faceids = interface->sub_local_faceids;
+        sub_local_faceids.resize( ndonors );
+
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ineighbor = donor_zonelocal[ donor_zoneid ];
+            std::vector<int> &donorfaces = neighbor_donorfaces[ ineighbor ];
+            int global_faceid = interface->global_faceids[ iFace ];
+            donorfaces.push_back( global_faceid );
+            int local_faceid = interface->local_faceids[ iFace ];
+
+            std::vector<int> & sub_local_faces = sub_local_faceids[ ineighbor ];
+            sub_local_faces.push_back( local_faceid );
+        }
+    }
+
+    Global::interfaceTopo.InitNeighborInfo();
+    Global::interfaceTopo.SwapNeighborInfo();
+
+    int kkk = 1;
+}
+
+void Solver::InitFields()
+{
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "Solver::InitFields() ZoneState::nZones = " << ZoneState::nZones <<  "\n";
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+    }
+
+    Boundary();
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        //std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        //std::cout << "it = " << it << " nt = " << Global::nt << "\n";
+        for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+        {
+            Field * field = Global::fields[ iZone ];
+            Zone * zone = Global::zones[ iZone ];
+            zone->zoneIndex = iZone;
+            field->Solve( zone );
+        }
+        Boundary();
+    }
+}
+
+void Solver::Boundary()
+{
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+    ExchangeInterfaceField();
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->UpdateOldField();
+    }
+}
+
+void Solver::UploadInterfaceField()
+{
+    //logFile << "UploadInterfaceField\n";
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        //logFile << "ilocal zone = " << iZone << " global zone = " << LocalZone::global_zoneids[ iZone ] << "\n";
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> & send_to_zones = interface->send_to_zones;
+        int nsend_zones = send_to_zones.size();
+
+        //logFile << "nsend_zones = " << nsend_zones << "\n";
+
+        std::vector<std::vector<int>> & donorfaces_for_send = interface->donorfaces_for_send;
+        std::vector<std::vector<int>> & donorijk_for_send = interface->donorijk_for_send;
+        std::vector<std::vector<double>> & donordata_for_send = interface->donordata_for_send;
+
+        Field * field = Global::fields[ iZone ];
+
+        for ( int iSend = 0; iSend < nsend_zones; ++ iSend )
+        {
+            int zone_to_send = send_to_zones[ iSend ];
+            std::vector<int> & donorfaces = donorfaces_for_send[ iSend ];
+            std::vector<int> & donorijks = donorijk_for_send[ iSend ];
+            std::vector<double> & donordatas = donordata_for_send[ iSend ];
+
+            //logFile << "iSend = " << iSend << " zone_to_send " << zone_to_send << "\n";
+            //logFile << "donorfaces = ";
+            //for ( int i = 0; i < donorfaces.size(); ++ i )
+            //{
+            //    logFile << donorfaces[ i ] << " ";
+            //}
+            //logFile << "\n";
+            //logFile << "donordatas = ";
+            //for ( int i = 0; i < donordatas.size(); ++ i )
+            //{
+            //    logFile << donordatas[ i ] << " ";
+            //}
+            //logFile << "\n";
+
+            int nface = donorfaces.size();
+            int index_dim = 1;
+            for ( int i = 0; i < nface; ++ i )
+            {
+                int ijkpos = index_dim * i;
+                int i_donor_cell = donorijks[ ijkpos + 0 ];
+                //logFile << "i = " << i << " nface " << nface << " i_donor_cell = " << i_donor_cell << "\n";
+                donordatas[ i ] = field->u[ i_donor_cell ];
+            }
+
+            //logFile << "donordatas after = ";
+            //for ( int i = 0; i < donordatas.size(); ++ i )
+            //{
+            //    logFile << donordatas[ i ] << " ";
+            //}
+            //logFile << "\n";
+        }
+    }
+}
+
+void Solver::UpdateInterfaceField()
+{
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        //logFile << "UpdateInterfaceField iZone = " << iZone << "\n";
+        int ndonor_zones = Global::interfaceTopo.linkmap[ iZone ].size();
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donor_zone = Global::interfaceTopo.linkmap[ iZone ][ iNei ];
+            int send_pid = ZoneState::pids[ iZone ];
+            int recv_pid = ZoneState::pids[ donor_zone ];
+            //logFile << "iZone = " << iZone << " donor_zone = " << donor_zone << "\n";
+            //logFile << "send_pid = " << send_pid << " recv_pid = " << recv_pid << "\n";
+            int nsend = -1;
+            std::vector<double> donordata;
+            //std::vector<int> donorface;
+            if ( Parallel::pid != send_pid && Parallel::pid != recv_pid ) continue;
+            if ( Parallel::pid == send_pid )
+            {
+                int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+                Interface * interface = Global::interfaces[ local_zoneid ];
+                donordata = interface->donordata_for_send[ iNei ];
+                //donorface = interface->donorfaces_for_send[ iNei ];
+                nsend = donordata.size();
+            }
+            HXSendRecvData( &nsend, 1, send_pid, recv_pid );
+
+            //logFile << "nsend = " << nsend << "\n";
+
+            if ( Parallel::pid == recv_pid )
+            {
+                donordata.resize( nsend );
+                //donorface.resize( nsend );
+            }
+            HXSendRecvData( donordata.data(), donordata.size(), send_pid, recv_pid );
+            //HXSendRecvData( donorface.data(), donorface.size(), send_pid, recv_pid );
+            //logFile << "donordata = ";
+            //for ( int i = 0; i < donordata.size(); ++ i )
+            //{
+            //    logFile << donordata[ i ] << " ";
+            //}
+            //logFile << "\n";
+            //logFile << "donorface = ";
+            //for ( int i = 0; i < donorface.size(); ++ i )
+            //{
+            //    logFile << donorface[ i ] << " ";
+            //}
+            //logFile << "\n";
+
+            if ( Parallel::pid == recv_pid )
+            {
+                int local_donor_zoneid = ZoneState::g2lzoneids[ donor_zone ];
+                Interface * donor_interface = Global::interfaces[ local_donor_zoneid ];
+                int nSize = donor_interface->neighbor_donor_zones.size();
+                int ipos = -1;
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    int nei_zone = donor_interface->neighbor_donor_zones[ i ];
+                    if ( nei_zone == iZone )
+                    {
+                        ipos = i;
+                        break;
+                    }
+                }
+
+                std::vector<int> & neighbor_donorfaces = donor_interface->neighbor_donorfaces[ ipos ];
+                std::vector<int> & sub_local_faceids = donor_interface->sub_local_faceids[ ipos ];
+                for ( int i = 0; i < neighbor_donorfaces.size(); ++ i )
+                {
+                    int local_faceid = sub_local_faceids[ i ];
+                    double donor_value = donordata[ i ];
+                    donor_interface->data_recv[ local_faceid ] = donor_value;
+                }
+            }
+        }
+    }
+}
+
+void Solver::DownloadInterfaceField()
+{
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+        Field * field = Global::fields[ iZone ];
+
+        //logFile << "DownloadInterfaceField\n";
+        //logFile << "LocalZone::nZones = " << LocalZone::nZones << "\n";
+        //logFile << "iZone = " << iZone << " LocalZone::global_zoneids[iZone] = " << LocalZone::global_zoneids[ iZone ] << "\n";
+
+        //logFile << "field->u[ 1 ] = " <<field->u[ 1 ] << "\n";
+        //logFile << "field->u[ 21 ] = " <<field->u[ 21 ] << "\n";
+
+        int nInterFaces = interface->data_recv.size();
+
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+
+            double donor_value = interface->data_recv[ iFace ];
+            //logFile << "donor_value = " << donor_value << "\n";
+            //logFile << "i_ghost_cell = " << i_ghost_cell << "\n";
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    this->UploadInterfaceField();
+    this->UpdateInterfaceField();
+    this->DownloadInterfaceField();
+}
+
+void Solver::PostProcess()
+{
+    Post post;
+    post.Process();
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        if ( !ZoneState::IsValid( iZone ) && !Parallel::IsServer() ) continue;
+
+        double xmin = 0.0;
+        double xmax = 0.0;
+
+        if ( ZoneState::IsValid( iZone ) )
+        {
+            int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+            Grid * grid = Global::grids[ local_zoneid ];
+            int ni = grid->x.size();
+            xmin = grid->x[ 0 ];
+            xmax = grid->x[ 0 ];
+            int imin = 0;
+            int imax = 0;
+            for ( int i = 0; i < ni; ++ i )
+            {
+                if ( xmin > grid->x[ i ] )
+                {
+                    xmin = grid->x[ i ];
+                    imin = i;
+                }
+                if ( xmax < grid->x[ i ] )
+                {
+                    xmax = grid->x[ i ];
+                    imax = i;
+                }
+            }
+        }
+
+        HXSendRecvData( &xmin, 1, ZoneState::pids[ iZone ], Parallel::serverid );
+        HXSendRecvData( &xmax, 1, ZoneState::pids[ iZone ], Parallel::serverid );
+
+        if ( Parallel::IsServer() )
+        {
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "xmin = " << xmin << "\n";
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "xmax = " << xmax << "\n";
+        }
+
+        if ( Parallel::IsServer() )
+        {
+            xmin_list.push_back( xmin );
+            xmax_list.push_back( xmax );
+        }
+    }
+
+    if ( Parallel::IsServer() )
+    {
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        for ( int i = 0; i < xmin_list.size(); ++ i )
+        {
+            std::cout << "(" << xmin_list[ i ] << "," << xmax_list[ i ] << ") ";
+        }
+        std::cout << "\n";
+    }
+
+    if ( Parallel::IsServer() )
+    {
+        std::vector<std::pair<double, int>> pairs;
+        int nSize = xmin_list.size();
+        for ( int i = 0; i < nSize; ++ i )
+        {
+            pairs.push_back( std::make_pair( xmin_list[ i ], i ) );
+        }
+
+        std::sort( pairs.begin(), pairs.end() );
+
+        for ( int i = 0; i < nSize; ++ i )
+        {
+            this->zoneids.push_back( pairs[ i ].second );
+        }
+    }
+
+    int kkk = 1;
+}
+
+bool IsLastZone( int iZone );
+bool IsLastZone( int iZone )
+{
+    return iZone == ZoneState::nZones - 1;
+}
+
+void Post::AddVector( std::vector<double> & a, std::vector<double> & b )
+{
+    for ( int i = 0; i < b.size(); ++ i )
+    {
+        a.push_back( b[ i ] );
+    }
+}
+
+void Post::GatherField()
+{
+    logFile << "Post::GatherField  1 \n";
+    this->zoneids.resize( ZoneState::nZones );
+    HXBcastData( this->zoneids.data(), this->zoneids.size(), Parallel::serverid );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "Post::GatherField() this->zoneids = \n";
+    for ( int i = 0; i < this->zoneids.size(); ++ i )
+    {
+        std::cout << this->zoneids[ i ] << " ";
+    }
+    std::cout << "\n";
+
+    logFile << "Post::GatherField  2 \n";
+
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+        logFile << "iZone = " << iZone << " zoneid = " << zoneid << "\n";
+        logFile << "ZoneState::pids[ iZone ] = " << ZoneState::pids[ iZone ] << "\n";
+
+        if ( !ZoneState::IsValid( zoneid ) && !Parallel::IsServer() ) continue;
+
+        int nSize = -1;
+        logFile << "nSize = " << nSize << "\n";
+        std::vector<double> local_x;
+        std::vector<double> local_u_e;
+        std::vector<double> local_un;
+        std::vector<double> local_u;
+
+        logFile << "Parallel::pid = " << Parallel::pid << " ZoneState::pids[ zoneid ] = " << ZoneState::pids[ zoneid ] << "\n";
+
+        if ( Parallel::pid == ZoneState::pids[ zoneid ] )
+        {
+            int local_zoneid = ZoneState::g2lzoneids[ zoneid ];
+            Grid * grid = Global::grids[ local_zoneid ];
+            Field * field = Global::fields[ local_zoneid ];
+            int ni = grid->x.size();
+
+            int ist = 1;
+            int ied = ni;
+
+            int dir = 1;
+            if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+            if ( dir == 1 )
+            {
+                if ( IsLastZone( iZone ) )
+                {
+                    for ( int i = ist; i <= ied; ++ i )
+                    {
+                        double xm = grid->x[ i - ist ];
+                        local_x.push_back( xm );
+                        local_u_e.push_back( field->u_e[ i ] );
+                        local_un.push_back( field->un[ i ] );
+                        local_u.push_back( field->u[ i ] );
+                    }
+                }
+                else
+                {
+                    for ( int i = ist; i <= ied - 1; ++ i )
+                    {
+                        double xm = grid->x[ i - ist ];
+                        local_x.push_back( xm );
+                        local_u_e.push_back( field->u_e[ i ] );
+                        local_un.push_back( field->un[ i ] );
+                        local_u.push_back( field->u[ i ] );
+                    }
+                }
+            }
+            else
+            {
+                if ( IsLastZone( iZone ) )
+                {
+                    for ( int i = ied; i >= ist; -- i )
+                    {
+                        double xm = grid->x[ i - ist ];
+                        local_x.push_back( xm );
+                        local_u_e.push_back( field->u_e[ i ] );
+                        local_un.push_back( field->un[ i ] );
+                        local_u.push_back( field->u[ i ] );
+                    }
+                }
+                else
+                {
+                    for ( int i = ied; i >= ist + 1; -- i )
+                    {
+                        double xm = grid->x[ i - ist ];
+                        local_x.push_back( xm );
+                        local_u_e.push_back( field->u_e[ i ] );
+                        local_un.push_back( field->un[ i ] );
+                        local_u.push_back( field->u[ i ] );
+                    }
+                }
+            }
+            nSize = local_x.size();
+        }
+
+        logFile << "Parallel::pid = " << Parallel::pid << "\n";
+        logFile << "ZoneState::pids[ zoneid ] = " << ZoneState::pids[ zoneid ] << "\n";
+        logFile << "Parallel::serverid = " << Parallel::serverid << "\n";
+
+        int send_pid = ZoneState::pids[ zoneid ];
+        logFile << "send_pid = " << send_pid << "\n";
+
+        HXSendRecvData( &nSize, 1, send_pid, Parallel::serverid );
+
+        logFile << "nSize = " << nSize << "\n";
+
+        if ( Parallel::IsServer() )
+        {
+            local_x.resize( nSize );
+            local_u_e.resize( nSize );
+            local_un.resize( nSize );
+            local_u.resize( nSize );
+        }
+
+        HXSendRecvData( local_x.data(), local_x.size(), send_pid, Parallel::serverid );
+        HXSendRecvData( local_u_e.data(), local_u_e.size(), send_pid, Parallel::serverid );
+        HXSendRecvData( local_un.data(), local_un.size(), send_pid, Parallel::serverid );
+        HXSendRecvData( local_u.data(), local_u.size(), send_pid, Parallel::serverid );
+
+        if ( Parallel::IsServer() )
+        {
+            this->AddVector( this->x, local_x );
+            this->AddVector( this->u_e, local_u_e );
+            this->AddVector( this->un, local_un );
+            this->AddVector( this->u, local_u );
+        }
+    }
+
+    logFile << "Post::GatherField  3 \n";
+}
+
+void Post::DumpField()
+{
+    //logFile << "Post::DumpField() \n";
+    if ( !Parallel::IsServer() ) return;
+    int ni_total = this->x.size();
+    //logFile << " DumpField x.size() = " << x.size() << "\n";
+    std::cout << " DumpField x.size() = " << x.size() << "\n";
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    //logFile << "DumpErrorDetails \n";
+
+    this->DumpErrorDetails( u_error );
+
+    //logFile << "DumpCsvFile \n";
+
+    std::string csvname = "field_final.csv";
+    this->DumpCsvFile( csvname, x, u_e, un, u_error );
+    //logFile << "DumpCsvFile End \n";
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.20f} {:.20f} {:.20f} {:.20f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/Solver.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/Solver.h
new file mode 100644
index 00000000..9914c1d7
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/Solver.h
@@ -0,0 +1,49 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+
+class Solver
+{
+public:
+    Solver();
+    ~Solver();
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveMultiZones();
+public:
+    void Boundary();
+    void UploadInterfaceField();
+    void UpdateInterfaceField();
+    void DownloadInterfaceField();
+    void ExchangeInterfaceField();
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcess();
+};
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+    std::vector<double> u;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+public:
+    void AddVector( std::vector<double> & a, std::vector<double> & b );
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/ZoneState.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/ZoneState.cpp
new file mode 100644
index 00000000..ff810849
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/ZoneState.cpp
@@ -0,0 +1,20 @@
+#include "ZoneState.h"
+#include "Parallel.h"
+
+int ZoneState::nZones = 0;
+std::vector<int> ZoneState::pids;
+std::vector<int> ZoneState::g2lzoneids;
+
+bool ZoneState::IsValid( int zoneid )
+{
+    return ZoneState::pids[ zoneid ] == Parallel::pid;
+}
+
+int ZoneState::GetProcID( int zoneid )
+{
+    return ZoneState::pids[ zoneid ];
+}
+
+int LocalZone::nZones = 0;
+std::vector<int> LocalZone::global_zoneids;
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/ZoneState.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/ZoneState.h
new file mode 100644
index 00000000..1096d632
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/ZoneState.h
@@ -0,0 +1,21 @@
+#pragma once
+#include <vector>
+
+class ZoneState
+{
+public:
+    static int nZones;
+    static int zone_id;
+    static std::vector<int> pids;
+    static std::vector<int> g2lzoneids; //global zone id to local zone id
+public:
+    static bool IsValid( int zoneid );
+    static int GetProcID( int zoneid );
+};
+
+class LocalZone
+{
+public:
+    static int nZones;
+    static std::vector<int> global_zoneids;
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/global.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/global.cpp
new file mode 100644
index 00000000..8562907f
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/global.cpp
@@ -0,0 +1,301 @@
+#include "global.h"
+#include "CgnsGrid.h"
+#include "ZoneState.h"
+#include "Parallel.h"
+#include <iostream>
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *> Global::interfaces;
+
+std::map<Face, int> Global::faceMap;
+std::map<FacePair, int> Global::facePairMap;
+std::vector<FacePair> Global::facePairList;
+std::vector<FacePair> Global::mpi_facePairList;
+
+std::vector<std::set<int>> Global::donor_zone_sets;
+std::vector<std::vector<int>> Global::donor_zones;
+
+InterfaceTopo Global::interfaceTopo;
+
+bool Face::operator < ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return this->zone < rhs.zone;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return this->i < rhs.i;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return this->j < rhs.j;
+    }
+
+    return this->k < rhs.k;
+}
+
+bool Face::operator == ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return false;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return false;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return false;
+    }
+
+    return this->k == rhs.k;
+}
+
+void Face::Print()
+{
+    std::cout << "(" << this->zone << "," << this->i << ")";
+}
+
+void FacePair::AddPair( const Face & face1, const Face & face2 )
+{
+    if ( face1 < face2 )
+    {
+        this->left = face1;
+        this->right = face2;
+    }
+    else
+    {
+        this->left = face2;
+        this->right = face1;
+    }
+}
+
+bool FacePair::operator < ( const FacePair & rhs ) const
+{
+    if ( this->left == rhs.left || this->left == rhs.right )
+    {
+        return false;
+    }
+
+    return this->left < rhs.left;
+}
+
+void FacePair::Print()
+{
+    this->left.Print();
+    std::cout << " ";
+    this->right.Print();
+    std::cout << "\n";
+}
+
+void InterfaceTopo::InitNeighborInfo()
+{
+    this->linkmap.resize( ZoneState::nZones );
+
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        if ( ! ZoneState::IsValid( iZone ) ) continue;
+
+        int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+
+        Interface * interface = Global::interfaces[ local_zoneid ];
+
+        std::vector<int> & t = this->linkmap[ iZone ];
+        t = interface->neighbor_donor_zones;
+    }
+}
+
+void InterfaceTopo::SwapNeighborInfo()
+{
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        int pid = ZoneState::pids[ iZone ];
+
+        std::vector<int> & donor_zones = this->linkmap[ iZone ];
+        int nNeighbor = donor_zones.size();
+
+        HXBcastData( &nNeighbor, 1, pid );
+
+        donor_zones.resize( nNeighbor );
+
+        HXBcastData( donor_zones.data(), donor_zones.size(), pid );
+    }
+
+    this->SwapNeighborDonorfaces();
+}
+
+void InterfaceTopo::SwapNeighborDonorfaces()
+{
+    int gl = 0;
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        int send_pid = ZoneState::pids[ iZone ];
+
+        std::vector<int> & donor_zones = this->linkmap[ iZone ];
+        int ndonor_zones = donor_zones.size();
+
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donor_zone = donor_zones[ iNei ];
+            int recv_pid = ZoneState::pids[ donor_zone ];
+            int nInterFaces = 0;
+            std::vector<int> donorfaces;
+
+            if ( Parallel::pid == send_pid )
+            {
+                int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+
+                Interface * interface = Global::interfaces[ local_zoneid ];
+
+                std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+
+                std::vector<int> & neighbor_donorface = neighbor_donorfaces[ iNei ];
+
+                nInterFaces = neighbor_donorface.size();
+
+                donorfaces = neighbor_donorface;
+            }
+
+            HXSendRecvData( &nInterFaces, 1, send_pid, recv_pid );
+
+            if ( Parallel::pid == recv_pid && send_pid != recv_pid )
+            {
+                donorfaces.resize( nInterFaces );
+            }
+
+            HXSendRecvData( donorfaces.data(), donorfaces.size(), send_pid, recv_pid );
+
+            if ( Parallel::pid == recv_pid )
+            {
+                int local_donor_zoneid = ZoneState::g2lzoneids[ donor_zone ];
+                Interface * interface_recv = Global::interfaces[ local_donor_zoneid ];
+                interface_recv->SendGeom( iZone, donorfaces );
+            }
+        }
+    }
+}
+
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->local_faceids.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        Face face;
+        face.zone = zoneid;
+        face.i = i;
+
+        int i_donor = index2[ 0 ];
+
+        Face face_donor;
+        face_donor.zone = donor_zoneid;
+        face_donor.i = i_donor;
+
+        FacePair facePair;
+        facePair.AddPair( face, face_donor );
+
+        Global::facePairList.push_back( facePair );
+        int nSize = Global::facePairList.size();
+        this->proc_global_faceids.push_back( nSize - 1 );
+
+        int i_ghost_cell = i + 1;
+        int i_local_donor_cell = i - 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+            i_local_donor_cell = i + 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+        ijk_donors.push_back( i_local_donor_cell );
+
+        icount ++;
+    }
+}
+
+void Interface::SendGeom( int zone, std::vector<int> & donorfaces )
+{
+    //Interface * interface = Global::interfaces[ donorzone ];
+    Interface * interface = this;
+
+    std::vector<int> & send_to_zones = interface->send_to_zones;
+
+    send_to_zones.push_back( zone );
+    interface->donorfaces_for_send.push_back( donorfaces );
+
+    int nface = donorfaces.size();
+    std::vector<int> sub_donorijk;
+    int index_dim = 1;
+    for ( int i = 0; i < nface; ++ i )
+    {
+        int global_faceid = donorfaces[ i ];
+        int local_faceid = interface->global_local_face_map[ global_faceid ];
+        int ijkpos = index_dim * local_faceid;
+        int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+        sub_donorijk.push_back( i_donor_cell );
+        int kkk = 1;
+    }
+
+    interface->donorijk_for_send.push_back( sub_donorijk );
+
+    std::vector<double> sub_donordata( sub_donorijk.size() );
+    interface->donordata_for_send.push_back( sub_donordata );
+}
+
+void Global::InsertFaceMap( const Face & face )
+{
+    std::map<Face, int>::iterator iter;
+    iter = Global::faceMap.find( face );
+    if ( iter == Global::faceMap.end() )
+    {
+        int faceid = Global::faceMap.size();
+        Global::faceMap.insert( std::make_pair( face, faceid ) );
+    }
+}
+
+int Global::InsertFacePairMap( const FacePair & facePair )
+{
+    std::map<FacePair, int>::iterator iter;
+    iter = Global::facePairMap.find( facePair );
+    if ( iter == Global::facePairMap.end() )
+    {
+        int facePairId = Global::facePairMap.size();
+        Global::facePairMap.insert( std::make_pair( facePair, facePairId ) );
+        return facePairId;
+    }
+    return iter->second;
+}
+
+void Global::AddFacePairList( std::vector<FacePair> & a, std::vector<FacePair> & b )
+{
+    for ( int i = 0; i < b.size(); ++ i )
+    {
+        a.push_back( b[ i ] );
+    }
+}
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/global.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/global.h
new file mode 100644
index 00000000..933cec05
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/global.h
@@ -0,0 +1,157 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <unordered_map>
+#include <set>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class Face
+{
+public:
+    int zone = 0;
+    int i = 0;
+    int j = 1;
+    int k = 1;
+public:
+    bool operator < ( const Face & rhs ) const;
+    bool operator == ( const Face & rhs ) const;
+public:
+    void Print();
+};
+
+class FacePair
+{
+public:
+    Face left;
+    Face right;
+public:
+    bool operator < ( const FacePair & rhs ) const;
+    void AddPair( const Face &face1, const Face &face2);
+public:
+    void Print();
+};
+
+class Transform;
+
+class InterfaceTopo
+{
+public:
+    std::vector<std::vector<int>> linkmap;
+public:
+    void InitNeighborInfo();
+    void SwapNeighborInfo();
+    void SwapNeighborDonorfaces();
+};
+
+
+class Interface
+{
+public:
+    int zoneid;
+    std::vector<int> zoneList;
+    std::vector<int> global_faceids;
+    std::vector<int> mpi_global_faceids;
+    std::vector<int> proc_global_faceids;
+    std::vector<int> local_faceids;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+    std::vector<double> data_recv;
+    std::vector<double> data_send;
+    std::unordered_map<int, int> global_local_face_map;
+public:
+    std::vector<int> neighbor_donor_zones;
+    std::vector<std::vector<int>> neighbor_donorfaces;
+    std::vector<std::vector<int>> sub_local_faceids;
+    std::vector<int> send_to_zones;
+    std::vector<std::vector<int>> donorfaces_for_send;
+    std::vector<std::vector<int>> donorijk_for_send;
+    std::vector<std::vector<double>> donordata_for_send;
+public:
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+    void SendGeom( int zone, std::vector<int> & donorfaces );
+};
+
+class Field;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+public:
+    static std::map<Face, int> faceMap;
+    static std::map<FacePair, int> facePairMap;
+    static std::vector<FacePair> facePairList;
+    static std::vector<FacePair> mpi_facePairList;
+    static std::vector<std::set<int>> donor_zone_sets;
+    static std::vector<std::vector<int>> donor_zones;
+    static InterfaceTopo interfaceTopo;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+public:
+    static void InsertFaceMap( const Face & face );
+    static int InsertFacePairMap( const FacePair & facePair );
+    static void AddFacePairList( std::vector<FacePair> & a, std::vector<FacePair> & b );
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/heat1d4blocksv1.cgns b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/heat1d4blocksv1.cgns
new file mode 100644
index 00000000..df5ffc5f
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/heat1d4blocksv1.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/main.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/main.cpp
new file mode 100644
index 00000000..df63b7da
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/main.cpp
@@ -0,0 +1,9 @@
+#include "Solver.h"
+#include "Parallel.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/plot.py b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02i/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/CMakeLists.txt
new file mode 100644
index 00000000..9e834b72
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/CMakeLists.txt
@@ -0,0 +1,99 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package ( MPI )
+
+message ( STATUS  "MPI_FOUND=${MPI_FOUND}" )
+message ( STATUS  "MPI_CXX_INCLUDE_DIRS=${MPI_CXX_INCLUDE_DIRS}" )
+message ( STATUS  "MPI_LIBRARIES=${MPI_LIBRARIES}" )
+if ( MPI_FOUND )
+	list ( APPEND PRJ_INCLUDE_DIRS ${MPI_CXX_INCLUDE_DIRS} )
+	list ( APPEND PRJ_LIBRARIES ${MPI_LIBRARIES} )
+endif ()
+
+#get_directory_property( my_import_targets DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} IMPORTED_TARGETS )
+#message( STATUS "my_import_targets=${my_import_targets}" )
+
+list ( APPEND PRJ_LIBRARIES MPI::MPI_C )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+list ( APPEND PRJ_COMPILE_DEFINITIONS HX_PARALLEL )
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	LogFile.h LogFile.cpp
+	Parallel.h Parallel.cpp
+	Solver.h Solver.cpp
+	ZoneState.h ZoneState.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/CgnsGrid.cpp
new file mode 100644
index 00000000..4baf036f
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/CgnsGrid.cpp
@@ -0,0 +1,858 @@
+#include "CgnsGrid.h"
+#include "Parallel.h"
+#include "cgnslib.h"
+#include "global.h"
+#include "ZoneState.h"
+#include <iostream>
+#include <vector>
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "fileId = " << fileId << "\n";
+    }
+    
+    int nbases = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_nbases( fileId, &nbases );
+    }
+    HXBcastData( &nbases, 1, Parallel::serverid );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "nbases = " << nbases << "\n";
+    
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        }
+
+        HXBcastData( &icelldim, 1, Parallel::serverid );
+        HXBcastData( &iphysdim, 1, Parallel::serverid );
+
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+
+        int nzones = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_nzones( fileId, baseId, &nzones );
+        }
+
+        HXBcastData( &nzones, 1, Parallel::serverid );
+
+        ZoneState::nZones = nzones;
+        ZoneState::pids.resize( nzones );
+        ZoneState::g2lzoneids.resize( nzones );
+
+        if ( Parallel::nProc == 1 )
+        {
+            for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+            {
+                ZoneState::pids[ iZone ] = 0;
+                ZoneState::g2lzoneids[ iZone ] = iZone;
+            }
+        }
+        else
+        {
+            for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+            {
+                ZoneState::pids[ iZone ] = iZone;
+                ZoneState::g2lzoneids[ iZone ] = 0;
+            }
+        }
+
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nzones = " << nzones << "\n";
+
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "iZone = " << iZone << "\n";
+
+            int index_dim = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            }
+            HXBcastData( &index_dim, 1, Parallel::serverid );
+
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            if ( Parallel::IsServer() )
+            {
+                cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            }
+
+            HXBcastData( zonename, 33, Parallel::serverid );
+            HXBcastData( isize.data(), isize.size(), Parallel::serverid);
+
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "zonename = " << zonename << "\n";
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+
+    if ( Parallel::IsServer() )
+    {
+        cg_close( fileId );
+    }
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+        std::cout << "fileId = " << fileId << "\n";
+    }
+    
+    int nbases = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_nbases( fileId, &nbases );
+    }
+    MPI_Bcast( &nbases, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        }
+
+        HXBcastData( &icelldim, 1, Parallel::serverid );
+        HXBcastData( &iphysdim, 1, Parallel::serverid );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+
+        int nzones = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_nzones( fileId, baseId, &nzones );
+        }
+        HXBcastData( &nzones, 1, Parallel::serverid );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nzones = " << nzones << "\n";
+
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            }
+            HXSendRecvData( &index_dim, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "index_dim = " << index_dim << "\n";
+            }
+
+            std::vector<cgsize_t> isize;
+            char zonename[ 33 ];
+            if ( Parallel::IsServer() )
+            {
+                isize.resize( index_dim * 3 );
+                cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            }
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                isize.resize( index_dim * 3 );
+            }
+
+            HXSendRecvData( zonename, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+            HXSendRecvData( isize.data(), index_dim * 3, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "zonename = " << zonename << "\n";
+
+                for ( int i = 0; i < isize.size(); ++ i )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+                }
+            }
+
+            std::vector<cgsize_t> irmin;
+            std::vector<cgsize_t> irmax;
+            int nNodes = 1;
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                irmin.resize( index_dim );
+                irmax.resize( index_dim );
+                for ( int m = 0; m < index_dim; ++ m )
+                {
+                    /* lower range index */
+                    irmin[ m ] = 1;
+                    /* upper range index of vertices */
+                    irmax[ m ] = isize[ m ];
+                    nNodes *= irmax[ m ];
+                }
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "nNodes = " << nNodes << "\n";
+            }
+
+            ZoneType_t zoneType;
+            if ( Parallel::IsServer() )
+            {
+                cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            }
+            HXSendRecvData( &zoneType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            }
+
+            Zone * zone = nullptr;
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                zone = new Zone();
+                Global::zones.push_back( zone );
+                LocalZone::global_zoneids.push_back( iZone );
+                LocalZone::nZones = LocalZone::global_zoneids.size();
+                for ( int m = 0; m < index_dim; ++ m )
+                {
+                    zone->nijk.push_back( isize[ m ] );
+                }
+            }
+
+            Grid * grid = nullptr;
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                grid = new Grid();
+                Global::grids.push_back( grid );
+            }
+
+            BaseZone baseZone;
+
+            int gZoneId = -1;
+            if ( Parallel::IsServer() )
+            {
+                baseZone.zone_name = zonename;
+                gZoneId = Global::zone_names.FindBaseZone( baseZone );
+            }
+
+            HXSendRecvData( &gZoneId, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "gZoneId = " << gZoneId << "\n";
+            }
+
+            int ncoords = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            }
+            HXSendRecvData( &ncoords, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "ncoords = " << ncoords << "\n";
+            }
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                if ( Parallel::IsServer() )
+                {
+                    cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                }
+                HXSendRecvData( coordname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &dataType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "coordname = " << coordname << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                }
+
+                std::vector<char> coord;
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    coord.resize( nNodes * sizeof( double ) );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coord.data() );
+                }
+
+                HXSendRecvData( coord.data(), coord.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                Coor * coor = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    coor = new Coor();
+                    zone->coors.push_back( coor );
+                    coor->coorname = coordname;
+                    coor->nNodes = nNodes;
+                    coor->coord = coord;
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    coor->DumpCoor();
+
+                    if ( icoord == 0 )
+                    {
+                        grid->x.resize( nNodes );
+                        coor->DumpCoorX( grid->x );
+                    }
+                }
+            }
+
+            int nbocos = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            }
+            HXSendRecvData( &nbocos, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "nbocos = " << nbocos << "\n";
+            }
+
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                if ( Parallel::IsServer() )
+                {
+                    cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                }
+                HXSendRecvData( &location, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+                }
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                //std::vector<int> normalIndex( index_dim, -1 );
+                std::vector<int> normalIndex;
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+                if ( Parallel::IsServer() )
+                {
+                    normalIndex.resize( index_dim );
+                    cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                        &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                }
+
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    normalIndex.resize( index_dim );
+                }
+                
+                HXSendRecvData( boconame, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &bocotype, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &ptset_type, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &npnts, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &normalDataType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &normalListSize, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( normalIndex.data(), index_dim, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &ndataset, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "npnts = " << npnts << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalListSize = " << normalListSize << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalIndex = ";
+                    for ( int i = 0; i < index_dim; ++ i )
+                    {
+                        std::cout << normalIndex[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "ndataset = " << ndataset << "\n";
+                }
+
+                std::vector<char> normalList;
+                std::vector<cgsize_t> pnts;
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    if ( normalDataType == DataTypeNull )
+                    {
+                        normalList.resize( sizeof( int ) );
+                    }
+                    else
+                    {
+                        int nSize = nNodes * index_dim * sizeof( double );
+                        normalList.resize( nSize );
+                    }
+                    pnts.resize( npnts * index_dim );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                }
+
+                HXSendRecvData( pnts.data(), npnts * index_dim, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "pnts = ";
+                    for ( int i = 0; i < pnts.size(); ++ i )
+                    {
+                        std::cout << pnts[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                }
+                HXSendRecvData( normalList.data(), normalList.size(), Parallel::serverid, ZoneState::GetProcID(iZone));
+
+                ZoneBc * zonebc = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    zonebc = new ZoneBc();
+                    zone->bccos.push_back( zonebc );
+                    zonebc->bcType = bocotype;
+                    for ( int i = 0; i < pnts.size(); ++ i )
+                    {
+                        zonebc->pnts.push_back( pnts[ i ] );
+                    }
+                }
+            }
+            int n1to1 = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            }
+
+            HXSendRecvData( &n1to1, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "n1to1 = " << n1to1 << "\n";
+            }
+
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range;
+                std::vector<cgsize_t> donor_range;
+                std::vector<int> transform;
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    range.resize( npnts * index_dim );
+                    donor_range.resize( npnts * index_dim );
+                    transform.resize( index_dim );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                }
+
+                HXSendRecvData( connectname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( donorname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( range.data(), range.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( donor_range.data(), donor_range.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( transform.data(), transform.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "connectname = " << connectname << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "donorname = " << donorname << "\n";
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "range = ";
+                    for ( int i = 0; i < range.size(); ++ i )
+                    {
+                        std::cout << range[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "donor_range = ";
+                    for ( int i = 0; i < donor_range.size(); ++ i )
+                    {
+                        std::cout << donor_range[ i ] << " ";
+                    }
+                    std::cout << "\n";
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "transform = ";
+                    for ( int i = 0; i < transform.size(); ++ i )
+                    {
+                        std::cout << transform[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                }
+
+                int gDonorZoneId = -1;
+                if ( Parallel::IsServer() )
+                {
+                    BaseZone baseZoneDonor;
+                    baseZoneDonor.zone_name = donorname;
+
+                    gDonorZoneId = Global::zone_names.FindBaseZone( baseZoneDonor );
+                }
+
+                HXSendRecvData( &gDonorZoneId, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                ZoneBc1To1 * zonebc_1to1 = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    zonebc_1to1 = new ZoneBc1To1();
+                    zone->bc1to1s.push_back( zonebc_1to1 );
+                    zonebc_1to1->zoneid = gZoneId;
+                    zonebc_1to1->transform = transform;
+                    zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                    for ( int i = 0; i < range.size(); ++ i )
+                    {
+                        zonebc_1to1->pnts.push_back( range[ i ] );
+                        zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                    }
+                }
+            }
+        }
+    }
+
+    {
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "Global::zones.size() = " << Global::zones.size() << "\n";
+    }
+
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/CgnsGrid.h
new file mode 100644
index 00000000..fddf1db6
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/CgnsGrid.h
@@ -0,0 +1,103 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    int zoneIndex;
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/Field.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/Field.cpp
new file mode 100644
index 00000000..c359a811
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/Field.cpp
@@ -0,0 +1,142 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+
+    std::vector<double> & x = grid->x;
+    this->dx = std::abs( x[ 1 ] - x[ 0 ] );
+    this->dt = dx / 10.0;
+    this->t = 1.0;
+    this->nt = std::round( t / dt );
+
+    double total_time = nt * dt;
+
+    std::cout << "this->dt   = " << this->dt << "\n";
+    std::cout << "this->t    = " << this->t << "\n";
+    std::cout << "this->nt   = " << this->nt << "\n";
+    std::cout << "this->ni   = " << this->ni << "\n";
+    std::cout << "total_time = " << total_time << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        u_e[ i ] = - std::exp( -total_time ) * std::sin( std::numbers::pi * xm ); //theory solution
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+    int kkk = 1;
+}
+
+void Field::Solve( Zone * zone )
+{
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+    }
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        //std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        //region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+        int kkk = 1;
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
+
+void Field::UpdateOldField()
+{
+    for ( int i = 0; i < this->u.size(); ++ i )
+    {
+        this->un[ i ] = this->u[ i ];
+    }
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/Field.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/Field.h
new file mode 100644
index 00000000..084ec9bd
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/Field.h
@@ -0,0 +1,36 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid );
+
+    void Solve( Zone * zone );
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void UpdateOldField();
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/LogFile.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/LogFile.cpp
new file mode 100644
index 00000000..08ccd453
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/LogFile.cpp
@@ -0,0 +1,138 @@
+#include "LogFile.h"
+#include "Parallel.h"
+#include <sstream>
+#include <iostream>
+
+#ifdef _WINDOWS
+#include <windows.h>
+#include <direct.h>
+#include <io.h>
+#else
+#include <sys/stat.h>
+#include <unistd.h>
+#endif
+
+LogFile logFile;
+
+class OStream : public std::ostringstream
+{
+public:
+    OStream() {}
+    ~OStream() {}
+public:
+    void ClearAll()
+    {
+        this->clear();
+        this->str("");
+    }
+};
+
+OStream StrIO;
+std::string GetPrjDirName( const std::string & fileName );
+bool DirExist( const std::string & dirName );
+void MakeDir( const std::string & dirName );
+
+std::string GetPrjDirName( const std::string & fileName )
+{
+    size_t pos = fileName.find_last_of("\\/");
+    if ( std::string::npos == pos )
+    {
+        return "";
+    }
+    else
+    {
+        return fileName.substr( 0, pos );
+    }
+}
+
+bool DirExist( const std::string & dirName )
+{
+#ifdef _WINDOWS
+    bool flag = ( _access( dirName.c_str(), 0 ) == 0 );
+    return flag;
+#else
+    bool flag = ( access( dirName.c_str(), 0 ) == 0 );
+    return flag;
+#endif
+}
+
+void MakeDir( const std::string & dirName )
+{
+    int flag;
+#ifdef _WINDOWS
+    flag = _mkdir( dirName.c_str() );
+#else
+    flag = mkdir( dirName.c_str(), S_IRWXU );
+#endif
+    if ( flag == 0 )
+    {
+        std::cout << dirName << " directory has been created successfully !\n";
+    }
+}
+
+void CreateDirIfNeeded( std::string & prjFileName )
+{
+    std::string prj_dir = GetPrjDirName( prjFileName );
+
+    if ( ! DirExist( prj_dir ) )
+    {
+        MakeDir( prj_dir );
+    }
+}
+
+
+void OpenLogFile( int logFileIndex, std::fstream & file )
+{
+    static int ifReWrite = 0;
+
+    StrIO.ClearAll();
+    StrIO << "log/log" << logFileIndex << ".log";
+    std::string fileName = StrIO.str();
+
+    std::ios_base::openmode openMode;
+
+    if ( ifReWrite == 0 )
+    {
+        CreateDirIfNeeded( fileName );
+
+        openMode = std::ios_base::out | std::ios_base::trunc;
+
+        ifReWrite = 1;
+    }
+    else
+    {
+        openMode = std::ios_base::out | std::ios_base::app;
+    }
+
+    file.open( fileName.c_str(), openMode );
+    if ( ! file )
+    {
+        std::cout << "could not open " << fileName << std::endl;
+        exit( 0 );
+    }
+}
+
+void CloseLogFile( std::fstream & file )
+{
+    file.close();
+    file.clear();
+}
+
+LogFile::LogFile()
+{
+}
+
+LogFile::~LogFile()
+{
+}
+
+void LogFile::Open()
+{
+    int pid = Parallel::pid;
+    OpenLogFile( pid, this->my_fstream );
+}
+
+void LogFile::Close()
+{
+    CloseLogFile( this->my_fstream );
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/LogFile.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/LogFile.h
new file mode 100644
index 00000000..00e775ab
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/LogFile.h
@@ -0,0 +1,27 @@
+#pragma once
+#include <fstream>
+
+void OpenLogFile( int logFileIndex, std::fstream & file );
+void CloseLogFile( std::fstream & file );
+class LogFile;
+extern LogFile logFile;
+
+class LogFile
+{
+public:
+    LogFile();
+    ~LogFile();
+    std::fstream my_fstream;
+public:
+    void Open();
+    void Close();
+};
+
+template< typename T >
+LogFile & operator << ( LogFile & f, const T & value )
+{
+    f.Open();
+    f.my_fstream << value;
+    f.Close();
+    return f;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/Parallel.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/Parallel.cpp
new file mode 100644
index 00000000..0bce1a60
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/Parallel.cpp
@@ -0,0 +1,54 @@
+#include "Parallel.h"
+#include <iostream>
+
+int Parallel::pid = 0;
+int Parallel::nProc = 1;
+int Parallel::serverid = 0;
+int Parallel::tag = 0;
+
+void Parallel::Init()
+{
+#ifdef HX_PARALLEL
+    int argc     = 0;
+    char ** argv = 0;
+    MPI_Init( &argc, &argv );
+    MPI_Comm_rank( MPI_COMM_WORLD, &Parallel::pid );
+    MPI_Comm_size( MPI_COMM_WORLD, &Parallel::nProc );
+    int len = -1;
+    char version[ MPI_MAX_LIBRARY_VERSION_STRING ];
+    MPI_Get_library_version( version, &len );
+    std::cout << "Hello, world!  I am " << Parallel::pid << " of " << Parallel::nProc
+        << "(" << version << ", " << len << ")" << std::endl;
+#endif
+}
+
+void Parallel::Finalize()
+{
+#ifdef HX_PARALLEL
+    MPI_Finalize();
+#endif
+}
+
+bool Parallel::IsServer()
+{
+    return Parallel::pid == Parallel::serverid;
+}
+
+void HXSendChar( void * data, int size, int pid, int tag )
+{
+#ifdef HX_PARALLEL
+    if ( size <= 0 ) return;
+    MPI_Send( data, size, MPI_CHAR, pid, tag, MPI_COMM_WORLD );
+#endif
+}
+
+void HXRecvChar( void * data, int size, int pid, int tag )
+{
+#ifdef HX_PARALLEL
+    if ( size <= 0 ) return;
+
+    MPI_Status status;
+    MPI_Recv( data, size, MPI_CHAR, pid, tag, MPI_COMM_WORLD, & status );
+#endif
+}
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/Parallel.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/Parallel.h
new file mode 100644
index 00000000..880a71cb
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/Parallel.h
@@ -0,0 +1,78 @@
+#pragma once
+#ifdef HX_PARALLEL
+#include "mpi.h"
+#endif
+#include <vector>
+#include "LogFile.h"
+
+class Parallel
+{
+public:
+    static int pid;
+    static int nProc;
+    static int serverid;
+    static int tag;
+public:
+    static void Init();
+    static void Finalize();
+public:
+    static bool IsServer();
+};
+
+void HXSendChar( void * data, int size, int pid, int tag );
+void HXRecvChar( void * data, int size, int pid, int tag );
+
+template< typename T >
+void HXSendData( T * field, int nElement, int recv_pid, int tag  );
+
+template< typename T >
+void HXRecvData( T * field, int nElement, int send_pid, int tag );
+
+template< typename T >
+void HXSendData( T * field, int nElement, int recv_pid, int tag = 0 )
+{
+    if ( nElement <= 0 ) return;
+
+    int buffer_size = nElement * sizeof( T );
+
+    HXSendChar( field, buffer_size, recv_pid, tag );
+}
+
+template< typename T >
+void HXRecvData( T * field, int nElement, int send_pid, int tag = 0 )
+{
+    if ( nElement <= 0 ) return;
+
+    int buffer_size = nElement * sizeof( T );
+
+    HXRecvChar( field, buffer_size, send_pid, tag );
+}
+
+template< typename T >
+void HXSendRecvData( T * field, int nElement, int send_pid, int recv_pid, int tag = 0 )
+{
+    if ( send_pid == recv_pid ) return;
+
+    if ( nElement <= 0 ) return;
+
+    int buffer_size = nElement * sizeof( T );
+
+    if ( Parallel::pid == send_pid )
+    {
+        HXSendChar( field, buffer_size, recv_pid, tag );
+    }
+    else if ( Parallel::pid == recv_pid )
+    {
+        HXRecvChar( field, buffer_size, send_pid, tag );
+    }
+}
+
+template< typename T >
+void HXBcastData( T * field, int nElement, int send_pid )
+{
+    if ( nElement <= 0 ) return;
+    int buffer_size = nElement * sizeof( T );
+#ifdef HX_PARALLEL
+    MPI_Bcast( field, buffer_size, MPI_CHAR, send_pid, MPI_COMM_WORLD );
+#endif
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/README.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/Solver.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/Solver.cpp
new file mode 100644
index 00000000..25038559
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/Solver.cpp
@@ -0,0 +1,680 @@
+#include "Solver.h"
+#include "Parallel.h"
+#include "ZoneState.h"
+#include "global.h"
+#include <fstream>
+#include <set>
+#include <unordered_map>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+Solver::Solver()
+{
+    Parallel::Init();
+}
+
+Solver::~Solver()
+{
+    Parallel::Finalize();
+}
+
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    this->InitTopo();
+    this->InitFields();
+    this->SolveMultiZones();
+    this->PostProcess();
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d4blocksv1.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    ReadCgnsGrid( fileName );
+}
+
+void Solver::InitTopo()
+{
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "Solver::InitTopo() " << "\n";
+
+    Global::donor_zone_sets.resize( LocalZone::nZones );
+    Global::donor_zones.resize( LocalZone::nZones );
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        int global_zoneid = LocalZone::global_zoneids[ iZone ];
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "iZone = " << iZone << " global_zoneid = " << global_zoneid << "\n";
+
+        Interface * interface = new Interface();
+        interface->zoneid = global_zoneid;
+        Global::interfaces.push_back( interface );
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+        Interface * interface = Global::interfaces[ iZone ];
+
+        int nbc1to1s = zone->bc1to1s.size();
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout <<  "nbc1to1s = " << nbc1to1s << "\n";
+
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "zoneid = " << zoneid << " donor_zoneid = " << donor_zoneid << "\n";
+
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+        int nInterfaces = interface->zoneList.size();
+        interface->data_recv.resize( nInterfaces );
+        interface->data_send.resize( nInterfaces );
+    }
+
+    for ( int iProc = 0; iProc < Parallel::nProc; ++ iProc )
+    {
+        int nSize = -1;
+        if ( iProc == Parallel::pid )
+        {
+            nSize = Global::facePairList.size();
+        }
+        HXBcastData( &nSize, 1, iProc );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nSize = " << nSize << "\n";
+        std::vector<FacePair> tmp;
+        if ( iProc == Parallel::pid )
+        {
+            tmp = Global::facePairList;
+        }
+        else
+        {
+            tmp.resize( nSize );
+        }
+
+        HXBcastData( tmp.data(), tmp.size(), iProc );
+        Global::AddFacePairList( Global::mpi_facePairList, tmp );
+    }
+
+    for ( int i = 0; i < Global::mpi_facePairList.size(); ++ i )
+    {
+        FacePair &facePair = Global::mpi_facePairList[ i ];
+        Global::InsertFacePairMap( facePair );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        facePair.Print();
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterfaces = interface->local_faceids.size();
+        for ( int iInterface = 0; iInterface < nInterfaces; ++ iInterface )
+        {
+            int local_faceid = interface->local_faceids[ iInterface ];
+            int proc_global_faceid = interface->proc_global_faceids[ iInterface ];
+            FacePair & facePair = Global::facePairList[ proc_global_faceid ];
+            int global_faceid = Global::InsertFacePairMap( facePair );
+            interface->global_faceids.push_back( global_faceid );
+            interface->global_local_face_map.insert( std::make_pair( global_faceid, local_faceid ) );
+        }
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        std::set<int> &donor_zoneSet = Global::donor_zone_sets[ iZone ];
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            donor_zoneSet.insert( donor_zoneid );
+        }
+
+        std::vector<int> &donor_zones = Global::donor_zones[ iZone ];
+        for ( std::set<int>::iterator iter = donor_zoneSet.begin(); iter != donor_zoneSet.end(); ++ iter )
+        {
+            donor_zones.push_back( *iter );
+        }
+
+        interface->neighbor_donor_zones = donor_zones;
+
+        std::unordered_map<int, int> donor_zonelocal;
+
+        for ( int idonor = 0; idonor < donor_zones.size(); ++ idonor )
+        {
+            int donor_zone = donor_zones[ idonor ];
+            donor_zonelocal.insert( std::make_pair( donor_zone, idonor ) );
+        }
+        int ndonors = donor_zones.size();
+        std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+        neighbor_donorfaces.resize( ndonors );
+
+        std::vector<std::vector<int>> & sub_local_faceids = interface->sub_local_faceids;
+        sub_local_faceids.resize( ndonors );
+
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ineighbor = donor_zonelocal[ donor_zoneid ];
+            std::vector<int> &donorfaces = neighbor_donorfaces[ ineighbor ];
+            int global_faceid = interface->global_faceids[ iFace ];
+            donorfaces.push_back( global_faceid );
+            int local_faceid = interface->local_faceids[ iFace ];
+
+            std::vector<int> & sub_local_faces = sub_local_faceids[ ineighbor ];
+            sub_local_faces.push_back( local_faceid );
+        }
+    }
+
+    Global::interfaceTopo.InitNeighborInfo();
+    Global::interfaceTopo.SwapNeighborInfo();
+
+    int kkk = 1;
+}
+
+void Solver::InitFields()
+{
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "Solver::InitFields() ZoneState::nZones = " << ZoneState::nZones <<  "\n";
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+    }
+
+    Boundary();
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        //std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        //std::cout << "it = " << it << " nt = " << Global::nt << "\n";
+        for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+        {
+            Field * field = Global::fields[ iZone ];
+            Zone * zone = Global::zones[ iZone ];
+            zone->zoneIndex = iZone;
+            field->Solve( zone );
+        }
+        Boundary();
+    }
+}
+
+void Solver::Boundary()
+{
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+    ExchangeInterfaceField();
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->UpdateOldField();
+    }
+}
+
+void Solver::UploadInterfaceField()
+{
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> & send_to_zones = interface->send_to_zones;
+        int nsend_zones = send_to_zones.size();
+
+        std::vector<std::vector<int>> & donorfaces_for_send = interface->donorfaces_for_send;
+        std::vector<std::vector<int>> & donorijk_for_send = interface->donorijk_for_send;
+        std::vector<std::vector<double>> & donordata_for_send = interface->donordata_for_send;
+
+        Field * field = Global::fields[ iZone ];
+
+        for ( int iSend = 0; iSend < nsend_zones; ++ iSend )
+        {
+            int zone_to_send = send_to_zones[ iSend ];
+            std::vector<int> & donorfaces = donorfaces_for_send[ iSend ];
+            std::vector<int> & donorijks = donorijk_for_send[ iSend ];
+            std::vector<double> & donordatas = donordata_for_send[ iSend ];
+
+            int nface = donorfaces.size();
+            int index_dim = 1;
+            for ( int i = 0; i < nface; ++ i )
+            {
+                int ijkpos = index_dim * i;
+                int i_donor_cell = donorijks[ ijkpos + 0 ];
+                donordatas[ i ] = field->u[ i_donor_cell ];
+            }
+        }
+    }
+}
+
+void Solver::UpdateInterfaceField()
+{
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        int ndonor_zones = Global::interfaceTopo.linkmap[ iZone ].size();
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donor_zone = Global::interfaceTopo.linkmap[ iZone ][ iNei ];
+            int send_pid = ZoneState::pids[ iZone ];
+            int recv_pid = ZoneState::pids[ donor_zone ];
+            int nsend = -1;
+            std::vector<double> donordata;
+            if ( Parallel::pid != send_pid && Parallel::pid != recv_pid ) continue;
+            if ( Parallel::pid == send_pid )
+            {
+                int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+                Interface * interface = Global::interfaces[ local_zoneid ];
+                donordata = interface->donordata_for_send[ iNei ];
+                nsend = donordata.size();
+            }
+            HXSendRecvData( &nsend, 1, send_pid, recv_pid );
+
+            if ( Parallel::pid == recv_pid )
+            {
+                donordata.resize( nsend );
+            }
+            HXSendRecvData( donordata.data(), donordata.size(), send_pid, recv_pid );
+
+            if ( Parallel::pid == recv_pid )
+            {
+                int local_donor_zoneid = ZoneState::g2lzoneids[ donor_zone ];
+                Interface * donor_interface = Global::interfaces[ local_donor_zoneid ];
+                int nSize = donor_interface->neighbor_donor_zones.size();
+                int ipos = -1;
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    int nei_zone = donor_interface->neighbor_donor_zones[ i ];
+                    if ( nei_zone == iZone )
+                    {
+                        ipos = i;
+                        break;
+                    }
+                }
+
+                std::vector<int> & neighbor_donorfaces = donor_interface->neighbor_donorfaces[ ipos ];
+                std::vector<int> & sub_local_faceids = donor_interface->sub_local_faceids[ ipos ];
+                for ( int i = 0; i < neighbor_donorfaces.size(); ++ i )
+                {
+                    int local_faceid = sub_local_faceids[ i ];
+                    double donor_value = donordata[ i ];
+                    donor_interface->data_recv[ local_faceid ] = donor_value;
+                }
+            }
+        }
+    }
+}
+
+void Solver::DownloadInterfaceField()
+{
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+        Field * field = Global::fields[ iZone ];
+
+        int nInterFaces = interface->data_recv.size();
+
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+
+            double donor_value = interface->data_recv[ iFace ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    this->UploadInterfaceField();
+    this->UpdateInterfaceField();
+    this->DownloadInterfaceField();
+}
+
+void Solver::PostProcess()
+{
+    Post post;
+    post.Process();
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        if ( !ZoneState::IsValid( iZone ) && !Parallel::IsServer() ) continue;
+
+        double xmin = 0.0;
+        double xmax = 0.0;
+
+        if ( ZoneState::IsValid( iZone ) )
+        {
+            int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+            Grid * grid = Global::grids[ local_zoneid ];
+            int ni = grid->x.size();
+            xmin = grid->x[ 0 ];
+            xmax = grid->x[ 0 ];
+            int imin = 0;
+            int imax = 0;
+            for ( int i = 0; i < ni; ++ i )
+            {
+                if ( xmin > grid->x[ i ] )
+                {
+                    xmin = grid->x[ i ];
+                    imin = i;
+                }
+                if ( xmax < grid->x[ i ] )
+                {
+                    xmax = grid->x[ i ];
+                    imax = i;
+                }
+            }
+        }
+
+        HXSendRecvData( &xmin, 1, ZoneState::pids[ iZone ], Parallel::serverid );
+        HXSendRecvData( &xmax, 1, ZoneState::pids[ iZone ], Parallel::serverid );
+
+        //if ( Parallel::IsServer() )
+        //{
+        //    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        //    std::cout << "xmin = " << xmin << "\n";
+        //    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        //    std::cout << "xmax = " << xmax << "\n";
+        //}
+
+        if ( Parallel::IsServer() )
+        {
+            xmin_list.push_back( xmin );
+            xmax_list.push_back( xmax );
+        }
+    }
+
+    //if ( Parallel::IsServer() )
+    //{
+    //    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    //    for ( int i = 0; i < xmin_list.size(); ++ i )
+    //    {
+    //        std::cout << "(" << xmin_list[ i ] << "," << xmax_list[ i ] << ") ";
+    //    }
+    //    std::cout << "\n";
+    //}
+
+    if ( Parallel::IsServer() )
+    {
+        std::vector<std::pair<double, int>> pairs;
+        int nSize = xmin_list.size();
+        for ( int i = 0; i < nSize; ++ i )
+        {
+            pairs.push_back( std::make_pair( xmin_list[ i ], i ) );
+        }
+
+        std::sort( pairs.begin(), pairs.end() );
+
+        for ( int i = 0; i < nSize; ++ i )
+        {
+            this->zoneids.push_back( pairs[ i ].second );
+        }
+    }
+
+    int kkk = 1;
+}
+
+bool IsLastZone( int iZone );
+bool IsLastZone( int iZone )
+{
+    return iZone == ZoneState::nZones - 1;
+}
+
+void Post::AddVector( std::vector<double> & a, std::vector<double> & b )
+{
+    for ( int i = 0; i < b.size(); ++ i )
+    {
+        a.push_back( b[ i ] );
+    }
+}
+
+void Post::GatherField()
+{
+    this->zoneids.resize( ZoneState::nZones );
+    HXBcastData( this->zoneids.data(), this->zoneids.size(), Parallel::serverid );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "Post::GatherField() this->zoneids = \n";
+    for ( int i = 0; i < this->zoneids.size(); ++ i )
+    {
+        std::cout << this->zoneids[ i ] << " ";
+    }
+    std::cout << "\n";
+
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+
+        if ( !ZoneState::IsValid( zoneid ) && !Parallel::IsServer() ) continue;
+
+        int nSize = -1;
+        std::vector<double> local_x;
+        std::vector<double> local_u_e;
+        std::vector<double> local_un;
+        std::vector<double> local_u;
+
+        if ( Parallel::pid == ZoneState::pids[ zoneid ] )
+        {
+            int local_zoneid = ZoneState::g2lzoneids[ zoneid ];
+            Grid * grid = Global::grids[ local_zoneid ];
+            Field * field = Global::fields[ local_zoneid ];
+            int ni = grid->x.size();
+
+            int ist = 1;
+            int ied = ni;
+
+            int dir = 1;
+            if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+            if ( dir == 1 )
+            {
+                if ( IsLastZone( iZone ) )
+                {
+                    for ( int i = ist; i <= ied; ++ i )
+                    {
+                        double xm = grid->x[ i - ist ];
+                        local_x.push_back( xm );
+                        local_u_e.push_back( field->u_e[ i ] );
+                        local_un.push_back( field->un[ i ] );
+                        local_u.push_back( field->u[ i ] );
+                    }
+                }
+                else
+                {
+                    for ( int i = ist; i <= ied - 1; ++ i )
+                    {
+                        double xm = grid->x[ i - ist ];
+                        local_x.push_back( xm );
+                        local_u_e.push_back( field->u_e[ i ] );
+                        local_un.push_back( field->un[ i ] );
+                        local_u.push_back( field->u[ i ] );
+                    }
+                }
+            }
+            else
+            {
+                if ( IsLastZone( iZone ) )
+                {
+                    for ( int i = ied; i >= ist; -- i )
+                    {
+                        double xm = grid->x[ i - ist ];
+                        local_x.push_back( xm );
+                        local_u_e.push_back( field->u_e[ i ] );
+                        local_un.push_back( field->un[ i ] );
+                        local_u.push_back( field->u[ i ] );
+                    }
+                }
+                else
+                {
+                    for ( int i = ied; i >= ist + 1; -- i )
+                    {
+                        double xm = grid->x[ i - ist ];
+                        local_x.push_back( xm );
+                        local_u_e.push_back( field->u_e[ i ] );
+                        local_un.push_back( field->un[ i ] );
+                        local_u.push_back( field->u[ i ] );
+                    }
+                }
+            }
+            nSize = local_x.size();
+        }
+
+        int send_pid = ZoneState::pids[ zoneid ];
+
+        HXSendRecvData( &nSize, 1, send_pid, Parallel::serverid );
+
+        if ( Parallel::IsServer() )
+        {
+            local_x.resize( nSize );
+            local_u_e.resize( nSize );
+            local_un.resize( nSize );
+            local_u.resize( nSize );
+        }
+
+        HXSendRecvData( local_x.data(), local_x.size(), send_pid, Parallel::serverid );
+        HXSendRecvData( local_u_e.data(), local_u_e.size(), send_pid, Parallel::serverid );
+        HXSendRecvData( local_un.data(), local_un.size(), send_pid, Parallel::serverid );
+        HXSendRecvData( local_u.data(), local_u.size(), send_pid, Parallel::serverid );
+
+        if ( Parallel::IsServer() )
+        {
+            this->AddVector( this->x, local_x );
+            this->AddVector( this->u_e, local_u_e );
+            this->AddVector( this->un, local_un );
+            this->AddVector( this->u, local_u );
+        }
+    }
+}
+
+void Post::DumpField()
+{
+    if ( !Parallel::IsServer() ) return;
+    int ni_total = this->x.size();
+    std::cout << " DumpField x.size() = " << x.size() << "\n";
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    this->DumpErrorDetails( u_error );
+
+    std::string csvname = "field_final.csv";
+    this->DumpCsvFile( csvname, x, u_e, un, u_error );
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.20f} {:.20f} {:.20f} {:.20f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/Solver.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/Solver.h
new file mode 100644
index 00000000..9914c1d7
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/Solver.h
@@ -0,0 +1,49 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+
+class Solver
+{
+public:
+    Solver();
+    ~Solver();
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveMultiZones();
+public:
+    void Boundary();
+    void UploadInterfaceField();
+    void UpdateInterfaceField();
+    void DownloadInterfaceField();
+    void ExchangeInterfaceField();
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcess();
+};
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+    std::vector<double> u;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+public:
+    void AddVector( std::vector<double> & a, std::vector<double> & b );
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/ZoneState.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/ZoneState.cpp
new file mode 100644
index 00000000..ff810849
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/ZoneState.cpp
@@ -0,0 +1,20 @@
+#include "ZoneState.h"
+#include "Parallel.h"
+
+int ZoneState::nZones = 0;
+std::vector<int> ZoneState::pids;
+std::vector<int> ZoneState::g2lzoneids;
+
+bool ZoneState::IsValid( int zoneid )
+{
+    return ZoneState::pids[ zoneid ] == Parallel::pid;
+}
+
+int ZoneState::GetProcID( int zoneid )
+{
+    return ZoneState::pids[ zoneid ];
+}
+
+int LocalZone::nZones = 0;
+std::vector<int> LocalZone::global_zoneids;
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/ZoneState.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/ZoneState.h
new file mode 100644
index 00000000..1096d632
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/ZoneState.h
@@ -0,0 +1,21 @@
+#pragma once
+#include <vector>
+
+class ZoneState
+{
+public:
+    static int nZones;
+    static int zone_id;
+    static std::vector<int> pids;
+    static std::vector<int> g2lzoneids; //global zone id to local zone id
+public:
+    static bool IsValid( int zoneid );
+    static int GetProcID( int zoneid );
+};
+
+class LocalZone
+{
+public:
+    static int nZones;
+    static std::vector<int> global_zoneids;
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/global.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/global.cpp
new file mode 100644
index 00000000..df1e6bae
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/global.cpp
@@ -0,0 +1,300 @@
+#include "global.h"
+#include "CgnsGrid.h"
+#include "ZoneState.h"
+#include "Parallel.h"
+#include <iostream>
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *> Global::interfaces;
+
+std::map<Face, int> Global::faceMap;
+std::map<FacePair, int> Global::facePairMap;
+std::vector<FacePair> Global::facePairList;
+std::vector<FacePair> Global::mpi_facePairList;
+
+std::vector<std::set<int>> Global::donor_zone_sets;
+std::vector<std::vector<int>> Global::donor_zones;
+
+InterfaceTopo Global::interfaceTopo;
+
+bool Face::operator < ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return this->zone < rhs.zone;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return this->i < rhs.i;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return this->j < rhs.j;
+    }
+
+    return this->k < rhs.k;
+}
+
+bool Face::operator == ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return false;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return false;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return false;
+    }
+
+    return this->k == rhs.k;
+}
+
+void Face::Print()
+{
+    std::cout << "(" << this->zone << "," << this->i << ")";
+}
+
+void FacePair::AddPair( const Face & face1, const Face & face2 )
+{
+    if ( face1 < face2 )
+    {
+        this->left = face1;
+        this->right = face2;
+    }
+    else
+    {
+        this->left = face2;
+        this->right = face1;
+    }
+}
+
+bool FacePair::operator < ( const FacePair & rhs ) const
+{
+    if ( this->left == rhs.left || this->left == rhs.right )
+    {
+        return false;
+    }
+
+    return this->left < rhs.left;
+}
+
+void FacePair::Print()
+{
+    this->left.Print();
+    std::cout << " ";
+    this->right.Print();
+    std::cout << "\n";
+}
+
+void InterfaceTopo::InitNeighborInfo()
+{
+    this->linkmap.resize( ZoneState::nZones );
+
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        if ( ! ZoneState::IsValid( iZone ) ) continue;
+
+        int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+
+        Interface * interface = Global::interfaces[ local_zoneid ];
+
+        std::vector<int> & t = this->linkmap[ iZone ];
+        t = interface->neighbor_donor_zones;
+    }
+}
+
+void InterfaceTopo::SwapNeighborInfo()
+{
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        int pid = ZoneState::pids[ iZone ];
+
+        std::vector<int> & donor_zones = this->linkmap[ iZone ];
+        int nNeighbor = donor_zones.size();
+
+        HXBcastData( &nNeighbor, 1, pid );
+
+        donor_zones.resize( nNeighbor );
+
+        HXBcastData( donor_zones.data(), donor_zones.size(), pid );
+    }
+
+    this->SwapNeighborDonorfaces();
+}
+
+void InterfaceTopo::SwapNeighborDonorfaces()
+{
+    int gl = 0;
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        int send_pid = ZoneState::pids[ iZone ];
+
+        std::vector<int> & donor_zones = this->linkmap[ iZone ];
+        int ndonor_zones = donor_zones.size();
+
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donor_zone = donor_zones[ iNei ];
+            int recv_pid = ZoneState::pids[ donor_zone ];
+            int nInterFaces = 0;
+            std::vector<int> donorfaces;
+
+            if ( Parallel::pid == send_pid )
+            {
+                int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+
+                Interface * interface = Global::interfaces[ local_zoneid ];
+
+                std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+
+                std::vector<int> & neighbor_donorface = neighbor_donorfaces[ iNei ];
+
+                nInterFaces = neighbor_donorface.size();
+
+                donorfaces = neighbor_donorface;
+            }
+
+            HXSendRecvData( &nInterFaces, 1, send_pid, recv_pid );
+
+            if ( Parallel::pid == recv_pid && send_pid != recv_pid )
+            {
+                donorfaces.resize( nInterFaces );
+            }
+
+            HXSendRecvData( donorfaces.data(), donorfaces.size(), send_pid, recv_pid );
+
+            if ( Parallel::pid == recv_pid )
+            {
+                int local_donor_zoneid = ZoneState::g2lzoneids[ donor_zone ];
+                Interface * interface_recv = Global::interfaces[ local_donor_zoneid ];
+                interface_recv->SendGeom( iZone, donorfaces );
+            }
+        }
+    }
+}
+
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->local_faceids.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        Face face;
+        face.zone = zoneid;
+        face.i = i;
+
+        int i_donor = index2[ 0 ];
+
+        Face face_donor;
+        face_donor.zone = donor_zoneid;
+        face_donor.i = i_donor;
+
+        FacePair facePair;
+        facePair.AddPair( face, face_donor );
+
+        Global::facePairList.push_back( facePair );
+        int nSize = Global::facePairList.size();
+        this->proc_global_faceids.push_back( nSize - 1 );
+
+        int i_ghost_cell = i + 1;
+        int i_local_donor_cell = i - 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+            i_local_donor_cell = i + 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+        ijk_donors.push_back( i_local_donor_cell );
+
+        icount ++;
+    }
+}
+
+void Interface::SendGeom( int zone, std::vector<int> & donorfaces )
+{
+    Interface * interface = this;
+
+    std::vector<int> & send_to_zones = interface->send_to_zones;
+
+    send_to_zones.push_back( zone );
+    interface->donorfaces_for_send.push_back( donorfaces );
+
+    int nface = donorfaces.size();
+    std::vector<int> sub_donorijk;
+    int index_dim = 1;
+    for ( int i = 0; i < nface; ++ i )
+    {
+        int global_faceid = donorfaces[ i ];
+        int local_faceid = interface->global_local_face_map[ global_faceid ];
+        int ijkpos = index_dim * local_faceid;
+        int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+        sub_donorijk.push_back( i_donor_cell );
+        int kkk = 1;
+    }
+
+    interface->donorijk_for_send.push_back( sub_donorijk );
+
+    std::vector<double> sub_donordata( sub_donorijk.size() );
+    interface->donordata_for_send.push_back( sub_donordata );
+}
+
+void Global::InsertFaceMap( const Face & face )
+{
+    std::map<Face, int>::iterator iter;
+    iter = Global::faceMap.find( face );
+    if ( iter == Global::faceMap.end() )
+    {
+        int faceid = Global::faceMap.size();
+        Global::faceMap.insert( std::make_pair( face, faceid ) );
+    }
+}
+
+int Global::InsertFacePairMap( const FacePair & facePair )
+{
+    std::map<FacePair, int>::iterator iter;
+    iter = Global::facePairMap.find( facePair );
+    if ( iter == Global::facePairMap.end() )
+    {
+        int facePairId = Global::facePairMap.size();
+        Global::facePairMap.insert( std::make_pair( facePair, facePairId ) );
+        return facePairId;
+    }
+    return iter->second;
+}
+
+void Global::AddFacePairList( std::vector<FacePair> & a, std::vector<FacePair> & b )
+{
+    for ( int i = 0; i < b.size(); ++ i )
+    {
+        a.push_back( b[ i ] );
+    }
+}
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/global.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/global.h
new file mode 100644
index 00000000..933cec05
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/global.h
@@ -0,0 +1,157 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <unordered_map>
+#include <set>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class Face
+{
+public:
+    int zone = 0;
+    int i = 0;
+    int j = 1;
+    int k = 1;
+public:
+    bool operator < ( const Face & rhs ) const;
+    bool operator == ( const Face & rhs ) const;
+public:
+    void Print();
+};
+
+class FacePair
+{
+public:
+    Face left;
+    Face right;
+public:
+    bool operator < ( const FacePair & rhs ) const;
+    void AddPair( const Face &face1, const Face &face2);
+public:
+    void Print();
+};
+
+class Transform;
+
+class InterfaceTopo
+{
+public:
+    std::vector<std::vector<int>> linkmap;
+public:
+    void InitNeighborInfo();
+    void SwapNeighborInfo();
+    void SwapNeighborDonorfaces();
+};
+
+
+class Interface
+{
+public:
+    int zoneid;
+    std::vector<int> zoneList;
+    std::vector<int> global_faceids;
+    std::vector<int> mpi_global_faceids;
+    std::vector<int> proc_global_faceids;
+    std::vector<int> local_faceids;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+    std::vector<double> data_recv;
+    std::vector<double> data_send;
+    std::unordered_map<int, int> global_local_face_map;
+public:
+    std::vector<int> neighbor_donor_zones;
+    std::vector<std::vector<int>> neighbor_donorfaces;
+    std::vector<std::vector<int>> sub_local_faceids;
+    std::vector<int> send_to_zones;
+    std::vector<std::vector<int>> donorfaces_for_send;
+    std::vector<std::vector<int>> donorijk_for_send;
+    std::vector<std::vector<double>> donordata_for_send;
+public:
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+    void SendGeom( int zone, std::vector<int> & donorfaces );
+};
+
+class Field;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+public:
+    static std::map<Face, int> faceMap;
+    static std::map<FacePair, int> facePairMap;
+    static std::vector<FacePair> facePairList;
+    static std::vector<FacePair> mpi_facePairList;
+    static std::vector<std::set<int>> donor_zone_sets;
+    static std::vector<std::vector<int>> donor_zones;
+    static InterfaceTopo interfaceTopo;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+public:
+    static void InsertFaceMap( const Face & face );
+    static int InsertFacePairMap( const FacePair & facePair );
+    static void AddFacePairList( std::vector<FacePair> & a, std::vector<FacePair> & b );
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/heat1d4blocksv1.cgns b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/heat1d4blocksv1.cgns
new file mode 100644
index 00000000..df5ffc5f
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/heat1d4blocksv1.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/main.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/main.cpp
new file mode 100644
index 00000000..df63b7da
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/main.cpp
@@ -0,0 +1,9 @@
+#include "Solver.h"
+#include "Parallel.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/plot.py b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/4blocks/02j/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/CMakeLists.txt
new file mode 100644
index 00000000..9e834b72
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/CMakeLists.txt
@@ -0,0 +1,99 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package ( MPI )
+
+message ( STATUS  "MPI_FOUND=${MPI_FOUND}" )
+message ( STATUS  "MPI_CXX_INCLUDE_DIRS=${MPI_CXX_INCLUDE_DIRS}" )
+message ( STATUS  "MPI_LIBRARIES=${MPI_LIBRARIES}" )
+if ( MPI_FOUND )
+	list ( APPEND PRJ_INCLUDE_DIRS ${MPI_CXX_INCLUDE_DIRS} )
+	list ( APPEND PRJ_LIBRARIES ${MPI_LIBRARIES} )
+endif ()
+
+#get_directory_property( my_import_targets DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} IMPORTED_TARGETS )
+#message( STATUS "my_import_targets=${my_import_targets}" )
+
+list ( APPEND PRJ_LIBRARIES MPI::MPI_C )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+list ( APPEND PRJ_COMPILE_DEFINITIONS HX_PARALLEL )
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	LogFile.h LogFile.cpp
+	Parallel.h Parallel.cpp
+	Solver.h Solver.cpp
+	ZoneState.h ZoneState.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/CgnsGrid.cpp
new file mode 100644
index 00000000..4baf036f
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/CgnsGrid.cpp
@@ -0,0 +1,858 @@
+#include "CgnsGrid.h"
+#include "Parallel.h"
+#include "cgnslib.h"
+#include "global.h"
+#include "ZoneState.h"
+#include <iostream>
+#include <vector>
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "fileId = " << fileId << "\n";
+    }
+    
+    int nbases = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_nbases( fileId, &nbases );
+    }
+    HXBcastData( &nbases, 1, Parallel::serverid );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "nbases = " << nbases << "\n";
+    
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        }
+
+        HXBcastData( &icelldim, 1, Parallel::serverid );
+        HXBcastData( &iphysdim, 1, Parallel::serverid );
+
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+
+        int nzones = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_nzones( fileId, baseId, &nzones );
+        }
+
+        HXBcastData( &nzones, 1, Parallel::serverid );
+
+        ZoneState::nZones = nzones;
+        ZoneState::pids.resize( nzones );
+        ZoneState::g2lzoneids.resize( nzones );
+
+        if ( Parallel::nProc == 1 )
+        {
+            for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+            {
+                ZoneState::pids[ iZone ] = 0;
+                ZoneState::g2lzoneids[ iZone ] = iZone;
+            }
+        }
+        else
+        {
+            for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+            {
+                ZoneState::pids[ iZone ] = iZone;
+                ZoneState::g2lzoneids[ iZone ] = 0;
+            }
+        }
+
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nzones = " << nzones << "\n";
+
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "iZone = " << iZone << "\n";
+
+            int index_dim = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            }
+            HXBcastData( &index_dim, 1, Parallel::serverid );
+
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            if ( Parallel::IsServer() )
+            {
+                cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            }
+
+            HXBcastData( zonename, 33, Parallel::serverid );
+            HXBcastData( isize.data(), isize.size(), Parallel::serverid);
+
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "zonename = " << zonename << "\n";
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+
+    if ( Parallel::IsServer() )
+    {
+        cg_close( fileId );
+    }
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+        std::cout << "fileId = " << fileId << "\n";
+    }
+    
+    int nbases = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_nbases( fileId, &nbases );
+    }
+    MPI_Bcast( &nbases, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        }
+
+        HXBcastData( &icelldim, 1, Parallel::serverid );
+        HXBcastData( &iphysdim, 1, Parallel::serverid );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+
+        int nzones = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_nzones( fileId, baseId, &nzones );
+        }
+        HXBcastData( &nzones, 1, Parallel::serverid );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nzones = " << nzones << "\n";
+
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            }
+            HXSendRecvData( &index_dim, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "index_dim = " << index_dim << "\n";
+            }
+
+            std::vector<cgsize_t> isize;
+            char zonename[ 33 ];
+            if ( Parallel::IsServer() )
+            {
+                isize.resize( index_dim * 3 );
+                cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            }
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                isize.resize( index_dim * 3 );
+            }
+
+            HXSendRecvData( zonename, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+            HXSendRecvData( isize.data(), index_dim * 3, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "zonename = " << zonename << "\n";
+
+                for ( int i = 0; i < isize.size(); ++ i )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+                }
+            }
+
+            std::vector<cgsize_t> irmin;
+            std::vector<cgsize_t> irmax;
+            int nNodes = 1;
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                irmin.resize( index_dim );
+                irmax.resize( index_dim );
+                for ( int m = 0; m < index_dim; ++ m )
+                {
+                    /* lower range index */
+                    irmin[ m ] = 1;
+                    /* upper range index of vertices */
+                    irmax[ m ] = isize[ m ];
+                    nNodes *= irmax[ m ];
+                }
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "nNodes = " << nNodes << "\n";
+            }
+
+            ZoneType_t zoneType;
+            if ( Parallel::IsServer() )
+            {
+                cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            }
+            HXSendRecvData( &zoneType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            }
+
+            Zone * zone = nullptr;
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                zone = new Zone();
+                Global::zones.push_back( zone );
+                LocalZone::global_zoneids.push_back( iZone );
+                LocalZone::nZones = LocalZone::global_zoneids.size();
+                for ( int m = 0; m < index_dim; ++ m )
+                {
+                    zone->nijk.push_back( isize[ m ] );
+                }
+            }
+
+            Grid * grid = nullptr;
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                grid = new Grid();
+                Global::grids.push_back( grid );
+            }
+
+            BaseZone baseZone;
+
+            int gZoneId = -1;
+            if ( Parallel::IsServer() )
+            {
+                baseZone.zone_name = zonename;
+                gZoneId = Global::zone_names.FindBaseZone( baseZone );
+            }
+
+            HXSendRecvData( &gZoneId, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "gZoneId = " << gZoneId << "\n";
+            }
+
+            int ncoords = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            }
+            HXSendRecvData( &ncoords, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "ncoords = " << ncoords << "\n";
+            }
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                if ( Parallel::IsServer() )
+                {
+                    cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                }
+                HXSendRecvData( coordname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &dataType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "coordname = " << coordname << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                }
+
+                std::vector<char> coord;
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    coord.resize( nNodes * sizeof( double ) );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coord.data() );
+                }
+
+                HXSendRecvData( coord.data(), coord.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                Coor * coor = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    coor = new Coor();
+                    zone->coors.push_back( coor );
+                    coor->coorname = coordname;
+                    coor->nNodes = nNodes;
+                    coor->coord = coord;
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    coor->DumpCoor();
+
+                    if ( icoord == 0 )
+                    {
+                        grid->x.resize( nNodes );
+                        coor->DumpCoorX( grid->x );
+                    }
+                }
+            }
+
+            int nbocos = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            }
+            HXSendRecvData( &nbocos, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "nbocos = " << nbocos << "\n";
+            }
+
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                if ( Parallel::IsServer() )
+                {
+                    cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                }
+                HXSendRecvData( &location, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+                }
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                //std::vector<int> normalIndex( index_dim, -1 );
+                std::vector<int> normalIndex;
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+                if ( Parallel::IsServer() )
+                {
+                    normalIndex.resize( index_dim );
+                    cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                        &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                }
+
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    normalIndex.resize( index_dim );
+                }
+                
+                HXSendRecvData( boconame, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &bocotype, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &ptset_type, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &npnts, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &normalDataType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &normalListSize, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( normalIndex.data(), index_dim, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &ndataset, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "npnts = " << npnts << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalListSize = " << normalListSize << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalIndex = ";
+                    for ( int i = 0; i < index_dim; ++ i )
+                    {
+                        std::cout << normalIndex[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "ndataset = " << ndataset << "\n";
+                }
+
+                std::vector<char> normalList;
+                std::vector<cgsize_t> pnts;
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    if ( normalDataType == DataTypeNull )
+                    {
+                        normalList.resize( sizeof( int ) );
+                    }
+                    else
+                    {
+                        int nSize = nNodes * index_dim * sizeof( double );
+                        normalList.resize( nSize );
+                    }
+                    pnts.resize( npnts * index_dim );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                }
+
+                HXSendRecvData( pnts.data(), npnts * index_dim, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "pnts = ";
+                    for ( int i = 0; i < pnts.size(); ++ i )
+                    {
+                        std::cout << pnts[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                }
+                HXSendRecvData( normalList.data(), normalList.size(), Parallel::serverid, ZoneState::GetProcID(iZone));
+
+                ZoneBc * zonebc = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    zonebc = new ZoneBc();
+                    zone->bccos.push_back( zonebc );
+                    zonebc->bcType = bocotype;
+                    for ( int i = 0; i < pnts.size(); ++ i )
+                    {
+                        zonebc->pnts.push_back( pnts[ i ] );
+                    }
+                }
+            }
+            int n1to1 = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            }
+
+            HXSendRecvData( &n1to1, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "n1to1 = " << n1to1 << "\n";
+            }
+
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range;
+                std::vector<cgsize_t> donor_range;
+                std::vector<int> transform;
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    range.resize( npnts * index_dim );
+                    donor_range.resize( npnts * index_dim );
+                    transform.resize( index_dim );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                }
+
+                HXSendRecvData( connectname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( donorname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( range.data(), range.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( donor_range.data(), donor_range.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( transform.data(), transform.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "connectname = " << connectname << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "donorname = " << donorname << "\n";
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "range = ";
+                    for ( int i = 0; i < range.size(); ++ i )
+                    {
+                        std::cout << range[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "donor_range = ";
+                    for ( int i = 0; i < donor_range.size(); ++ i )
+                    {
+                        std::cout << donor_range[ i ] << " ";
+                    }
+                    std::cout << "\n";
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "transform = ";
+                    for ( int i = 0; i < transform.size(); ++ i )
+                    {
+                        std::cout << transform[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                }
+
+                int gDonorZoneId = -1;
+                if ( Parallel::IsServer() )
+                {
+                    BaseZone baseZoneDonor;
+                    baseZoneDonor.zone_name = donorname;
+
+                    gDonorZoneId = Global::zone_names.FindBaseZone( baseZoneDonor );
+                }
+
+                HXSendRecvData( &gDonorZoneId, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                ZoneBc1To1 * zonebc_1to1 = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    zonebc_1to1 = new ZoneBc1To1();
+                    zone->bc1to1s.push_back( zonebc_1to1 );
+                    zonebc_1to1->zoneid = gZoneId;
+                    zonebc_1to1->transform = transform;
+                    zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                    for ( int i = 0; i < range.size(); ++ i )
+                    {
+                        zonebc_1to1->pnts.push_back( range[ i ] );
+                        zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                    }
+                }
+            }
+        }
+    }
+
+    {
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "Global::zones.size() = " << Global::zones.size() << "\n";
+    }
+
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/CgnsGrid.h
new file mode 100644
index 00000000..fddf1db6
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/CgnsGrid.h
@@ -0,0 +1,103 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    int zoneIndex;
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/Field.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/Field.cpp
new file mode 100644
index 00000000..c359a811
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/Field.cpp
@@ -0,0 +1,142 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+
+    std::vector<double> & x = grid->x;
+    this->dx = std::abs( x[ 1 ] - x[ 0 ] );
+    this->dt = dx / 10.0;
+    this->t = 1.0;
+    this->nt = std::round( t / dt );
+
+    double total_time = nt * dt;
+
+    std::cout << "this->dt   = " << this->dt << "\n";
+    std::cout << "this->t    = " << this->t << "\n";
+    std::cout << "this->nt   = " << this->nt << "\n";
+    std::cout << "this->ni   = " << this->ni << "\n";
+    std::cout << "total_time = " << total_time << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        u_e[ i ] = - std::exp( -total_time ) * std::sin( std::numbers::pi * xm ); //theory solution
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+    int kkk = 1;
+}
+
+void Field::Solve( Zone * zone )
+{
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+    }
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        //std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        //region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+        int kkk = 1;
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
+
+void Field::UpdateOldField()
+{
+    for ( int i = 0; i < this->u.size(); ++ i )
+    {
+        this->un[ i ] = this->u[ i ];
+    }
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/Field.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/Field.h
new file mode 100644
index 00000000..084ec9bd
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/Field.h
@@ -0,0 +1,36 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid );
+
+    void Solve( Zone * zone );
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void UpdateOldField();
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/LogFile.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/LogFile.cpp
new file mode 100644
index 00000000..08ccd453
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/LogFile.cpp
@@ -0,0 +1,138 @@
+#include "LogFile.h"
+#include "Parallel.h"
+#include <sstream>
+#include <iostream>
+
+#ifdef _WINDOWS
+#include <windows.h>
+#include <direct.h>
+#include <io.h>
+#else
+#include <sys/stat.h>
+#include <unistd.h>
+#endif
+
+LogFile logFile;
+
+class OStream : public std::ostringstream
+{
+public:
+    OStream() {}
+    ~OStream() {}
+public:
+    void ClearAll()
+    {
+        this->clear();
+        this->str("");
+    }
+};
+
+OStream StrIO;
+std::string GetPrjDirName( const std::string & fileName );
+bool DirExist( const std::string & dirName );
+void MakeDir( const std::string & dirName );
+
+std::string GetPrjDirName( const std::string & fileName )
+{
+    size_t pos = fileName.find_last_of("\\/");
+    if ( std::string::npos == pos )
+    {
+        return "";
+    }
+    else
+    {
+        return fileName.substr( 0, pos );
+    }
+}
+
+bool DirExist( const std::string & dirName )
+{
+#ifdef _WINDOWS
+    bool flag = ( _access( dirName.c_str(), 0 ) == 0 );
+    return flag;
+#else
+    bool flag = ( access( dirName.c_str(), 0 ) == 0 );
+    return flag;
+#endif
+}
+
+void MakeDir( const std::string & dirName )
+{
+    int flag;
+#ifdef _WINDOWS
+    flag = _mkdir( dirName.c_str() );
+#else
+    flag = mkdir( dirName.c_str(), S_IRWXU );
+#endif
+    if ( flag == 0 )
+    {
+        std::cout << dirName << " directory has been created successfully !\n";
+    }
+}
+
+void CreateDirIfNeeded( std::string & prjFileName )
+{
+    std::string prj_dir = GetPrjDirName( prjFileName );
+
+    if ( ! DirExist( prj_dir ) )
+    {
+        MakeDir( prj_dir );
+    }
+}
+
+
+void OpenLogFile( int logFileIndex, std::fstream & file )
+{
+    static int ifReWrite = 0;
+
+    StrIO.ClearAll();
+    StrIO << "log/log" << logFileIndex << ".log";
+    std::string fileName = StrIO.str();
+
+    std::ios_base::openmode openMode;
+
+    if ( ifReWrite == 0 )
+    {
+        CreateDirIfNeeded( fileName );
+
+        openMode = std::ios_base::out | std::ios_base::trunc;
+
+        ifReWrite = 1;
+    }
+    else
+    {
+        openMode = std::ios_base::out | std::ios_base::app;
+    }
+
+    file.open( fileName.c_str(), openMode );
+    if ( ! file )
+    {
+        std::cout << "could not open " << fileName << std::endl;
+        exit( 0 );
+    }
+}
+
+void CloseLogFile( std::fstream & file )
+{
+    file.close();
+    file.clear();
+}
+
+LogFile::LogFile()
+{
+}
+
+LogFile::~LogFile()
+{
+}
+
+void LogFile::Open()
+{
+    int pid = Parallel::pid;
+    OpenLogFile( pid, this->my_fstream );
+}
+
+void LogFile::Close()
+{
+    CloseLogFile( this->my_fstream );
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/LogFile.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/LogFile.h
new file mode 100644
index 00000000..00e775ab
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/LogFile.h
@@ -0,0 +1,27 @@
+#pragma once
+#include <fstream>
+
+void OpenLogFile( int logFileIndex, std::fstream & file );
+void CloseLogFile( std::fstream & file );
+class LogFile;
+extern LogFile logFile;
+
+class LogFile
+{
+public:
+    LogFile();
+    ~LogFile();
+    std::fstream my_fstream;
+public:
+    void Open();
+    void Close();
+};
+
+template< typename T >
+LogFile & operator << ( LogFile & f, const T & value )
+{
+    f.Open();
+    f.my_fstream << value;
+    f.Close();
+    return f;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/Parallel.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/Parallel.cpp
new file mode 100644
index 00000000..0bce1a60
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/Parallel.cpp
@@ -0,0 +1,54 @@
+#include "Parallel.h"
+#include <iostream>
+
+int Parallel::pid = 0;
+int Parallel::nProc = 1;
+int Parallel::serverid = 0;
+int Parallel::tag = 0;
+
+void Parallel::Init()
+{
+#ifdef HX_PARALLEL
+    int argc     = 0;
+    char ** argv = 0;
+    MPI_Init( &argc, &argv );
+    MPI_Comm_rank( MPI_COMM_WORLD, &Parallel::pid );
+    MPI_Comm_size( MPI_COMM_WORLD, &Parallel::nProc );
+    int len = -1;
+    char version[ MPI_MAX_LIBRARY_VERSION_STRING ];
+    MPI_Get_library_version( version, &len );
+    std::cout << "Hello, world!  I am " << Parallel::pid << " of " << Parallel::nProc
+        << "(" << version << ", " << len << ")" << std::endl;
+#endif
+}
+
+void Parallel::Finalize()
+{
+#ifdef HX_PARALLEL
+    MPI_Finalize();
+#endif
+}
+
+bool Parallel::IsServer()
+{
+    return Parallel::pid == Parallel::serverid;
+}
+
+void HXSendChar( void * data, int size, int pid, int tag )
+{
+#ifdef HX_PARALLEL
+    if ( size <= 0 ) return;
+    MPI_Send( data, size, MPI_CHAR, pid, tag, MPI_COMM_WORLD );
+#endif
+}
+
+void HXRecvChar( void * data, int size, int pid, int tag )
+{
+#ifdef HX_PARALLEL
+    if ( size <= 0 ) return;
+
+    MPI_Status status;
+    MPI_Recv( data, size, MPI_CHAR, pid, tag, MPI_COMM_WORLD, & status );
+#endif
+}
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/Parallel.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/Parallel.h
new file mode 100644
index 00000000..880a71cb
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/Parallel.h
@@ -0,0 +1,78 @@
+#pragma once
+#ifdef HX_PARALLEL
+#include "mpi.h"
+#endif
+#include <vector>
+#include "LogFile.h"
+
+class Parallel
+{
+public:
+    static int pid;
+    static int nProc;
+    static int serverid;
+    static int tag;
+public:
+    static void Init();
+    static void Finalize();
+public:
+    static bool IsServer();
+};
+
+void HXSendChar( void * data, int size, int pid, int tag );
+void HXRecvChar( void * data, int size, int pid, int tag );
+
+template< typename T >
+void HXSendData( T * field, int nElement, int recv_pid, int tag  );
+
+template< typename T >
+void HXRecvData( T * field, int nElement, int send_pid, int tag );
+
+template< typename T >
+void HXSendData( T * field, int nElement, int recv_pid, int tag = 0 )
+{
+    if ( nElement <= 0 ) return;
+
+    int buffer_size = nElement * sizeof( T );
+
+    HXSendChar( field, buffer_size, recv_pid, tag );
+}
+
+template< typename T >
+void HXRecvData( T * field, int nElement, int send_pid, int tag = 0 )
+{
+    if ( nElement <= 0 ) return;
+
+    int buffer_size = nElement * sizeof( T );
+
+    HXRecvChar( field, buffer_size, send_pid, tag );
+}
+
+template< typename T >
+void HXSendRecvData( T * field, int nElement, int send_pid, int recv_pid, int tag = 0 )
+{
+    if ( send_pid == recv_pid ) return;
+
+    if ( nElement <= 0 ) return;
+
+    int buffer_size = nElement * sizeof( T );
+
+    if ( Parallel::pid == send_pid )
+    {
+        HXSendChar( field, buffer_size, recv_pid, tag );
+    }
+    else if ( Parallel::pid == recv_pid )
+    {
+        HXRecvChar( field, buffer_size, send_pid, tag );
+    }
+}
+
+template< typename T >
+void HXBcastData( T * field, int nElement, int send_pid )
+{
+    if ( nElement <= 0 ) return;
+    int buffer_size = nElement * sizeof( T );
+#ifdef HX_PARALLEL
+    MPI_Bcast( field, buffer_size, MPI_CHAR, send_pid, MPI_COMM_WORLD );
+#endif
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/README.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/README.txt
new file mode 100644
index 00000000..5a4410fb
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/README.txt
@@ -0,0 +1,3 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
+
+PS D:\github\OneFLOW\example\1d-heat-equation\ftcs\cpp\multiblock\parallel\8blocks\01\build> mpiexec -n 8 .\Debug\testprj.exe
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/Solver.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/Solver.cpp
new file mode 100644
index 00000000..6035f616
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/Solver.cpp
@@ -0,0 +1,680 @@
+#include "Solver.h"
+#include "Parallel.h"
+#include "ZoneState.h"
+#include "global.h"
+#include <fstream>
+#include <set>
+#include <unordered_map>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+Solver::Solver()
+{
+    Parallel::Init();
+}
+
+Solver::~Solver()
+{
+    Parallel::Finalize();
+}
+
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    this->InitTopo();
+    this->InitFields();
+    this->SolveMultiZones();
+    this->PostProcess();
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d8blocksv1.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    ReadCgnsGrid( fileName );
+}
+
+void Solver::InitTopo()
+{
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "Solver::InitTopo() " << "\n";
+
+    Global::donor_zone_sets.resize( LocalZone::nZones );
+    Global::donor_zones.resize( LocalZone::nZones );
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        int global_zoneid = LocalZone::global_zoneids[ iZone ];
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "iZone = " << iZone << " global_zoneid = " << global_zoneid << "\n";
+
+        Interface * interface = new Interface();
+        interface->zoneid = global_zoneid;
+        Global::interfaces.push_back( interface );
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+        Interface * interface = Global::interfaces[ iZone ];
+
+        int nbc1to1s = zone->bc1to1s.size();
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout <<  "nbc1to1s = " << nbc1to1s << "\n";
+
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "zoneid = " << zoneid << " donor_zoneid = " << donor_zoneid << "\n";
+
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+        int nInterfaces = interface->zoneList.size();
+        interface->data_recv.resize( nInterfaces );
+        interface->data_send.resize( nInterfaces );
+    }
+
+    for ( int iProc = 0; iProc < Parallel::nProc; ++ iProc )
+    {
+        int nSize = -1;
+        if ( iProc == Parallel::pid )
+        {
+            nSize = Global::facePairList.size();
+        }
+        HXBcastData( &nSize, 1, iProc );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nSize = " << nSize << "\n";
+        std::vector<FacePair> tmp;
+        if ( iProc == Parallel::pid )
+        {
+            tmp = Global::facePairList;
+        }
+        else
+        {
+            tmp.resize( nSize );
+        }
+
+        HXBcastData( tmp.data(), tmp.size(), iProc );
+        Global::AddFacePairList( Global::mpi_facePairList, tmp );
+    }
+
+    for ( int i = 0; i < Global::mpi_facePairList.size(); ++ i )
+    {
+        FacePair &facePair = Global::mpi_facePairList[ i ];
+        Global::InsertFacePairMap( facePair );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        facePair.Print();
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterfaces = interface->local_faceids.size();
+        for ( int iInterface = 0; iInterface < nInterfaces; ++ iInterface )
+        {
+            int local_faceid = interface->local_faceids[ iInterface ];
+            int proc_global_faceid = interface->proc_global_faceids[ iInterface ];
+            FacePair & facePair = Global::facePairList[ proc_global_faceid ];
+            int global_faceid = Global::InsertFacePairMap( facePair );
+            interface->global_faceids.push_back( global_faceid );
+            interface->global_local_face_map.insert( std::make_pair( global_faceid, local_faceid ) );
+        }
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        std::set<int> &donor_zoneSet = Global::donor_zone_sets[ iZone ];
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            donor_zoneSet.insert( donor_zoneid );
+        }
+
+        std::vector<int> &donor_zones = Global::donor_zones[ iZone ];
+        for ( std::set<int>::iterator iter = donor_zoneSet.begin(); iter != donor_zoneSet.end(); ++ iter )
+        {
+            donor_zones.push_back( *iter );
+        }
+
+        interface->neighbor_donor_zones = donor_zones;
+
+        std::unordered_map<int, int> donor_zonelocal;
+
+        for ( int idonor = 0; idonor < donor_zones.size(); ++ idonor )
+        {
+            int donor_zone = donor_zones[ idonor ];
+            donor_zonelocal.insert( std::make_pair( donor_zone, idonor ) );
+        }
+        int ndonors = donor_zones.size();
+        std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+        neighbor_donorfaces.resize( ndonors );
+
+        std::vector<std::vector<int>> & sub_local_faceids = interface->sub_local_faceids;
+        sub_local_faceids.resize( ndonors );
+
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ineighbor = donor_zonelocal[ donor_zoneid ];
+            std::vector<int> &donorfaces = neighbor_donorfaces[ ineighbor ];
+            int global_faceid = interface->global_faceids[ iFace ];
+            donorfaces.push_back( global_faceid );
+            int local_faceid = interface->local_faceids[ iFace ];
+
+            std::vector<int> & sub_local_faces = sub_local_faceids[ ineighbor ];
+            sub_local_faces.push_back( local_faceid );
+        }
+    }
+
+    Global::interfaceTopo.InitNeighborInfo();
+    Global::interfaceTopo.SwapNeighborInfo();
+
+    int kkk = 1;
+}
+
+void Solver::InitFields()
+{
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "Solver::InitFields() ZoneState::nZones = " << ZoneState::nZones <<  "\n";
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+    }
+
+    Boundary();
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        //std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        //std::cout << "it = " << it << " nt = " << Global::nt << "\n";
+        for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+        {
+            Field * field = Global::fields[ iZone ];
+            Zone * zone = Global::zones[ iZone ];
+            zone->zoneIndex = iZone;
+            field->Solve( zone );
+        }
+        Boundary();
+    }
+}
+
+void Solver::Boundary()
+{
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+    ExchangeInterfaceField();
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->UpdateOldField();
+    }
+}
+
+void Solver::UploadInterfaceField()
+{
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> & send_to_zones = interface->send_to_zones;
+        int nsend_zones = send_to_zones.size();
+
+        std::vector<std::vector<int>> & donorfaces_for_send = interface->donorfaces_for_send;
+        std::vector<std::vector<int>> & donorijk_for_send = interface->donorijk_for_send;
+        std::vector<std::vector<double>> & donordata_for_send = interface->donordata_for_send;
+
+        Field * field = Global::fields[ iZone ];
+
+        for ( int iSend = 0; iSend < nsend_zones; ++ iSend )
+        {
+            int zone_to_send = send_to_zones[ iSend ];
+            std::vector<int> & donorfaces = donorfaces_for_send[ iSend ];
+            std::vector<int> & donorijks = donorijk_for_send[ iSend ];
+            std::vector<double> & donordatas = donordata_for_send[ iSend ];
+
+            int nface = donorfaces.size();
+            int index_dim = 1;
+            for ( int i = 0; i < nface; ++ i )
+            {
+                int ijkpos = index_dim * i;
+                int i_donor_cell = donorijks[ ijkpos + 0 ];
+                donordatas[ i ] = field->u[ i_donor_cell ];
+            }
+        }
+    }
+}
+
+void Solver::UpdateInterfaceField()
+{
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        int ndonor_zones = Global::interfaceTopo.linkmap[ iZone ].size();
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donor_zone = Global::interfaceTopo.linkmap[ iZone ][ iNei ];
+            int send_pid = ZoneState::pids[ iZone ];
+            int recv_pid = ZoneState::pids[ donor_zone ];
+            int nsend = -1;
+            std::vector<double> donordata;
+            if ( Parallel::pid != send_pid && Parallel::pid != recv_pid ) continue;
+            if ( Parallel::pid == send_pid )
+            {
+                int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+                Interface * interface = Global::interfaces[ local_zoneid ];
+                donordata = interface->donordata_for_send[ iNei ];
+                nsend = donordata.size();
+            }
+            HXSendRecvData( &nsend, 1, send_pid, recv_pid );
+
+            if ( Parallel::pid == recv_pid )
+            {
+                donordata.resize( nsend );
+            }
+            HXSendRecvData( donordata.data(), donordata.size(), send_pid, recv_pid );
+
+            if ( Parallel::pid == recv_pid )
+            {
+                int local_donor_zoneid = ZoneState::g2lzoneids[ donor_zone ];
+                Interface * donor_interface = Global::interfaces[ local_donor_zoneid ];
+                int nSize = donor_interface->neighbor_donor_zones.size();
+                int ipos = -1;
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    int nei_zone = donor_interface->neighbor_donor_zones[ i ];
+                    if ( nei_zone == iZone )
+                    {
+                        ipos = i;
+                        break;
+                    }
+                }
+
+                std::vector<int> & neighbor_donorfaces = donor_interface->neighbor_donorfaces[ ipos ];
+                std::vector<int> & sub_local_faceids = donor_interface->sub_local_faceids[ ipos ];
+                for ( int i = 0; i < neighbor_donorfaces.size(); ++ i )
+                {
+                    int local_faceid = sub_local_faceids[ i ];
+                    double donor_value = donordata[ i ];
+                    donor_interface->data_recv[ local_faceid ] = donor_value;
+                }
+            }
+        }
+    }
+}
+
+void Solver::DownloadInterfaceField()
+{
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+        Field * field = Global::fields[ iZone ];
+
+        int nInterFaces = interface->data_recv.size();
+
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+
+            double donor_value = interface->data_recv[ iFace ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    this->UploadInterfaceField();
+    this->UpdateInterfaceField();
+    this->DownloadInterfaceField();
+}
+
+void Solver::PostProcess()
+{
+    Post post;
+    post.Process();
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        if ( !ZoneState::IsValid( iZone ) && !Parallel::IsServer() ) continue;
+
+        double xmin = 0.0;
+        double xmax = 0.0;
+
+        if ( ZoneState::IsValid( iZone ) )
+        {
+            int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+            Grid * grid = Global::grids[ local_zoneid ];
+            int ni = grid->x.size();
+            xmin = grid->x[ 0 ];
+            xmax = grid->x[ 0 ];
+            int imin = 0;
+            int imax = 0;
+            for ( int i = 0; i < ni; ++ i )
+            {
+                if ( xmin > grid->x[ i ] )
+                {
+                    xmin = grid->x[ i ];
+                    imin = i;
+                }
+                if ( xmax < grid->x[ i ] )
+                {
+                    xmax = grid->x[ i ];
+                    imax = i;
+                }
+            }
+        }
+
+        HXSendRecvData( &xmin, 1, ZoneState::pids[ iZone ], Parallel::serverid );
+        HXSendRecvData( &xmax, 1, ZoneState::pids[ iZone ], Parallel::serverid );
+
+        //if ( Parallel::IsServer() )
+        //{
+        //    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        //    std::cout << "xmin = " << xmin << "\n";
+        //    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        //    std::cout << "xmax = " << xmax << "\n";
+        //}
+
+        if ( Parallel::IsServer() )
+        {
+            xmin_list.push_back( xmin );
+            xmax_list.push_back( xmax );
+        }
+    }
+
+    //if ( Parallel::IsServer() )
+    //{
+    //    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    //    for ( int i = 0; i < xmin_list.size(); ++ i )
+    //    {
+    //        std::cout << "(" << xmin_list[ i ] << "," << xmax_list[ i ] << ") ";
+    //    }
+    //    std::cout << "\n";
+    //}
+
+    if ( Parallel::IsServer() )
+    {
+        std::vector<std::pair<double, int>> pairs;
+        int nSize = xmin_list.size();
+        for ( int i = 0; i < nSize; ++ i )
+        {
+            pairs.push_back( std::make_pair( xmin_list[ i ], i ) );
+        }
+
+        std::sort( pairs.begin(), pairs.end() );
+
+        for ( int i = 0; i < nSize; ++ i )
+        {
+            this->zoneids.push_back( pairs[ i ].second );
+        }
+    }
+
+    int kkk = 1;
+}
+
+bool IsLastZone( int iZone );
+bool IsLastZone( int iZone )
+{
+    return iZone == ZoneState::nZones - 1;
+}
+
+void Post::AddVector( std::vector<double> & a, std::vector<double> & b )
+{
+    for ( int i = 0; i < b.size(); ++ i )
+    {
+        a.push_back( b[ i ] );
+    }
+}
+
+void Post::GatherField()
+{
+    this->zoneids.resize( ZoneState::nZones );
+    HXBcastData( this->zoneids.data(), this->zoneids.size(), Parallel::serverid );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "Post::GatherField() this->zoneids = \n";
+    for ( int i = 0; i < this->zoneids.size(); ++ i )
+    {
+        std::cout << this->zoneids[ i ] << " ";
+    }
+    std::cout << "\n";
+
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+
+        if ( !ZoneState::IsValid( zoneid ) && !Parallel::IsServer() ) continue;
+
+        int nSize = -1;
+        std::vector<double> local_x;
+        std::vector<double> local_u_e;
+        std::vector<double> local_un;
+        std::vector<double> local_u;
+
+        if ( Parallel::pid == ZoneState::pids[ zoneid ] )
+        {
+            int local_zoneid = ZoneState::g2lzoneids[ zoneid ];
+            Grid * grid = Global::grids[ local_zoneid ];
+            Field * field = Global::fields[ local_zoneid ];
+            int ni = grid->x.size();
+
+            int ist = 1;
+            int ied = ni;
+
+            int dir = 1;
+            if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+            if ( dir == 1 )
+            {
+                if ( IsLastZone( iZone ) )
+                {
+                    for ( int i = ist; i <= ied; ++ i )
+                    {
+                        double xm = grid->x[ i - ist ];
+                        local_x.push_back( xm );
+                        local_u_e.push_back( field->u_e[ i ] );
+                        local_un.push_back( field->un[ i ] );
+                        local_u.push_back( field->u[ i ] );
+                    }
+                }
+                else
+                {
+                    for ( int i = ist; i <= ied - 1; ++ i )
+                    {
+                        double xm = grid->x[ i - ist ];
+                        local_x.push_back( xm );
+                        local_u_e.push_back( field->u_e[ i ] );
+                        local_un.push_back( field->un[ i ] );
+                        local_u.push_back( field->u[ i ] );
+                    }
+                }
+            }
+            else
+            {
+                if ( IsLastZone( iZone ) )
+                {
+                    for ( int i = ied; i >= ist; -- i )
+                    {
+                        double xm = grid->x[ i - ist ];
+                        local_x.push_back( xm );
+                        local_u_e.push_back( field->u_e[ i ] );
+                        local_un.push_back( field->un[ i ] );
+                        local_u.push_back( field->u[ i ] );
+                    }
+                }
+                else
+                {
+                    for ( int i = ied; i >= ist + 1; -- i )
+                    {
+                        double xm = grid->x[ i - ist ];
+                        local_x.push_back( xm );
+                        local_u_e.push_back( field->u_e[ i ] );
+                        local_un.push_back( field->un[ i ] );
+                        local_u.push_back( field->u[ i ] );
+                    }
+                }
+            }
+            nSize = local_x.size();
+        }
+
+        int send_pid = ZoneState::pids[ zoneid ];
+
+        HXSendRecvData( &nSize, 1, send_pid, Parallel::serverid );
+
+        if ( Parallel::IsServer() )
+        {
+            local_x.resize( nSize );
+            local_u_e.resize( nSize );
+            local_un.resize( nSize );
+            local_u.resize( nSize );
+        }
+
+        HXSendRecvData( local_x.data(), local_x.size(), send_pid, Parallel::serverid );
+        HXSendRecvData( local_u_e.data(), local_u_e.size(), send_pid, Parallel::serverid );
+        HXSendRecvData( local_un.data(), local_un.size(), send_pid, Parallel::serverid );
+        HXSendRecvData( local_u.data(), local_u.size(), send_pid, Parallel::serverid );
+
+        if ( Parallel::IsServer() )
+        {
+            this->AddVector( this->x, local_x );
+            this->AddVector( this->u_e, local_u_e );
+            this->AddVector( this->un, local_un );
+            this->AddVector( this->u, local_u );
+        }
+    }
+}
+
+void Post::DumpField()
+{
+    if ( !Parallel::IsServer() ) return;
+    int ni_total = this->x.size();
+    std::cout << " DumpField x.size() = " << x.size() << "\n";
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    this->DumpErrorDetails( u_error );
+
+    std::string csvname = "field_final.csv";
+    this->DumpCsvFile( csvname, x, u_e, un, u_error );
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.20f} {:.20f} {:.20f} {:.20f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/Solver.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/Solver.h
new file mode 100644
index 00000000..9914c1d7
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/Solver.h
@@ -0,0 +1,49 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+
+class Solver
+{
+public:
+    Solver();
+    ~Solver();
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveMultiZones();
+public:
+    void Boundary();
+    void UploadInterfaceField();
+    void UpdateInterfaceField();
+    void DownloadInterfaceField();
+    void ExchangeInterfaceField();
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcess();
+};
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+    std::vector<double> u;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+public:
+    void AddVector( std::vector<double> & a, std::vector<double> & b );
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/ZoneState.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/ZoneState.cpp
new file mode 100644
index 00000000..ff810849
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/ZoneState.cpp
@@ -0,0 +1,20 @@
+#include "ZoneState.h"
+#include "Parallel.h"
+
+int ZoneState::nZones = 0;
+std::vector<int> ZoneState::pids;
+std::vector<int> ZoneState::g2lzoneids;
+
+bool ZoneState::IsValid( int zoneid )
+{
+    return ZoneState::pids[ zoneid ] == Parallel::pid;
+}
+
+int ZoneState::GetProcID( int zoneid )
+{
+    return ZoneState::pids[ zoneid ];
+}
+
+int LocalZone::nZones = 0;
+std::vector<int> LocalZone::global_zoneids;
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/ZoneState.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/ZoneState.h
new file mode 100644
index 00000000..1096d632
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/ZoneState.h
@@ -0,0 +1,21 @@
+#pragma once
+#include <vector>
+
+class ZoneState
+{
+public:
+    static int nZones;
+    static int zone_id;
+    static std::vector<int> pids;
+    static std::vector<int> g2lzoneids; //global zone id to local zone id
+public:
+    static bool IsValid( int zoneid );
+    static int GetProcID( int zoneid );
+};
+
+class LocalZone
+{
+public:
+    static int nZones;
+    static std::vector<int> global_zoneids;
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/global.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/global.cpp
new file mode 100644
index 00000000..df1e6bae
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/global.cpp
@@ -0,0 +1,300 @@
+#include "global.h"
+#include "CgnsGrid.h"
+#include "ZoneState.h"
+#include "Parallel.h"
+#include <iostream>
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *> Global::interfaces;
+
+std::map<Face, int> Global::faceMap;
+std::map<FacePair, int> Global::facePairMap;
+std::vector<FacePair> Global::facePairList;
+std::vector<FacePair> Global::mpi_facePairList;
+
+std::vector<std::set<int>> Global::donor_zone_sets;
+std::vector<std::vector<int>> Global::donor_zones;
+
+InterfaceTopo Global::interfaceTopo;
+
+bool Face::operator < ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return this->zone < rhs.zone;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return this->i < rhs.i;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return this->j < rhs.j;
+    }
+
+    return this->k < rhs.k;
+}
+
+bool Face::operator == ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return false;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return false;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return false;
+    }
+
+    return this->k == rhs.k;
+}
+
+void Face::Print()
+{
+    std::cout << "(" << this->zone << "," << this->i << ")";
+}
+
+void FacePair::AddPair( const Face & face1, const Face & face2 )
+{
+    if ( face1 < face2 )
+    {
+        this->left = face1;
+        this->right = face2;
+    }
+    else
+    {
+        this->left = face2;
+        this->right = face1;
+    }
+}
+
+bool FacePair::operator < ( const FacePair & rhs ) const
+{
+    if ( this->left == rhs.left || this->left == rhs.right )
+    {
+        return false;
+    }
+
+    return this->left < rhs.left;
+}
+
+void FacePair::Print()
+{
+    this->left.Print();
+    std::cout << " ";
+    this->right.Print();
+    std::cout << "\n";
+}
+
+void InterfaceTopo::InitNeighborInfo()
+{
+    this->linkmap.resize( ZoneState::nZones );
+
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        if ( ! ZoneState::IsValid( iZone ) ) continue;
+
+        int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+
+        Interface * interface = Global::interfaces[ local_zoneid ];
+
+        std::vector<int> & t = this->linkmap[ iZone ];
+        t = interface->neighbor_donor_zones;
+    }
+}
+
+void InterfaceTopo::SwapNeighborInfo()
+{
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        int pid = ZoneState::pids[ iZone ];
+
+        std::vector<int> & donor_zones = this->linkmap[ iZone ];
+        int nNeighbor = donor_zones.size();
+
+        HXBcastData( &nNeighbor, 1, pid );
+
+        donor_zones.resize( nNeighbor );
+
+        HXBcastData( donor_zones.data(), donor_zones.size(), pid );
+    }
+
+    this->SwapNeighborDonorfaces();
+}
+
+void InterfaceTopo::SwapNeighborDonorfaces()
+{
+    int gl = 0;
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        int send_pid = ZoneState::pids[ iZone ];
+
+        std::vector<int> & donor_zones = this->linkmap[ iZone ];
+        int ndonor_zones = donor_zones.size();
+
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donor_zone = donor_zones[ iNei ];
+            int recv_pid = ZoneState::pids[ donor_zone ];
+            int nInterFaces = 0;
+            std::vector<int> donorfaces;
+
+            if ( Parallel::pid == send_pid )
+            {
+                int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+
+                Interface * interface = Global::interfaces[ local_zoneid ];
+
+                std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+
+                std::vector<int> & neighbor_donorface = neighbor_donorfaces[ iNei ];
+
+                nInterFaces = neighbor_donorface.size();
+
+                donorfaces = neighbor_donorface;
+            }
+
+            HXSendRecvData( &nInterFaces, 1, send_pid, recv_pid );
+
+            if ( Parallel::pid == recv_pid && send_pid != recv_pid )
+            {
+                donorfaces.resize( nInterFaces );
+            }
+
+            HXSendRecvData( donorfaces.data(), donorfaces.size(), send_pid, recv_pid );
+
+            if ( Parallel::pid == recv_pid )
+            {
+                int local_donor_zoneid = ZoneState::g2lzoneids[ donor_zone ];
+                Interface * interface_recv = Global::interfaces[ local_donor_zoneid ];
+                interface_recv->SendGeom( iZone, donorfaces );
+            }
+        }
+    }
+}
+
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->local_faceids.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        Face face;
+        face.zone = zoneid;
+        face.i = i;
+
+        int i_donor = index2[ 0 ];
+
+        Face face_donor;
+        face_donor.zone = donor_zoneid;
+        face_donor.i = i_donor;
+
+        FacePair facePair;
+        facePair.AddPair( face, face_donor );
+
+        Global::facePairList.push_back( facePair );
+        int nSize = Global::facePairList.size();
+        this->proc_global_faceids.push_back( nSize - 1 );
+
+        int i_ghost_cell = i + 1;
+        int i_local_donor_cell = i - 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+            i_local_donor_cell = i + 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+        ijk_donors.push_back( i_local_donor_cell );
+
+        icount ++;
+    }
+}
+
+void Interface::SendGeom( int zone, std::vector<int> & donorfaces )
+{
+    Interface * interface = this;
+
+    std::vector<int> & send_to_zones = interface->send_to_zones;
+
+    send_to_zones.push_back( zone );
+    interface->donorfaces_for_send.push_back( donorfaces );
+
+    int nface = donorfaces.size();
+    std::vector<int> sub_donorijk;
+    int index_dim = 1;
+    for ( int i = 0; i < nface; ++ i )
+    {
+        int global_faceid = donorfaces[ i ];
+        int local_faceid = interface->global_local_face_map[ global_faceid ];
+        int ijkpos = index_dim * local_faceid;
+        int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+        sub_donorijk.push_back( i_donor_cell );
+        int kkk = 1;
+    }
+
+    interface->donorijk_for_send.push_back( sub_donorijk );
+
+    std::vector<double> sub_donordata( sub_donorijk.size() );
+    interface->donordata_for_send.push_back( sub_donordata );
+}
+
+void Global::InsertFaceMap( const Face & face )
+{
+    std::map<Face, int>::iterator iter;
+    iter = Global::faceMap.find( face );
+    if ( iter == Global::faceMap.end() )
+    {
+        int faceid = Global::faceMap.size();
+        Global::faceMap.insert( std::make_pair( face, faceid ) );
+    }
+}
+
+int Global::InsertFacePairMap( const FacePair & facePair )
+{
+    std::map<FacePair, int>::iterator iter;
+    iter = Global::facePairMap.find( facePair );
+    if ( iter == Global::facePairMap.end() )
+    {
+        int facePairId = Global::facePairMap.size();
+        Global::facePairMap.insert( std::make_pair( facePair, facePairId ) );
+        return facePairId;
+    }
+    return iter->second;
+}
+
+void Global::AddFacePairList( std::vector<FacePair> & a, std::vector<FacePair> & b )
+{
+    for ( int i = 0; i < b.size(); ++ i )
+    {
+        a.push_back( b[ i ] );
+    }
+}
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/global.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/global.h
new file mode 100644
index 00000000..933cec05
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/global.h
@@ -0,0 +1,157 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <unordered_map>
+#include <set>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class Face
+{
+public:
+    int zone = 0;
+    int i = 0;
+    int j = 1;
+    int k = 1;
+public:
+    bool operator < ( const Face & rhs ) const;
+    bool operator == ( const Face & rhs ) const;
+public:
+    void Print();
+};
+
+class FacePair
+{
+public:
+    Face left;
+    Face right;
+public:
+    bool operator < ( const FacePair & rhs ) const;
+    void AddPair( const Face &face1, const Face &face2);
+public:
+    void Print();
+};
+
+class Transform;
+
+class InterfaceTopo
+{
+public:
+    std::vector<std::vector<int>> linkmap;
+public:
+    void InitNeighborInfo();
+    void SwapNeighborInfo();
+    void SwapNeighborDonorfaces();
+};
+
+
+class Interface
+{
+public:
+    int zoneid;
+    std::vector<int> zoneList;
+    std::vector<int> global_faceids;
+    std::vector<int> mpi_global_faceids;
+    std::vector<int> proc_global_faceids;
+    std::vector<int> local_faceids;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+    std::vector<double> data_recv;
+    std::vector<double> data_send;
+    std::unordered_map<int, int> global_local_face_map;
+public:
+    std::vector<int> neighbor_donor_zones;
+    std::vector<std::vector<int>> neighbor_donorfaces;
+    std::vector<std::vector<int>> sub_local_faceids;
+    std::vector<int> send_to_zones;
+    std::vector<std::vector<int>> donorfaces_for_send;
+    std::vector<std::vector<int>> donorijk_for_send;
+    std::vector<std::vector<double>> donordata_for_send;
+public:
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+    void SendGeom( int zone, std::vector<int> & donorfaces );
+};
+
+class Field;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+public:
+    static std::map<Face, int> faceMap;
+    static std::map<FacePair, int> facePairMap;
+    static std::vector<FacePair> facePairList;
+    static std::vector<FacePair> mpi_facePairList;
+    static std::vector<std::set<int>> donor_zone_sets;
+    static std::vector<std::vector<int>> donor_zones;
+    static InterfaceTopo interfaceTopo;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+public:
+    static void InsertFaceMap( const Face & face );
+    static int InsertFacePairMap( const FacePair & facePair );
+    static void AddFacePairList( std::vector<FacePair> & a, std::vector<FacePair> & b );
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/heat1d4blocksv1.cgns b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/heat1d4blocksv1.cgns
new file mode 100644
index 00000000..df5ffc5f
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/heat1d4blocksv1.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/heat1d8blocksv1.cgns b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/heat1d8blocksv1.cgns
new file mode 100644
index 00000000..4dc174d4
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/heat1d8blocksv1.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/main.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/main.cpp
new file mode 100644
index 00000000..df63b7da
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/main.cpp
@@ -0,0 +1,9 @@
+#include "Solver.h"
+#include "Parallel.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/plot.py b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/CMakeLists.txt
new file mode 100644
index 00000000..9e834b72
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/CMakeLists.txt
@@ -0,0 +1,99 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package ( MPI )
+
+message ( STATUS  "MPI_FOUND=${MPI_FOUND}" )
+message ( STATUS  "MPI_CXX_INCLUDE_DIRS=${MPI_CXX_INCLUDE_DIRS}" )
+message ( STATUS  "MPI_LIBRARIES=${MPI_LIBRARIES}" )
+if ( MPI_FOUND )
+	list ( APPEND PRJ_INCLUDE_DIRS ${MPI_CXX_INCLUDE_DIRS} )
+	list ( APPEND PRJ_LIBRARIES ${MPI_LIBRARIES} )
+endif ()
+
+#get_directory_property( my_import_targets DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} IMPORTED_TARGETS )
+#message( STATUS "my_import_targets=${my_import_targets}" )
+
+list ( APPEND PRJ_LIBRARIES MPI::MPI_C )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+list ( APPEND PRJ_COMPILE_DEFINITIONS HX_PARALLEL )
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	LogFile.h LogFile.cpp
+	Parallel.h Parallel.cpp
+	Solver.h Solver.cpp
+	ZoneState.h ZoneState.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/CgnsGrid.cpp
new file mode 100644
index 00000000..825442a2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/CgnsGrid.cpp
@@ -0,0 +1,850 @@
+#include "CgnsGrid.h"
+#include "Parallel.h"
+#include "cgnslib.h"
+#include "global.h"
+#include "ZoneState.h"
+#include <iostream>
+#include <vector>
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "fileId = " << fileId << "\n";
+    }
+    
+    int nbases = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_nbases( fileId, &nbases );
+    }
+    HXBcastData( &nbases, 1, Parallel::serverid );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "nbases = " << nbases << "\n";
+    
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        }
+
+        HXBcastData( &icelldim, 1, Parallel::serverid );
+        HXBcastData( &iphysdim, 1, Parallel::serverid );
+
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+
+        int nzones = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_nzones( fileId, baseId, &nzones );
+        }
+
+        HXBcastData( &nzones, 1, Parallel::serverid );
+
+        ZoneState::nZones = nzones;
+        ZoneState::pids.resize( nzones );
+        ZoneState::g2lzoneids.resize( nzones );
+        std::vector<int> pcount( Parallel::nProc, 0 );
+
+        for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+        {
+            int zone_pid = iZone % Parallel::nProc;
+            ZoneState::pids[ iZone ] = zone_pid;
+            ZoneState::g2lzoneids[ iZone ] = pcount[ zone_pid ];
+            pcount[ zone_pid ] ++;
+        }
+
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nzones = " << nzones << "\n";
+
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "iZone = " << iZone << "\n";
+
+            int index_dim = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            }
+            HXBcastData( &index_dim, 1, Parallel::serverid );
+
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            if ( Parallel::IsServer() )
+            {
+                cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            }
+
+            HXBcastData( zonename, 33, Parallel::serverid );
+            HXBcastData( isize.data(), isize.size(), Parallel::serverid);
+
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "zonename = " << zonename << "\n";
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+
+    if ( Parallel::IsServer() )
+    {
+        cg_close( fileId );
+    }
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+        std::cout << "fileId = " << fileId << "\n";
+    }
+    
+    int nbases = -1;
+    if ( Parallel::IsServer() )
+    {
+        cg_nbases( fileId, &nbases );
+    }
+    MPI_Bcast( &nbases, 1, MPI_INT, Parallel::serverid, MPI_COMM_WORLD );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        }
+
+        HXBcastData( &icelldim, 1, Parallel::serverid );
+        HXBcastData( &iphysdim, 1, Parallel::serverid );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+
+        int nzones = -1;
+        if ( Parallel::IsServer() )
+        {
+            cg_nzones( fileId, baseId, &nzones );
+        }
+        HXBcastData( &nzones, 1, Parallel::serverid );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nzones = " << nzones << "\n";
+
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            }
+            HXSendRecvData( &index_dim, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "index_dim = " << index_dim << "\n";
+            }
+
+            std::vector<cgsize_t> isize;
+            char zonename[ 33 ];
+            if ( Parallel::IsServer() )
+            {
+                isize.resize( index_dim * 3 );
+                cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            }
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                isize.resize( index_dim * 3 );
+            }
+
+            HXSendRecvData( zonename, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+            HXSendRecvData( isize.data(), index_dim * 3, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "zonename = " << zonename << "\n";
+
+                for ( int i = 0; i < isize.size(); ++ i )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+                }
+            }
+
+            std::vector<cgsize_t> irmin;
+            std::vector<cgsize_t> irmax;
+            int nNodes = 1;
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                irmin.resize( index_dim );
+                irmax.resize( index_dim );
+                for ( int m = 0; m < index_dim; ++ m )
+                {
+                    /* lower range index */
+                    irmin[ m ] = 1;
+                    /* upper range index of vertices */
+                    irmax[ m ] = isize[ m ];
+                    nNodes *= irmax[ m ];
+                }
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "nNodes = " << nNodes << "\n";
+            }
+
+            ZoneType_t zoneType;
+            if ( Parallel::IsServer() )
+            {
+                cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            }
+            HXSendRecvData( &zoneType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            }
+
+            Zone * zone = nullptr;
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                zone = new Zone();
+                Global::zones.push_back( zone );
+                LocalZone::global_zoneids.push_back( iZone );
+                LocalZone::nZones = LocalZone::global_zoneids.size();
+                for ( int m = 0; m < index_dim; ++ m )
+                {
+                    zone->nijk.push_back( isize[ m ] );
+                }
+            }
+
+            Grid * grid = nullptr;
+            if ( ZoneState::IsValid( iZone ) )
+            {
+                grid = new Grid();
+                Global::grids.push_back( grid );
+            }
+
+            BaseZone baseZone;
+
+            int gZoneId = -1;
+            if ( Parallel::IsServer() )
+            {
+                baseZone.zone_name = zonename;
+                gZoneId = Global::zone_names.FindBaseZone( baseZone );
+            }
+
+            HXSendRecvData( &gZoneId, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "gZoneId = " << gZoneId << "\n";
+            }
+
+            int ncoords = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            }
+            HXSendRecvData( &ncoords, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "ncoords = " << ncoords << "\n";
+            }
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                if ( Parallel::IsServer() )
+                {
+                    cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                }
+                HXSendRecvData( coordname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &dataType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "coordname = " << coordname << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                }
+
+                std::vector<char> coord;
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    coord.resize( nNodes * sizeof( double ) );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coord.data() );
+                }
+
+                HXSendRecvData( coord.data(), coord.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                Coor * coor = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    coor = new Coor();
+                    zone->coors.push_back( coor );
+                    coor->coorname = coordname;
+                    coor->nNodes = nNodes;
+                    coor->coord = coord;
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    coor->DumpCoor();
+
+                    if ( icoord == 0 )
+                    {
+                        grid->x.resize( nNodes );
+                        coor->DumpCoorX( grid->x );
+                    }
+                }
+            }
+
+            int nbocos = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            }
+            HXSendRecvData( &nbocos, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "nbocos = " << nbocos << "\n";
+            }
+
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                if ( Parallel::IsServer() )
+                {
+                    cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                }
+                HXSendRecvData( &location, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+                }
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                //std::vector<int> normalIndex( index_dim, -1 );
+                std::vector<int> normalIndex;
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+                if ( Parallel::IsServer() )
+                {
+                    normalIndex.resize( index_dim );
+                    cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                        &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                }
+
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    normalIndex.resize( index_dim );
+                }
+                
+                HXSendRecvData( boconame, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &bocotype, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &ptset_type, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &npnts, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &normalDataType, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &normalListSize, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( normalIndex.data(), index_dim, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( &ndataset, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "npnts = " << npnts << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalListSize = " << normalListSize << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "normalIndex = ";
+                    for ( int i = 0; i < index_dim; ++ i )
+                    {
+                        std::cout << normalIndex[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "ndataset = " << ndataset << "\n";
+                }
+
+                std::vector<char> normalList;
+                std::vector<cgsize_t> pnts;
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    if ( normalDataType == DataTypeNull )
+                    {
+                        normalList.resize( sizeof( int ) );
+                    }
+                    else
+                    {
+                        int nSize = nNodes * index_dim * sizeof( double );
+                        normalList.resize( nSize );
+                    }
+                    pnts.resize( npnts * index_dim );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                }
+
+                HXSendRecvData( pnts.data(), npnts * index_dim, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "pnts = ";
+                    for ( int i = 0; i < pnts.size(); ++ i )
+                    {
+                        std::cout << pnts[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                }
+                HXSendRecvData( normalList.data(), normalList.size(), Parallel::serverid, ZoneState::GetProcID(iZone));
+
+                ZoneBc * zonebc = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    zonebc = new ZoneBc();
+                    zone->bccos.push_back( zonebc );
+                    zonebc->bcType = bocotype;
+                    for ( int i = 0; i < pnts.size(); ++ i )
+                    {
+                        zonebc->pnts.push_back( pnts[ i ] );
+                    }
+                }
+            }
+            int n1to1 = -1;
+            if ( Parallel::IsServer() )
+            {
+                cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            }
+
+            HXSendRecvData( &n1to1, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+            if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+            {
+                std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                std::cout << "n1to1 = " << n1to1 << "\n";
+            }
+
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range;
+                std::vector<cgsize_t> donor_range;
+                std::vector<int> transform;
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    range.resize( npnts * index_dim );
+                    donor_range.resize( npnts * index_dim );
+                    transform.resize( index_dim );
+                }
+
+                if ( Parallel::IsServer() )
+                {
+                    cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                }
+
+                HXSendRecvData( connectname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( donorname, 33, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( range.data(), range.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( donor_range.data(), donor_range.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+                HXSendRecvData( transform.data(), transform.size(), Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                if ( ZoneState::IsValid( iZone ) || Parallel::IsServer() )
+                {
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "connectname = " << connectname << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "donorname = " << donorname << "\n";
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "range = ";
+                    for ( int i = 0; i < range.size(); ++ i )
+                    {
+                        std::cout << range[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "donor_range = ";
+                    for ( int i = 0; i < donor_range.size(); ++ i )
+                    {
+                        std::cout << donor_range[ i ] << " ";
+                    }
+                    std::cout << "\n";
+
+                    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+                    std::cout << "transform = ";
+                    for ( int i = 0; i < transform.size(); ++ i )
+                    {
+                        std::cout << transform[ i ] << " ";
+                    }
+                    std::cout << "\n";
+                }
+
+                int gDonorZoneId = -1;
+                if ( Parallel::IsServer() )
+                {
+                    BaseZone baseZoneDonor;
+                    baseZoneDonor.zone_name = donorname;
+
+                    gDonorZoneId = Global::zone_names.FindBaseZone( baseZoneDonor );
+                }
+
+                HXSendRecvData( &gDonorZoneId, 1, Parallel::serverid, ZoneState::GetProcID( iZone ) );
+
+                ZoneBc1To1 * zonebc_1to1 = nullptr;
+                if ( ZoneState::IsValid( iZone ) )
+                {
+                    zonebc_1to1 = new ZoneBc1To1();
+                    zone->bc1to1s.push_back( zonebc_1to1 );
+                    zonebc_1to1->zoneid = gZoneId;
+                    zonebc_1to1->transform = transform;
+                    zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                    for ( int i = 0; i < range.size(); ++ i )
+                    {
+                        zonebc_1to1->pnts.push_back( range[ i ] );
+                        zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                    }
+                }
+            }
+        }
+    }
+
+    {
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "Global::zones.size() = " << Global::zones.size() << "\n";
+    }
+
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/CgnsGrid.h
new file mode 100644
index 00000000..fddf1db6
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/CgnsGrid.h
@@ -0,0 +1,103 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    int zoneIndex;
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/Field.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/Field.cpp
new file mode 100644
index 00000000..c359a811
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/Field.cpp
@@ -0,0 +1,142 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+
+    std::vector<double> & x = grid->x;
+    this->dx = std::abs( x[ 1 ] - x[ 0 ] );
+    this->dt = dx / 10.0;
+    this->t = 1.0;
+    this->nt = std::round( t / dt );
+
+    double total_time = nt * dt;
+
+    std::cout << "this->dt   = " << this->dt << "\n";
+    std::cout << "this->t    = " << this->t << "\n";
+    std::cout << "this->nt   = " << this->nt << "\n";
+    std::cout << "this->ni   = " << this->ni << "\n";
+    std::cout << "total_time = " << total_time << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        u_e[ i ] = - std::exp( -total_time ) * std::sin( std::numbers::pi * xm ); //theory solution
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+    int kkk = 1;
+}
+
+void Field::Solve( Zone * zone )
+{
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+    }
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        //std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        //region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+        int kkk = 1;
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
+
+void Field::UpdateOldField()
+{
+    for ( int i = 0; i < this->u.size(); ++ i )
+    {
+        this->un[ i ] = this->u[ i ];
+    }
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/Field.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/Field.h
new file mode 100644
index 00000000..084ec9bd
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/Field.h
@@ -0,0 +1,36 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid );
+
+    void Solve( Zone * zone );
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void UpdateOldField();
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/LogFile.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/LogFile.cpp
new file mode 100644
index 00000000..08ccd453
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/LogFile.cpp
@@ -0,0 +1,138 @@
+#include "LogFile.h"
+#include "Parallel.h"
+#include <sstream>
+#include <iostream>
+
+#ifdef _WINDOWS
+#include <windows.h>
+#include <direct.h>
+#include <io.h>
+#else
+#include <sys/stat.h>
+#include <unistd.h>
+#endif
+
+LogFile logFile;
+
+class OStream : public std::ostringstream
+{
+public:
+    OStream() {}
+    ~OStream() {}
+public:
+    void ClearAll()
+    {
+        this->clear();
+        this->str("");
+    }
+};
+
+OStream StrIO;
+std::string GetPrjDirName( const std::string & fileName );
+bool DirExist( const std::string & dirName );
+void MakeDir( const std::string & dirName );
+
+std::string GetPrjDirName( const std::string & fileName )
+{
+    size_t pos = fileName.find_last_of("\\/");
+    if ( std::string::npos == pos )
+    {
+        return "";
+    }
+    else
+    {
+        return fileName.substr( 0, pos );
+    }
+}
+
+bool DirExist( const std::string & dirName )
+{
+#ifdef _WINDOWS
+    bool flag = ( _access( dirName.c_str(), 0 ) == 0 );
+    return flag;
+#else
+    bool flag = ( access( dirName.c_str(), 0 ) == 0 );
+    return flag;
+#endif
+}
+
+void MakeDir( const std::string & dirName )
+{
+    int flag;
+#ifdef _WINDOWS
+    flag = _mkdir( dirName.c_str() );
+#else
+    flag = mkdir( dirName.c_str(), S_IRWXU );
+#endif
+    if ( flag == 0 )
+    {
+        std::cout << dirName << " directory has been created successfully !\n";
+    }
+}
+
+void CreateDirIfNeeded( std::string & prjFileName )
+{
+    std::string prj_dir = GetPrjDirName( prjFileName );
+
+    if ( ! DirExist( prj_dir ) )
+    {
+        MakeDir( prj_dir );
+    }
+}
+
+
+void OpenLogFile( int logFileIndex, std::fstream & file )
+{
+    static int ifReWrite = 0;
+
+    StrIO.ClearAll();
+    StrIO << "log/log" << logFileIndex << ".log";
+    std::string fileName = StrIO.str();
+
+    std::ios_base::openmode openMode;
+
+    if ( ifReWrite == 0 )
+    {
+        CreateDirIfNeeded( fileName );
+
+        openMode = std::ios_base::out | std::ios_base::trunc;
+
+        ifReWrite = 1;
+    }
+    else
+    {
+        openMode = std::ios_base::out | std::ios_base::app;
+    }
+
+    file.open( fileName.c_str(), openMode );
+    if ( ! file )
+    {
+        std::cout << "could not open " << fileName << std::endl;
+        exit( 0 );
+    }
+}
+
+void CloseLogFile( std::fstream & file )
+{
+    file.close();
+    file.clear();
+}
+
+LogFile::LogFile()
+{
+}
+
+LogFile::~LogFile()
+{
+}
+
+void LogFile::Open()
+{
+    int pid = Parallel::pid;
+    OpenLogFile( pid, this->my_fstream );
+}
+
+void LogFile::Close()
+{
+    CloseLogFile( this->my_fstream );
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/LogFile.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/LogFile.h
new file mode 100644
index 00000000..00e775ab
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/LogFile.h
@@ -0,0 +1,27 @@
+#pragma once
+#include <fstream>
+
+void OpenLogFile( int logFileIndex, std::fstream & file );
+void CloseLogFile( std::fstream & file );
+class LogFile;
+extern LogFile logFile;
+
+class LogFile
+{
+public:
+    LogFile();
+    ~LogFile();
+    std::fstream my_fstream;
+public:
+    void Open();
+    void Close();
+};
+
+template< typename T >
+LogFile & operator << ( LogFile & f, const T & value )
+{
+    f.Open();
+    f.my_fstream << value;
+    f.Close();
+    return f;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/Parallel.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/Parallel.cpp
new file mode 100644
index 00000000..0bce1a60
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/Parallel.cpp
@@ -0,0 +1,54 @@
+#include "Parallel.h"
+#include <iostream>
+
+int Parallel::pid = 0;
+int Parallel::nProc = 1;
+int Parallel::serverid = 0;
+int Parallel::tag = 0;
+
+void Parallel::Init()
+{
+#ifdef HX_PARALLEL
+    int argc     = 0;
+    char ** argv = 0;
+    MPI_Init( &argc, &argv );
+    MPI_Comm_rank( MPI_COMM_WORLD, &Parallel::pid );
+    MPI_Comm_size( MPI_COMM_WORLD, &Parallel::nProc );
+    int len = -1;
+    char version[ MPI_MAX_LIBRARY_VERSION_STRING ];
+    MPI_Get_library_version( version, &len );
+    std::cout << "Hello, world!  I am " << Parallel::pid << " of " << Parallel::nProc
+        << "(" << version << ", " << len << ")" << std::endl;
+#endif
+}
+
+void Parallel::Finalize()
+{
+#ifdef HX_PARALLEL
+    MPI_Finalize();
+#endif
+}
+
+bool Parallel::IsServer()
+{
+    return Parallel::pid == Parallel::serverid;
+}
+
+void HXSendChar( void * data, int size, int pid, int tag )
+{
+#ifdef HX_PARALLEL
+    if ( size <= 0 ) return;
+    MPI_Send( data, size, MPI_CHAR, pid, tag, MPI_COMM_WORLD );
+#endif
+}
+
+void HXRecvChar( void * data, int size, int pid, int tag )
+{
+#ifdef HX_PARALLEL
+    if ( size <= 0 ) return;
+
+    MPI_Status status;
+    MPI_Recv( data, size, MPI_CHAR, pid, tag, MPI_COMM_WORLD, & status );
+#endif
+}
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/Parallel.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/Parallel.h
new file mode 100644
index 00000000..880a71cb
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/Parallel.h
@@ -0,0 +1,78 @@
+#pragma once
+#ifdef HX_PARALLEL
+#include "mpi.h"
+#endif
+#include <vector>
+#include "LogFile.h"
+
+class Parallel
+{
+public:
+    static int pid;
+    static int nProc;
+    static int serverid;
+    static int tag;
+public:
+    static void Init();
+    static void Finalize();
+public:
+    static bool IsServer();
+};
+
+void HXSendChar( void * data, int size, int pid, int tag );
+void HXRecvChar( void * data, int size, int pid, int tag );
+
+template< typename T >
+void HXSendData( T * field, int nElement, int recv_pid, int tag  );
+
+template< typename T >
+void HXRecvData( T * field, int nElement, int send_pid, int tag );
+
+template< typename T >
+void HXSendData( T * field, int nElement, int recv_pid, int tag = 0 )
+{
+    if ( nElement <= 0 ) return;
+
+    int buffer_size = nElement * sizeof( T );
+
+    HXSendChar( field, buffer_size, recv_pid, tag );
+}
+
+template< typename T >
+void HXRecvData( T * field, int nElement, int send_pid, int tag = 0 )
+{
+    if ( nElement <= 0 ) return;
+
+    int buffer_size = nElement * sizeof( T );
+
+    HXRecvChar( field, buffer_size, send_pid, tag );
+}
+
+template< typename T >
+void HXSendRecvData( T * field, int nElement, int send_pid, int recv_pid, int tag = 0 )
+{
+    if ( send_pid == recv_pid ) return;
+
+    if ( nElement <= 0 ) return;
+
+    int buffer_size = nElement * sizeof( T );
+
+    if ( Parallel::pid == send_pid )
+    {
+        HXSendChar( field, buffer_size, recv_pid, tag );
+    }
+    else if ( Parallel::pid == recv_pid )
+    {
+        HXRecvChar( field, buffer_size, send_pid, tag );
+    }
+}
+
+template< typename T >
+void HXBcastData( T * field, int nElement, int send_pid )
+{
+    if ( nElement <= 0 ) return;
+    int buffer_size = nElement * sizeof( T );
+#ifdef HX_PARALLEL
+    MPI_Bcast( field, buffer_size, MPI_CHAR, send_pid, MPI_COMM_WORLD );
+#endif
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/README.txt b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/README.txt
new file mode 100644
index 00000000..5a4410fb
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/README.txt
@@ -0,0 +1,3 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
+
+PS D:\github\OneFLOW\example\1d-heat-equation\ftcs\cpp\multiblock\parallel\8blocks\01\build> mpiexec -n 8 .\Debug\testprj.exe
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/Solver.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/Solver.cpp
new file mode 100644
index 00000000..6035f616
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/Solver.cpp
@@ -0,0 +1,680 @@
+#include "Solver.h"
+#include "Parallel.h"
+#include "ZoneState.h"
+#include "global.h"
+#include <fstream>
+#include <set>
+#include <unordered_map>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+Solver::Solver()
+{
+    Parallel::Init();
+}
+
+Solver::~Solver()
+{
+    Parallel::Finalize();
+}
+
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    this->InitTopo();
+    this->InitFields();
+    this->SolveMultiZones();
+    this->PostProcess();
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d8blocksv1.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    ReadCgnsGrid( fileName );
+}
+
+void Solver::InitTopo()
+{
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "Solver::InitTopo() " << "\n";
+
+    Global::donor_zone_sets.resize( LocalZone::nZones );
+    Global::donor_zones.resize( LocalZone::nZones );
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        int global_zoneid = LocalZone::global_zoneids[ iZone ];
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "iZone = " << iZone << " global_zoneid = " << global_zoneid << "\n";
+
+        Interface * interface = new Interface();
+        interface->zoneid = global_zoneid;
+        Global::interfaces.push_back( interface );
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+        Interface * interface = Global::interfaces[ iZone ];
+
+        int nbc1to1s = zone->bc1to1s.size();
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout <<  "nbc1to1s = " << nbc1to1s << "\n";
+
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            std::cout << "Parallel::pid = " << Parallel::pid << " ";
+            std::cout << "zoneid = " << zoneid << " donor_zoneid = " << donor_zoneid << "\n";
+
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+        int nInterfaces = interface->zoneList.size();
+        interface->data_recv.resize( nInterfaces );
+        interface->data_send.resize( nInterfaces );
+    }
+
+    for ( int iProc = 0; iProc < Parallel::nProc; ++ iProc )
+    {
+        int nSize = -1;
+        if ( iProc == Parallel::pid )
+        {
+            nSize = Global::facePairList.size();
+        }
+        HXBcastData( &nSize, 1, iProc );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        std::cout << "nSize = " << nSize << "\n";
+        std::vector<FacePair> tmp;
+        if ( iProc == Parallel::pid )
+        {
+            tmp = Global::facePairList;
+        }
+        else
+        {
+            tmp.resize( nSize );
+        }
+
+        HXBcastData( tmp.data(), tmp.size(), iProc );
+        Global::AddFacePairList( Global::mpi_facePairList, tmp );
+    }
+
+    for ( int i = 0; i < Global::mpi_facePairList.size(); ++ i )
+    {
+        FacePair &facePair = Global::mpi_facePairList[ i ];
+        Global::InsertFacePairMap( facePair );
+        std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        facePair.Print();
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterfaces = interface->local_faceids.size();
+        for ( int iInterface = 0; iInterface < nInterfaces; ++ iInterface )
+        {
+            int local_faceid = interface->local_faceids[ iInterface ];
+            int proc_global_faceid = interface->proc_global_faceids[ iInterface ];
+            FacePair & facePair = Global::facePairList[ proc_global_faceid ];
+            int global_faceid = Global::InsertFacePairMap( facePair );
+            interface->global_faceids.push_back( global_faceid );
+            interface->global_local_face_map.insert( std::make_pair( global_faceid, local_faceid ) );
+        }
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        std::set<int> &donor_zoneSet = Global::donor_zone_sets[ iZone ];
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            donor_zoneSet.insert( donor_zoneid );
+        }
+
+        std::vector<int> &donor_zones = Global::donor_zones[ iZone ];
+        for ( std::set<int>::iterator iter = donor_zoneSet.begin(); iter != donor_zoneSet.end(); ++ iter )
+        {
+            donor_zones.push_back( *iter );
+        }
+
+        interface->neighbor_donor_zones = donor_zones;
+
+        std::unordered_map<int, int> donor_zonelocal;
+
+        for ( int idonor = 0; idonor < donor_zones.size(); ++ idonor )
+        {
+            int donor_zone = donor_zones[ idonor ];
+            donor_zonelocal.insert( std::make_pair( donor_zone, idonor ) );
+        }
+        int ndonors = donor_zones.size();
+        std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+        neighbor_donorfaces.resize( ndonors );
+
+        std::vector<std::vector<int>> & sub_local_faceids = interface->sub_local_faceids;
+        sub_local_faceids.resize( ndonors );
+
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ineighbor = donor_zonelocal[ donor_zoneid ];
+            std::vector<int> &donorfaces = neighbor_donorfaces[ ineighbor ];
+            int global_faceid = interface->global_faceids[ iFace ];
+            donorfaces.push_back( global_faceid );
+            int local_faceid = interface->local_faceids[ iFace ];
+
+            std::vector<int> & sub_local_faces = sub_local_faceids[ ineighbor ];
+            sub_local_faces.push_back( local_faceid );
+        }
+    }
+
+    Global::interfaceTopo.InitNeighborInfo();
+    Global::interfaceTopo.SwapNeighborInfo();
+
+    int kkk = 1;
+}
+
+void Solver::InitFields()
+{
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "Solver::InitFields() ZoneState::nZones = " << ZoneState::nZones <<  "\n";
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+    }
+
+    Boundary();
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        //std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        //std::cout << "it = " << it << " nt = " << Global::nt << "\n";
+        for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+        {
+            Field * field = Global::fields[ iZone ];
+            Zone * zone = Global::zones[ iZone ];
+            zone->zoneIndex = iZone;
+            field->Solve( zone );
+        }
+        Boundary();
+    }
+}
+
+void Solver::Boundary()
+{
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+    ExchangeInterfaceField();
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        Zone * zone = Global::zones[ iZone ];
+        field->UpdateOldField();
+    }
+}
+
+void Solver::UploadInterfaceField()
+{
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+
+        std::vector<int> & send_to_zones = interface->send_to_zones;
+        int nsend_zones = send_to_zones.size();
+
+        std::vector<std::vector<int>> & donorfaces_for_send = interface->donorfaces_for_send;
+        std::vector<std::vector<int>> & donorijk_for_send = interface->donorijk_for_send;
+        std::vector<std::vector<double>> & donordata_for_send = interface->donordata_for_send;
+
+        Field * field = Global::fields[ iZone ];
+
+        for ( int iSend = 0; iSend < nsend_zones; ++ iSend )
+        {
+            int zone_to_send = send_to_zones[ iSend ];
+            std::vector<int> & donorfaces = donorfaces_for_send[ iSend ];
+            std::vector<int> & donorijks = donorijk_for_send[ iSend ];
+            std::vector<double> & donordatas = donordata_for_send[ iSend ];
+
+            int nface = donorfaces.size();
+            int index_dim = 1;
+            for ( int i = 0; i < nface; ++ i )
+            {
+                int ijkpos = index_dim * i;
+                int i_donor_cell = donorijks[ ijkpos + 0 ];
+                donordatas[ i ] = field->u[ i_donor_cell ];
+            }
+        }
+    }
+}
+
+void Solver::UpdateInterfaceField()
+{
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        int ndonor_zones = Global::interfaceTopo.linkmap[ iZone ].size();
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donor_zone = Global::interfaceTopo.linkmap[ iZone ][ iNei ];
+            int send_pid = ZoneState::pids[ iZone ];
+            int recv_pid = ZoneState::pids[ donor_zone ];
+            int nsend = -1;
+            std::vector<double> donordata;
+            if ( Parallel::pid != send_pid && Parallel::pid != recv_pid ) continue;
+            if ( Parallel::pid == send_pid )
+            {
+                int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+                Interface * interface = Global::interfaces[ local_zoneid ];
+                donordata = interface->donordata_for_send[ iNei ];
+                nsend = donordata.size();
+            }
+            HXSendRecvData( &nsend, 1, send_pid, recv_pid );
+
+            if ( Parallel::pid == recv_pid )
+            {
+                donordata.resize( nsend );
+            }
+            HXSendRecvData( donordata.data(), donordata.size(), send_pid, recv_pid );
+
+            if ( Parallel::pid == recv_pid )
+            {
+                int local_donor_zoneid = ZoneState::g2lzoneids[ donor_zone ];
+                Interface * donor_interface = Global::interfaces[ local_donor_zoneid ];
+                int nSize = donor_interface->neighbor_donor_zones.size();
+                int ipos = -1;
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    int nei_zone = donor_interface->neighbor_donor_zones[ i ];
+                    if ( nei_zone == iZone )
+                    {
+                        ipos = i;
+                        break;
+                    }
+                }
+
+                std::vector<int> & neighbor_donorfaces = donor_interface->neighbor_donorfaces[ ipos ];
+                std::vector<int> & sub_local_faceids = donor_interface->sub_local_faceids[ ipos ];
+                for ( int i = 0; i < neighbor_donorfaces.size(); ++ i )
+                {
+                    int local_faceid = sub_local_faceids[ i ];
+                    double donor_value = donordata[ i ];
+                    donor_interface->data_recv[ local_faceid ] = donor_value;
+                }
+            }
+        }
+    }
+}
+
+void Solver::DownloadInterfaceField()
+{
+    for ( int iZone = 0; iZone < LocalZone::nZones; ++ iZone )
+    {
+        Interface * interface = Global::interfaces[ iZone ];
+        Field * field = Global::fields[ iZone ];
+
+        int nInterFaces = interface->data_recv.size();
+
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+
+            double donor_value = interface->data_recv[ iFace ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    this->UploadInterfaceField();
+    this->UpdateInterfaceField();
+    this->DownloadInterfaceField();
+}
+
+void Solver::PostProcess()
+{
+    Post post;
+    post.Process();
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        if ( !ZoneState::IsValid( iZone ) && !Parallel::IsServer() ) continue;
+
+        double xmin = 0.0;
+        double xmax = 0.0;
+
+        if ( ZoneState::IsValid( iZone ) )
+        {
+            int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+            Grid * grid = Global::grids[ local_zoneid ];
+            int ni = grid->x.size();
+            xmin = grid->x[ 0 ];
+            xmax = grid->x[ 0 ];
+            int imin = 0;
+            int imax = 0;
+            for ( int i = 0; i < ni; ++ i )
+            {
+                if ( xmin > grid->x[ i ] )
+                {
+                    xmin = grid->x[ i ];
+                    imin = i;
+                }
+                if ( xmax < grid->x[ i ] )
+                {
+                    xmax = grid->x[ i ];
+                    imax = i;
+                }
+            }
+        }
+
+        HXSendRecvData( &xmin, 1, ZoneState::pids[ iZone ], Parallel::serverid );
+        HXSendRecvData( &xmax, 1, ZoneState::pids[ iZone ], Parallel::serverid );
+
+        //if ( Parallel::IsServer() )
+        //{
+        //    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        //    std::cout << "xmin = " << xmin << "\n";
+        //    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+        //    std::cout << "xmax = " << xmax << "\n";
+        //}
+
+        if ( Parallel::IsServer() )
+        {
+            xmin_list.push_back( xmin );
+            xmax_list.push_back( xmax );
+        }
+    }
+
+    //if ( Parallel::IsServer() )
+    //{
+    //    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    //    for ( int i = 0; i < xmin_list.size(); ++ i )
+    //    {
+    //        std::cout << "(" << xmin_list[ i ] << "," << xmax_list[ i ] << ") ";
+    //    }
+    //    std::cout << "\n";
+    //}
+
+    if ( Parallel::IsServer() )
+    {
+        std::vector<std::pair<double, int>> pairs;
+        int nSize = xmin_list.size();
+        for ( int i = 0; i < nSize; ++ i )
+        {
+            pairs.push_back( std::make_pair( xmin_list[ i ], i ) );
+        }
+
+        std::sort( pairs.begin(), pairs.end() );
+
+        for ( int i = 0; i < nSize; ++ i )
+        {
+            this->zoneids.push_back( pairs[ i ].second );
+        }
+    }
+
+    int kkk = 1;
+}
+
+bool IsLastZone( int iZone );
+bool IsLastZone( int iZone )
+{
+    return iZone == ZoneState::nZones - 1;
+}
+
+void Post::AddVector( std::vector<double> & a, std::vector<double> & b )
+{
+    for ( int i = 0; i < b.size(); ++ i )
+    {
+        a.push_back( b[ i ] );
+    }
+}
+
+void Post::GatherField()
+{
+    this->zoneids.resize( ZoneState::nZones );
+    HXBcastData( this->zoneids.data(), this->zoneids.size(), Parallel::serverid );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "Post::GatherField() this->zoneids = \n";
+    for ( int i = 0; i < this->zoneids.size(); ++ i )
+    {
+        std::cout << this->zoneids[ i ] << " ";
+    }
+    std::cout << "\n";
+
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+
+        if ( !ZoneState::IsValid( zoneid ) && !Parallel::IsServer() ) continue;
+
+        int nSize = -1;
+        std::vector<double> local_x;
+        std::vector<double> local_u_e;
+        std::vector<double> local_un;
+        std::vector<double> local_u;
+
+        if ( Parallel::pid == ZoneState::pids[ zoneid ] )
+        {
+            int local_zoneid = ZoneState::g2lzoneids[ zoneid ];
+            Grid * grid = Global::grids[ local_zoneid ];
+            Field * field = Global::fields[ local_zoneid ];
+            int ni = grid->x.size();
+
+            int ist = 1;
+            int ied = ni;
+
+            int dir = 1;
+            if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+            if ( dir == 1 )
+            {
+                if ( IsLastZone( iZone ) )
+                {
+                    for ( int i = ist; i <= ied; ++ i )
+                    {
+                        double xm = grid->x[ i - ist ];
+                        local_x.push_back( xm );
+                        local_u_e.push_back( field->u_e[ i ] );
+                        local_un.push_back( field->un[ i ] );
+                        local_u.push_back( field->u[ i ] );
+                    }
+                }
+                else
+                {
+                    for ( int i = ist; i <= ied - 1; ++ i )
+                    {
+                        double xm = grid->x[ i - ist ];
+                        local_x.push_back( xm );
+                        local_u_e.push_back( field->u_e[ i ] );
+                        local_un.push_back( field->un[ i ] );
+                        local_u.push_back( field->u[ i ] );
+                    }
+                }
+            }
+            else
+            {
+                if ( IsLastZone( iZone ) )
+                {
+                    for ( int i = ied; i >= ist; -- i )
+                    {
+                        double xm = grid->x[ i - ist ];
+                        local_x.push_back( xm );
+                        local_u_e.push_back( field->u_e[ i ] );
+                        local_un.push_back( field->un[ i ] );
+                        local_u.push_back( field->u[ i ] );
+                    }
+                }
+                else
+                {
+                    for ( int i = ied; i >= ist + 1; -- i )
+                    {
+                        double xm = grid->x[ i - ist ];
+                        local_x.push_back( xm );
+                        local_u_e.push_back( field->u_e[ i ] );
+                        local_un.push_back( field->un[ i ] );
+                        local_u.push_back( field->u[ i ] );
+                    }
+                }
+            }
+            nSize = local_x.size();
+        }
+
+        int send_pid = ZoneState::pids[ zoneid ];
+
+        HXSendRecvData( &nSize, 1, send_pid, Parallel::serverid );
+
+        if ( Parallel::IsServer() )
+        {
+            local_x.resize( nSize );
+            local_u_e.resize( nSize );
+            local_un.resize( nSize );
+            local_u.resize( nSize );
+        }
+
+        HXSendRecvData( local_x.data(), local_x.size(), send_pid, Parallel::serverid );
+        HXSendRecvData( local_u_e.data(), local_u_e.size(), send_pid, Parallel::serverid );
+        HXSendRecvData( local_un.data(), local_un.size(), send_pid, Parallel::serverid );
+        HXSendRecvData( local_u.data(), local_u.size(), send_pid, Parallel::serverid );
+
+        if ( Parallel::IsServer() )
+        {
+            this->AddVector( this->x, local_x );
+            this->AddVector( this->u_e, local_u_e );
+            this->AddVector( this->un, local_un );
+            this->AddVector( this->u, local_u );
+        }
+    }
+}
+
+void Post::DumpField()
+{
+    if ( !Parallel::IsServer() ) return;
+    int ni_total = this->x.size();
+    std::cout << " DumpField x.size() = " << x.size() << "\n";
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    this->DumpErrorDetails( u_error );
+
+    std::string csvname = "field_final.csv";
+    this->DumpCsvFile( csvname, x, u_e, un, u_error );
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "Parallel::pid = " << Parallel::pid << " ";
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.20f} {:.20f} {:.20f} {:.20f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/Solver.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/Solver.h
new file mode 100644
index 00000000..9914c1d7
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/Solver.h
@@ -0,0 +1,49 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+
+class Solver
+{
+public:
+    Solver();
+    ~Solver();
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveMultiZones();
+public:
+    void Boundary();
+    void UploadInterfaceField();
+    void UpdateInterfaceField();
+    void DownloadInterfaceField();
+    void ExchangeInterfaceField();
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcess();
+};
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+    std::vector<double> u;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+public:
+    void AddVector( std::vector<double> & a, std::vector<double> & b );
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/ZoneState.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/ZoneState.cpp
new file mode 100644
index 00000000..ff810849
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/ZoneState.cpp
@@ -0,0 +1,20 @@
+#include "ZoneState.h"
+#include "Parallel.h"
+
+int ZoneState::nZones = 0;
+std::vector<int> ZoneState::pids;
+std::vector<int> ZoneState::g2lzoneids;
+
+bool ZoneState::IsValid( int zoneid )
+{
+    return ZoneState::pids[ zoneid ] == Parallel::pid;
+}
+
+int ZoneState::GetProcID( int zoneid )
+{
+    return ZoneState::pids[ zoneid ];
+}
+
+int LocalZone::nZones = 0;
+std::vector<int> LocalZone::global_zoneids;
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/ZoneState.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/ZoneState.h
new file mode 100644
index 00000000..1096d632
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/ZoneState.h
@@ -0,0 +1,21 @@
+#pragma once
+#include <vector>
+
+class ZoneState
+{
+public:
+    static int nZones;
+    static int zone_id;
+    static std::vector<int> pids;
+    static std::vector<int> g2lzoneids; //global zone id to local zone id
+public:
+    static bool IsValid( int zoneid );
+    static int GetProcID( int zoneid );
+};
+
+class LocalZone
+{
+public:
+    static int nZones;
+    static std::vector<int> global_zoneids;
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/global.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/global.cpp
new file mode 100644
index 00000000..df1e6bae
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/global.cpp
@@ -0,0 +1,300 @@
+#include "global.h"
+#include "CgnsGrid.h"
+#include "ZoneState.h"
+#include "Parallel.h"
+#include <iostream>
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *> Global::interfaces;
+
+std::map<Face, int> Global::faceMap;
+std::map<FacePair, int> Global::facePairMap;
+std::vector<FacePair> Global::facePairList;
+std::vector<FacePair> Global::mpi_facePairList;
+
+std::vector<std::set<int>> Global::donor_zone_sets;
+std::vector<std::vector<int>> Global::donor_zones;
+
+InterfaceTopo Global::interfaceTopo;
+
+bool Face::operator < ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return this->zone < rhs.zone;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return this->i < rhs.i;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return this->j < rhs.j;
+    }
+
+    return this->k < rhs.k;
+}
+
+bool Face::operator == ( const Face & rhs ) const
+{
+    if ( this->zone != rhs.zone )
+    {
+        return false;
+    }
+
+    if ( this->i != rhs.i )
+    {
+        return false;
+    }
+
+    if ( this->j != rhs.j )
+    {
+        return false;
+    }
+
+    return this->k == rhs.k;
+}
+
+void Face::Print()
+{
+    std::cout << "(" << this->zone << "," << this->i << ")";
+}
+
+void FacePair::AddPair( const Face & face1, const Face & face2 )
+{
+    if ( face1 < face2 )
+    {
+        this->left = face1;
+        this->right = face2;
+    }
+    else
+    {
+        this->left = face2;
+        this->right = face1;
+    }
+}
+
+bool FacePair::operator < ( const FacePair & rhs ) const
+{
+    if ( this->left == rhs.left || this->left == rhs.right )
+    {
+        return false;
+    }
+
+    return this->left < rhs.left;
+}
+
+void FacePair::Print()
+{
+    this->left.Print();
+    std::cout << " ";
+    this->right.Print();
+    std::cout << "\n";
+}
+
+void InterfaceTopo::InitNeighborInfo()
+{
+    this->linkmap.resize( ZoneState::nZones );
+
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        if ( ! ZoneState::IsValid( iZone ) ) continue;
+
+        int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+
+        Interface * interface = Global::interfaces[ local_zoneid ];
+
+        std::vector<int> & t = this->linkmap[ iZone ];
+        t = interface->neighbor_donor_zones;
+    }
+}
+
+void InterfaceTopo::SwapNeighborInfo()
+{
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        int pid = ZoneState::pids[ iZone ];
+
+        std::vector<int> & donor_zones = this->linkmap[ iZone ];
+        int nNeighbor = donor_zones.size();
+
+        HXBcastData( &nNeighbor, 1, pid );
+
+        donor_zones.resize( nNeighbor );
+
+        HXBcastData( donor_zones.data(), donor_zones.size(), pid );
+    }
+
+    this->SwapNeighborDonorfaces();
+}
+
+void InterfaceTopo::SwapNeighborDonorfaces()
+{
+    int gl = 0;
+    for ( int iZone = 0; iZone < ZoneState::nZones; ++ iZone )
+    {
+        int send_pid = ZoneState::pids[ iZone ];
+
+        std::vector<int> & donor_zones = this->linkmap[ iZone ];
+        int ndonor_zones = donor_zones.size();
+
+        for ( int iNei = 0; iNei < ndonor_zones; ++ iNei )
+        {
+            int donor_zone = donor_zones[ iNei ];
+            int recv_pid = ZoneState::pids[ donor_zone ];
+            int nInterFaces = 0;
+            std::vector<int> donorfaces;
+
+            if ( Parallel::pid == send_pid )
+            {
+                int local_zoneid = ZoneState::g2lzoneids[ iZone ];
+
+                Interface * interface = Global::interfaces[ local_zoneid ];
+
+                std::vector<std::vector<int>> & neighbor_donorfaces = interface->neighbor_donorfaces;
+
+                std::vector<int> & neighbor_donorface = neighbor_donorfaces[ iNei ];
+
+                nInterFaces = neighbor_donorface.size();
+
+                donorfaces = neighbor_donorface;
+            }
+
+            HXSendRecvData( &nInterFaces, 1, send_pid, recv_pid );
+
+            if ( Parallel::pid == recv_pid && send_pid != recv_pid )
+            {
+                donorfaces.resize( nInterFaces );
+            }
+
+            HXSendRecvData( donorfaces.data(), donorfaces.size(), send_pid, recv_pid );
+
+            if ( Parallel::pid == recv_pid )
+            {
+                int local_donor_zoneid = ZoneState::g2lzoneids[ donor_zone ];
+                Interface * interface_recv = Global::interfaces[ local_donor_zoneid ];
+                interface_recv->SendGeom( iZone, donorfaces );
+            }
+        }
+    }
+}
+
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->local_faceids.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        Face face;
+        face.zone = zoneid;
+        face.i = i;
+
+        int i_donor = index2[ 0 ];
+
+        Face face_donor;
+        face_donor.zone = donor_zoneid;
+        face_donor.i = i_donor;
+
+        FacePair facePair;
+        facePair.AddPair( face, face_donor );
+
+        Global::facePairList.push_back( facePair );
+        int nSize = Global::facePairList.size();
+        this->proc_global_faceids.push_back( nSize - 1 );
+
+        int i_ghost_cell = i + 1;
+        int i_local_donor_cell = i - 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+            i_local_donor_cell = i + 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+        ijk_donors.push_back( i_local_donor_cell );
+
+        icount ++;
+    }
+}
+
+void Interface::SendGeom( int zone, std::vector<int> & donorfaces )
+{
+    Interface * interface = this;
+
+    std::vector<int> & send_to_zones = interface->send_to_zones;
+
+    send_to_zones.push_back( zone );
+    interface->donorfaces_for_send.push_back( donorfaces );
+
+    int nface = donorfaces.size();
+    std::vector<int> sub_donorijk;
+    int index_dim = 1;
+    for ( int i = 0; i < nface; ++ i )
+    {
+        int global_faceid = donorfaces[ i ];
+        int local_faceid = interface->global_local_face_map[ global_faceid ];
+        int ijkpos = index_dim * local_faceid;
+        int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+        sub_donorijk.push_back( i_donor_cell );
+        int kkk = 1;
+    }
+
+    interface->donorijk_for_send.push_back( sub_donorijk );
+
+    std::vector<double> sub_donordata( sub_donorijk.size() );
+    interface->donordata_for_send.push_back( sub_donordata );
+}
+
+void Global::InsertFaceMap( const Face & face )
+{
+    std::map<Face, int>::iterator iter;
+    iter = Global::faceMap.find( face );
+    if ( iter == Global::faceMap.end() )
+    {
+        int faceid = Global::faceMap.size();
+        Global::faceMap.insert( std::make_pair( face, faceid ) );
+    }
+}
+
+int Global::InsertFacePairMap( const FacePair & facePair )
+{
+    std::map<FacePair, int>::iterator iter;
+    iter = Global::facePairMap.find( facePair );
+    if ( iter == Global::facePairMap.end() )
+    {
+        int facePairId = Global::facePairMap.size();
+        Global::facePairMap.insert( std::make_pair( facePair, facePairId ) );
+        return facePairId;
+    }
+    return iter->second;
+}
+
+void Global::AddFacePairList( std::vector<FacePair> & a, std::vector<FacePair> & b )
+{
+    for ( int i = 0; i < b.size(); ++ i )
+    {
+        a.push_back( b[ i ] );
+    }
+}
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/global.h b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/global.h
new file mode 100644
index 00000000..933cec05
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/global.h
@@ -0,0 +1,157 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <unordered_map>
+#include <set>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class Face
+{
+public:
+    int zone = 0;
+    int i = 0;
+    int j = 1;
+    int k = 1;
+public:
+    bool operator < ( const Face & rhs ) const;
+    bool operator == ( const Face & rhs ) const;
+public:
+    void Print();
+};
+
+class FacePair
+{
+public:
+    Face left;
+    Face right;
+public:
+    bool operator < ( const FacePair & rhs ) const;
+    void AddPair( const Face &face1, const Face &face2);
+public:
+    void Print();
+};
+
+class Transform;
+
+class InterfaceTopo
+{
+public:
+    std::vector<std::vector<int>> linkmap;
+public:
+    void InitNeighborInfo();
+    void SwapNeighborInfo();
+    void SwapNeighborDonorfaces();
+};
+
+
+class Interface
+{
+public:
+    int zoneid;
+    std::vector<int> zoneList;
+    std::vector<int> global_faceids;
+    std::vector<int> mpi_global_faceids;
+    std::vector<int> proc_global_faceids;
+    std::vector<int> local_faceids;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+    std::vector<double> data_recv;
+    std::vector<double> data_send;
+    std::unordered_map<int, int> global_local_face_map;
+public:
+    std::vector<int> neighbor_donor_zones;
+    std::vector<std::vector<int>> neighbor_donorfaces;
+    std::vector<std::vector<int>> sub_local_faceids;
+    std::vector<int> send_to_zones;
+    std::vector<std::vector<int>> donorfaces_for_send;
+    std::vector<std::vector<int>> donorijk_for_send;
+    std::vector<std::vector<double>> donordata_for_send;
+public:
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+    void SendGeom( int zone, std::vector<int> & donorfaces );
+};
+
+class Field;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+public:
+    static std::map<Face, int> faceMap;
+    static std::map<FacePair, int> facePairMap;
+    static std::vector<FacePair> facePairList;
+    static std::vector<FacePair> mpi_facePairList;
+    static std::vector<std::set<int>> donor_zone_sets;
+    static std::vector<std::vector<int>> donor_zones;
+    static InterfaceTopo interfaceTopo;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+public:
+    static void InsertFaceMap( const Face & face );
+    static int InsertFacePairMap( const FacePair & facePair );
+    static void AddFacePairList( std::vector<FacePair> & a, std::vector<FacePair> & b );
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/heat1d4blocksv1.cgns b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/heat1d4blocksv1.cgns
new file mode 100644
index 00000000..df5ffc5f
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/heat1d4blocksv1.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/heat1d8blocksv1.cgns b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/heat1d8blocksv1.cgns
new file mode 100644
index 00000000..4dc174d4
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/heat1d8blocksv1.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/main.cpp b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/main.cpp
new file mode 100644
index 00000000..df63b7da
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/main.cpp
@@ -0,0 +1,9 @@
+#include "Solver.h"
+#include "Parallel.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/plot.py b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/multiblock/parallel/8blocks/01a/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/single_block/01/CMakeLists.txt
new file mode 100644
index 00000000..ee758c31
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01/CMakeLists.txt
@@ -0,0 +1,79 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	Solver.h Solver.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/single_block/01/CgnsGrid.cpp
new file mode 100644
index 00000000..e186c2f4
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01/CgnsGrid.cpp
@@ -0,0 +1,578 @@
+#include "CgnsGrid.h"
+#include "cgnslib.h"
+#include "global.h"
+#include <iostream>
+#include <vector>
+
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            Grid * grid = new Grid();
+            Global::grids.push_back( grid );
+
+            BC * bc = new BC();
+            Global::bcs.push_back( bc );
+
+            InterFaceZone * interfacezone = new InterFaceZone();
+            Global::interfacezones.push_back( interfacezone );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                //std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+
+                coor->DumpCoor();
+                if ( icoord == 0 )
+                {
+                    coor->DumpCoorX( grid->x );
+                }
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    Global::boundary_points.AddPoint( grid->x[ pnts[ i ] - 1 ] );
+                }
+
+                if ( index_dim == 1 )
+                {
+                    int p1 = pnts[ 0 ];
+                    double x1 = grid->x[ p1 - 1 ];
+                    int id = Global::boundary_points.AddPoint( x1 );
+                    Face face;
+                    std::vector<int> nodes;
+                    nodes.push_back( id );
+                    face.AddFace( nodes );
+                    Global::boundary_faces.AddFace( face );
+
+                    bc->bctypes.push_back( bocotype );
+                    bc->faceids.push_back( p1 - 1 );
+                }
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    Global::boundary_points.AddPoint( grid->x[ range[ i ] - 1 ] );
+                }
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+                if ( index_dim == 1 )
+                {
+                    int p1 = range[ 0 ];
+                    double x1 = grid->x[ p1 - 1 ];
+                    int id = Global::boundary_points.AddPoint( x1 );
+                    Face face;
+                    std::vector<int> nodes;
+                    nodes.push_back( id );
+                    face.AddFace( nodes );
+                    Global::boundary_faces.AddFace( face );
+                    Global::inter_faces.AddFace( face );
+
+                    bc->bctypes.push_back( BCTypeUserDefined );
+                    bc->faceids.push_back( p1 - 1 );
+
+                    interfacezone->face_ids.push_back( p1 );
+
+                    interfacezone->left_zones.push_back( gZoneId );
+                    interfacezone->left_cells.push_back( p1 - 1 );
+
+                    int q = donor_range[ 0 ];
+                    interfacezone->right_zones.push_back( gDonorZoneId );
+                    interfacezone->right_cells.push_back( q - 1 );
+                }
+            }
+        }
+    }
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/single_block/01/CgnsGrid.h
new file mode 100644
index 00000000..42633021
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01/CgnsGrid.h
@@ -0,0 +1,102 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01/Field.cpp b/example/1d-heat-equation/ftcs/cpp/single_block/01/Field.cpp
new file mode 100644
index 00000000..25c64637
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01/Field.cpp
@@ -0,0 +1,173 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+
+    std::vector<double> & x = grid->x;
+    this->dx = x[ 1 ] - x[ 0 ];
+    this->dt = dx / 10.0;
+    this->t = 1.0;
+    this->nt = std::round( t / dt );
+    std::cout << "nt = " << nt << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+    std::cout << "alpha = " << std::setprecision( 15 ) << this->alpha << "\n";
+    std::cout << "beta = " << std::setprecision( 15 ) << this->beta << "\n";
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+
+    int ist = 1;
+    int ied = ni;
+
+    // 0(bc) 1(ist) 2 3 ... ni
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        u_e[ i ] = - std::exp( -t ) * std::sin( std::numbers::pi * xm ); //theory solution
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+}
+
+void Field::Solve( Zone * zone )
+{
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+    }
+
+    this->PhysicalBoundary( zone );
+
+    this->Update( un, u );
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ i ] = 0.0;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        this->u[ i ] = 0.0;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
+
+void Field::AddData( PointFactory &ptfactory, Grid * grid, std::vector<double> &global_x, std::vector<double> &global_ue, std::vector<double> &global_un )
+{
+    int ni = grid->x.size();
+    for ( int i = 0; i < ni; ++ i )
+    {
+        double xm = grid->x[ i ];
+        bool flag = ptfactory.FindPoint( Point( xm ) );
+        if ( i == 0 || ( i == ni - 1 ) )
+        {
+            if ( ! flag )
+            {
+                ptfactory.AddPoint( Point( xm ) );
+                global_x.push_back( grid->x[ i ] );
+                global_ue.push_back( this->u_e[ i ] );
+                global_un.push_back( this->un[ i ] );
+            }
+        }
+        else
+        {
+            global_x.push_back( grid->x[ i ] );
+            global_ue.push_back( this->u_e[ i ] );
+            global_un.push_back( this->un[ i ] );
+        }
+    }
+}
+
+void Field::Update( std::vector<double> &un, std::vector<double> &u )
+{
+    for ( int i = 0; i < u.size(); ++ i )
+    {
+        un[ i ] = u[ i ];
+    }
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01/Field.h b/example/1d-heat-equation/ftcs/cpp/single_block/01/Field.h
new file mode 100644
index 00000000..fd3c5004
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01/Field.h
@@ -0,0 +1,37 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid );
+
+    void Solve( Zone * zone );
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void AddData( PointFactory & ptfactory, Grid * grid, std::vector<double> & global_x, std::vector<double> & global_ue, std::vector<double> & global_un );
+    void Update( std::vector<double> & un, std::vector<double> & u );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01/README.txt b/example/1d-heat-equation/ftcs/cpp/single_block/01/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01/Solver.cpp b/example/1d-heat-equation/ftcs/cpp/single_block/01/Solver.cpp
new file mode 100644
index 00000000..4382ad01
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01/Solver.cpp
@@ -0,0 +1,381 @@
+#include "Solver.h"
+#include <fstream>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    this->InitTopo();
+    this->InitFields();
+    this->SolveMultiZones();
+    this->PostProcess();
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d1blocksv1.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    ReadCgnsGrid( fileName );
+    int nZones = Global::grids.size();
+    PointFactory ptfactory;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        grid->zoneIndex = iZone;
+        int ni = grid->x.size();
+        for ( int i = 0; i < ni; ++ i )
+        {
+            int pid = ptfactory.AddPoint( Point( grid->x[ i ] ) );
+        }
+        int kkk = 1;
+    }
+}
+
+void Solver::InitTopo()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Interface * interface = new Interface();
+        Global::interfaces.push_back( interface );
+
+        IJK * ijk = new IJK();
+        Global::ijks.push_back( ijk );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+        Interface * interface = Global::interfaces[ iZone ];
+
+        int nbc1to1s = zone->bc1to1s.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+    }
+}
+
+void Solver::InitFields()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+
+    ExchangeInterfaceField();
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        field->Update( field->un, field->u );
+    }
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        ExchangeInterfaceField();
+        int nZones = Global::grids.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Field * field = Global::fields[ iZone ];
+            Zone * zone = Global::zones[ iZone ];
+            field->Solve( zone );
+        }
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    int nZones = Global::interfaces.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+            int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+            
+            Field * donor_field = Global::fields[ donor_zoneid ];
+
+            double donor_value = donor_field->u[ i_donor_cell ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::ExchangeInterfaceValue()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        InterFaceZone * interfacezone = Global::interfacezones[ iZone ];
+        int nInterFace = interfacezone->left_zones.size();
+        interfacezone->left_u.resize( nInterFace );
+        interfacezone->right_u.resize( nInterFace );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        InterFaceZone * interfacezone = Global::interfacezones[ iZone ];
+        int nInterFace = interfacezone->left_zones.size();
+
+        for ( int i = 0; i < nInterFace; ++ i )
+        {
+            int left_cell = interfacezone->left_cells[ i ];
+            int donor_zoneid = interfacezone->right_zones[ i ];
+            int donor_cell = interfacezone->right_cells[ i ];
+            Field * donor_field = Global::fields[ donor_zoneid ];
+
+            interfacezone->left_u[ i ] = field->u[ left_cell ];
+            interfacezone->right_u[ i ] = donor_field->u[ donor_cell ];
+        }
+    }
+}
+
+void Solver::PostProcess()
+{
+    Post post;
+    post.Process();
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    int nZones = Global::grids.size();
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        int ni = grid->x.size();
+        double xmin = grid->x[ 0 ];
+        double xmax = grid->x[ 0 ];
+        int imin = 0;
+        int imax = 0;
+        for ( int i = 0; i < ni; ++ i )
+        {
+            if ( xmin > grid->x[ i ] )
+            {
+                xmin = grid->x[ i ];
+                imin = i;
+            }
+            if ( xmax < grid->x[ i ] )
+            {
+                xmax = grid->x[ i ];
+                imax = i;
+            }
+        }
+        xmin_list.push_back( xmin );
+        xmax_list.push_back( xmax );
+    }
+    std::vector<std::pair<double, int>> pairs;
+    int nSize = xmin_list.size();
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        pairs.push_back( std::make_pair( xmin_list[i], i ) );
+    }
+
+    std::sort( pairs.begin(), pairs.end() );
+
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        this->zoneids.push_back( pairs[i].second );
+    }
+
+    int kkk = 1;
+}
+
+void Post::GatherField()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+        Grid * grid = Global::grids[ zoneid ];
+        Field * field = Global::fields[ zoneid ];
+
+        int ni = grid->x.size();
+
+        int ist = 1;
+        int ied = ni;
+
+        int dir = 1;
+        if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+        if ( dir == 1 )
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ist; i <= ied; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                }
+
+            }
+            else
+            {
+                for ( int i = ist; i <= ied - 1; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                }
+            }
+        }
+        else
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ied; i >= ist; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                }
+            }
+            for ( int i = ied; i >= ist + 1; -- i )
+            {
+                double xm = grid->x[ i - ist ];
+                this->x.push_back( xm );
+                this->u_e.push_back( field->u_e[ i ] );
+                this->un.push_back( field->un[ i ] );
+            }
+        }
+    }
+}
+
+void Post::DumpField()
+{
+    int ni_total = this->x.size();
+    std::cout << " DumpField x.size() = " << x.size() << "\n";
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    this->DumpErrorDetails( u_error );
+
+    std::string csvname = "field_final.csv";
+    this->DumpCsvFile( csvname, x, u_e, un, u_error );
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.16f} {:.16f} {:.16f} {:.16f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01/Solver.h b/example/1d-heat-equation/ftcs/cpp/single_block/01/Solver.h
new file mode 100644
index 00000000..3ce472a7
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01/Solver.h
@@ -0,0 +1,41 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+
+class Solver
+{
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveMultiZones();
+    void ExchangeInterfaceValue();
+public:
+    void ExchangeInterfaceField();
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcess();
+};
+
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01/global.cpp b/example/1d-heat-equation/ftcs/cpp/single_block/01/global.cpp
new file mode 100644
index 00000000..be237bec
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01/global.cpp
@@ -0,0 +1,59 @@
+#include "global.h"
+#include "CgnsGrid.h"
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+std::vector<BC *> Global::bcs;
+std::vector<InterFaceZone *> Global::interfacezones;
+PointFactory Global::boundary_points;
+FaceList Global::boundary_faces;
+FaceList Global::inter_faces;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *>  Global::interfaces;
+std::vector<IJK *> Global::ijks;
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> &start,  std::vector<int> &end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->faceidList.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        int i_donor = index2[ 0 ];
+
+        int i_ghost_cell = i + 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+
+        int i_donor_cell = i_donor - 1;
+
+        if ( i_donor == 1 )
+        {
+            i_donor_cell = i_donor + 1;
+        }
+
+        this->ijk_donors.push_back( i_donor_cell );
+
+
+        icount ++;
+    }
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01/global.h b/example/1d-heat-equation/ftcs/cpp/single_block/01/global.h
new file mode 100644
index 00000000..665ba466
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01/global.h
@@ -0,0 +1,239 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class Point
+{
+public:
+    typedef Point point_type;
+    using value_type = double;
+public:
+    Point()
+    {
+        this->x = 0;
+    }
+    Point( const value_type & x )
+    {
+        this->x = x;
+    }
+public:
+    value_type x;
+public:
+    bool operator < ( const Point & rhs ) const
+    {
+        value_type dx = x - rhs.x;
+        value_type diff = 1.0e-10;
+
+        if ( std::abs( dx ) > diff ) return x < rhs.x;
+
+        return false;
+    }
+};
+
+class PointFactory
+{
+public:
+    using value_type = double;
+    using point_type = Point;
+    using iterator = std::map< point_type, int >::iterator;
+protected:
+    std::map< point_type, int > pointList;
+    std::vector<point_type> pointArray;
+public:
+    int GetNPoints() { return pointArray.size(); }
+    bool FindPoint( const point_type & point )
+    {
+        iterator iter = pointList.find( point );
+        if ( iter == pointList.end() )
+        {
+            return false;
+        }
+        return true;
+    }
+private:
+    bool FindPoint( const point_type & point, iterator & iter )
+    {
+        iter = pointList.find( point );
+        if ( iter == pointList.end() )
+        {
+            return false;
+        }
+        return true;
+    }
+public:
+    int AddPoint( const point_type & point )
+    {
+        PointFactory::iterator iter;
+        if ( FindPoint( point, iter ) )
+        {
+            return iter->second;
+        }
+        else
+        {
+            int index = this->GetNPoints();
+
+            pointList.insert( std::make_pair(point, index) );
+            pointArray.push_back( point );
+
+            return index;
+        }
+    }
+};
+
+class Face
+{
+public:
+    std::vector<int> nodes;
+    std::vector<int> sorted_nodes;
+public:
+    void AddFace( std::vector<int> & nodes )
+    {
+        this->nodes = nodes;
+        this->sorted_nodes = nodes;
+        std::sort( this->sorted_nodes.begin(), this->sorted_nodes.end() );
+    }
+    bool operator < ( const Face & rhs ) const
+    {
+        return this->sorted_nodes < rhs.sorted_nodes;
+    } 
+};
+
+class FaceList
+{
+public:
+    std::map<Face, int> face_map;
+public:
+    void AddFace( const Face & face )
+    {
+        std::map<Face, int>::iterator iter;
+        iter = face_map.find( face );
+        if ( iter == face_map.end() )
+        {
+            int id = face_map.size();
+            face_map.insert( std::make_pair( face, id ) );
+        }
+    }
+};
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class BC
+{
+public:
+    std::vector<int> bctypes;
+    std::vector<int> faceids;
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class InterFaceZone
+{
+public:
+    std::vector<int> face_ids;
+    std::vector<int> left_zones;
+    std::vector<int> right_zones;
+    std::vector<int> left_cells;
+    std::vector<int> right_cells;
+    std::vector<double> left_u;
+    std::vector<double> right_u;
+};
+
+class Transform;
+
+class Interface
+{
+public:
+    std::vector<int> zoneList;
+    std::vector<int> faceidList;
+    std::vector<int> ijkList;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+    std::vector<double> uList;
+public:
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+};
+
+class IJK
+{
+public:
+    std::vector<int> iList;
+    std::vector<int> jList;
+    std::vector<int> kList;
+};
+
+class Field;
+class BC;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+    static std::vector<BC *> bcs;
+    static std::vector<InterFaceZone *> interfacezones;
+    static PointFactory boundary_points;
+    static FaceList boundary_faces;
+    static FaceList inter_faces;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+    static std::vector<IJK *> ijks;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01/heat1d1blocksv1.cgns b/example/1d-heat-equation/ftcs/cpp/single_block/01/heat1d1blocksv1.cgns
new file mode 100644
index 00000000..a367704f
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/single_block/01/heat1d1blocksv1.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01/main.cpp b/example/1d-heat-equation/ftcs/cpp/single_block/01/main.cpp
new file mode 100644
index 00000000..5ff48a4e
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01/main.cpp
@@ -0,0 +1,12 @@
+#include "cgnslib.h"
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+#include "Solver.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01/plot.py b/example/1d-heat-equation/ftcs/cpp/single_block/01/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/single_block/01/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01a/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/single_block/01a/CMakeLists.txt
new file mode 100644
index 00000000..ee758c31
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01a/CMakeLists.txt
@@ -0,0 +1,79 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	Solver.h Solver.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01a/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/single_block/01a/CgnsGrid.cpp
new file mode 100644
index 00000000..e186c2f4
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01a/CgnsGrid.cpp
@@ -0,0 +1,578 @@
+#include "CgnsGrid.h"
+#include "cgnslib.h"
+#include "global.h"
+#include <iostream>
+#include <vector>
+
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            Grid * grid = new Grid();
+            Global::grids.push_back( grid );
+
+            BC * bc = new BC();
+            Global::bcs.push_back( bc );
+
+            InterFaceZone * interfacezone = new InterFaceZone();
+            Global::interfacezones.push_back( interfacezone );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                //std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+
+                coor->DumpCoor();
+                if ( icoord == 0 )
+                {
+                    coor->DumpCoorX( grid->x );
+                }
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    Global::boundary_points.AddPoint( grid->x[ pnts[ i ] - 1 ] );
+                }
+
+                if ( index_dim == 1 )
+                {
+                    int p1 = pnts[ 0 ];
+                    double x1 = grid->x[ p1 - 1 ];
+                    int id = Global::boundary_points.AddPoint( x1 );
+                    Face face;
+                    std::vector<int> nodes;
+                    nodes.push_back( id );
+                    face.AddFace( nodes );
+                    Global::boundary_faces.AddFace( face );
+
+                    bc->bctypes.push_back( bocotype );
+                    bc->faceids.push_back( p1 - 1 );
+                }
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    Global::boundary_points.AddPoint( grid->x[ range[ i ] - 1 ] );
+                }
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+                if ( index_dim == 1 )
+                {
+                    int p1 = range[ 0 ];
+                    double x1 = grid->x[ p1 - 1 ];
+                    int id = Global::boundary_points.AddPoint( x1 );
+                    Face face;
+                    std::vector<int> nodes;
+                    nodes.push_back( id );
+                    face.AddFace( nodes );
+                    Global::boundary_faces.AddFace( face );
+                    Global::inter_faces.AddFace( face );
+
+                    bc->bctypes.push_back( BCTypeUserDefined );
+                    bc->faceids.push_back( p1 - 1 );
+
+                    interfacezone->face_ids.push_back( p1 );
+
+                    interfacezone->left_zones.push_back( gZoneId );
+                    interfacezone->left_cells.push_back( p1 - 1 );
+
+                    int q = donor_range[ 0 ];
+                    interfacezone->right_zones.push_back( gDonorZoneId );
+                    interfacezone->right_cells.push_back( q - 1 );
+                }
+            }
+        }
+    }
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01a/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/single_block/01a/CgnsGrid.h
new file mode 100644
index 00000000..42633021
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01a/CgnsGrid.h
@@ -0,0 +1,102 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01a/Field.cpp b/example/1d-heat-equation/ftcs/cpp/single_block/01a/Field.cpp
new file mode 100644
index 00000000..31f53a1f
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01a/Field.cpp
@@ -0,0 +1,174 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+
+    std::vector<double> & x = grid->x;
+    this->dx = x[ 1 ] - x[ 0 ];
+    this->dt = dx / 10.0;
+    this->t = 1.0;
+    this->nt = std::round( t / dt );
+    std::cout << "nt = " << nt << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+    std::cout << "alpha = " << std::setprecision( 15 ) << this->alpha << "\n";
+    std::cout << "beta = " << std::setprecision( 15 ) << this->beta << "\n";
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+
+    int ist = 1;
+    int ied = ni;
+
+    // 0(bc) 1(ist) 2 3 ... ni
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        u_e[ i ] = - std::exp( -t ) * std::sin( std::numbers::pi * xm ); //theory solution
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+}
+
+void Field::Solve( Zone * zone )
+{
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+    }
+
+    this->PhysicalBoundary( zone );
+
+    this->Update( un, u );
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        //std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        //region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        //this->u[ i ] = 0.0;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+        int kkk = 1;
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        //this->u[ i ] = 0.0;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
+
+void Field::AddData( PointFactory &ptfactory, Grid * grid, std::vector<double> &global_x, std::vector<double> &global_ue, std::vector<double> &global_un )
+{
+    int ni = grid->x.size();
+    for ( int i = 0; i < ni; ++ i )
+    {
+        double xm = grid->x[ i ];
+        bool flag = ptfactory.FindPoint( Point( xm ) );
+        if ( i == 0 || ( i == ni - 1 ) )
+        {
+            if ( ! flag )
+            {
+                ptfactory.AddPoint( Point( xm ) );
+                global_x.push_back( grid->x[ i ] );
+                global_ue.push_back( this->u_e[ i ] );
+                global_un.push_back( this->un[ i ] );
+            }
+        }
+        else
+        {
+            global_x.push_back( grid->x[ i ] );
+            global_ue.push_back( this->u_e[ i ] );
+            global_un.push_back( this->un[ i ] );
+        }
+    }
+}
+
+void Field::Update( std::vector<double> &un, std::vector<double> &u )
+{
+    for ( int i = 0; i < u.size(); ++ i )
+    {
+        un[ i ] = u[ i ];
+    }
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01a/Field.h b/example/1d-heat-equation/ftcs/cpp/single_block/01a/Field.h
new file mode 100644
index 00000000..fd3c5004
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01a/Field.h
@@ -0,0 +1,37 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void Init( Grid * grid );
+
+    void Solve( Zone * zone );
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void AddData( PointFactory & ptfactory, Grid * grid, std::vector<double> & global_x, std::vector<double> & global_ue, std::vector<double> & global_un );
+    void Update( std::vector<double> & un, std::vector<double> & u );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01a/README.txt b/example/1d-heat-equation/ftcs/cpp/single_block/01a/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01a/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01a/Solver.cpp b/example/1d-heat-equation/ftcs/cpp/single_block/01a/Solver.cpp
new file mode 100644
index 00000000..4382ad01
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01a/Solver.cpp
@@ -0,0 +1,381 @@
+#include "Solver.h"
+#include <fstream>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    this->InitTopo();
+    this->InitFields();
+    this->SolveMultiZones();
+    this->PostProcess();
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d1blocksv1.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    ReadCgnsGrid( fileName );
+    int nZones = Global::grids.size();
+    PointFactory ptfactory;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        grid->zoneIndex = iZone;
+        int ni = grid->x.size();
+        for ( int i = 0; i < ni; ++ i )
+        {
+            int pid = ptfactory.AddPoint( Point( grid->x[ i ] ) );
+        }
+        int kkk = 1;
+    }
+}
+
+void Solver::InitTopo()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Interface * interface = new Interface();
+        Global::interfaces.push_back( interface );
+
+        IJK * ijk = new IJK();
+        Global::ijks.push_back( ijk );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+        Interface * interface = Global::interfaces[ iZone ];
+
+        int nbc1to1s = zone->bc1to1s.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+    }
+}
+
+void Solver::InitFields()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+
+    ExchangeInterfaceField();
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        field->Update( field->un, field->u );
+    }
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        ExchangeInterfaceField();
+        int nZones = Global::grids.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Field * field = Global::fields[ iZone ];
+            Zone * zone = Global::zones[ iZone ];
+            field->Solve( zone );
+        }
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    int nZones = Global::interfaces.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+            int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+            
+            Field * donor_field = Global::fields[ donor_zoneid ];
+
+            double donor_value = donor_field->u[ i_donor_cell ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::ExchangeInterfaceValue()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        InterFaceZone * interfacezone = Global::interfacezones[ iZone ];
+        int nInterFace = interfacezone->left_zones.size();
+        interfacezone->left_u.resize( nInterFace );
+        interfacezone->right_u.resize( nInterFace );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        InterFaceZone * interfacezone = Global::interfacezones[ iZone ];
+        int nInterFace = interfacezone->left_zones.size();
+
+        for ( int i = 0; i < nInterFace; ++ i )
+        {
+            int left_cell = interfacezone->left_cells[ i ];
+            int donor_zoneid = interfacezone->right_zones[ i ];
+            int donor_cell = interfacezone->right_cells[ i ];
+            Field * donor_field = Global::fields[ donor_zoneid ];
+
+            interfacezone->left_u[ i ] = field->u[ left_cell ];
+            interfacezone->right_u[ i ] = donor_field->u[ donor_cell ];
+        }
+    }
+}
+
+void Solver::PostProcess()
+{
+    Post post;
+    post.Process();
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    int nZones = Global::grids.size();
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        int ni = grid->x.size();
+        double xmin = grid->x[ 0 ];
+        double xmax = grid->x[ 0 ];
+        int imin = 0;
+        int imax = 0;
+        for ( int i = 0; i < ni; ++ i )
+        {
+            if ( xmin > grid->x[ i ] )
+            {
+                xmin = grid->x[ i ];
+                imin = i;
+            }
+            if ( xmax < grid->x[ i ] )
+            {
+                xmax = grid->x[ i ];
+                imax = i;
+            }
+        }
+        xmin_list.push_back( xmin );
+        xmax_list.push_back( xmax );
+    }
+    std::vector<std::pair<double, int>> pairs;
+    int nSize = xmin_list.size();
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        pairs.push_back( std::make_pair( xmin_list[i], i ) );
+    }
+
+    std::sort( pairs.begin(), pairs.end() );
+
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        this->zoneids.push_back( pairs[i].second );
+    }
+
+    int kkk = 1;
+}
+
+void Post::GatherField()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+        Grid * grid = Global::grids[ zoneid ];
+        Field * field = Global::fields[ zoneid ];
+
+        int ni = grid->x.size();
+
+        int ist = 1;
+        int ied = ni;
+
+        int dir = 1;
+        if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+        if ( dir == 1 )
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ist; i <= ied; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                }
+
+            }
+            else
+            {
+                for ( int i = ist; i <= ied - 1; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                }
+            }
+        }
+        else
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ied; i >= ist; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                }
+            }
+            for ( int i = ied; i >= ist + 1; -- i )
+            {
+                double xm = grid->x[ i - ist ];
+                this->x.push_back( xm );
+                this->u_e.push_back( field->u_e[ i ] );
+                this->un.push_back( field->un[ i ] );
+            }
+        }
+    }
+}
+
+void Post::DumpField()
+{
+    int ni_total = this->x.size();
+    std::cout << " DumpField x.size() = " << x.size() << "\n";
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    this->DumpErrorDetails( u_error );
+
+    std::string csvname = "field_final.csv";
+    this->DumpCsvFile( csvname, x, u_e, un, u_error );
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.16f} {:.16f} {:.16f} {:.16f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01a/Solver.h b/example/1d-heat-equation/ftcs/cpp/single_block/01a/Solver.h
new file mode 100644
index 00000000..3ce472a7
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01a/Solver.h
@@ -0,0 +1,41 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+
+class Solver
+{
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveMultiZones();
+    void ExchangeInterfaceValue();
+public:
+    void ExchangeInterfaceField();
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcess();
+};
+
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01a/global.cpp b/example/1d-heat-equation/ftcs/cpp/single_block/01a/global.cpp
new file mode 100644
index 00000000..be237bec
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01a/global.cpp
@@ -0,0 +1,59 @@
+#include "global.h"
+#include "CgnsGrid.h"
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+std::vector<BC *> Global::bcs;
+std::vector<InterFaceZone *> Global::interfacezones;
+PointFactory Global::boundary_points;
+FaceList Global::boundary_faces;
+FaceList Global::inter_faces;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *>  Global::interfaces;
+std::vector<IJK *> Global::ijks;
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> &start,  std::vector<int> &end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->faceidList.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        int i_donor = index2[ 0 ];
+
+        int i_ghost_cell = i + 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+
+        int i_donor_cell = i_donor - 1;
+
+        if ( i_donor == 1 )
+        {
+            i_donor_cell = i_donor + 1;
+        }
+
+        this->ijk_donors.push_back( i_donor_cell );
+
+
+        icount ++;
+    }
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01a/global.h b/example/1d-heat-equation/ftcs/cpp/single_block/01a/global.h
new file mode 100644
index 00000000..665ba466
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01a/global.h
@@ -0,0 +1,239 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class Point
+{
+public:
+    typedef Point point_type;
+    using value_type = double;
+public:
+    Point()
+    {
+        this->x = 0;
+    }
+    Point( const value_type & x )
+    {
+        this->x = x;
+    }
+public:
+    value_type x;
+public:
+    bool operator < ( const Point & rhs ) const
+    {
+        value_type dx = x - rhs.x;
+        value_type diff = 1.0e-10;
+
+        if ( std::abs( dx ) > diff ) return x < rhs.x;
+
+        return false;
+    }
+};
+
+class PointFactory
+{
+public:
+    using value_type = double;
+    using point_type = Point;
+    using iterator = std::map< point_type, int >::iterator;
+protected:
+    std::map< point_type, int > pointList;
+    std::vector<point_type> pointArray;
+public:
+    int GetNPoints() { return pointArray.size(); }
+    bool FindPoint( const point_type & point )
+    {
+        iterator iter = pointList.find( point );
+        if ( iter == pointList.end() )
+        {
+            return false;
+        }
+        return true;
+    }
+private:
+    bool FindPoint( const point_type & point, iterator & iter )
+    {
+        iter = pointList.find( point );
+        if ( iter == pointList.end() )
+        {
+            return false;
+        }
+        return true;
+    }
+public:
+    int AddPoint( const point_type & point )
+    {
+        PointFactory::iterator iter;
+        if ( FindPoint( point, iter ) )
+        {
+            return iter->second;
+        }
+        else
+        {
+            int index = this->GetNPoints();
+
+            pointList.insert( std::make_pair(point, index) );
+            pointArray.push_back( point );
+
+            return index;
+        }
+    }
+};
+
+class Face
+{
+public:
+    std::vector<int> nodes;
+    std::vector<int> sorted_nodes;
+public:
+    void AddFace( std::vector<int> & nodes )
+    {
+        this->nodes = nodes;
+        this->sorted_nodes = nodes;
+        std::sort( this->sorted_nodes.begin(), this->sorted_nodes.end() );
+    }
+    bool operator < ( const Face & rhs ) const
+    {
+        return this->sorted_nodes < rhs.sorted_nodes;
+    } 
+};
+
+class FaceList
+{
+public:
+    std::map<Face, int> face_map;
+public:
+    void AddFace( const Face & face )
+    {
+        std::map<Face, int>::iterator iter;
+        iter = face_map.find( face );
+        if ( iter == face_map.end() )
+        {
+            int id = face_map.size();
+            face_map.insert( std::make_pair( face, id ) );
+        }
+    }
+};
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class BC
+{
+public:
+    std::vector<int> bctypes;
+    std::vector<int> faceids;
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class InterFaceZone
+{
+public:
+    std::vector<int> face_ids;
+    std::vector<int> left_zones;
+    std::vector<int> right_zones;
+    std::vector<int> left_cells;
+    std::vector<int> right_cells;
+    std::vector<double> left_u;
+    std::vector<double> right_u;
+};
+
+class Transform;
+
+class Interface
+{
+public:
+    std::vector<int> zoneList;
+    std::vector<int> faceidList;
+    std::vector<int> ijkList;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+    std::vector<double> uList;
+public:
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+};
+
+class IJK
+{
+public:
+    std::vector<int> iList;
+    std::vector<int> jList;
+    std::vector<int> kList;
+};
+
+class Field;
+class BC;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+    static std::vector<BC *> bcs;
+    static std::vector<InterFaceZone *> interfacezones;
+    static PointFactory boundary_points;
+    static FaceList boundary_faces;
+    static FaceList inter_faces;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+    static std::vector<IJK *> ijks;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01a/heat1d1blocksv1.cgns b/example/1d-heat-equation/ftcs/cpp/single_block/01a/heat1d1blocksv1.cgns
new file mode 100644
index 00000000..a367704f
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/single_block/01a/heat1d1blocksv1.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01a/main.cpp b/example/1d-heat-equation/ftcs/cpp/single_block/01a/main.cpp
new file mode 100644
index 00000000..5ff48a4e
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01a/main.cpp
@@ -0,0 +1,12 @@
+#include "cgnslib.h"
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+#include "Solver.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01a/plot.py b/example/1d-heat-equation/ftcs/cpp/single_block/01a/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01a/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01a/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/single_block/01a/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01a/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01b/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/single_block/01b/CMakeLists.txt
new file mode 100644
index 00000000..ee758c31
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01b/CMakeLists.txt
@@ -0,0 +1,79 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	global.h global.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	Field.h Field.cpp
+	Solver.h Solver.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01b/CgnsGrid.cpp b/example/1d-heat-equation/ftcs/cpp/single_block/01b/CgnsGrid.cpp
new file mode 100644
index 00000000..e186c2f4
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01b/CgnsGrid.cpp
@@ -0,0 +1,578 @@
+#include "CgnsGrid.h"
+#include "cgnslib.h"
+#include "global.h"
+#include <iostream>
+#include <vector>
+
+
+Region::Region()
+{
+}
+
+Region::~Region()
+{
+}
+
+Region & Region::operator = ( const Region & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+void Region::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    this->start.resize( index_dim );
+    this->end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+void Region::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+void Coor::DumpCoorX( std::vector<double> &x )
+{
+    double * xd = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        x[ i ] = xd[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+int Trans::M[ 3 ][ 3 ];
+std::vector<int> Trans::transform;
+
+int Trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int Trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void Trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            Trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void Trans::CalcTransformMatrix()
+{
+    int dim = Trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = Trans::transform[ 0 ];
+        int sgna = Trans::sgn( a );
+        int a1 = Trans::del( a, 1 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = Trans::transform[ 0 ];
+        int b = Trans::transform[ 1 ];
+        int c = Trans::transform[ 2 ];
+        int sgna = Trans::sgn( a );
+        int sgnb = Trans::sgn( b );
+        int sgnc = Trans::sgn( c );
+        int a1 = Trans::del( a, 1 );
+        int a2 = Trans::del( a, 2 );
+        int a3 = Trans::del( a, 3 );
+        int b1 = Trans::del( b, 1 );
+        int b2 = Trans::del( b, 2 );
+        int b3 = Trans::del( b, 3 );
+        int c1 = Trans::del( c, 1 );
+        int c2 = Trans::del( c, 2 );
+        int c3 = Trans::del( c, 3 );
+        Trans::M[ 0 ][ 0 ] = sgna * a1;
+        Trans::M[ 1 ][ 0 ] = sgna * a2;
+        Trans::M[ 2 ][ 0 ] = sgna * a3;
+        Trans::M[ 0 ][ 1 ] = sgnb * b1;
+        Trans::M[ 1 ][ 1 ] = sgnb * b2;
+        Trans::M[ 2 ][ 1 ] = sgnb * b3;
+        Trans::M[ 0 ][ 2 ] = sgnc * c1;
+        Trans::M[ 1 ][ 2 ] = sgnc * c2;
+        Trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+Transform::Transform()
+{
+    //int dim = Dim::dim;
+    int dim = 1;
+    this->diff.resize( dim );
+    this->mul.resize( dim );
+}
+
+Transform::~Transform()
+{
+    ;
+}
+
+void Transform::Init()
+{
+    Trans::ZeroMatrix();
+    Trans::transform = this->transform;
+    Trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = Trans::M[ i ][ j ];
+        }
+    }
+}
+
+void Transform::MapIndex( std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = index1.size();
+    for ( int m = 0; m < dim; ++ m )
+    {
+        this->diff[ m ] = index1[ m ] - this->begin1[ m ];
+    }
+
+    this->Multiply( diff, this->mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = this->mul[ m ] + this->begin2[ m ];
+    }
+
+}
+
+void Transform::Multiply( std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = a.size();
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += this->Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[ 33 ];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[ i ] << "\n";
+            }
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[ zoneType ] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            Grid * grid = new Grid();
+            Global::grids.push_back( grid );
+
+            BC * bc = new BC();
+            Global::bcs.push_back( bc );
+
+            InterFaceZone * interfacezone = new InterFaceZone();
+            Global::interfacezones.push_back( interfacezone );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " << DataTypeName[ dataType ] << "\n";
+                //std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+
+                coor->DumpCoor();
+                if ( icoord == 0 )
+                {
+                    coor->DumpCoorX( grid->x );
+                }
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame << " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[ bocotype ] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    Global::boundary_points.AddPoint( grid->x[ pnts[ i ] - 1 ] );
+                }
+
+                if ( index_dim == 1 )
+                {
+                    int p1 = pnts[ 0 ];
+                    double x1 = grid->x[ p1 - 1 ];
+                    int id = Global::boundary_points.AddPoint( x1 );
+                    Face face;
+                    std::vector<int> nodes;
+                    nodes.push_back( id );
+                    face.AddFace( nodes );
+                    Global::boundary_faces.AddFace( face );
+
+                    bc->bctypes.push_back( bocotype );
+                    bc->faceids.push_back( p1 - 1 );
+                }
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    Global::boundary_points.AddPoint( grid->x[ range[ i ] - 1 ] );
+                }
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+                if ( index_dim == 1 )
+                {
+                    int p1 = range[ 0 ];
+                    double x1 = grid->x[ p1 - 1 ];
+                    int id = Global::boundary_points.AddPoint( x1 );
+                    Face face;
+                    std::vector<int> nodes;
+                    nodes.push_back( id );
+                    face.AddFace( nodes );
+                    Global::boundary_faces.AddFace( face );
+                    Global::inter_faces.AddFace( face );
+
+                    bc->bctypes.push_back( BCTypeUserDefined );
+                    bc->faceids.push_back( p1 - 1 );
+
+                    interfacezone->face_ids.push_back( p1 );
+
+                    interfacezone->left_zones.push_back( gZoneId );
+                    interfacezone->left_cells.push_back( p1 - 1 );
+
+                    int q = donor_range[ 0 ];
+                    interfacezone->right_zones.push_back( gDonorZoneId );
+                    interfacezone->right_cells.push_back( q - 1 );
+                }
+            }
+        }
+    }
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01b/CgnsGrid.h b/example/1d-heat-equation/ftcs/cpp/single_block/01b/CgnsGrid.h
new file mode 100644
index 00000000..fddf1db6
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01b/CgnsGrid.h
@@ -0,0 +1,103 @@
+#pragma once
+#include <string>
+#include <vector>
+
+class Region
+{
+public:
+    Region();
+    ~Region();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    Region & operator = ( const Region & rhs );
+    void SetRegion( std::vector<int> & pnts );
+    void Print();
+};
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+    void DumpCoorX( std::vector<double> & x );
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    int zoneIndex;
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class Trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class Transform
+{
+public:
+    Transform();
+    ~Transform();
+private:
+    std::vector<int> diff;
+    std::vector<int> mul;
+public:
+    int Mt[ 3 ][ 3 ];
+    std::vector<int> begin1;
+    std::vector<int> begin2;
+    std::vector<int> transform;
+public:
+    void Init();
+    void MapIndex( std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( std::vector<int> & a, std::vector<int> & b );
+};
+
+void ReadCgnsGridBaseZone( const std::string & filename );
+void ReadCgnsGrid( const std::string & filename );
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01b/Field.cpp b/example/1d-heat-equation/ftcs/cpp/single_block/01b/Field.cpp
new file mode 100644
index 00000000..ac6e1419
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01b/Field.cpp
@@ -0,0 +1,248 @@
+#include "Field.h"
+#include "CgnsGrid.h"
+
+int Para::nt = -1;
+double Para::dx = 0;
+double Para::dt = 0;
+double Para::t = 0;
+double Para::alpha = 0;
+double Para::beta = 0;
+
+void Para::Init()
+{
+    Para::dx = 0.025;
+    Para::dt = dx / 10.0;
+    Para::t = 1.0;
+    //Para::nt = std::round( t / dt );
+    Para::nt = 2;
+    //Para::nt = 1;
+}
+
+void GenGrid( std::vector<double> & gx );
+void GenGrid( std::vector<double> & gx )
+{
+    const int ni = 81;
+    gx.resize( ni );
+
+    double x_l = -1.0;
+    double x_r = 1.0;
+
+    double dx = ( x_r - x_l ) / ( ni - 1 );
+
+    for ( int i = 0; i < ni; ++ i )
+    {
+        gx[ i ] = x_l + i * dx;
+    }
+}
+
+void Field::ModifyGrid( Grid * grid )
+{
+    std::vector<double> globalx;
+    GenGrid( globalx );
+
+    this->ni = grid->x.size();
+
+    int ishift = 0;
+
+    if ( grid->zoneIndex == 1 )
+    {
+        ishift = ni - 1;
+    }
+
+    for ( int i = 0; i < ni; ++ i )
+    {
+        grid->x[ i ] = globalx[ i + ishift ];
+    }
+}
+
+void Field::Init( Grid * grid )
+{
+    this->ni = grid->x.size();
+    std::cout << "ni = " << ni << "\n";
+    this->ModifyGrid( grid );
+
+    std::vector<double> & x = grid->x;
+    //this->dx = std::abs( x[ 1 ] - x[ 0 ] );
+    //this->dt = dx / 10.0;
+    //this->t = 1.0;
+    //this->nt = std::round( t / dt );
+
+    this->dx = Para::dx;
+    this->dt = Para::dt;
+    this->t = Para::t;
+    this->nt = Para::nt;
+
+    double total_time = nt * dt;
+
+    std::cout << "this->dt = " << this->dt << "\n";
+    std::cout << "this->t = " << this->t << "\n";
+    std::cout << "this->nt = " << this->nt << "\n";
+    std::cout << "this->ni = " << this->ni << "\n";
+    std::cout << "total_time = " << std::setprecision( 25 ) << total_time << "\n";
+
+    Global::nt = nt;
+
+    this->alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+    this->beta = this->alpha * dt / ( dx * dx );
+    std::cout << "alpha = " << std::setprecision( 25 ) << this->alpha << "\n";
+    std::cout << "beta = " << std::setprecision( 25 ) << this->beta << "\n";
+
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    u_e.resize( ni_total );
+    u.resize( ni_total );
+    un.resize( ni_total );
+
+    // 0 1 2 ... ni-1 ni ni+1
+
+    int ist = 1;
+    int ied = ni;
+
+    // 0(bc) 1(ist) 2 3 ... ni
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double xm = x[ i - ist ];
+        u_e[ i ] = - std::exp( -total_time ) * std::sin( std::numbers::pi * xm ); //theory solution
+        if ( std::abs( xm - 0.2 ) < 1.0e-5 )
+        {
+            double term1 = xm;
+            double term2 = std::sin( std::numbers::pi * xm );
+            double term3 = std::exp( -total_time );
+            double term4 = term2 * term3;
+            std::cout << "this->dx = " << std::setprecision( 25 ) << this->dx << "\n";
+            std::cout << "x[0] = " << std::setprecision( 25 ) << x[ 0 ] << "\n";
+            std::cout << "x[1] = " << std::setprecision( 25 ) << x[ 1 ] << "\n";
+            std::cout << "this->dt = " << std::setprecision( 25 ) << this->dt << "\n";
+            std::cout << "total_time = " << std::setprecision( 25 ) << total_time << "\n";
+            std::cout << "term1 = " << std::setprecision( 25 ) << term1 << "\n";
+            std::cout << "term2 = " << std::setprecision( 25 ) << term2 << "\n";
+            std::cout << "term3 = " << std::setprecision( 25 ) << term3 << "\n";
+            std::cout << "term4 = " << std::setprecision( 25 ) << term4 << "\n";
+        }
+        u[ i ] = - std::sin( std::numbers::pi * xm ); //initial condition @ t=0
+    }
+}
+
+void Field::Solve( Zone * zone )
+{
+    int nghost = 2;
+    int ni_total = ni + nghost;
+
+    int ist = 1;
+    int ied = ni;
+
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        double term1 = un[ i - 1 ];
+        double term2 = un[ i ];
+        double term3 = un[ i + 1 ];
+        double term4 = term1 -2.0 * term2 + term3;
+        double term5 = beta * term4;
+        double term6 = term2 + term5;
+        if ( ( zone->zoneIndex == 0 && i== 41 ) )
+        {
+            std::cout << "zone->zoneIndex = " << zone->zoneIndex << "\n";
+            std::cout << "term1 = " << std::setprecision( 25 ) << term1 << "\n";
+            std::cout << "term2 = " << std::setprecision( 25 ) << term2 << "\n";
+            std::cout << "term3 = " << std::setprecision( 25 ) << term3 << "\n";
+            std::cout << "term4 = " << std::setprecision( 25 ) << term4 << "\n";
+            std::cout << "term5 = " << std::setprecision( 25 ) << term5 << "\n";
+            std::cout << "term6 = " << std::setprecision( 25 ) << term6 << "\n";
+        }
+        //u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+        u[ i ] = term6;
+    }
+
+    this->PhysicalBoundary( zone );
+
+    this->Update( un, u );
+}
+
+void Field::PhysicalBoundary( Zone * zone )
+{
+    int nbccos = zone->bccos.size();
+    for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+    {
+        ZoneBc * zonebc = zone->bccos[ ibcco ];
+        //std::cout << "zonebc->bcType = " << zonebc->bcType << "\n";
+        Region region;
+        region.SetRegion( zonebc->pnts );
+        //region.Print();
+        Boundary( region, zonebc->bcType );
+    }
+}
+
+void Field::Boundary( Region &region, int bcType )
+{
+    if ( bcType == BCInflow )
+    {
+        this->InflowBc( region );
+    }
+    else if ( bcType == BCExtrapolate )
+    {
+        this->OutflowBc( region );
+    }
+}
+
+void Field::InflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        //this->u[ i ] = 0.0;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+        int kkk = 1;
+    }
+}
+
+void Field::OutflowBc( Region &region )
+{
+    int index_dim = region.start.size();
+    if ( index_dim != 1 ) return;
+    int st = region.start[ 0 ];
+    int ed = region.end[ 0 ];
+    for ( int i = st; i <= ed; ++ i )
+    {
+        int idir = 1;
+        if ( i == 1 )
+        {
+            idir = -1;
+        }
+        int ighost = i + idir;
+        int iinner = i - idir;
+        //this->u[ i ] = 0.0;
+        this->u[ ighost ] = 2 * this->u[ i ] - this->u[ iinner ];
+    }
+}
+
+
+void Field::PostProcess( Grid * grid )
+{
+    std::vector<double> & x = grid->x;
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni );
+    for ( int i = 0; i < ni; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+}
+
+void Field::Update( std::vector<double> &un, std::vector<double> &u )
+{
+    for ( int i = 0; i < u.size(); ++ i )
+    {
+        un[ i ] = u[ i ];
+    }
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01b/Field.h b/example/1d-heat-equation/ftcs/cpp/single_block/01b/Field.h
new file mode 100644
index 00000000..45c9da82
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01b/Field.h
@@ -0,0 +1,47 @@
+#pragma once
+#include <vector>
+#include <iostream>
+#include <iomanip> 
+#include <numbers>
+#include "global.h"
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+class Zone;
+class Grid;
+
+class Para
+{
+public:
+    static int nt;
+    static double dx, dt, t;
+    static double alpha, beta;
+public:
+    static void Init();
+};
+
+class Field
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u, un;
+    std::vector<double> error;
+public:
+    int ni;
+    int nt;
+    double dx, dt, t;
+    double alpha, beta;
+public:
+    void ModifyGrid( Grid * grid );
+    void Init( Grid * grid );
+
+    void Solve( Zone * zone );
+    void Boundary( Region & region, int bcType );
+    void InflowBc( Region & region );
+    void OutflowBc( Region & region );
+
+    void PhysicalBoundary( Zone * zone );
+
+    void PostProcess( Grid * grid );
+    void Update( std::vector<double> & un, std::vector<double> & u );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01b/README.txt b/example/1d-heat-equation/ftcs/cpp/single_block/01b/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01b/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01b/Solver.cpp b/example/1d-heat-equation/ftcs/cpp/single_block/01b/Solver.cpp
new file mode 100644
index 00000000..78058e55
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01b/Solver.cpp
@@ -0,0 +1,377 @@
+#include "Solver.h"
+#include <fstream>
+
+double compute_l2norm( int ni, std::vector<double> & r )
+{
+    double rms = 0.0;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        rms += r[ i ] * r[ i ];
+    }
+    rms = std::sqrt( rms / ( ni - 2 ) );
+    return rms;
+}
+
+double compute_max_error( int ni, std::vector<double> & u_error )
+{
+    double val_max = -1;
+    int ipos = -1;
+    for ( int i = 1; i < ni - 1; ++ i )
+    {
+        if ( val_max < std::abs( u_error[ i ] ) )
+        {
+            ipos = i;
+            val_max = std::abs( u_error[ i ] );
+        }
+    }
+    std::cout << " ipos = " << ipos << "\n";
+    return val_max;
+}
+
+void Solver::Run()
+{
+    this->ReadGrid();
+    this->InitTopo();
+    this->InitFields();
+    this->SolveMultiZones();
+    this->PostProcess();
+}
+
+void Solver::ReadGrid()
+{
+    std::string fileName = "../heat1d1blocksv1.cgns";
+    ReadCgnsGridBaseZone( fileName );
+    ReadCgnsGrid( fileName );
+    int nZones = Global::grids.size();
+    PointFactory ptfactory;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        grid->zoneIndex = iZone;
+        int ni = grid->x.size();
+        for ( int i = 0; i < ni; ++ i )
+        {
+            int pid = ptfactory.AddPoint( Point( grid->x[ i ] ) );
+        }
+        int kkk = 1;
+    }
+}
+
+void Solver::InitTopo()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Interface * interface = new Interface();
+        Global::interfaces.push_back( interface );
+
+        IJK * ijk = new IJK();
+        Global::ijks.push_back( ijk );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Zone * zone = Global::zones[ iZone ];
+        Interface * interface = Global::interfaces[ iZone ];
+
+        int nbc1to1s = zone->bc1to1s.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * bc1to1 = zone->bc1to1s[ ibc1to1 ];
+            int zoneid = bc1to1->zoneid;
+            int donor_zoneid = bc1to1->donor_zoneid;
+            Region region;
+            region.SetRegion( bc1to1->pnts );
+
+            Region donor_region;
+            donor_region.SetRegion( bc1to1->donor_pnts );
+
+            Transform transform;
+            transform.begin1 = region.start;
+            transform.begin2 = donor_region.start;
+            transform.transform = bc1to1->transform;
+            transform.Init();
+
+            interface->CalcInterface( &transform, region.start, region.end, donor_zoneid );
+        }
+    }
+}
+
+void Solver::InitFields()
+{
+    Para::Init();
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = new Field();
+        Global::fields.push_back( field );
+    }
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        Field * field = Global::fields[ iZone ];
+        field->Init( grid );
+        Zone * zone = Global::zones[ iZone ];
+        field->PhysicalBoundary( zone );
+    }
+
+    ExchangeInterfaceField();
+
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+        field->Update( field->un, field->u );
+    }
+}
+
+void Solver::SolveMultiZones()
+{
+    for ( int it = 0; it < Global::nt; ++ it )
+    {
+        ExchangeInterfaceField();
+        int nZones = Global::grids.size();
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            Field * field = Global::fields[ iZone ];
+            Zone * zone = Global::zones[ iZone ];
+            zone->zoneIndex = iZone;
+            field->Solve( zone );
+        }
+    }
+}
+
+void Solver::ExchangeInterfaceField()
+{
+    int nZones = Global::interfaces.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Field * field = Global::fields[ iZone ];
+
+        Interface * interface = Global::interfaces[ iZone ];
+        int nInterFaces = interface->zoneList.size();
+        int index_dim = 1;
+        for ( int iFace = 0; iFace < nInterFaces; ++ iFace )
+        {
+            int donor_zoneid = interface->zoneList[ iFace ];
+            int ijkpos = index_dim * iFace;
+            int i_ghost_cell = interface->ijk_ghosts[ ijkpos + 0 ];
+            int i_donor_cell = interface->ijk_donors[ ijkpos + 0 ];
+            
+            Field * donor_field = Global::fields[ donor_zoneid ];
+
+            double donor_value = donor_field->u[ i_donor_cell ];
+            field->u[ i_ghost_cell ] = donor_value;
+        }
+    }
+}
+
+void Solver::PostProcess()
+{
+    Post post;
+    post.Process();
+}
+
+void Solver::PrintField( std::vector<double> &f )
+{
+    int icount = 0;
+    for ( int i = 0; i < f.size(); ++ i )
+    {
+        std::cout << std::setprecision(15) << f[ i ] << " ";
+        icount ++;
+        if ( icount % 5 == 0 )
+        {
+            std::cout << "\n";
+        }
+    }
+    std::cout << "\n";
+    std::cout << "\n";
+}
+
+
+void Post::Process()
+{
+    this->ReorderZones();
+    this->GatherField();
+    this->DumpField();
+}
+
+void Post::ReorderZones()
+{
+    int nZones = Global::grids.size();
+    std::vector<double> xmin_list;
+    std::vector<double> xmax_list;
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        Grid * grid = Global::grids[ iZone ];
+        int ni = grid->x.size();
+        double xmin = grid->x[ 0 ];
+        double xmax = grid->x[ 0 ];
+        int imin = 0;
+        int imax = 0;
+        for ( int i = 0; i < ni; ++ i )
+        {
+            if ( xmin > grid->x[ i ] )
+            {
+                xmin = grid->x[ i ];
+                imin = i;
+            }
+            if ( xmax < grid->x[ i ] )
+            {
+                xmax = grid->x[ i ];
+                imax = i;
+            }
+        }
+        xmin_list.push_back( xmin );
+        xmax_list.push_back( xmax );
+    }
+    std::vector<std::pair<double, int>> pairs;
+    int nSize = xmin_list.size();
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        pairs.push_back( std::make_pair( xmin_list[i], i ) );
+    }
+
+    std::sort( pairs.begin(), pairs.end() );
+
+    for ( int i = 0; i < nSize; ++ i )
+    {
+        this->zoneids.push_back( pairs[i].second );
+    }
+
+    int kkk = 1;
+}
+
+void Post::GatherField()
+{
+    int nZones = Global::grids.size();
+    for ( int iZone = 0; iZone < nZones; ++ iZone )
+    {
+        int zoneid = this->zoneids[ iZone ];
+        Grid * grid = Global::grids[ zoneid ];
+        Field * field = Global::fields[ zoneid ];
+
+        int ni = grid->x.size();
+
+        int ist = 1;
+        int ied = ni;
+
+        int dir = 1;
+        if ( grid->x[ 0 ] > grid->x[ 1 ] ) dir = -1;
+
+        if ( dir == 1 )
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ist; i <= ied; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+
+            }
+            else
+            {
+                for ( int i = ist; i <= ied - 1; ++ i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+        }
+        else
+        {
+            if ( iZone == nZones - 1 )
+            {
+                for ( int i = ied; i >= ist; -- i )
+                {
+                    double xm = grid->x[ i - ist ];
+                    this->x.push_back( xm );
+                    this->u_e.push_back( field->u_e[ i ] );
+                    this->un.push_back( field->un[ i ] );
+                    this->u.push_back( field->u[ i ] );
+                }
+            }
+            for ( int i = ied; i >= ist + 1; -- i )
+            {
+                double xm = grid->x[ i - ist ];
+                this->x.push_back( xm );
+                this->u_e.push_back( field->u_e[ i ] );
+                this->un.push_back( field->un[ i ] );
+                this->u.push_back( field->u[ i ] );
+            }
+        }
+    }
+}
+
+void Post::DumpField()
+{
+    int ni_total = this->x.size();
+    std::cout << " DumpField x.size() = " << x.size() << "\n";
+    //compute L2 norm of the error
+    std::vector<double> u_error( ni_total );
+    for ( int i = 0; i < ni_total; ++ i )
+    {
+        u_error[ i ] = un[ i ] - u_e[ i ];
+    }
+
+    this->DumpErrorDetails( u_error );
+
+    //std::string csvname = "field_final.csv";
+    //this->DumpCsvFile( csvname, x, u_e, un, u_error );
+    //std::string csvname_test = "field_final_test.csv";
+    //this->DumpCsvFile( csvname_test, x, u_e, un, u, u_error );
+
+    std::string csvname = "field_final0.csv";
+    this->DumpCsvFile( csvname, x, u_e, un, u_error );
+    std::string csvname_test = "field_final_test0.csv";
+    this->DumpCsvFile( csvname_test, x, u_e, un, u, u_error );
+
+}
+
+void Post::DumpErrorDetails( std::vector<double> &u_error )
+{
+    int ni = u_error.size();
+    double rms_error = compute_l2norm( ni, u_error );
+    double max_error = compute_max_error( ni, u_error );
+    std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+    //create output file for L2-norm
+    std::fstream file;
+    file.open("output.txt", std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+    std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+    std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        std::format_to(std::ostream_iterator<char>(file), "{:.20f} {:.20f} {:.20f} {:.20f}\n", x[i], ue[i], un[i], uerror[i] );
+    }
+    file.close();
+}
+
+void Post::DumpCsvFile( const std::string &filename, std::vector<double> &x, std::vector<double> &ue, std::vector<double> &un, std::vector<double> &u, std::vector<double> &uerror )
+{
+    std::fstream file;
+    file.open(filename.c_str(), std::fstream::out);
+    std::format_to(std::ostream_iterator<char>(file), "x ue un u uerror\n");
+    for ( int i = 0; i < x.size(); ++ i )
+    {
+        //std::format_to(std::ostream_iterator<char>(file), "{:.16f} {:.16f} {:.16f} {:.16f}\n", x[i], ue[i], un[i], uerror[i] );
+        std::format_to(std::ostream_iterator<char>(file), "{:.20f} {:.20f} {:.20f} {:.20f} {:.20f}\n", x[i], ue[i], un[i], u[i], uerror[i] );
+    }
+    file.close();
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01b/Solver.h b/example/1d-heat-equation/ftcs/cpp/single_block/01b/Solver.h
new file mode 100644
index 00000000..a0d8ad69
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01b/Solver.h
@@ -0,0 +1,42 @@
+#pragma once
+#include <vector>
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+
+double compute_l2norm( int ni, std::vector<double> & r );
+double compute_max_error( int ni, std::vector<double> & u_error );
+
+class Solver
+{
+public:
+    void Run();
+    void ReadGrid();
+    void InitFields();
+    void InitTopo();
+    void SolveMultiZones();
+public:
+    void ExchangeInterfaceField();
+    void PrintField( std::vector<double> & f );
+public:
+    void PostProcess();
+};
+
+
+class Post
+{
+public:
+    std::vector<int> zoneids;
+    std::vector<double> x;
+    std::vector<double> u_e;
+    std::vector<double> un;
+    std::vector<double> u;
+public:
+    void Process();
+    void ReorderZones();
+    void GatherField();
+    void DumpField();
+    void DumpErrorDetails( std::vector<double> & u_error );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & uerror );
+    void DumpCsvFile( const std::string & filename, std::vector<double> & x, std::vector<double> & ue, std::vector<double> & un, std::vector<double> & u, std::vector<double> & uerror );
+};
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01b/global.cpp b/example/1d-heat-equation/ftcs/cpp/single_block/01b/global.cpp
new file mode 100644
index 00000000..be237bec
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01b/global.cpp
@@ -0,0 +1,59 @@
+#include "global.h"
+#include "CgnsGrid.h"
+
+std::vector<Grid *> Global::grids;
+std::vector<Field *> Global::fields;
+std::vector<BC *> Global::bcs;
+std::vector<InterFaceZone *> Global::interfacezones;
+PointFactory Global::boundary_points;
+FaceList Global::boundary_faces;
+FaceList Global::inter_faces;
+
+int Global::nt = -1;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+std::vector<Interface *>  Global::interfaces;
+std::vector<IJK *> Global::ijks;
+
+void Interface::CalcInterface( Transform * transform, std::vector<int> &start,  std::vector<int> &end, int donor_zoneid )
+{
+    int ist = start[ 0 ];
+    int ied = end[ 0 ];
+    int dim = start.size();
+    std::vector<int> index1( dim );
+    std::vector<int> index2( dim );
+
+    int icount = this->zoneList.size();
+    for ( int i = ist; i <= ied; ++ i )
+    {
+        int faceid = icount;
+        this->zoneList.push_back( donor_zoneid );
+        this->faceidList.push_back( faceid );
+        index1[ 0 ] = i;
+        transform->MapIndex( index1, index2 );
+        int i_donor = index2[ 0 ];
+
+        int i_ghost_cell = i + 1;
+
+        if ( i == 1 )
+        {
+            i_ghost_cell = i - 1;
+        }
+        ijk_ghosts.push_back( i_ghost_cell );
+
+        int i_donor_cell = i_donor - 1;
+
+        if ( i_donor == 1 )
+        {
+            i_donor_cell = i_donor + 1;
+        }
+
+        this->ijk_donors.push_back( i_donor_cell );
+
+
+        icount ++;
+    }
+}
\ No newline at end of file
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01b/global.h b/example/1d-heat-equation/ftcs/cpp/single_block/01b/global.h
new file mode 100644
index 00000000..665ba466
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01b/global.h
@@ -0,0 +1,239 @@
+#pragma once
+#include <vector>
+#include <map>
+#include <algorithm>
+#include <string>
+#include "CgnsGrid.h"
+
+class Grid;
+
+class Point
+{
+public:
+    typedef Point point_type;
+    using value_type = double;
+public:
+    Point()
+    {
+        this->x = 0;
+    }
+    Point( const value_type & x )
+    {
+        this->x = x;
+    }
+public:
+    value_type x;
+public:
+    bool operator < ( const Point & rhs ) const
+    {
+        value_type dx = x - rhs.x;
+        value_type diff = 1.0e-10;
+
+        if ( std::abs( dx ) > diff ) return x < rhs.x;
+
+        return false;
+    }
+};
+
+class PointFactory
+{
+public:
+    using value_type = double;
+    using point_type = Point;
+    using iterator = std::map< point_type, int >::iterator;
+protected:
+    std::map< point_type, int > pointList;
+    std::vector<point_type> pointArray;
+public:
+    int GetNPoints() { return pointArray.size(); }
+    bool FindPoint( const point_type & point )
+    {
+        iterator iter = pointList.find( point );
+        if ( iter == pointList.end() )
+        {
+            return false;
+        }
+        return true;
+    }
+private:
+    bool FindPoint( const point_type & point, iterator & iter )
+    {
+        iter = pointList.find( point );
+        if ( iter == pointList.end() )
+        {
+            return false;
+        }
+        return true;
+    }
+public:
+    int AddPoint( const point_type & point )
+    {
+        PointFactory::iterator iter;
+        if ( FindPoint( point, iter ) )
+        {
+            return iter->second;
+        }
+        else
+        {
+            int index = this->GetNPoints();
+
+            pointList.insert( std::make_pair(point, index) );
+            pointArray.push_back( point );
+
+            return index;
+        }
+    }
+};
+
+class Face
+{
+public:
+    std::vector<int> nodes;
+    std::vector<int> sorted_nodes;
+public:
+    void AddFace( std::vector<int> & nodes )
+    {
+        this->nodes = nodes;
+        this->sorted_nodes = nodes;
+        std::sort( this->sorted_nodes.begin(), this->sorted_nodes.end() );
+    }
+    bool operator < ( const Face & rhs ) const
+    {
+        return this->sorted_nodes < rhs.sorted_nodes;
+    } 
+};
+
+class FaceList
+{
+public:
+    std::map<Face, int> face_map;
+public:
+    void AddFace( const Face & face )
+    {
+        std::map<Face, int>::iterator iter;
+        iter = face_map.find( face );
+        if ( iter == face_map.end() )
+        {
+            int id = face_map.size();
+            face_map.insert( std::make_pair( face, id ) );
+        }
+    }
+};
+
+class BaseZone
+{
+public:
+    //int baseId;
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        //if ( this->baseId != rhs.baseId )
+        //{
+        //    return this->baseId < rhs.baseId;
+        //}
+
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class BC
+{
+public:
+    std::vector<int> bctypes;
+    std::vector<int> faceids;
+};
+
+class Grid
+{
+public:
+    int zoneIndex;
+    std::vector<double> x;
+};
+
+class InterFaceZone
+{
+public:
+    std::vector<int> face_ids;
+    std::vector<int> left_zones;
+    std::vector<int> right_zones;
+    std::vector<int> left_cells;
+    std::vector<int> right_cells;
+    std::vector<double> left_u;
+    std::vector<double> right_u;
+};
+
+class Transform;
+
+class Interface
+{
+public:
+    std::vector<int> zoneList;
+    std::vector<int> faceidList;
+    std::vector<int> ijkList;
+    std::vector<int> ijk_ghosts;
+    std::vector<int> ijk_donors;
+    std::vector<double> uList;
+public:
+    void CalcInterface( Transform * transform, std::vector<int> & start, std::vector<int> & end, int donor_zoneid );
+};
+
+class IJK
+{
+public:
+    std::vector<int> iList;
+    std::vector<int> jList;
+    std::vector<int> kList;
+};
+
+class Field;
+class BC;
+class InterFaceZone;
+
+class Global
+{
+public:
+    static std::vector<Grid *> grids;
+    static std::vector<Field *> fields;
+    static std::vector<BC *> bcs;
+    static std::vector<InterFaceZone *> interfacezones;
+    static PointFactory boundary_points;
+    static FaceList boundary_faces;
+    static FaceList inter_faces;
+public:
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+    static std::vector<Interface *> interfaces;
+    static std::vector<IJK *> ijks;
+public:
+    static int nt;
+    static int cell_dim;
+    static int phys_dim;
+};
+
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01b/heat1d1blocksv1.cgns b/example/1d-heat-equation/ftcs/cpp/single_block/01b/heat1d1blocksv1.cgns
new file mode 100644
index 00000000..a367704f
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/single_block/01b/heat1d1blocksv1.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01b/main.cpp b/example/1d-heat-equation/ftcs/cpp/single_block/01b/main.cpp
new file mode 100644
index 00000000..5ff48a4e
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01b/main.cpp
@@ -0,0 +1,12 @@
+#include "cgnslib.h"
+#include "global.h"
+#include "CgnsGrid.h"
+#include "Field.h"
+#include "Solver.h"
+
+int main( int argc, char ** argv )
+{
+    Solver solver;
+    solver.Run();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01b/plot.py b/example/1d-heat-equation/ftcs/cpp/single_block/01b/plot.py
new file mode 100644
index 00000000..dcc55c0b
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01b/plot.py
@@ -0,0 +1,58 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import csv
+
+x_list = []
+ue_list = []
+un_list = []
+uerror_list = []
+
+with open('field_final.csv', newline='') as csvfile:
+    readCSV = csv.reader(csvfile, delimiter= ' ')
+    icount = 0
+    for row in readCSV:
+        #print(row)
+        #print(row[0])
+        #print(row[0], row[1], row[2], row[3])
+        if ( icount != 0 ) :
+            x_list.append(row[0])
+            ue_list.append(row[1])
+            un_list.append(row[2])
+            uerror_list.append(row[3])
+        icount += 1
+
+ni = icount - 1
+print("ni=",ni)
+
+x = np.zeros( ni )
+ue = np.zeros( ni )
+un = np.zeros( ni )
+uerror = np.zeros( ni )
+
+for i in range(0, ni):
+    x[i] = float(x_list[i])
+    ue[i] = float(ue_list[i])
+    un[i] = float(un_list[i])
+    uerror[i] = float(uerror_list[i])
+    
+plt.figure("OneFLOW-CFD Solver", figsize=(10, 4), dpi=100)
+plt.subplot(1, 2, 1)
+plt.plot(x, ue, "k-", linewidth=1.0, label="Exact solution")
+plt.scatter(x, un, facecolor="none", edgecolor="blue", s=20, linewidths=0.5, label="FTCS solution")
+plt.xlabel("$x$")
+plt.ylabel("$u$")
+plt.title("Solution field")
+plt.legend()
+plt.tight_layout()
+
+plt.subplot(1, 2, 2)
+plt.scatter(x, np.abs(uerror), facecolor="none", edgecolor="green", s=20, linewidths=0.5)
+plt.ylabel(r"$\epsilon$")
+plt.xlabel("$x$")
+plt.title("Discretization error")
+plt.tight_layout()
+plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
+
+plt.show();    
+    
+
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/01b/plotting2.jl b/example/1d-heat-equation/ftcs/cpp/single_block/01b/plotting2.jl
new file mode 100644
index 00000000..c74255b2
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/01b/plotting2.jl
@@ -0,0 +1,49 @@
+using CSV
+using DataFrames
+using PyPlot
+rc("font", family="Arial", size=16.0)
+
+
+final_field = CSV.read("field_final.csv", DataFrame)#, datarow = 2, type=Float64)
+
+x = convert(Array,final_field[:,1])
+
+u_e = convert(Array,final_field[:,2])
+u_n = convert(Array,final_field[:,3])
+u_error = convert(Array,final_field[:,4])
+
+u = Array{Float64}(undef, length(u_e), 2)
+u[:,1] = u_e
+u[:,2] = u_n
+
+for i = 1:Int64(length(u_error))
+    u_error[i] = abs(u_error[i])
+end
+
+fig = figure("FTCS", figsize=(14,6));
+ax1 = fig[:add_subplot](1,2,1);
+ax2 = fig[:add_subplot](1,2,2);
+
+ax1.plot(x, u_e, lw=4, ls = "-", color="b", label="Exact solution")
+ax1.plot(x, u_n, lw=4, ls = "--", color="r", label="FTCS solution")
+ax1.set_xlabel("\$x\$")
+ax1.set_ylabel("\$u\$")
+ax1.set_title("Solution field")
+ax1.set_xlim(-1,1)
+ax1.legend(fontsize=14, loc=0)
+
+ax2.plot(x, u_error, marker = "o", markeredgecolor="k",
+        markersize=8, color="g", lw=4)
+ax2.set_xlabel("\$x\$")
+ax2.set_ylabel("\$ϵ\$")
+ax2.set_title("Discretization error")
+ax2.set_xlim(-1,1)
+#ax2.legend(fontsize=14, loc=0)
+
+#plt[:subplot](ax1);
+#plt[:subplot](ax2);
+
+fig.tight_layout()
+fig.savefig("ftcs.pdf")
+
+show()
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/compare/01/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/single_block/compare/01/CMakeLists.txt
new file mode 100644
index 00000000..bfdbab14
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/compare/01/CMakeLists.txt
@@ -0,0 +1,75 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/compare/01/README.txt b/example/1d-heat-equation/ftcs/cpp/single_block/compare/01/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/compare/01/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/compare/01/heat1dni81.cgns b/example/1d-heat-equation/ftcs/cpp/single_block/compare/01/heat1dni81.cgns
new file mode 100644
index 00000000..b7d4954a
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/single_block/compare/01/heat1dni81.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/compare/01/main.cpp b/example/1d-heat-equation/ftcs/cpp/single_block/compare/01/main.cpp
new file mode 100644
index 00000000..774700bb
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/compare/01/main.cpp
@@ -0,0 +1,268 @@
+#include "cgnslib.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip> 
+
+class Grid;
+void ReadCgnsGrid( const std::string & filename, Grid * grid );
+
+class Grid
+{
+public:
+    std::vector<double> x;
+};
+
+class Solver
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u,un;
+    std::vector<double> error;
+public:
+    void solve()
+    {
+        std::cout << "solve()\n";
+        Grid grid;
+        ReadCgnsGrid( "../heat1dni81.cgns", &grid );
+        int ni = grid.x.size();
+        std::cout << "ni = " << ni << "\n";
+
+        std::vector<double> & x = grid.x;
+        double dx = x[ 1 ] - x[ 0 ];
+        //double dt = 0.0025;
+        double dt = dx / 10.0;
+        double t = 1.0;
+        int nt = std::round( t / dt );
+
+        std::cout << "dt = " << dt << "\n";
+        std::cout << "t = " << t << "\n";
+        std::cout << "nt = " << nt << "\n";
+        std::cout << "ni = " << ni << "\n";
+
+        u_e.resize( ni );
+        u.resize( ni );
+        un.resize( ni );
+
+        for ( int i = 0; i < ni; ++ i )
+        {
+            u_e[ i ] = - std::exp( -t ) * std::sin( std::numbers::pi * x[i] ); //theory solution
+            un[ i ] = - std::sin( std::numbers::pi * x[ i ] ); //initial condition @ t=0
+        }
+        un[ 0 ] = 0.0;
+        un[ ni - 1 ] = 0.0;
+
+        double alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+        double beta = alpha * dt / ( dx * dx );
+        std::cout << "alpha = " << std::setprecision(15) << alpha << "\n";
+        std::cout << "beta = " << std::setprecision(15) << beta << "\n";
+
+        for ( int it = 0; it < nt; ++ it )
+        {
+            for ( int i = 1; i < ni - 1; ++ i )
+            {
+                u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+            }
+            //boundary
+            u[ 0 ] = 0.0; // boundary condition at x = -1
+            u[ ni - 1 ] = 0.0; // boundary condition at x = 1
+            this->update( un, u );
+        }
+
+        //compute L2 norm of the error
+        std::vector<double> u_error( ni );
+        //icount = 0;
+        for ( int i = 0; i < ni; ++ i )
+        {
+            u_error[ i ] = un[ i ] - u_e[ i ];
+        }
+
+        double rms_error = compute_l2norm( ni, u_error );
+        double max_error = compute_max_error( ni, u_error );
+        std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+        //create output file for L2-norm
+        std::fstream file;
+        file.open("output.txt", std::fstream::out);
+        std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+        std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+        std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+        file.close();
+        int kkk = 1;
+    }
+
+    void update( std::vector<double> &un, std::vector<double> &u )
+    {
+        for ( int i = 0; i < u.size(); ++ i )
+        {
+            un[ i ] = u[ i ];
+        }
+    }
+
+    double compute_l2norm( int ni, std::vector<double> & r )
+    {
+        double rms = 0.0;
+        for ( int i = 1; i < ni - 1; ++ i )
+        {
+            rms += r[ i ] * r[ i ];
+        }
+        rms = std::sqrt( rms / ( ni - 2 ) );
+        return rms;
+    }
+
+    double compute_max_error( int ni, std::vector<double> & u_error )
+    {
+        double val_max = -1;
+        int ipos = -1;
+        for ( int i = 1; i < ni - 1; ++ i )
+        {
+            //val_max = std::max( val_max, std::abs( u_error[ i ] ) );
+            if ( val_max < std::abs( u_error[ i ] ) )
+            {
+                ipos = i;
+                val_max = std::abs( u_error[ i ] );
+            }
+        }
+        std::cout << " ipos = " << ipos << "\n";
+        return val_max;
+    }
+};
+
+void ReadCgnsGrid( const std::string & filename, Grid * grid )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones(fileId, baseId, &nzones);
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize(index_dim*3);
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[33];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                //std::vector<double> coord( nNodes );
+                std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coord.data() );
+                double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+                for ( int i = 0; i < nNodes; ++ i )
+                {
+                    //std::cout << xd[i] << " ";
+                    grid->x[ i ] = xd[ i ];
+                    //if( (i+1)%5 == 0 ) std::cout << "\n";
+                }
+                //std::cout << "\n";
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex(index_dim,-1);
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type, 
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset);
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[i] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[normalDataType] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList(nNodes*iphysdim*sizeof(double));
+
+                std::vector<cgsize_t> pnts(npnts*index_dim);
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double*>(const_cast<char *>(normalList.data()));
+            }
+        }
+    }
+    cg_close(fileId);
+}
+
+int main(int argc, char **argv)
+{
+    Solver solver;
+    solver.solve();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/compare/01a/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/single_block/compare/01a/CMakeLists.txt
new file mode 100644
index 00000000..bfdbab14
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/compare/01a/CMakeLists.txt
@@ -0,0 +1,75 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/compare/01a/README.txt b/example/1d-heat-equation/ftcs/cpp/single_block/compare/01a/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/compare/01a/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/compare/01a/heat1d1blocksv1.cgns b/example/1d-heat-equation/ftcs/cpp/single_block/compare/01a/heat1d1blocksv1.cgns
new file mode 100644
index 00000000..a367704f
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/single_block/compare/01a/heat1d1blocksv1.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/compare/01a/main.cpp b/example/1d-heat-equation/ftcs/cpp/single_block/compare/01a/main.cpp
new file mode 100644
index 00000000..3078dc74
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/compare/01a/main.cpp
@@ -0,0 +1,269 @@
+#include "cgnslib.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip> 
+
+class Grid;
+void ReadCgnsGrid( const std::string & filename, Grid * grid );
+
+class Grid
+{
+public:
+    std::vector<double> x;
+};
+
+class Solver
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u,un;
+    std::vector<double> error;
+public:
+    void solve()
+    {
+        std::cout << "solve()\n";
+        Grid grid;
+        //ReadCgnsGrid( "../heat1dni81.cgns", &grid );
+        ReadCgnsGrid( "../heat1d1blocksv1.cgns", &grid );
+        int ni = grid.x.size();
+        std::cout << "ni = " << ni << "\n";
+
+        std::vector<double> & x = grid.x;
+        double dx = x[ 1 ] - x[ 0 ];
+        //double dt = 0.0025;
+        double dt = dx / 10.0;
+        double t = 1.0;
+        int nt = std::round( t / dt );
+
+        std::cout << "dt = " << dt << "\n";
+        std::cout << "t = " << t << "\n";
+        std::cout << "nt = " << nt << "\n";
+        std::cout << "ni = " << ni << "\n";
+
+        u_e.resize( ni );
+        u.resize( ni );
+        un.resize( ni );
+
+        for ( int i = 0; i < ni; ++ i )
+        {
+            u_e[ i ] = - std::exp( -t ) * std::sin( std::numbers::pi * x[i] ); //theory solution
+            un[ i ] = - std::sin( std::numbers::pi * x[ i ] ); //initial condition @ t=0
+        }
+        un[ 0 ] = 0.0;
+        un[ ni - 1 ] = 0.0;
+
+        double alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+        double beta = alpha * dt / ( dx * dx );
+        std::cout << "alpha = " << std::setprecision(15) << alpha << "\n";
+        std::cout << "beta = " << std::setprecision(15) << beta << "\n";
+
+        for ( int it = 0; it < nt; ++ it )
+        {
+            for ( int i = 1; i < ni - 1; ++ i )
+            {
+                u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+            }
+            //boundary
+            u[ 0 ] = 0.0; // boundary condition at x = -1
+            u[ ni - 1 ] = 0.0; // boundary condition at x = 1
+            this->update( un, u );
+        }
+
+        //compute L2 norm of the error
+        std::vector<double> u_error( ni );
+        //icount = 0;
+        for ( int i = 0; i < ni; ++ i )
+        {
+            u_error[ i ] = un[ i ] - u_e[ i ];
+        }
+
+        double rms_error = compute_l2norm( ni, u_error );
+        double max_error = compute_max_error( ni, u_error );
+        std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+        //create output file for L2-norm
+        std::fstream file;
+        file.open("output.txt", std::fstream::out);
+        std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+        std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+        std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+        file.close();
+        int kkk = 1;
+    }
+
+    void update( std::vector<double> &un, std::vector<double> &u )
+    {
+        for ( int i = 0; i < u.size(); ++ i )
+        {
+            un[ i ] = u[ i ];
+        }
+    }
+
+    double compute_l2norm( int ni, std::vector<double> & r )
+    {
+        double rms = 0.0;
+        for ( int i = 1; i < ni - 1; ++ i )
+        {
+            rms += r[ i ] * r[ i ];
+        }
+        rms = std::sqrt( rms / ( ni - 2 ) );
+        return rms;
+    }
+
+    double compute_max_error( int ni, std::vector<double> & u_error )
+    {
+        double val_max = -1;
+        int ipos = -1;
+        for ( int i = 1; i < ni - 1; ++ i )
+        {
+            //val_max = std::max( val_max, std::abs( u_error[ i ] ) );
+            if ( val_max < std::abs( u_error[ i ] ) )
+            {
+                ipos = i;
+                val_max = std::abs( u_error[ i ] );
+            }
+        }
+        std::cout << " ipos = " << ipos << "\n";
+        return val_max;
+    }
+};
+
+void ReadCgnsGrid( const std::string & filename, Grid * grid )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones(fileId, baseId, &nzones);
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize(index_dim*3);
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[33];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                //std::vector<double> coord( nNodes );
+                std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coord.data() );
+                double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+                for ( int i = 0; i < nNodes; ++ i )
+                {
+                    //std::cout << xd[i] << " ";
+                    grid->x[ i ] = xd[ i ];
+                    //if( (i+1)%5 == 0 ) std::cout << "\n";
+                }
+                //std::cout << "\n";
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex(index_dim,-1);
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type, 
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset);
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[i] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[normalDataType] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList(nNodes*iphysdim*sizeof(double));
+
+                std::vector<cgsize_t> pnts(npnts*index_dim);
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double*>(const_cast<char *>(normalList.data()));
+            }
+        }
+    }
+    cg_close(fileId);
+}
+
+int main(int argc, char **argv)
+{
+    Solver solver;
+    solver.solve();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/compare/01b/CMakeLists.txt b/example/1d-heat-equation/ftcs/cpp/single_block/compare/01b/CMakeLists.txt
new file mode 100644
index 00000000..bfdbab14
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/compare/01b/CMakeLists.txt
@@ -0,0 +1,75 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/compare/01b/README.txt b/example/1d-heat-equation/ftcs/cpp/single_block/compare/01b/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/compare/01b/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/compare/01b/heat1d1blocksv1.cgns b/example/1d-heat-equation/ftcs/cpp/single_block/compare/01b/heat1d1blocksv1.cgns
new file mode 100644
index 00000000..a367704f
Binary files /dev/null and b/example/1d-heat-equation/ftcs/cpp/single_block/compare/01b/heat1d1blocksv1.cgns differ
diff --git a/example/1d-heat-equation/ftcs/cpp/single_block/compare/01b/main.cpp b/example/1d-heat-equation/ftcs/cpp/single_block/compare/01b/main.cpp
new file mode 100644
index 00000000..25ce7e72
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/cpp/single_block/compare/01b/main.cpp
@@ -0,0 +1,273 @@
+#include "cgnslib.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip> 
+
+class Grid;
+void ReadCgnsGrid( const std::string & filename, Grid * grid );
+
+class Grid
+{
+public:
+    std::vector<double> x;
+};
+
+class Solver
+{
+public:
+    std::vector<double> u_e;
+    std::vector<double> u,un;
+    std::vector<double> error;
+public:
+    void solve()
+    {
+        std::cout << "solve()\n";
+        Grid grid;
+        ReadCgnsGrid( "../heat1d1blocksv1.cgns", &grid );
+        int ni = grid.x.size();
+        std::cout << "ni = " << ni << "\n";
+
+        std::vector<double> & x = grid.x;
+        double dx = x[ 1 ] - x[ 0 ];
+        //double dt = 0.0025;
+        double dt = dx / 10.0;
+        double t = 1.0;
+        int nt = std::round( t / dt );
+        //int nt = 1;
+
+        double total_time = nt * dt;
+
+        std::cout << "dt = " << dt << "\n";
+        std::cout << "t = " << t << "\n";
+        std::cout << "nt = " << nt << "\n";
+        std::cout << "ni = " << ni << "\n";
+        std::cout << "total_time = " << total_time << "\n";
+
+        u_e.resize( ni );
+        u.resize( ni );
+        un.resize( ni );
+
+        for ( int i = 0; i < ni; ++ i )
+        {
+            //u_e[ i ] = - std::exp( -t ) * std::sin( std::numbers::pi * x[i] ); //theory solution
+            u_e[ i ] = - std::exp( -total_time ) * std::sin( std::numbers::pi * x[i] ); //theory solution
+            un[ i ] = - std::sin( std::numbers::pi * x[ i ] ); //initial condition @ t=0
+        }
+        un[ 0 ] = 0.0;
+        un[ ni - 1 ] = 0.0;
+
+        double alpha = 1 / ( std::numbers::pi * std::numbers::pi );
+        double beta = alpha * dt / ( dx * dx );
+        std::cout << "alpha = " << std::setprecision(15) << alpha << "\n";
+        std::cout << "beta = " << std::setprecision(15) << beta << "\n";
+
+        for ( int it = 0; it < nt; ++ it )
+        {
+            for ( int i = 1; i < ni - 1; ++ i )
+            {
+                u[ i ] = un[ i ] + beta * ( un[ i + 1 ] - 2.0 * un[ i ] + un[ i - 1 ] );
+            }
+            //boundary
+            u[ 0 ] = 0.0; // boundary condition at x = -1
+            u[ ni - 1 ] = 0.0; // boundary condition at x = 1
+            this->update( un, u );
+        }
+
+        //compute L2 norm of the error
+        std::vector<double> u_error( ni );
+        //icount = 0;
+        for ( int i = 0; i < ni; ++ i )
+        {
+            u_error[ i ] = un[ i ] - u_e[ i ];
+        }
+
+        double rms_error = compute_l2norm( ni, u_error );
+        double max_error = compute_max_error( ni, u_error );
+        std::cout << "max_error = " << std::setprecision(15) << max_error << "\n";
+        //create output file for L2-norm
+        std::fstream file;
+        file.open("output.txt", std::fstream::out);
+        std::format_to(std::ostream_iterator<char>(file), "Error details: \n");
+        std::format_to(std::ostream_iterator<char>(file), "L-2 Norm = {0}\n", rms_error);
+        std::format_to(std::ostream_iterator<char>(file), "Maximum Norm = {0}\n", max_error);
+        file.close();
+        int kkk = 1;
+    }
+
+    void update( std::vector<double> &un, std::vector<double> &u )
+    {
+        for ( int i = 0; i < u.size(); ++ i )
+        {
+            un[ i ] = u[ i ];
+        }
+    }
+
+    double compute_l2norm( int ni, std::vector<double> & r )
+    {
+        double rms = 0.0;
+        for ( int i = 1; i < ni - 1; ++ i )
+        {
+            rms += r[ i ] * r[ i ];
+        }
+        rms = std::sqrt( rms / ( ni - 2 ) );
+        return rms;
+    }
+
+    double compute_max_error( int ni, std::vector<double> & u_error )
+    {
+        double val_max = -1;
+        int ipos = -1;
+        for ( int i = 1; i < ni - 1; ++ i )
+        {
+            //val_max = std::max( val_max, std::abs( u_error[ i ] ) );
+            if ( val_max < std::abs( u_error[ i ] ) )
+            {
+                ipos = i;
+                val_max = std::abs( u_error[ i ] );
+            }
+        }
+        std::cout << " ipos = " << ipos << "\n";
+        return val_max;
+    }
+};
+
+void ReadCgnsGrid( const std::string & filename, Grid * grid )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones(fileId, baseId, &nzones);
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize(index_dim*3);
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[33];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                //std::vector<double> coord( nNodes );
+                std::vector<char> coord( nNodes * sizeof(double) );
+                grid->x.resize( nNodes );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coord.data() );
+                double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+                for ( int i = 0; i < nNodes; ++ i )
+                {
+                    //std::cout << xd[i] << " ";
+                    grid->x[ i ] = xd[ i ];
+                    //if( (i+1)%5 == 0 ) std::cout << "\n";
+                }
+                //std::cout << "\n";
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex(index_dim,-1);
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type, 
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset);
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[i] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[normalDataType] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList(nNodes*iphysdim*sizeof(double));
+
+                std::vector<cgsize_t> pnts(npnts*index_dim);
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double*>(const_cast<char *>(normalList.data()));
+            }
+        }
+    }
+    cg_close(fileId);
+}
+
+int main(int argc, char **argv)
+{
+    Solver solver;
+    solver.solve();
+    return 0;
+}
diff --git a/example/1d-heat-equation/ftcs/fft.ipynb b/example/1d-heat-equation/ftcs/python/fft.ipynb
similarity index 100%
rename from example/1d-heat-equation/ftcs/fft.ipynb
rename to example/1d-heat-equation/ftcs/python/fft.ipynb
diff --git a/example/1d-heat-equation/ftcs/ftcs.py b/example/1d-heat-equation/ftcs/python/ftcs.py
similarity index 65%
rename from example/1d-heat-equation/ftcs/ftcs.py
rename to example/1d-heat-equation/ftcs/python/ftcs.py
index f9b80031..10819ad7 100644
--- a/example/1d-heat-equation/ftcs/ftcs.py
+++ b/example/1d-heat-equation/ftcs/python/ftcs.py
@@ -10,6 +10,16 @@ def compute_l2norm(nx,r):
         rms += r[i] * r[i]
     rms = np.sqrt( rms / ( ( nx - 1 ) ) )
     return rms
+    
+def compute_max_error( nx, u_error ):
+    val_max = -1;
+    ipos = -1;
+    for i in range(1, nx):
+        if ( val_max < np.abs( u_error[ i ] ) ):
+            ipos = i;
+            val_max = np.abs( u_error[ i ] )
+    print( " ipos = ", ipos )
+    return val_max;
 
 x_l = -1.0
 x_r = 1.0
@@ -21,6 +31,7 @@ def compute_l2norm(nx,r):
 dt = 0.0025
 t  = 1.0
 nt = int( t / dt )
+#nt = 1
 print( " nt = ", nt )
 
 alpha = 1 / ( np.pi**2 )
@@ -39,16 +50,57 @@ def compute_l2norm(nx,r):
 un[0,0 ] = 0.0
 un[0,nx] = 0.0
 
+icount = 0
+for i in range(0, nx+1):
+    print("{0:.15f}".format(un[0,i]), end = " ")
+    icount += 1
+    if( icount % 5 == 0 ):
+        print("")
+print()
+print()
+
 beta = alpha * dt / ( dx**2 )
 
+print(" alpha ={0:.15f}".format(alpha))
+print(" beta ={0:.15f}".format(beta))
+
 for k in range(1, nt+1):
     for i in range(1, nx):
         un[k,i] = un[k-1,i] + beta * ( un[k-1,i+1] - 2.0 * un[k-1,i] + un[k-1,i-1] )
     un[k,0 ] = 0.0 # boundary condition at x = -1
     un[k,nx] = 0.0 # boundary condition at x = 1
+    
+icount = 0
+for i in range(0, nx+1):
+    print("{0:.15f}".format(un[1,i]), end = " ")
+    icount += 1
+    if( icount % 5 == 0 ):
+        print("")
+print()
+print()    
 
 # compute L2 norm of the error
 u_error = un[nt,:] - u_e
+icount = 0
+for i in range(0, nx+1):
+    print("{0:.15f}".format(u_error[i]), end = " ")
+    #print(u_error[i], " ")
+    icount += 1
+    if( icount % 5 == 0 ):
+        print("")
+print()
+print()
+
+icount = 0
+for i in range(0, nx+1):
+    print("{0:.15f}".format(u_e[i]), end = " ")
+    icount += 1
+    if( icount % 5 == 0 ):
+        print("")     
+
+my_max_error = compute_max_error( nx, u_error )
+print("my_max_error = {0:.15f}".format(my_max_error))
+
 rms_error = compute_l2norm(nx,u_error)
 max_error = np.max( np.abs(u_error) )
 
@@ -77,4 +129,4 @@ def compute_l2norm(nx,r):
 plt.tight_layout()
 plt.ticklabel_format(axis='y', style='sci', scilimits=(-4,-4))
 
-plt.show();
\ No newline at end of file
+plt.show();
diff --git a/example/1d-heat-equation/ftcs/python/output.txt b/example/1d-heat-equation/ftcs/python/output.txt
new file mode 100644
index 00000000..77c008ea
--- /dev/null
+++ b/example/1d-heat-equation/ftcs/python/output.txt
@@ -0,0 +1,3 @@
+Error details: 
+L-2 Norm = 0.00019281858911820367
+Maximum Norm = 0.0002709770126991251
diff --git a/example/1d-heat-equation/grid/01/CMakeLists.txt b/example/1d-heat-equation/grid/01/CMakeLists.txt
new file mode 100644
index 00000000..ec3f9fb1
--- /dev/null
+++ b/example/1d-heat-equation/grid/01/CMakeLists.txt
@@ -0,0 +1,70 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+#list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_14 )
+
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/1d-heat-equation/grid/01/main.cpp b/example/1d-heat-equation/grid/01/main.cpp
new file mode 100644
index 00000000..f5f778be
--- /dev/null
+++ b/example/1d-heat-equation/grid/01/main.cpp
@@ -0,0 +1,78 @@
+#include "cgnslib.h"
+#include <iostream>
+#include <vector>
+
+void write_grid_str();
+//void write_con2zn_str();
+
+void write_grid_str()
+{
+    const int ni = 101;
+    double x[ni];
+    cgsize_t isize[9];
+    int index_file,icelldim,iphysdim,index_base;
+    int index_zone,index_coord;
+    char basename[33],zonename[33];
+    cgsize_t ipnts[ 2 ];
+    int ilo,ihi;
+
+    double x_l = -1.0;
+    double x_r = 1.0;
+
+    double dx = ( x_r - x_l ) / ( ni - 1 );
+
+    /* create gridpoints for simple example: */
+    for ( int i = 0; i < ni; ++ i )
+    {
+        x[ i ] = x_l + i * dx;
+    }
+
+    if (cg_open("heat1d.cgns",CG_MODE_WRITE,&index_file)) cg_error_exit();
+
+    strcpy(basename,"Base");
+    icelldim=1;
+    iphysdim=3;
+    cg_base_write(index_file,basename,icelldim,iphysdim,&index_base);
+    /*  vertex size */
+    isize[0]=ni;
+    /*  cell size */
+    isize[1]=ni-1;
+    /*  boundary vertex size (always zero for structured grids) */
+    isize[2]=0;
+    isize[3]=0;
+    isize[4]=0;
+    isize[5]=0;
+    isize[6]=0;
+    isize[7]=0;
+    isize[8]=0;
+
+    ilo=1;
+    ihi=isize[0];
+    strcpy(zonename,"Zone 1");
+    cg_zone_write(index_file,index_base,zonename,isize,CGNS_ENUMV(Structured),&index_zone);
+    cg_coord_write(index_file,index_base,index_zone,CGNS_ENUMV(RealDouble),"x",x,&index_coord);
+
+    /* lower point of range */
+    ipnts[0]=ilo;
+    /* upper point of range */
+    ipnts[1]=ilo;
+
+    int index_bc = -1;
+    cg_boco_write(index_file,index_base,index_zone,"L",CGNS_ENUMV(BCInflow),CGNS_ENUMV(PointRange),2,ipnts,&index_bc);
+
+    /* lower point of range */
+    ipnts[0]=ihi;
+    /* upper point of range */
+    ipnts[1]=ihi;
+
+    cg_boco_write(index_file,index_base,index_zone,"R",CGNS_ENUMV(BCOutflow),CGNS_ENUMV(PointRange),2,ipnts,&index_bc);
+
+    cg_close(index_file);
+}
+
+int main(int argc, char **argv)
+{
+    write_grid_str();
+    return 0;
+}
+
diff --git a/example/partition/struct/1d/01/CMakeLists.txt b/example/partition/struct/1d/01/CMakeLists.txt
new file mode 100644
index 00000000..9fa577c8
--- /dev/null
+++ b/example/partition/struct/1d/01/CMakeLists.txt
@@ -0,0 +1,77 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	Partition.h Partition.cpp
+	CgnsGrid.h CgnsGrid.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/partition/struct/1d/01/CgnsGrid.cpp b/example/partition/struct/1d/01/CgnsGrid.cpp
new file mode 100644
index 00000000..055545c4
--- /dev/null
+++ b/example/partition/struct/1d/01/CgnsGrid.cpp
@@ -0,0 +1,217 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+Grid::Grid()
+{
+    ;
+}
+
+Grid::~Grid()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if( (i+1)%5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+std::vector<Zone *> Global::zones;
+
+Global::Global()
+{
+    ;
+}
+
+Global::~Global()
+{
+}
+
+void Global::FreeData()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+    zones.resize( 0 );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones(fileId, baseId, &nzones);
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize(index_dim*3);
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[33];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                std::vector<char> coord( nNodes * sizeof(double) );
+                //grid->x.resize( nNodes );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+                coor->DumpCoor();
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex(index_dim,-1);
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type, 
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset);
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[i] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[normalDataType] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList(nNodes*iphysdim*sizeof(double));
+
+                std::vector<cgsize_t> pnts(npnts*index_dim);
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double*>(const_cast<char *>(normalList.data()));
+
+                //std::cout << "normalList = ";
+                //for ( int i = 0; i < nNodes*iphysdim; ++ i )
+                //{
+                //    std::cout << normal_d[ i ] << " ";
+                //}
+                //std::cout << "\n";
+            }
+        }
+    }
+    cg_close(fileId);
+}
\ No newline at end of file
diff --git a/example/partition/struct/1d/01/CgnsGrid.h b/example/partition/struct/1d/01/CgnsGrid.h
new file mode 100644
index 00000000..72c47bb8
--- /dev/null
+++ b/example/partition/struct/1d/01/CgnsGrid.h
@@ -0,0 +1,62 @@
+#pragma once
+#include <iostream>
+#include <vector>
+
+class Grid;
+
+class Zone;
+
+class Grid
+{
+public:
+    Grid();
+    ~Grid();
+public:
+    int nZone;
+    std::vector<double> x;
+    std::vector<Zone *> zones;
+};
+
+class ZoneBc;
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+};
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<Coor *> coors;
+};
+
+class ZoneBc
+{
+public:
+};
+
+class Global
+{
+public:
+    Global();
+    ~Global();
+public:
+    static std::vector<Zone *> zones;
+    static void FreeData();
+};
+
+void ReadCgnsGrid( const std::string & filename );
diff --git a/example/partition/struct/1d/01/Partition.cpp b/example/partition/struct/1d/01/Partition.cpp
new file mode 100644
index 00000000..2977d8a1
--- /dev/null
+++ b/example/partition/struct/1d/01/Partition.cpp
@@ -0,0 +1,636 @@
+#include "Partition.h"
+#include "CgnsGrid.h"
+#include "cgnslib.h"
+#include <string>
+
+DimInfo::DimInfo()
+{
+    this->dim = 1;
+    dimList.resize( this->dim, 1 );
+    oriPoint.resize( this->dim, 0 );
+}
+
+DimInfo::~DimInfo()
+{
+}
+
+DimInfo & DimInfo::operator = ( const DimInfo & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->dim = rhs.dim;
+    this->dimList = rhs.dimList;
+    this->oriPoint = rhs.oriPoint;
+
+    return * this;
+}
+
+void DimInfo::Init( std::vector<int> & dimList )
+{
+    this->dimList = dimList;
+    std::vector<int> zero( dimList.size(), 0 );
+    this->oriPoint = zero;
+}
+
+void DimInfo::SetNewDimension( int axis, int newStart, int newWidth )
+{
+    this->oriPoint[ axis ] = newStart;
+    this->dimList [ axis ] = newWidth;
+}
+
+SplitZone::SplitZone()
+{
+    ;
+}
+
+SplitZone::~SplitZone()
+{
+    ;
+}
+
+int SplitZone::GetNCell()
+{
+    int numberOfCells = 1;
+    for ( int i = 0; i < this->dimInfo.dim; ++ i )
+    {
+        numberOfCells *= std::max( 1, ( this->dimInfo.dimList[ i ] - 1 ) );
+    }
+
+    return numberOfCells; 
+}
+
+void SplitZone::SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int leftStart = 0;
+    int leftWidth = iSplit - 0;
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, leftStart , leftWidth  );
+}
+
+void SplitZone::SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int rightStart = iSplit - 1;
+    int rightWidth = dimList[ axisNeedSplit ] - ( iSplit - 1 );
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, rightStart, rightWidth );
+}
+
+void SplitZone::Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell )
+{
+    //Find the longest axis
+    int axisNeedSplit = this->FindAxisNeedSplit();
+    int iSplit        = this->FindSplitPosition( axisNeedSplit, nCell );
+
+    zoneL = new SplitZone();
+    zoneL->SetParent( this );
+
+    zoneR = new SplitZone();
+    zoneR->SetParent( this );
+
+    zoneL->SetLeftDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+    zoneR->SetRightDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+
+    //zoneL->CreateBc();
+    //zoneR->CreateBc();
+
+    //CreateInterfaceBc( zoneL, zoneR );
+}
+
+int SplitZone::FindAxisNeedSplit()
+{
+    //Find the longest axis
+    int axisNeedSplit = 0;
+    int maxN = this->dimInfo.dimList[ 0 ];
+
+    for ( int m = 1; m < this->dimInfo.dimList.size(); ++ m )
+    {
+        if ( this->IsPoleBc( m ) )
+        {
+            continue;
+        }
+        int Nm = this->dimInfo.dimList[ m ];
+        if ( maxN < Nm )
+        {
+            maxN = Nm;
+            axisNeedSplit = m;
+        }
+    }
+
+    return axisNeedSplit;
+}
+
+int SplitZone::GetCrossSection( int axis )
+{
+    int nDim = this->dimInfo.dimList.size();
+    int crossSection = 1;
+    int N = nDim - 1;
+    for ( int m = 0; m < N; ++ m )
+    {
+         int mm = ( axis + 1 ) % nDim;
+         int nLineElements = std::max( 1, ( this->dimInfo.dimList[ mm ] - 1 ) );
+         crossSection *= nLineElements;
+    }
+    return crossSection;
+}
+
+int SplitZone::FindSplitPosition( int axisNeedSplit, double nCell )
+{
+    int nDim = this->dimInfo.dimList.size();
+    std::vector<int> crossSections( nDim );
+    for ( int m = 0; m < nDim; ++ m )
+    {
+        crossSections[ m ] = this->GetCrossSection( m );
+    }
+
+    //guess the value
+    double dSplit = nCell / crossSections[ axisNeedSplit ];
+    int  iSplit = 1 + static_cast< int >( std::floor( dSplit + 0.5 ) );
+    return iSplit;
+}
+
+
+bool SplitZone::IsPoleBc( int splitDirection )
+{
+    return false;
+}
+
+
+double CalSumOfProcSpeed( std::vector<double> & procSpeed );
+double CalSumOfProcSpeed( std::vector<double> & procSpeed )
+{
+    int nProc = procSpeed.size();
+    double sumOfProcSpeed = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        sumOfProcSpeed += procSpeed[ iProc ];
+    }
+    return sumOfProcSpeed;
+}
+
+Partition::Partition()
+{
+    ;
+}
+
+Partition::~Partition()
+{
+    ;
+}
+
+int Partition::GetMinValueIndex( double * data, int numberOfData )
+{
+    double minValue = data[ 0 ];
+    int minimumValueIndex = 0;
+
+    for ( int iData = 1; iData < numberOfData; ++ iData )
+    {
+        if ( minValue > data[ iData ] )
+        {
+            minValue      = data[ iData ];
+            minimumValueIndex = iData;
+        }
+    }
+    return minimumValueIndex;
+}
+
+int Partition::GetMinLoadProc()
+{
+    return this->GetMinValueIndex( this->timeProc.data(), this->nProc );
+}
+
+SplitZone * Partition::GetLargestZone()
+{
+    SplitZone * largestZone = 0;
+
+    double nMaxCell = 0.0;
+
+    for ( std::set< SplitZone * >::iterator iter = unsignedZoneGroup.begin(); iter != unsignedZoneGroup.end(); ++ iter )
+    {
+        double nSize = ( * iter )->GetNCell();
+        if ( nMaxCell < nSize )
+        {
+            nMaxCell    = nSize;
+            largestZone = * iter;
+        }
+    }
+
+    return largestZone;
+}
+
+void Partition::Solve()
+{
+    std::cout << "Partition::Split()\n";
+    this->nProc = 2;
+    this->ReadGrid();
+    this->Split();
+    this->DumpPartitionedGridFile();
+    this->FreeAllZones();
+}
+
+void Partition::ReadGrid()
+{
+    ReadCgnsGrid( "../heat1dni81.cgns" );
+
+    this->nOriZone = ::Global::zones.size();
+
+    std::cout << "numberOfBlocks = " << nOriZone << "\n";
+
+    this->refZone.resize( nOriZone );
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        refZone[ iZone ] = new SplitZone();
+        refZone[ iZone ]->SetZoneIndex( iZone );
+        refZone[ iZone ]->oriZoneId = iZone;
+        refZone[ iZone ]->SetProcId( 0 );
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        Zone * zone = ::Global::zones[ iZone ];
+
+        splitZone->dimInfo.dimList = zone->nijk;
+
+        int nBcRegion = zone->bccos.size();
+        std::cout << "nBcRegion = " << nBcRegion << "\n";
+
+        //HXVector< ZoneBc * > & bcList = splitZone->GetZoneBcList();
+        //bcList.resize( nBcRegion );
+
+        for ( int iBcRegion = 0; iBcRegion < nBcRegion; ++ iBcRegion )
+        {
+        }
+
+        //splitZone->NormalizeBc();
+    }
+}
+
+void Partition::Split()
+{
+    this->InitSplit();
+    this->BinarySplit();
+    //this->SetZoneIndex();
+}
+
+void Partition::InitSplit()
+{
+    //nZone is the number of zones in the original grid
+    //nProc is not the number of blocks in the end, but the number of processes that need to be divided.
+    //This difference occurs because the structure grid can have many blocks per process.
+
+    //this->nProc    = nProc;
+    //this->nPhyBlocks = referenceBlock.size();
+    //this->nZone  = this->nPhyBlocks;
+
+    //tj Computation time on processor j
+    //Nk Number of internal grid-cells for zone j
+    //aveFloatOp:  Number of Real operations per gridcell
+    //Gj The set of blocks allocated to process j
+    //Pj Real operations per second for process j
+
+    //The Greedy Load Balancing Algorithm
+    //1.Compute an "ideal" uniprocessor time, Tuni = sum ( Nk * aveFloatOp )/ sum( Pj ).
+    //2.Set the group of unassigned blocks, Gu, to contain all blocks. The number of blocks in Nu=M, where M is the total number of blocks in the mesh.
+    //3.Start all processors with a very small fictitious zone to get a start tj=delt aveFloatOp/Pj, where delt<<1 is the size of the very small fictious zone.
+    //This is used to find the fastest processor in a heterogeneous system, tj could otherwise be set to 0 in the homogeneous case.
+    this->aveFloatOp = 1.0;
+    this->delta      = 1.0e-5;
+    this->procSpeed.resize( nProc );
+    this->timeProc.resize( nProc );
+
+    this->nTZone = this->nOriZone;
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        procSpeed[ iProc ] = 1.0;
+    }
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        timeProc[ iProc ] = delta * aveFloatOp / procSpeed[ iProc ];
+    }
+
+    double sumProcSpeed = CalSumOfProcSpeed( procSpeed );
+
+    double sumProcOp = 0.0;
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        sumProcOp += refZone[ iZone ]->GetNCell() * aveFloatOp;
+    }
+
+    this->idealUniProcTime = sumProcOp / sumProcSpeed;
+
+    this->eps = 0.05;
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        unsignedZoneGroup.insert( refZone[ iZone ] );
+    }
+
+    //Init zoneStorage
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        zoneStorage.insert( refZone[ iZone ] );
+    }
+
+    //Assign procSplitZone to each process
+    procSplitZone.resize( nProc );
+
+    this->minNode = 3 * 3 * 2;
+}
+
+void Partition::FreeAllZones()
+{
+    int iCount = 0;
+    for ( std::set < SplitZone * >::iterator iter = zoneStorage.begin(); iter != zoneStorage.end(); ++ iter )
+    {
+        //cout << "iCount = " << iCount << "\n";
+        ++ iCount;
+        delete * iter;
+    }
+}
+
+int Partition::GetNZones( int iProc )
+{
+    return this->procSplitZone[ iProc ].size();
+}
+
+SplitZone * Partition::GetSplitZone( int iProc, int zoneId )
+{
+    return this->procSplitZone[ iProc ][ zoneId ];
+}
+
+void Partition::AddZoneToUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.insert( zone );
+}
+
+void Partition::RemoveZoneFromUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.erase( zone );
+}
+
+void Partition::AddZoneToProcess( int iProc, SplitZone * zone )
+{
+    this->procSplitZone[ iProc ].push_back( zone );
+}
+
+void Partition::AddNewZone( SplitZone * zone )
+{
+    zone->SetZoneIndex( nTZone ++ );
+
+    this->AddZoneToUnsignedGroup( zone );
+
+    this->zoneStorage.insert( zone );
+}
+
+SplitZone * Partition::Split( SplitZone * zone, double nCell )
+{
+    SplitZone * zoneL = 0;
+    SplitZone * zoneR = 0;
+
+    zone->Split( zoneL, zoneR, nCell );
+
+    this->AddNewZone( zoneL );
+    this->AddNewZone( zoneR );
+    this->RemoveZoneFromUnsignedGroup( zone );
+
+    return zoneL;
+}
+
+void Partition::BinarySplit()
+{
+    while ( ! unsignedZoneGroup.empty() )
+    {
+        std::cout << "number of unsigned zone = " << unsignedZoneGroup.size() << "\n";
+        int iProc = this->GetMinLoadProc();
+
+        //Get the block with the largest number of grids and its size
+        SplitZone * largestZone = this->GetLargestZone();
+
+        double nMaxCell = largestZone->GetNCell();
+
+        double aveFloatOp = this->aveFloatOp;
+        double tau = timeProc[ iProc ] + nMaxCell * aveFloatOp / procSpeed[ iProc ];
+
+        int kkk = 1;
+
+        //It seems that EPS is still necessary
+        //The idea here is as follows. For the candidate blocks which can be divided into blocks, 
+        //if the difference between the target blocks and the candidate blocks is too wide, 
+        //the binarySplit method is adopted. The binarySplit blocks do not directly join the process,
+        //but enter the next round of screening.
+
+        if ( tau > idealUniProcTime * ( 1.0 + eps ) )
+        {
+            double nRest = ( tau - idealUniProcTime ) * procSpeed[ iProc ] / aveFloatOp;
+
+            double nTarget = nMaxCell - nRest;
+            if ( nRest > this->minNode && nTarget > this->minNode )
+            {
+                //It is necessary to divide blocks only when a certain number of points are satisfied.
+                double nHalf = nMaxCell / 2.0;
+                nMaxCell = nTarget;
+                double ratio = nMaxCell / nRest;
+                double oRatio = 1.0 / ratio;
+
+                if ( std::max( ratio, oRatio ) < 3.0 )
+                {
+                    int kkk = 1;
+                    largestZone = this->Split( largestZone, nMaxCell );
+                    timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                    this->RemoveZoneFromUnsignedGroup( largestZone );
+                    this->AddZoneToProcess( iProc, largestZone );
+                }
+                else
+                {
+                    this->Split( largestZone, nHalf );
+                }
+            }
+            else
+            {
+                //If the block is of the right size, join the process directly, and there is no need to split it.
+                timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                this->RemoveZoneFromUnsignedGroup( largestZone );
+                this->AddZoneToProcess( iProc, largestZone );
+            }
+        }
+        else
+        {
+            //If the block is of the right size, join the process directly, and there is no need to split it.
+            timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+            this->RemoveZoneFromUnsignedGroup( largestZone );
+            this->AddZoneToProcess( iProc, largestZone );
+        }
+    }
+}
+
+void Partition::DumpPartitionedGridFile()
+{
+    int fileId = -1;
+    std::string filename = "split1d.cgns";
+    cg_open( filename.c_str(), CG_MODE_WRITE, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        int icelldim = 1;
+        int iphysdim = 1;
+        std::string basename = "Base" + std::to_string( iProc );
+
+        int baseId = -1;
+        cg_base_write( fileId, basename.c_str(), icelldim, iphysdim, &baseId );
+
+        std::cout << "baseId = " << baseId << "\n";
+
+        int nZones = this->GetNZones( iProc );
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            ZoneType_t zoneType = Structured;
+
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+
+            int index_dim = splitZone->dimInfo.dimList.size();
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3, 0 );
+            for ( int i = 0; i < index_dim; ++ i )
+            {
+                isize[ i ] = splitZone->dimInfo.dimList[ i ];
+            }
+            for ( int i = 0; i < index_dim; ++ i )
+            {
+                int ii = index_dim * 1;
+                isize[ ii + i ] = splitZone->dimInfo.dimList[ i ] - 1;
+            }
+            for ( int i = 0; i < index_dim; ++ i )
+            {
+                int ii = index_dim * 2;
+                isize[ ii + i ] = 0;
+            }
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            int zoneId = -1;
+
+            std::string zonename = "B" + std::to_string( iProc ) + "Zone" + std::to_string( iZone );
+            cg_zone_write( fileId, baseId, zonename.c_str(), isize.data(), zoneType, &zoneId );
+
+            std::cout << "zoneId = " << zoneId << "\n";
+                
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            int ncoords = 1;
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType = RealDouble;
+                std::string coordname = "X";
+                //cg_coord_write( fileId, baseId, zoneId, dataType, coordname.c_str(), const void * coord_ptr, &coorId );
+                //    
+                //    
+
+                //
+                //char coordname[33];
+                //cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                //std::cout << "coordname = " << coordname << "\n";
+                //std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                ////std::vector<double> coord( nNodes );
+                //std::vector<char> coord( nNodes * sizeof(double) );
+                //grid->x.resize( nNodes );
+
+                //cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coord.data() );
+                //double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+                //for ( int i = 0; i < nNodes; ++ i )
+                //{
+                //    //std::cout << coord[i] << " ";
+                //    std::cout << xd[i] << " ";
+                //    grid->x[ i ] = xd[ i ];
+                //    if( (i+1)%5 == 0 ) std::cout << "\n";
+                //}
+                //std::cout << "\n";
+            }
+
+            //int nbocos = -1;
+
+            //cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            //std::cout << "nbocos = " << nbocos << "\n";
+            //for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            //{
+            //    int bccoId = iboco + 1;
+            //    GridLocation_t location;
+            //    cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+            //    std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+            //    ZoneBc * zonebc = new ZoneBc();
+            //    zone->bccos.push_back( zonebc );
+
+            //    char boconame[ 33 ];
+            //    BCType_t bocotype;
+            //    PointSetType_t ptset_type;
+            //    cgsize_t npnts = 0;
+            //    std::vector<int> normalIndex(index_dim,-1);
+            //    cgsize_t normalListSize = 0;
+            //    DataType_t normalDataType;
+            //    int ndataset = -1;
+
+            //    cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type, 
+            //        &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset);
+            //    std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+            //    std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+            //    std::cout << "npnts = " << npnts << "\n";
+            //    std::cout << "normalIndex = ";
+            //    for ( int i = 0; i < index_dim; ++ i )
+            //    {
+            //        std::cout << normalIndex[i] << " ";
+            //    }
+            //    std::cout << "\n";
+            //    std::cout << "normalListSize = " << normalListSize << "\n";
+            //    std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[normalDataType] << "\n";
+            //    std::cout << "ndataset = " << ndataset << "\n";
+
+            //    std::vector<char> normalList(nNodes*iphysdim*sizeof(double));
+
+            //    std::vector<cgsize_t> pnts(npnts*index_dim);
+            //    cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+            //    std::cout << "pnts = ";
+            //    for ( int i = 0; i < pnts.size(); ++ i )
+            //    {
+            //        std::cout << pnts[ i ] << " ";
+            //    }
+            //    std::cout << "\n";
+
+            //    double * normal_d = reinterpret_cast<double*>(const_cast<char *>(normalList.data()));
+
+            //    //std::cout << "normalList = ";
+            //    //for ( int i = 0; i < nNodes*iphysdim; ++ i )
+            //    //{
+            //    //    std::cout << normal_d[ i ] << " ";
+            //    //}
+            //    //std::cout << "\n";
+            //}
+        }
+    }
+    cg_close(fileId);
+}
\ No newline at end of file
diff --git a/example/partition/struct/1d/01/Partition.h b/example/partition/struct/1d/01/Partition.h
new file mode 100644
index 00000000..c15e8bf5
--- /dev/null
+++ b/example/partition/struct/1d/01/Partition.h
@@ -0,0 +1,93 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class SplitZone;
+
+class DimInfo
+{
+public:
+    DimInfo();
+    ~DimInfo();
+public:
+    int dim;
+    std::vector<int> dimList;
+    std::vector<int> oriPoint;
+public:
+    int GetSize() const { return dim; }
+    DimInfo & operator = ( const DimInfo & rhs );
+public:
+    void Init( std::vector<int> & dimList );
+    void SetNewDimension( int axis, int newStart, int newWidth );
+};
+
+class SplitZone
+{
+public:
+    SplitZone();
+    ~SplitZone();
+public:
+    DimInfo dimInfo;
+    int zoneIndex, iProc;
+    int oriZoneId;
+protected:
+    SplitZone * parent;
+public:
+    int GetNCell();
+    void SetZoneIndex( int zoneIndex ) { this->zoneIndex = zoneIndex; }
+    int  GetZoneIndex() { return zoneIndex; }
+    void SetProcId( int iProc ) { this->iProc = iProc; }
+    void SetParent( SplitZone * parent ) { this->parent = parent; };
+public:
+    void Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell );
+    void SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+    void SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+private:
+    int FindAxisNeedSplit();
+    int FindSplitPosition( int axisNeedSplit, double nCell );
+    bool IsPoleBc( int splitDirection );
+    int GetCrossSection( int axis );
+};
+
+class Partition
+{
+public:
+    Partition();
+    ~Partition();
+protected:
+    std::set < SplitZone * > zoneStorage;
+    std::set < SplitZone * > unsignedZoneGroup;
+    std::vector< SplitZone * > refZone;
+    std::vector< std::vector< SplitZone * > > procSplitZone;
+    std::vector<double> procSpeed;
+    std::vector<double> timeProc;
+    double aveFloatOp, delta;
+    double idealUniProcTime, eps;
+    double minNode;
+    int nTZone;
+    int nOriZone;
+    int nProc;
+public:
+    void Solve();
+    void ReadGrid();
+    void Split();
+    void InitSplit();
+    void BinarySplit();
+    //void GreedySplit();
+public:
+    void AddNewZone( SplitZone * zone );
+    void AddZoneToUnsignedGroup( SplitZone * zone );
+    void RemoveZoneFromUnsignedGroup( SplitZone * zone );
+    void AddZoneToProcess( int iProc, SplitZone * zone );
+    void DumpPartitionedGridFile();
+    void FreeAllZones();
+    int GetNZones( int iProc );
+    SplitZone * GetSplitZone( int iProc, int zoneId );
+private:
+    int GetMinValueIndex( double * data, int numberOfData );
+    int GetMinLoadProc();
+    SplitZone * GetLargestZone();
+    SplitZone * Split( SplitZone * zone, double nCell );
+};
+
diff --git a/example/partition/struct/1d/01/README.txt b/example/partition/struct/1d/01/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/partition/struct/1d/01/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/partition/struct/1d/01/heat1dni81.cgns b/example/partition/struct/1d/01/heat1dni81.cgns
new file mode 100644
index 00000000..b7d4954a
Binary files /dev/null and b/example/partition/struct/1d/01/heat1dni81.cgns differ
diff --git a/example/partition/struct/1d/01/main.cpp b/example/partition/struct/1d/01/main.cpp
new file mode 100644
index 00000000..5da1de7c
--- /dev/null
+++ b/example/partition/struct/1d/01/main.cpp
@@ -0,0 +1,18 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include "Partition.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip>
+
+int main(int argc, char **argv)
+{
+    Partition * partition = new Partition();
+    partition->Solve();
+    delete partition;
+
+    return 0;
+}
diff --git a/example/partition/struct/1d/01a/CMakeLists.txt b/example/partition/struct/1d/01a/CMakeLists.txt
new file mode 100644
index 00000000..9fa577c8
--- /dev/null
+++ b/example/partition/struct/1d/01a/CMakeLists.txt
@@ -0,0 +1,77 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	Partition.h Partition.cpp
+	CgnsGrid.h CgnsGrid.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/partition/struct/1d/01a/CgnsGrid.cpp b/example/partition/struct/1d/01a/CgnsGrid.cpp
new file mode 100644
index 00000000..055545c4
--- /dev/null
+++ b/example/partition/struct/1d/01a/CgnsGrid.cpp
@@ -0,0 +1,217 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+Grid::Grid()
+{
+    ;
+}
+
+Grid::~Grid()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if( (i+1)%5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+std::vector<Zone *> Global::zones;
+
+Global::Global()
+{
+    ;
+}
+
+Global::~Global()
+{
+}
+
+void Global::FreeData()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+    zones.resize( 0 );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones(fileId, baseId, &nzones);
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize(index_dim*3);
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[33];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                std::vector<char> coord( nNodes * sizeof(double) );
+                //grid->x.resize( nNodes );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+                coor->DumpCoor();
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex(index_dim,-1);
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type, 
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset);
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[i] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[normalDataType] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList(nNodes*iphysdim*sizeof(double));
+
+                std::vector<cgsize_t> pnts(npnts*index_dim);
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double*>(const_cast<char *>(normalList.data()));
+
+                //std::cout << "normalList = ";
+                //for ( int i = 0; i < nNodes*iphysdim; ++ i )
+                //{
+                //    std::cout << normal_d[ i ] << " ";
+                //}
+                //std::cout << "\n";
+            }
+        }
+    }
+    cg_close(fileId);
+}
\ No newline at end of file
diff --git a/example/partition/struct/1d/01a/CgnsGrid.h b/example/partition/struct/1d/01a/CgnsGrid.h
new file mode 100644
index 00000000..72c47bb8
--- /dev/null
+++ b/example/partition/struct/1d/01a/CgnsGrid.h
@@ -0,0 +1,62 @@
+#pragma once
+#include <iostream>
+#include <vector>
+
+class Grid;
+
+class Zone;
+
+class Grid
+{
+public:
+    Grid();
+    ~Grid();
+public:
+    int nZone;
+    std::vector<double> x;
+    std::vector<Zone *> zones;
+};
+
+class ZoneBc;
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+};
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<Coor *> coors;
+};
+
+class ZoneBc
+{
+public:
+};
+
+class Global
+{
+public:
+    Global();
+    ~Global();
+public:
+    static std::vector<Zone *> zones;
+    static void FreeData();
+};
+
+void ReadCgnsGrid( const std::string & filename );
diff --git a/example/partition/struct/1d/01a/Partition.cpp b/example/partition/struct/1d/01a/Partition.cpp
new file mode 100644
index 00000000..2af0e965
--- /dev/null
+++ b/example/partition/struct/1d/01a/Partition.cpp
@@ -0,0 +1,776 @@
+#include "Partition.h"
+#include "CgnsGrid.h"
+#include "cgnslib.h"
+#include <string>
+
+DimInfo::DimInfo()
+{
+    this->dim = 1;
+    dimList.resize( this->dim, 1 );
+    oriPoint.resize( this->dim, 0 );
+}
+
+DimInfo::~DimInfo()
+{
+}
+
+DimInfo & DimInfo::operator = ( const DimInfo & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->dim = rhs.dim;
+    this->dimList = rhs.dimList;
+    this->oriPoint = rhs.oriPoint;
+
+    return * this;
+}
+
+int DimInfo::ComputeNumNodes()
+{
+    int nNodes = 1;
+    for ( int m = 0; m < this->dimList.size(); ++ m )
+    {
+        nNodes *= this->dimList[ m ];
+    }
+    return nNodes;
+}
+
+void DimInfo::ComputeISize()
+{
+    int index_dim = this->dimList.size();
+    this->isize.resize( index_dim * 3, 0 );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        isize[ m ] = this->dimList[ m ];
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 1;
+        isize[ start + m ] = this->dimList[ m ] - 1;
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 2;
+        isize[ start + m ] = 0;
+    }
+
+    for ( int i = 0; i < isize.size(); ++ i )
+    {
+        std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+    }
+}
+
+void DimInfo::ComputeRminmax( std::vector<int> & ref )
+{
+    int index_dim = this->dimList.size();
+    this->rmin.resize( index_dim );
+    this->rmax.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        rmin[ m ] = ref[ m ] + 1;
+        rmax[ m ] = ref[ m ] + this->dimList[ m ];
+    }
+
+    std::cout << "rmin, rmax = \n";
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        std::cout << rmin[ m ] << " " << rmax[ m ] << "\n";
+    }
+}
+
+void DimInfo::Init( std::vector<int> & dimList )
+{
+    this->dimList = dimList;
+    std::vector<int> zero( dimList.size(), 0 );
+    this->oriPoint = zero;
+}
+
+void DimInfo::SetNewDimension( int axis, int newStart, int newWidth )
+{
+    this->oriPoint[ axis ] = newStart;
+    this->dimList [ axis ] = newWidth;
+}
+
+SplitZone::SplitZone()
+{
+    this->oriZoneId = -1;
+    this->parent  = 0;
+    this->zoneIndex = 0;
+    this->iProc = 0;
+}
+
+SplitZone::~SplitZone()
+{
+    ;
+}
+
+void SplitZone::ComputeRminmax()
+{
+    int index_dim = this->dimInfo.dimList.size();
+    std::vector<int> ref( index_dim, 0 );
+
+    SplitZone * rootSplitZone = 0;
+    this->GetRootInfo( rootSplitZone, ref );
+
+    this->oriZoneId = rootSplitZone->oriZoneId;
+    std::cout << "this->oriZoneId = " << this->oriZoneId << "\n";
+
+    this->dimInfo.ComputeRminmax( ref );
+}
+
+void SplitZone::GetRootInfo( SplitZone *& root, std::vector<int> & ref )
+{
+    for ( int i = 0; i < this->dimInfo.dimList.size(); ++ i )
+    {
+        ref[ i ] += this->dimInfo.oriPoint[ i ];
+    }
+
+    if ( this->parent )
+    {
+        this->parent->GetRootInfo( root, ref );
+    }
+    else
+    {
+        root = this;
+    }
+}
+
+
+int SplitZone::GetNCell()
+{
+    int numberOfCells = 1;
+    for ( int i = 0; i < this->dimInfo.dim; ++ i )
+    {
+        numberOfCells *= std::max( 1, ( this->dimInfo.dimList[ i ] - 1 ) );
+    }
+
+    return numberOfCells; 
+}
+
+void SplitZone::SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int leftStart = 0;
+    int leftWidth = iSplit - 0;
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, leftStart , leftWidth  );
+}
+
+void SplitZone::SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int rightStart = iSplit - 1;
+    int rightWidth = dimList[ axisNeedSplit ] - ( iSplit - 1 );
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, rightStart, rightWidth );
+}
+
+void SplitZone::Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell )
+{
+    //Find the longest axis
+    int axisNeedSplit = this->FindAxisNeedSplit();
+    int iSplit        = this->FindSplitPosition( axisNeedSplit, nCell );
+
+    zoneL = new SplitZone();
+    zoneL->SetParent( this );
+
+    zoneR = new SplitZone();
+    zoneR->SetParent( this );
+
+    zoneL->SetLeftDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+    zoneR->SetRightDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+
+    //zoneL->CreateBc();
+    //zoneR->CreateBc();
+
+    //CreateInterfaceBc( zoneL, zoneR );
+}
+
+int SplitZone::FindAxisNeedSplit()
+{
+    //Find the longest axis
+    int axisNeedSplit = 0;
+    int maxN = this->dimInfo.dimList[ 0 ];
+
+    for ( int m = 1; m < this->dimInfo.dimList.size(); ++ m )
+    {
+        if ( this->IsPoleBc( m ) )
+        {
+            continue;
+        }
+        int Nm = this->dimInfo.dimList[ m ];
+        if ( maxN < Nm )
+        {
+            maxN = Nm;
+            axisNeedSplit = m;
+        }
+    }
+
+    return axisNeedSplit;
+}
+
+int SplitZone::GetCrossSection( int axis )
+{
+    int nDim = this->dimInfo.dimList.size();
+    int crossSection = 1;
+    int N = nDim - 1;
+    for ( int m = 0; m < N; ++ m )
+    {
+         int mm = ( axis + 1 ) % nDim;
+         int nLineElements = std::max( 1, ( this->dimInfo.dimList[ mm ] - 1 ) );
+         crossSection *= nLineElements;
+    }
+    return crossSection;
+}
+
+int SplitZone::FindSplitPosition( int axisNeedSplit, double nCell )
+{
+    int nDim = this->dimInfo.dimList.size();
+    std::vector<int> crossSections( nDim );
+    for ( int m = 0; m < nDim; ++ m )
+    {
+        crossSections[ m ] = this->GetCrossSection( m );
+    }
+
+    //guess the value
+    double dSplit = nCell / crossSections[ axisNeedSplit ];
+    int  iSplit = 1 + static_cast< int >( std::floor( dSplit + 0.5 ) );
+    return iSplit;
+}
+
+
+bool SplitZone::IsPoleBc( int splitDirection )
+{
+    return false;
+}
+
+
+double CalSumOfProcSpeed( std::vector<double> & procSpeed );
+double CalSumOfProcSpeed( std::vector<double> & procSpeed )
+{
+    int nProc = procSpeed.size();
+    double sumOfProcSpeed = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        sumOfProcSpeed += procSpeed[ iProc ];
+    }
+    return sumOfProcSpeed;
+}
+
+Partition::Partition()
+{
+    ;
+}
+
+Partition::~Partition()
+{
+    ;
+}
+
+int Partition::GetMinValueIndex( double * data, int numberOfData )
+{
+    double minValue = data[ 0 ];
+    int minimumValueIndex = 0;
+
+    for ( int iData = 1; iData < numberOfData; ++ iData )
+    {
+        if ( minValue > data[ iData ] )
+        {
+            minValue      = data[ iData ];
+            minimumValueIndex = iData;
+        }
+    }
+    return minimumValueIndex;
+}
+
+int Partition::GetMinLoadProc()
+{
+    return this->GetMinValueIndex( this->timeProc.data(), this->nProc );
+}
+
+SplitZone * Partition::GetLargestZone()
+{
+    SplitZone * largestZone = 0;
+
+    double nMaxCell = 0.0;
+
+    for ( std::set< SplitZone * >::iterator iter = unsignedZoneGroup.begin(); iter != unsignedZoneGroup.end(); ++ iter )
+    {
+        double nSize = ( * iter )->GetNCell();
+        if ( nMaxCell < nSize )
+        {
+            nMaxCell    = nSize;
+            largestZone = * iter;
+        }
+    }
+
+    return largestZone;
+}
+
+void Partition::Solve()
+{
+    std::cout << "Partition::Split()\n";
+    this->nProc = 2;
+    this->ReadGrid();
+    this->Split();
+    this->DumpPartitionedGridFile();
+    this->FreeAllZones();
+}
+
+void Partition::ReadGrid()
+{
+    ReadCgnsGrid( "../heat1dni81.cgns" );
+
+    this->nOriZone = ::Global::zones.size();
+
+    std::cout << "numberOfBlocks = " << nOriZone << "\n";
+
+    this->refZone.resize( nOriZone );
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        refZone[ iZone ] = new SplitZone();
+        refZone[ iZone ]->SetZoneIndex( iZone );
+        refZone[ iZone ]->oriZoneId = iZone;
+        refZone[ iZone ]->SetProcId( 0 );
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        Zone * zone = ::Global::zones[ iZone ];
+
+        splitZone->dimInfo.dimList = zone->nijk;
+
+        int nBcRegion = zone->bccos.size();
+        std::cout << "nBcRegion = " << nBcRegion << "\n";
+
+        //HXVector< ZoneBc * > & bcList = splitZone->GetZoneBcList();
+        //bcList.resize( nBcRegion );
+
+        for ( int iBcRegion = 0; iBcRegion < nBcRegion; ++ iBcRegion )
+        {
+        }
+
+        //splitZone->NormalizeBc();
+    }
+}
+
+void Partition::Split()
+{
+    this->InitSplit();
+    this->BinarySplit();
+    //this->SetZoneIndex();
+}
+
+void Partition::InitSplit()
+{
+    //nZone is the number of zones in the original grid
+    //nProc is not the number of blocks in the end, but the number of processes that need to be divided.
+    //This difference occurs because the structure grid can have many blocks per process.
+
+    //this->nProc    = nProc;
+    //this->nPhyBlocks = referenceBlock.size();
+    //this->nZone  = this->nPhyBlocks;
+
+    //tj Computation time on processor j
+    //Nk Number of internal grid-cells for zone j
+    //aveFloatOp:  Number of Real operations per gridcell
+    //Gj The set of blocks allocated to process j
+    //Pj Real operations per second for process j
+
+    //The Greedy Load Balancing Algorithm
+    //1.Compute an "ideal" uniprocessor time, Tuni = sum ( Nk * aveFloatOp )/ sum( Pj ).
+    //2.Set the group of unassigned blocks, Gu, to contain all blocks. The number of blocks in Nu=M, where M is the total number of blocks in the mesh.
+    //3.Start all processors with a very small fictitious zone to get a start tj=delt aveFloatOp/Pj, where delt<<1 is the size of the very small fictious zone.
+    //This is used to find the fastest processor in a heterogeneous system, tj could otherwise be set to 0 in the homogeneous case.
+    this->aveFloatOp = 1.0;
+    this->delta      = 1.0e-5;
+    this->procSpeed.resize( nProc );
+    this->timeProc.resize( nProc );
+
+    this->nTZone = this->nOriZone;
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        procSpeed[ iProc ] = 1.0;
+    }
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        timeProc[ iProc ] = delta * aveFloatOp / procSpeed[ iProc ];
+    }
+
+    double sumProcSpeed = CalSumOfProcSpeed( procSpeed );
+
+    double sumProcOp = 0.0;
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        sumProcOp += refZone[ iZone ]->GetNCell() * aveFloatOp;
+    }
+
+    this->idealUniProcTime = sumProcOp / sumProcSpeed;
+
+    this->eps = 0.05;
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        unsignedZoneGroup.insert( refZone[ iZone ] );
+    }
+
+    //Init zoneStorage
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        zoneStorage.insert( refZone[ iZone ] );
+    }
+
+    //Assign procSplitZone to each process
+    procSplitZone.resize( nProc );
+
+    this->minNode = 3 * 3 * 2;
+}
+
+void Partition::FreeAllZones()
+{
+    int iCount = 0;
+    for ( std::set < SplitZone * >::iterator iter = zoneStorage.begin(); iter != zoneStorage.end(); ++ iter )
+    {
+        //cout << "iCount = " << iCount << "\n";
+        ++ iCount;
+        delete * iter;
+    }
+}
+
+int Partition::GetNZones( int iProc )
+{
+    return this->procSplitZone[ iProc ].size();
+}
+
+SplitZone * Partition::GetSplitZone( int iProc, int zoneId )
+{
+    return this->procSplitZone[ iProc ][ zoneId ];
+}
+
+void Partition::AddZoneToUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.insert( zone );
+}
+
+void Partition::RemoveZoneFromUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.erase( zone );
+}
+
+void Partition::AddZoneToProcess( int iProc, SplitZone * zone )
+{
+    this->procSplitZone[ iProc ].push_back( zone );
+}
+
+void Partition::AddNewZone( SplitZone * zone )
+{
+    zone->SetZoneIndex( nTZone ++ );
+
+    this->AddZoneToUnsignedGroup( zone );
+
+    this->zoneStorage.insert( zone );
+}
+
+SplitZone * Partition::Split( SplitZone * zone, double nCell )
+{
+    SplitZone * zoneL = 0;
+    SplitZone * zoneR = 0;
+
+    zone->Split( zoneL, zoneR, nCell );
+
+    this->AddNewZone( zoneL );
+    this->AddNewZone( zoneR );
+    this->RemoveZoneFromUnsignedGroup( zone );
+
+    return zoneL;
+}
+
+void Partition::BinarySplit()
+{
+    while ( ! unsignedZoneGroup.empty() )
+    {
+        std::cout << "number of unsigned zone = " << unsignedZoneGroup.size() << "\n";
+        int iProc = this->GetMinLoadProc();
+
+        //Get the block with the largest number of grids and its size
+        SplitZone * largestZone = this->GetLargestZone();
+
+        double nMaxCell = largestZone->GetNCell();
+
+        double aveFloatOp = this->aveFloatOp;
+        double tau = timeProc[ iProc ] + nMaxCell * aveFloatOp / procSpeed[ iProc ];
+
+        int kkk = 1;
+
+        //It seems that EPS is still necessary
+        //The idea here is as follows. For the candidate blocks which can be divided into blocks, 
+        //if the difference between the target blocks and the candidate blocks is too wide, 
+        //the binarySplit method is adopted. The binarySplit blocks do not directly join the process,
+        //but enter the next round of screening.
+
+        if ( tau > idealUniProcTime * ( 1.0 + eps ) )
+        {
+            double nRest = ( tau - idealUniProcTime ) * procSpeed[ iProc ] / aveFloatOp;
+
+            double nTarget = nMaxCell - nRest;
+            if ( nRest > this->minNode && nTarget > this->minNode )
+            {
+                //It is necessary to divide blocks only when a certain number of points are satisfied.
+                double nHalf = nMaxCell / 2.0;
+                nMaxCell = nTarget;
+                double ratio = nMaxCell / nRest;
+                double oRatio = 1.0 / ratio;
+
+                if ( std::max( ratio, oRatio ) < 3.0 )
+                {
+                    int kkk = 1;
+                    largestZone = this->Split( largestZone, nMaxCell );
+                    timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                    this->RemoveZoneFromUnsignedGroup( largestZone );
+                    this->AddZoneToProcess( iProc, largestZone );
+                }
+                else
+                {
+                    this->Split( largestZone, nHalf );
+                }
+            }
+            else
+            {
+                //If the block is of the right size, join the process directly, and there is no need to split it.
+                timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                this->RemoveZoneFromUnsignedGroup( largestZone );
+                this->AddZoneToProcess( iProc, largestZone );
+            }
+        }
+        else
+        {
+            //If the block is of the right size, join the process directly, and there is no need to split it.
+            timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+            this->RemoveZoneFromUnsignedGroup( largestZone );
+            this->AddZoneToProcess( iProc, largestZone );
+        }
+    }
+}
+
+void Partition::DumpPartitionedGridFile()
+{
+    int fileId = -1;
+    std::string filename = "split1d.cgns";
+    cg_open( filename.c_str(), CG_MODE_WRITE, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        int icelldim = 1;
+        int iphysdim = 1;
+        std::string basename = "Base" + std::to_string( iProc );
+
+        int baseId = -1;
+        cg_base_write( fileId, basename.c_str(), icelldim, iphysdim, &baseId );
+
+        std::cout << "baseId = " << baseId << "\n";
+
+        int nZones = this->GetNZones( iProc );
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            ZoneType_t zoneType = Structured;
+
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+
+            int index_dim = splitZone->dimInfo.dimList.size();
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            splitZone->dimInfo.ComputeISize();
+
+            int isize_dim = index_dim * 3;
+
+            std::vector<cgsize_t> isize( index_dim * 3, 0 );
+            for ( int m = 0; m < isize_dim; ++ m )
+            {
+                isize[ m ] = splitZone->dimInfo.isize[ m ];
+            }
+
+            int zoneId = -1;
+
+            std::string zonename = "B" + std::to_string( iProc ) + "Zone" + std::to_string( iZone );
+            cg_zone_write( fileId, baseId, zonename.c_str(), isize.data(), zoneType, &zoneId );
+
+            std::cout << "zoneId = " << zoneId << "\n";
+                
+            std::vector<cgsize_t> irmin( index_dim );
+            std::vector<cgsize_t> irmax( index_dim );
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            std::cout << "irmin, irmax = \n";
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                std::cout << irmin[ m ] << " " << irmax[ m ] << "\n";
+            }
+
+            //std::vector<int> ref( index_dim, 0 );
+
+            //SplitZone * rootSplitZone = 0;
+            //splitZone->GetRootInfo( rootSplitZone, ref );
+
+            //int oriZoneId = rootSplitZone->oriZoneId;
+            //std::cout << "oriZoneId = " << oriZoneId << "\n";
+            splitZone->ComputeRminmax();
+
+            Zone * zone = Global::zones[ splitZone->oriZoneId ];
+
+            //std::vector<cgsize_t> rmin( index_dim );
+            //std::vector<cgsize_t> rmax( index_dim );
+
+            //for ( int m = 0; m < index_dim; ++ m )
+            //{
+            //    rmin[ m ] = ref[ m ] + 1;
+            //    rmax[ m ] = ref[ m ] + splitZone->dimInfo.dimList[ m ];
+            //}
+
+            //std::cout << "rmin, rmax = \n";
+            //for ( int m = 0; m < index_dim; ++ m )
+            //{
+            //    std::cout << rmin[ m ] << " " << rmax[ m ] << "\n";
+            //}
+
+            int ncoords = 1;
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = -1;
+                DataType_t dataType = RealDouble;
+                std::string coordname = "X";
+                Coor * coor = zone->coors[ icoord ];
+
+                int nNodes = splitZone->dimInfo.ComputeNumNodes();
+                std::cout << "nNodes = " << nNodes << "\n";
+
+                std::vector<char> coord( nNodes * sizeof(double) );
+                {
+                    double * xlocal = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+                    double * xglobal = reinterpret_cast<double *>( const_cast<char *>( coor->coord.data() ) );
+                    if ( index_dim == 1 )
+                    {
+                        int icount = 0;
+                        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+                        int imax = splitZone->dimInfo.rmax[ 0 ];
+                        for ( int i = imin; i < imax; ++ i )
+                        {
+                            xlocal[ icount++ ] = xglobal[ i ];
+                        }
+                    }
+                    else if ( index_dim == 2 )
+                    {
+                        int icount = 0;
+                        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+                        int imax = splitZone->dimInfo.rmax[ 0 ];
+                        int jmin = splitZone->dimInfo.rmin[ 1 ] - 1;
+                        int jmax = splitZone->dimInfo.rmax[ 1 ];
+                        int ni = splitZone->dimInfo.dimList[ 0 ];
+                        int nj = splitZone->dimInfo.dimList[ 1 ];
+                        for ( int j = jmin; j < jmax; ++ j )
+                        {
+                            int jstride = j * ni;
+                            for ( int i = imin; i < imax; ++ i )
+                            {
+                                xlocal[ icount++ ] = xglobal[ jstride + i ];
+                            }
+                        }
+                    }
+                    //for ( int i = 0; i < nNodes; ++ i )
+                    //{
+                    //    int j = i + ref[ 0 ];
+                    //    xlocal[ i ] = xglobal[j];
+                    //    std::cout << xlocal[ i ] << " ";
+                    //    if ( ( i + 1 ) % 5 == 0 ) std::cout << "\n";
+                    //}
+                    //std::cout << "\n";
+                }
+
+                cg_coord_write( fileId, baseId, zoneId, dataType, coordname.c_str(), coord.data(), &coorId );
+
+                std::cout << "cg_get_error() = " << cg_get_error() << "\n";
+                std::cout << "fileId = " << fileId  << " baseId = " << baseId << " zoneId = " << zoneId  << " coorId = " << coorId << "\n";
+            }
+
+            //int nbocos = -1;
+
+            //cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            //std::cout << "nbocos = " << nbocos << "\n";
+            //for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            //{
+            //    int bccoId = iboco + 1;
+            //    GridLocation_t location;
+            //    cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+            //    std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+            //    ZoneBc * zonebc = new ZoneBc();
+            //    zone->bccos.push_back( zonebc );
+
+            //    char boconame[ 33 ];
+            //    BCType_t bocotype;
+            //    PointSetType_t ptset_type;
+            //    cgsize_t npnts = 0;
+            //    std::vector<int> normalIndex(index_dim,-1);
+            //    cgsize_t normalListSize = 0;
+            //    DataType_t normalDataType;
+            //    int ndataset = -1;
+
+            //    cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type, 
+            //        &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset);
+            //    std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+            //    std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+            //    std::cout << "npnts = " << npnts << "\n";
+            //    std::cout << "normalIndex = ";
+            //    for ( int i = 0; i < index_dim; ++ i )
+            //    {
+            //        std::cout << normalIndex[i] << " ";
+            //    }
+            //    std::cout << "\n";
+            //    std::cout << "normalListSize = " << normalListSize << "\n";
+            //    std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[normalDataType] << "\n";
+            //    std::cout << "ndataset = " << ndataset << "\n";
+
+            //    std::vector<char> normalList(nNodes*iphysdim*sizeof(double));
+
+            //    std::vector<cgsize_t> pnts(npnts*index_dim);
+            //    cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+            //    std::cout << "pnts = ";
+            //    for ( int i = 0; i < pnts.size(); ++ i )
+            //    {
+            //        std::cout << pnts[ i ] << " ";
+            //    }
+            //    std::cout << "\n";
+
+            //    double * normal_d = reinterpret_cast<double*>(const_cast<char *>(normalList.data()));
+
+            //    //std::cout << "normalList = ";
+            //    //for ( int i = 0; i < nNodes*iphysdim; ++ i )
+            //    //{
+            //    //    std::cout << normal_d[ i ] << " ";
+            //    //}
+            //    //std::cout << "\n";
+            //}
+        }
+    }
+    cg_close(fileId);
+}
\ No newline at end of file
diff --git a/example/partition/struct/1d/01a/Partition.h b/example/partition/struct/1d/01a/Partition.h
new file mode 100644
index 00000000..2c2052cf
--- /dev/null
+++ b/example/partition/struct/1d/01a/Partition.h
@@ -0,0 +1,101 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class SplitZone;
+
+class DimInfo
+{
+public:
+    DimInfo();
+    ~DimInfo();
+public:
+    int dim;
+    std::vector<int> dimList;
+    std::vector<int> oriPoint;
+    std::vector<int> isize;
+    std::vector<int> rmin;
+    std::vector<int> rmax;
+public:
+    int GetSize() const { return dim; }
+    DimInfo & operator = ( const DimInfo & rhs );
+public:
+    int ComputeNumNodes();
+    void ComputeISize();
+    void ComputeRminmax( std::vector<int> & ref );
+    void Init( std::vector<int> & dimList );
+    void SetNewDimension( int axis, int newStart, int newWidth );
+};
+
+class SplitZone
+{
+public:
+    SplitZone();
+    ~SplitZone();
+public:
+    DimInfo dimInfo;
+    int zoneIndex, iProc;
+    int oriZoneId;
+protected:
+    SplitZone * parent;
+public:
+    int GetNCell();
+    void ComputeRminmax();
+    void GetRootInfo( SplitZone *& root, std::vector<int> & ref );
+    void SetZoneIndex( int zoneIndex ) { this->zoneIndex = zoneIndex; }
+    int  GetZoneIndex() { return zoneIndex; }
+    void SetProcId( int iProc ) { this->iProc = iProc; }
+    void SetParent( SplitZone * parent ) { this->parent = parent; };
+public:
+    void Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell );
+    void SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+    void SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+private:
+    int FindAxisNeedSplit();
+    int FindSplitPosition( int axisNeedSplit, double nCell );
+    bool IsPoleBc( int splitDirection );
+    int GetCrossSection( int axis );
+};
+
+class Partition
+{
+public:
+    Partition();
+    ~Partition();
+protected:
+    std::set < SplitZone * > zoneStorage;
+    std::set < SplitZone * > unsignedZoneGroup;
+    std::vector< SplitZone * > refZone;
+    std::vector< std::vector< SplitZone * > > procSplitZone;
+    std::vector<double> procSpeed;
+    std::vector<double> timeProc;
+    double aveFloatOp, delta;
+    double idealUniProcTime, eps;
+    double minNode;
+    int nTZone;
+    int nOriZone;
+    int nProc;
+public:
+    void Solve();
+    void ReadGrid();
+    void Split();
+    void InitSplit();
+    void BinarySplit();
+    //void GreedySplit();
+public:
+    void AddNewZone( SplitZone * zone );
+    void AddZoneToUnsignedGroup( SplitZone * zone );
+    void RemoveZoneFromUnsignedGroup( SplitZone * zone );
+    void AddZoneToProcess( int iProc, SplitZone * zone );
+    void DumpPartitionedGridFile();
+    void FreeAllZones();
+    int GetNZones( int iProc );
+    SplitZone * GetSplitZone( int iProc, int zoneId );
+private:
+    int GetMinValueIndex( double * data, int numberOfData );
+    int GetMinLoadProc();
+    SplitZone * GetLargestZone();
+    SplitZone * Split( SplitZone * zone, double nCell );
+};
+
diff --git a/example/partition/struct/1d/01a/README.txt b/example/partition/struct/1d/01a/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/partition/struct/1d/01a/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/partition/struct/1d/01a/heat1dni81.cgns b/example/partition/struct/1d/01a/heat1dni81.cgns
new file mode 100644
index 00000000..b7d4954a
Binary files /dev/null and b/example/partition/struct/1d/01a/heat1dni81.cgns differ
diff --git a/example/partition/struct/1d/01a/main.cpp b/example/partition/struct/1d/01a/main.cpp
new file mode 100644
index 00000000..5da1de7c
--- /dev/null
+++ b/example/partition/struct/1d/01a/main.cpp
@@ -0,0 +1,18 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include "Partition.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip>
+
+int main(int argc, char **argv)
+{
+    Partition * partition = new Partition();
+    partition->Solve();
+    delete partition;
+
+    return 0;
+}
diff --git a/example/partition/struct/1d/01b/CMakeLists.txt b/example/partition/struct/1d/01b/CMakeLists.txt
new file mode 100644
index 00000000..9fa577c8
--- /dev/null
+++ b/example/partition/struct/1d/01b/CMakeLists.txt
@@ -0,0 +1,77 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	Partition.h Partition.cpp
+	CgnsGrid.h CgnsGrid.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/partition/struct/1d/01b/CgnsGrid.cpp b/example/partition/struct/1d/01b/CgnsGrid.cpp
new file mode 100644
index 00000000..ff8aa2f8
--- /dev/null
+++ b/example/partition/struct/1d/01b/CgnsGrid.cpp
@@ -0,0 +1,227 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+Grid::Grid()
+{
+    ;
+}
+
+Grid::~Grid()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if( (i+1)%5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+std::vector<Zone *> Global::zones;
+
+Global::Global()
+{
+    ;
+}
+
+Global::~Global()
+{
+}
+
+void Global::FreeData()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+    zones.resize( 0 );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones(fileId, baseId, &nzones);
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize(index_dim*3);
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[33];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                std::vector<char> coord( nNodes * sizeof(double) );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+                coor->DumpCoor();
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex(index_dim,-1);
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type, 
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset);
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[i] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[normalDataType] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList(nNodes*iphysdim*sizeof(double));
+
+                std::vector<cgsize_t> pnts(npnts*index_dim);
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double*>(const_cast<char *>(normalList.data()));
+
+                //std::cout << "normalList = ";
+                //for ( int i = 0; i < nNodes*iphysdim; ++ i )
+                //{
+                //    std::cout << normal_d[ i ] << " ";
+                //}
+                //std::cout << "\n";
+            }
+        }
+    }
+    cg_close(fileId);
+}
\ No newline at end of file
diff --git a/example/partition/struct/1d/01b/CgnsGrid.h b/example/partition/struct/1d/01b/CgnsGrid.h
new file mode 100644
index 00000000..12e7bb21
--- /dev/null
+++ b/example/partition/struct/1d/01b/CgnsGrid.h
@@ -0,0 +1,67 @@
+#pragma once
+#include <iostream>
+#include <vector>
+
+class Grid;
+
+class Zone;
+
+class Grid
+{
+public:
+    Grid();
+    ~Grid();
+public:
+    int nZone;
+    std::vector<double> x;
+    std::vector<Zone *> zones;
+};
+
+class ZoneBc;
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+};
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<Coor *> coors;
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    std::vector<int> pnts;
+};
+
+class Global
+{
+public:
+    Global();
+    ~Global();
+public:
+    static std::vector<Zone *> zones;
+    static void FreeData();
+};
+
+void ReadCgnsGrid( const std::string & filename );
diff --git a/example/partition/struct/1d/01b/Partition.cpp b/example/partition/struct/1d/01b/Partition.cpp
new file mode 100644
index 00000000..6ca6dfad
--- /dev/null
+++ b/example/partition/struct/1d/01b/Partition.cpp
@@ -0,0 +1,970 @@
+#include "Partition.h"
+#include "CgnsGrid.h"
+#include "cgnslib.h"
+#include <string>
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox  )
+{
+    domainBox.start = zoneBox.start;
+    domainBox.end = zoneBox.end;
+
+    int axis = iDomain / 2;
+    int direction = iDomain % 2;
+
+    if ( direction == 0 )
+    {
+        domainBox.end[ axis ] = domainBox.start[ axis ];
+    }
+    else if ( direction == 1 )
+    {
+        domainBox.start[ axis ] = domainBox.end[ axis ];
+    }
+}
+
+DimInfo::DimInfo()
+{
+    this->dim = 1;
+    dimList.resize( this->dim, 1 );
+    oriPoint.resize( this->dim, 0 );
+}
+
+DimInfo::~DimInfo()
+{
+}
+
+DimInfo & DimInfo::operator = ( const DimInfo & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->dim = rhs.dim;
+    this->dimList = rhs.dimList;
+    this->oriPoint = rhs.oriPoint;
+
+    return * this;
+}
+
+int DimInfo::ComputeNumNodes()
+{
+    int nNodes = 1;
+    for ( int m = 0; m < this->dimList.size(); ++ m )
+    {
+        nNodes *= this->dimList[ m ];
+    }
+    return nNodes;
+}
+
+void DimInfo::ComputeISize()
+{
+    int index_dim = this->dimList.size();
+    this->isize.resize( index_dim * 3, 0 );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        isize[ m ] = this->dimList[ m ];
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 1;
+        isize[ start + m ] = this->dimList[ m ] - 1;
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 2;
+        isize[ start + m ] = 0;
+    }
+
+    for ( int i = 0; i < isize.size(); ++ i )
+    {
+        std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+    }
+}
+
+void DimInfo::ComputeRminmax( std::vector<int> & ref )
+{
+    int index_dim = this->dimList.size();
+    this->rmin.resize( index_dim );
+    this->rmax.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        rmin[ m ] = ref[ m ] + 1;
+        rmax[ m ] = ref[ m ] + this->dimList[ m ];
+    }
+
+    std::cout << "rmin, rmax = \n";
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        std::cout << rmin[ m ] << " " << rmax[ m ] << "\n";
+    }
+}
+
+void DimInfo::Init( std::vector<int> & dimList )
+{
+    this->dimList = dimList;
+    std::vector<int> zero( dimList.size(), 0 );
+    this->oriPoint = zero;
+}
+
+void DimInfo::SetNewDimension( int axis, int newStart, int newWidth )
+{
+    this->oriPoint[ axis ] = newStart;
+    this->dimList [ axis ] = newWidth;
+}
+
+void DimInfo::GetZoneBox( RangeRegion &zoneBox )
+{
+    int index_dim = this->dimList.size();
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        zoneBox.start[ m ] = this->oriPoint[ m ] + 1;
+        zoneBox.end[ m ] = this->oriPoint[ m ] + this->dimList[ m ];
+    }
+}
+
+RangeRegion::RangeRegion( int nSize )
+{
+    this->start.resize( nSize );
+    this->end.resize( nSize );
+}
+
+RangeRegion::~RangeRegion()
+{
+}
+
+RangeRegion & RangeRegion::operator = ( const RangeRegion & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+    this->regionAxis = rhs.regionAxis;
+
+    return * this;
+}
+
+void RangeRegion::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+    this->ComputeRegionAxis();
+}
+
+int RangeRegion::ComputeRegionAxis()
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] == this->end[ m ] )
+        {
+            this->regionAxis = m;
+            return this->regionAxis;
+        }
+    }
+    return this->regionAxis;
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion );
+
+bool ComputeOverlapRegion( RangeRegion & region1, RangeRegion & region2, RangeRegion & overlapRegion )
+{
+    int index_dim = region1.start.size();
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        overlapRegion.start[ m ] = std::max( region1.start[ m ], region2.start[ m ] );
+        overlapRegion.end  [ m ] = std::min( region1.end  [ m ], region2.end  [ m ] );
+    }
+
+    return CheckOverLapping( overlapRegion );
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion )
+{
+    int index_dim = overlapRegion.start.size();
+    int iCount = 0;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        if ( overlapRegion.start[ m ] == overlapRegion.end[ m ] )
+        {
+            ++ iCount;
+        }
+    }
+
+    return ( iCount == 1 );
+}
+
+SplitBc * CreateSplitBc( RangeRegion & bcRegion, RangeRegion & zoneDomainRegion )
+{
+    int sRegionAxis = bcRegion.ComputeRegionAxis();
+    int tRegionAxis = zoneDomainRegion.ComputeRegionAxis();
+
+    //Two regions in different directions
+    if ( sRegionAxis != tRegionAxis )
+    {
+        return 0;
+    }
+
+    //Although the two regions are in the same direction, the coordinates are inconsistent.
+    if ( bcRegion.start[ sRegionAxis ] != zoneDomainRegion.start[ sRegionAxis ] )
+    {
+        return 0;
+    }
+
+    RangeRegion overlapRegion;
+    ComputeOverlapRegion( bcRegion, zoneDomainRegion, overlapRegion );
+
+    if ( CheckOverLapping( overlapRegion ) )
+    {
+        SplitBc * splitBc = new SplitBc();
+        splitBc->SetRegion( overlapRegion );
+        return splitBc;
+    }
+
+    int kkk = 1;
+
+    return 0;
+}
+
+
+SplitBc::SplitBc()
+{
+}
+
+SplitBc::~SplitBc()
+{
+}
+
+void SplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void SplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+void SplitBc::SetZoneBcFromParentBc( SplitBc * parentSplitBc )
+{
+    this->bcType = parentSplitBc->bcType;
+    //this->LocalCoordinate();
+    this->region.regionAxis = parentSplitBc->region.regionAxis;
+    this->InheritPatchBc( parentSplitBc );
+}
+
+void SplitBc::InheritPatchBc( SplitBc * parentSplitBc )
+{
+    if ( ! ( this->bcType < 0 ) ) return;
+
+    this->patch = new SplitBcPatch();
+
+    this->patch->splitZone = parentSplitBc->patch->splitZone;
+    this->patch->faceAxis = parentSplitBc->patch->faceAxis;
+
+}
+
+SplitBcPatch::SplitBcPatch()
+{
+}
+
+SplitBcPatch::~SplitBcPatch()
+{
+}
+
+SplitZone::SplitZone()
+{
+    this->oriZoneId = -1;
+    this->parent  = 0;
+    this->zoneIndex = 0;
+    this->iProc = 0;
+}
+
+SplitZone::~SplitZone()
+{
+    ;
+}
+
+void SplitZone::ComputeRminmax()
+{
+    int index_dim = this->dimInfo.dimList.size();
+    std::vector<int> ref( index_dim, 0 );
+
+    SplitZone * rootSplitZone = 0;
+    this->GetRootInfo( rootSplitZone, ref );
+
+    this->oriZoneId = rootSplitZone->oriZoneId;
+    std::cout << "this->oriZoneId = " << this->oriZoneId << "\n";
+
+    this->dimInfo.ComputeRminmax( ref );
+}
+
+void SplitZone::GetRootInfo( SplitZone *& root, std::vector<int> & ref )
+{
+    for ( int i = 0; i < this->dimInfo.dimList.size(); ++ i )
+    {
+        ref[ i ] += this->dimInfo.oriPoint[ i ];
+    }
+
+    if ( this->parent )
+    {
+        this->parent->GetRootInfo( root, ref );
+    }
+    else
+    {
+        root = this;
+    }
+}
+
+
+int SplitZone::GetNCell()
+{
+    int numberOfCells = 1;
+    for ( int i = 0; i < this->dimInfo.dim; ++ i )
+    {
+        numberOfCells *= std::max( 1, ( this->dimInfo.dimList[ i ] - 1 ) );
+    }
+
+    return numberOfCells; 
+}
+
+void SplitZone::SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int leftStart = 0;
+    int leftWidth = iSplit - 0;
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, leftStart , leftWidth  );
+}
+
+void SplitZone::SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int rightStart = iSplit - 1;
+    int rightWidth = dimList[ axisNeedSplit ] - ( iSplit - 1 );
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, rightStart, rightWidth );
+}
+
+void SplitZone::Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell )
+{
+    //Find the longest axis
+    int axisNeedSplit = this->FindAxisNeedSplit();
+    int iSplit        = this->FindSplitPosition( axisNeedSplit, nCell );
+
+    zoneL = new SplitZone();
+    zoneL->SetParent( this );
+
+    zoneR = new SplitZone();
+    zoneR->SetParent( this );
+
+    zoneL->SetLeftDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+    zoneR->SetRightDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+
+    zoneL->CreateBcFromParent();
+    zoneR->CreateBcFromParent();
+
+    //CreateInterfaceBc( zoneL, zoneR );
+}
+
+void SplitZone::CreateBcFromParent()
+{
+    std::vector< SplitBc * > & parentSplitBcList = this->parent->GetSplitBcList();
+
+    int nParentSplitBcs = parentSplitBcList.size();
+
+    for ( int iParentBc = 0; iParentBc < nParentSplitBcs; ++ iParentBc )
+    {
+        SplitBc * parentSplitBc = parentSplitBcList[ iParentBc ];
+
+        this->CreateSplitBc( parentSplitBc );
+    }
+}
+
+void SplitZone::AddSplitBc( SplitBc * splitBc )
+{
+    if ( ! splitBc ) return;
+    this->splitBcList.push_back( splitBc );
+}
+
+void SplitZone::CreateSplitBc( SplitBc * parentSplitBc )
+{
+    if ( ! parentSplitBc->child )
+    {
+        int index_dim = this->dimInfo.dimList.size();
+        int nDomains = 2 * index_dim;
+        RangeRegion zoneBoxRegion( index_dim );
+        this->dimInfo.GetZoneBox( zoneBoxRegion );
+
+        for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+        {
+            RangeRegion domainRegion( index_dim );
+            GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+            RangeRegion overlapRegion;
+            bool overlap_flag = ComputeOverlapRegion( parentSplitBc->region, domainRegion, overlapRegion );
+            if ( ! overlap_flag ) continue;
+
+            SplitBc * splitBc = new SplitBc();
+            this->AddSplitBc( splitBc );
+
+            splitBc->SetRegion( overlapRegion );
+            splitBc->bcType = parentSplitBc->bcType;
+            splitBc->splitZone = this;
+            //splitBc->LocalCoordinate();
+            //splitBc->CreatePatchBc( parentSplitBc );
+
+            int kkk = 1;
+        }
+    }
+    //else
+    //{
+    //    int nChild = parentBc->GetChild()->size();
+    //    for ( int iChild = 0; iChild < nChild; ++ iChild )
+    //    {
+    //        this->CreateBc( ( * parentBc->GetChild() )[ iChild ] );
+    //    }
+    //}
+}
+
+
+int SplitZone::FindAxisNeedSplit()
+{
+    //Find the longest axis
+    int axisNeedSplit = 0;
+    int maxN = this->dimInfo.dimList[ 0 ];
+
+    for ( int m = 1; m < this->dimInfo.dimList.size(); ++ m )
+    {
+        if ( this->IsPoleBc( m ) )
+        {
+            continue;
+        }
+        int Nm = this->dimInfo.dimList[ m ];
+        if ( maxN < Nm )
+        {
+            maxN = Nm;
+            axisNeedSplit = m;
+        }
+    }
+
+    return axisNeedSplit;
+}
+
+int SplitZone::GetCrossSection( int axis )
+{
+    int nDim = this->dimInfo.dimList.size();
+    int crossSection = 1;
+    int N = nDim - 1;
+    for ( int m = 0; m < N; ++ m )
+    {
+         int mm = ( axis + 1 ) % nDim;
+         int nLineElements = std::max( 1, ( this->dimInfo.dimList[ mm ] - 1 ) );
+         crossSection *= nLineElements;
+    }
+    return crossSection;
+}
+
+int SplitZone::FindSplitPosition( int axisNeedSplit, double nCell )
+{
+    int nDim = this->dimInfo.dimList.size();
+    std::vector<int> crossSections( nDim );
+    for ( int m = 0; m < nDim; ++ m )
+    {
+        crossSections[ m ] = this->GetCrossSection( m );
+    }
+
+    //guess the value
+    double dSplit = nCell / crossSections[ axisNeedSplit ];
+    int  iSplit = 1 + static_cast< int >( std::floor( dSplit + 0.5 ) );
+    return iSplit;
+}
+
+
+bool SplitZone::IsPoleBc( int splitDirection )
+{
+    return false;
+}
+
+
+double CalSumOfProcSpeed( std::vector<double> & procSpeed );
+double CalSumOfProcSpeed( std::vector<double> & procSpeed )
+{
+    int nProc = procSpeed.size();
+    double sumOfProcSpeed = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        sumOfProcSpeed += procSpeed[ iProc ];
+    }
+    return sumOfProcSpeed;
+}
+
+Partition::Partition()
+{
+    ;
+}
+
+Partition::~Partition()
+{
+    ;
+}
+
+int Partition::GetMinValueIndex( double * data, int numberOfData )
+{
+    double minValue = data[ 0 ];
+    int minimumValueIndex = 0;
+
+    for ( int iData = 1; iData < numberOfData; ++ iData )
+    {
+        if ( minValue > data[ iData ] )
+        {
+            minValue      = data[ iData ];
+            minimumValueIndex = iData;
+        }
+    }
+    return minimumValueIndex;
+}
+
+int Partition::GetMinLoadProc()
+{
+    return this->GetMinValueIndex( this->timeProc.data(), this->nProc );
+}
+
+SplitZone * Partition::GetLargestZone()
+{
+    SplitZone * largestZone = 0;
+
+    double nMaxCell = 0.0;
+
+    for ( std::set< SplitZone * >::iterator iter = unsignedZoneGroup.begin(); iter != unsignedZoneGroup.end(); ++ iter )
+    {
+        double nSize = ( * iter )->GetNCell();
+        if ( nMaxCell < nSize )
+        {
+            nMaxCell    = nSize;
+            largestZone = * iter;
+        }
+    }
+
+    return largestZone;
+}
+
+void Partition::Solve()
+{
+    std::cout << "Partition::Split()\n";
+    this->nProc = 2;
+    this->ReadGrid();
+    this->Split();
+    this->DumpPartitionedGridFile();
+    this->FreeAllZones();
+}
+
+void Partition::ReadGrid()
+{
+    ReadCgnsGrid( "../heat1dni81.cgns" );
+
+    this->nOriZone = ::Global::zones.size();
+
+    std::cout << "numberOfBlocks = " << nOriZone << "\n";
+
+    this->refZone.resize( nOriZone );
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        refZone[ iZone ] = new SplitZone();
+        refZone[ iZone ]->SetZoneIndex( iZone );
+        refZone[ iZone ]->oriZoneId = iZone;
+        refZone[ iZone ]->SetProcId( 0 );
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        Zone * zone = ::Global::zones[ iZone ];
+
+        splitZone->dimInfo.dimList = zone->nijk;
+
+        int nBcRegion = zone->bccos.size();
+        std::cout << "nBcRegion = " << nBcRegion << "\n";
+
+        std::vector< SplitBc * > & splitBcList = splitZone->splitBcList;
+
+        for ( int iBcRegion = 0; iBcRegion < nBcRegion; ++ iBcRegion )
+        {
+            SplitBc * splitBc = new SplitBc();
+            splitBcList.push_back( splitBc );
+
+            ZoneBc * zoneBc = zone->bccos[ iBcRegion ];
+
+            splitBc->splitZone = splitZone;
+            splitBc->bcType = zoneBc->bcType;
+            splitBc->SetRegion( zoneBc->pnts );
+        }
+
+        int kkk = 1;
+
+        //splitZone->NormalizeBc();
+    }
+}
+
+void Partition::Split()
+{
+    this->InitSplit();
+    this->BinarySplit();
+    //this->SetZoneIndex();
+}
+
+void Partition::InitSplit()
+{
+    //nZone is the number of zones in the original grid
+    //nProc is not the number of blocks in the end, but the number of processes that need to be divided.
+    //This difference occurs because the structure grid can have many blocks per process.
+
+    //this->nProc    = nProc;
+    //this->nPhyBlocks = referenceBlock.size();
+    //this->nZone  = this->nPhyBlocks;
+
+    //tj Computation time on processor j
+    //Nk Number of internal grid-cells for zone j
+    //aveFloatOp:  Number of Real operations per gridcell
+    //Gj The set of blocks allocated to process j
+    //Pj Real operations per second for process j
+
+    //The Greedy Load Balancing Algorithm
+    //1.Compute an "ideal" uniprocessor time, Tuni = sum ( Nk * aveFloatOp )/ sum( Pj ).
+    //2.Set the group of unassigned blocks, Gu, to contain all blocks. The number of blocks in Nu=M, where M is the total number of blocks in the mesh.
+    //3.Start all processors with a very small fictitious zone to get a start tj=delt aveFloatOp/Pj, where delt<<1 is the size of the very small fictious zone.
+    //This is used to find the fastest processor in a heterogeneous system, tj could otherwise be set to 0 in the homogeneous case.
+    this->aveFloatOp = 1.0;
+    this->delta      = 1.0e-5;
+    this->procSpeed.resize( nProc );
+    this->timeProc.resize( nProc );
+
+    this->nTZone = this->nOriZone;
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        procSpeed[ iProc ] = 1.0;
+    }
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        timeProc[ iProc ] = delta * aveFloatOp / procSpeed[ iProc ];
+    }
+
+    double sumProcSpeed = CalSumOfProcSpeed( procSpeed );
+
+    double sumProcOp = 0.0;
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        sumProcOp += refZone[ iZone ]->GetNCell() * aveFloatOp;
+    }
+
+    this->idealUniProcTime = sumProcOp / sumProcSpeed;
+
+    this->eps = 0.05;
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        unsignedZoneGroup.insert( refZone[ iZone ] );
+    }
+
+    //Init zoneStorage
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        zoneStorage.insert( refZone[ iZone ] );
+    }
+
+    //Assign procSplitZone to each process
+    procSplitZone.resize( nProc );
+
+    this->minNode = 3 * 3 * 2;
+}
+
+void Partition::FreeAllZones()
+{
+    int iCount = 0;
+    for ( std::set < SplitZone * >::iterator iter = zoneStorage.begin(); iter != zoneStorage.end(); ++ iter )
+    {
+        //cout << "iCount = " << iCount << "\n";
+        ++ iCount;
+        delete * iter;
+    }
+}
+
+int Partition::GetNZones( int iProc )
+{
+    return this->procSplitZone[ iProc ].size();
+}
+
+SplitZone * Partition::GetSplitZone( int iProc, int zoneId )
+{
+    return this->procSplitZone[ iProc ][ zoneId ];
+}
+
+void Partition::AddZoneToUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.insert( zone );
+}
+
+void Partition::RemoveZoneFromUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.erase( zone );
+}
+
+void Partition::AddZoneToProcess( int iProc, SplitZone * zone )
+{
+    this->procSplitZone[ iProc ].push_back( zone );
+}
+
+void Partition::AddNewZone( SplitZone * zone )
+{
+    zone->SetZoneIndex( nTZone ++ );
+
+    this->AddZoneToUnsignedGroup( zone );
+
+    this->zoneStorage.insert( zone );
+}
+
+SplitZone * Partition::Split( SplitZone * zone, double nCell )
+{
+    SplitZone * zoneL = 0;
+    SplitZone * zoneR = 0;
+
+    zone->Split( zoneL, zoneR, nCell );
+
+    this->AddNewZone( zoneL );
+    this->AddNewZone( zoneR );
+    this->RemoveZoneFromUnsignedGroup( zone );
+
+    return zoneL;
+}
+
+void Partition::BinarySplit()
+{
+    while ( ! unsignedZoneGroup.empty() )
+    {
+        std::cout << "number of unsigned zone = " << unsignedZoneGroup.size() << "\n";
+        int iProc = this->GetMinLoadProc();
+
+        //Get the block with the largest number of grids and its size
+        SplitZone * largestZone = this->GetLargestZone();
+
+        double nMaxCell = largestZone->GetNCell();
+
+        double aveFloatOp = this->aveFloatOp;
+        double tau = timeProc[ iProc ] + nMaxCell * aveFloatOp / procSpeed[ iProc ];
+
+        int kkk = 1;
+
+        //It seems that EPS is still necessary
+        //The idea here is as follows. For the candidate blocks which can be divided into blocks, 
+        //if the difference between the target blocks and the candidate blocks is too wide, 
+        //the binarySplit method is adopted. The binarySplit blocks do not directly join the process,
+        //but enter the next round of screening.
+
+        if ( tau > idealUniProcTime * ( 1.0 + eps ) )
+        {
+            double nRest = ( tau - idealUniProcTime ) * procSpeed[ iProc ] / aveFloatOp;
+
+            double nTarget = nMaxCell - nRest;
+            if ( nRest > this->minNode && nTarget > this->minNode )
+            {
+                //It is necessary to divide blocks only when a certain number of points are satisfied.
+                double nHalf = nMaxCell / 2.0;
+                nMaxCell = nTarget;
+                double ratio = nMaxCell / nRest;
+                double oRatio = 1.0 / ratio;
+
+                if ( std::max( ratio, oRatio ) < 3.0 )
+                {
+                    int kkk = 1;
+                    largestZone = this->Split( largestZone, nMaxCell );
+                    timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                    this->RemoveZoneFromUnsignedGroup( largestZone );
+                    this->AddZoneToProcess( iProc, largestZone );
+                }
+                else
+                {
+                    this->Split( largestZone, nHalf );
+                }
+            }
+            else
+            {
+                //If the block is of the right size, join the process directly, and there is no need to split it.
+                timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                this->RemoveZoneFromUnsignedGroup( largestZone );
+                this->AddZoneToProcess( iProc, largestZone );
+            }
+        }
+        else
+        {
+            //If the block is of the right size, join the process directly, and there is no need to split it.
+            timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+            this->RemoveZoneFromUnsignedGroup( largestZone );
+            this->AddZoneToProcess( iProc, largestZone );
+        }
+    }
+}
+
+void Partition::ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord )
+{
+    Zone * zone = Global::zones[ splitZone->oriZoneId ];
+    SplitZone * rootSplitZone = this->refZone[ splitZone->oriZoneId ];
+
+    int nNodes = splitZone->dimInfo.ComputeNumNodes();
+    std::cout << "nNodes = " << nNodes << "\n";
+
+    coord.resize( nNodes * sizeof(double) );
+
+    int index_dim = splitZone->dimInfo.dimList.size();
+    Coor * coor = zone->coors[ icoord ];
+
+    double * xlocal = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    double * xglobal = reinterpret_cast<double *>( const_cast<char *>( coor->coord.data() ) );
+    if ( index_dim == 1 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        for ( int i = imin; i < imax; ++ i )
+        {
+            xlocal[ icount++ ] = xglobal[ i ];
+        }
+    }
+    else if ( index_dim == 2 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        int jmin = splitZone->dimInfo.rmin[ 1 ] - 1;
+        int jmax = splitZone->dimInfo.rmax[ 1 ];
+        int ni = rootSplitZone->dimInfo.dimList[ 0 ];
+        int nj = rootSplitZone->dimInfo.dimList[ 1 ];
+        for ( int j = jmin; j < jmax; ++ j )
+        {
+            int jstride = j * ni;
+            for ( int i = imin; i < imax; ++ i )
+            {
+                xlocal[ icount++ ] = xglobal[ jstride + i ];
+            }
+        }
+    }
+}
+
+void Partition::DumpBc( SplitZone * splitZone )
+{
+}
+
+void Partition::DumpPartitionedGridFile()
+{
+    int fileId = -1;
+    std::string filename = "split1d.cgns";
+    cg_open( filename.c_str(), CG_MODE_WRITE, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        int icelldim = 1;
+        int iphysdim = 1;
+        std::string basename = "Base" + std::to_string( iProc );
+
+        int baseId = -1;
+        cg_base_write( fileId, basename.c_str(), icelldim, iphysdim, &baseId );
+
+        std::cout << "baseId = " << baseId << "\n";
+
+        int nZones = this->GetNZones( iProc );
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            ZoneType_t zoneType = Structured;
+
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+
+            int index_dim = splitZone->dimInfo.dimList.size();
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            splitZone->dimInfo.ComputeISize();
+
+            int isize_dim = index_dim * 3;
+
+            std::vector<cgsize_t> isize( index_dim * 3, 0 );
+            for ( int m = 0; m < isize_dim; ++ m )
+            {
+                isize[ m ] = splitZone->dimInfo.isize[ m ];
+            }
+
+            int zoneId = -1;
+
+            std::string zonename = "B" + std::to_string( iProc ) + "Zone" + std::to_string( iZone );
+            cg_zone_write( fileId, baseId, zonename.c_str(), isize.data(), zoneType, &zoneId );
+
+            std::cout << "zoneId = " << zoneId << "\n";
+                
+            splitZone->ComputeRminmax();
+
+            Zone * zone = Global::zones[ splitZone->oriZoneId ];
+            SplitZone * rootSplitZone = this->refZone[ splitZone->oriZoneId ];
+
+            int ncoords = zone->coors.size();
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = -1;
+                DataType_t dataType = RealDouble;
+                std::string coordname = "X";
+                Coor * coor = zone->coors[ icoord ];
+
+                int nNodes = splitZone->dimInfo.ComputeNumNodes();
+                std::cout << "nNodes = " << nNodes << "\n";
+
+                std::vector<char> coord;
+                ComputeCoor( splitZone, icoord, coord );
+
+                cg_coord_write( fileId, baseId, zoneId, dataType, coordname.c_str(), coord.data(), &coorId );
+
+                std::cout << "cg_get_error() = " << cg_get_error() << "\n";
+                std::cout << "fileId = " << fileId  << " baseId = " << baseId << " zoneId = " << zoneId  << " coorId = " << coorId << "\n";
+            }
+
+            std::vector<ZoneBc *> bccos;
+
+            //this->DumpBc( splitZone );
+
+            int nbocos = splitZone->splitBcList.size();
+
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = -1;
+                GridLocation_t location = Vertex;
+
+                std::string boconame = "BC" + std::to_string( iboco + 1 );
+
+                SplitBc * splitBc = splitZone->splitBcList[ iboco ];
+                BCType_t bocotype = static_cast<BCType_t>( splitBc->bcType );
+                PointSetType_t ptset_type = PointRange;
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> pnts;
+                int nSize = splitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.end[ i ] );
+                }
+
+                cg_boco_write( fileId, baseId, zoneId, boconame.c_str(), bocotype, ptset_type, npnts, pnts.data(), & bccoId);
+            }
+        }
+    }
+    cg_close(fileId);
+}
\ No newline at end of file
diff --git a/example/partition/struct/1d/01b/Partition.h b/example/partition/struct/1d/01b/Partition.h
new file mode 100644
index 00000000..cc2bb13f
--- /dev/null
+++ b/example/partition/struct/1d/01b/Partition.h
@@ -0,0 +1,164 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class SplitZone;
+class RangeRegion;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox );
+
+class DimInfo
+{
+public:
+    DimInfo();
+    ~DimInfo();
+public:
+    int dim;
+    std::vector<int> dimList;
+    std::vector<int> oriPoint;
+    std::vector<int> isize;
+    std::vector<int> rmin;
+    std::vector<int> rmax;
+public:
+    int GetSize() const { return dim; }
+    DimInfo & operator = ( const DimInfo & rhs );
+public:
+    int ComputeNumNodes();
+    void ComputeISize();
+    void ComputeRminmax( std::vector<int> & ref );
+    void Init( std::vector<int> & dimList );
+    void SetNewDimension( int axis, int newStart, int newWidth );
+    void GetZoneBox( RangeRegion & zoneBox );
+};
+
+class SplitZone;
+class SplitBcPatch;
+
+class RangeRegion
+{
+public:
+    RangeRegion( int nSize = 1 );
+    ~RangeRegion();
+public:
+    int regionAxis = -1;
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    RangeRegion & operator = ( const RangeRegion & rhs );
+    void SetRegion( std::vector<int> &pnts );
+    int ComputeRegionAxis();
+};
+
+class SplitBc
+{
+public:
+    SplitBc();
+    ~SplitBc();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone = nullptr;
+    SplitBcPatch * patch = nullptr;
+    std::vector< SplitBc * > * child = nullptr;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+public:
+    void SetZoneBcFromParentBc( SplitBc * parentSplitBc );
+    void InheritPatchBc( SplitBc * parentSplitBc );
+};
+
+class SplitBcPatch
+{
+public:
+    SplitBcPatch ();
+    ~SplitBcPatch();
+public:
+    int bcType;
+    int faceAxis;
+public:
+    SplitZone * splitZone;
+};
+
+
+class SplitZone
+{
+public:
+    SplitZone();
+    ~SplitZone();
+public:
+    DimInfo dimInfo;
+    int zoneIndex, iProc;
+    int oriZoneId;
+protected:
+    SplitZone * parent;
+public:
+    std::vector< SplitBc * > splitBcList;
+public:
+    int GetNCell();
+    void ComputeRminmax();
+    void GetRootInfo( SplitZone *& root, std::vector<int> & ref );
+    void SetZoneIndex( int zoneIndex ) { this->zoneIndex = zoneIndex; }
+    int  GetZoneIndex() { return zoneIndex; }
+    void SetProcId( int iProc ) { this->iProc = iProc; }
+    void SetParent( SplitZone * parent ) { this->parent = parent; };
+    std::vector< SplitBc * > & GetSplitBcList() { return this->splitBcList; };
+    void CreateBcFromParent();
+    void CreateSplitBc( SplitBc * parentSplitBc );
+    void AddSplitBc( SplitBc * splitBc );
+public:
+    void Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell );
+    void SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+    void SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+private:
+    int FindAxisNeedSplit();
+    int FindSplitPosition( int axisNeedSplit, double nCell );
+    bool IsPoleBc( int splitDirection );
+    int GetCrossSection( int axis );
+};
+
+class Partition
+{
+public:
+    Partition();
+    ~Partition();
+protected:
+    std::set < SplitZone * > zoneStorage;
+    std::set < SplitZone * > unsignedZoneGroup;
+    std::vector< SplitZone * > refZone;
+    std::vector< std::vector< SplitZone * > > procSplitZone;
+    std::vector<double> procSpeed;
+    std::vector<double> timeProc;
+    double aveFloatOp, delta;
+    double idealUniProcTime, eps;
+    double minNode;
+    int nTZone;
+    int nOriZone;
+    int nProc;
+public:
+    void Solve();
+    void ReadGrid();
+    void Split();
+    void InitSplit();
+    void BinarySplit();
+    //void GreedySplit();
+public:
+    void AddNewZone( SplitZone * zone );
+    void AddZoneToUnsignedGroup( SplitZone * zone );
+    void RemoveZoneFromUnsignedGroup( SplitZone * zone );
+    void AddZoneToProcess( int iProc, SplitZone * zone );
+    void DumpPartitionedGridFile();
+    void FreeAllZones();
+    int GetNZones( int iProc );
+    SplitZone * GetSplitZone( int iProc, int zoneId );
+    void ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord );
+    void DumpBc( SplitZone * splitZone );
+private:
+    int GetMinValueIndex( double * data, int numberOfData );
+    int GetMinLoadProc();
+    SplitZone * GetLargestZone();
+    SplitZone * Split( SplitZone * zone, double nCell );
+};
+
diff --git a/example/partition/struct/1d/01b/README.txt b/example/partition/struct/1d/01b/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/partition/struct/1d/01b/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/partition/struct/1d/01b/heat1dni81.cgns b/example/partition/struct/1d/01b/heat1dni81.cgns
new file mode 100644
index 00000000..b7d4954a
Binary files /dev/null and b/example/partition/struct/1d/01b/heat1dni81.cgns differ
diff --git a/example/partition/struct/1d/01b/main.cpp b/example/partition/struct/1d/01b/main.cpp
new file mode 100644
index 00000000..5da1de7c
--- /dev/null
+++ b/example/partition/struct/1d/01b/main.cpp
@@ -0,0 +1,18 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include "Partition.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip>
+
+int main(int argc, char **argv)
+{
+    Partition * partition = new Partition();
+    partition->Solve();
+    delete partition;
+
+    return 0;
+}
diff --git a/example/partition/struct/1d/01c/CMakeLists.txt b/example/partition/struct/1d/01c/CMakeLists.txt
new file mode 100644
index 00000000..9fa577c8
--- /dev/null
+++ b/example/partition/struct/1d/01c/CMakeLists.txt
@@ -0,0 +1,77 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	Partition.h Partition.cpp
+	CgnsGrid.h CgnsGrid.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/partition/struct/1d/01c/CgnsGrid.cpp b/example/partition/struct/1d/01c/CgnsGrid.cpp
new file mode 100644
index 00000000..e58aa1ec
--- /dev/null
+++ b/example/partition/struct/1d/01c/CgnsGrid.cpp
@@ -0,0 +1,231 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+Grid::Grid()
+{
+    ;
+}
+
+Grid::~Grid()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if( (i+1)%5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+std::vector<Zone *> Global::zones;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+Global::Global()
+{
+    ;
+}
+
+Global::~Global()
+{
+}
+
+void Global::FreeData()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+    zones.resize( 0 );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones(fileId, baseId, &nzones);
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize(index_dim*3);
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[33];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                std::vector<char> coord( nNodes * sizeof(double) );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+                coor->DumpCoor();
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex(index_dim,-1);
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type, 
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset);
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[i] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[normalDataType] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList(nNodes*iphysdim*sizeof(double));
+
+                std::vector<cgsize_t> pnts(npnts*index_dim);
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double*>(const_cast<char *>(normalList.data()));
+
+                //std::cout << "normalList = ";
+                //for ( int i = 0; i < nNodes*iphysdim; ++ i )
+                //{
+                //    std::cout << normal_d[ i ] << " ";
+                //}
+                //std::cout << "\n";
+            }
+        }
+    }
+    cg_close(fileId);
+}
\ No newline at end of file
diff --git a/example/partition/struct/1d/01c/CgnsGrid.h b/example/partition/struct/1d/01c/CgnsGrid.h
new file mode 100644
index 00000000..b84abd1d
--- /dev/null
+++ b/example/partition/struct/1d/01c/CgnsGrid.h
@@ -0,0 +1,69 @@
+#pragma once
+#include <iostream>
+#include <vector>
+
+class Grid;
+
+class Zone;
+
+class Grid
+{
+public:
+    Grid();
+    ~Grid();
+public:
+    int nZone;
+    std::vector<double> x;
+    std::vector<Zone *> zones;
+};
+
+class ZoneBc;
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+};
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<Coor *> coors;
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    std::vector<int> pnts;
+};
+
+class Global
+{
+public:
+    Global();
+    ~Global();
+public:
+    static std::vector<Zone *> zones;
+    static void FreeData();
+    static int cell_dim;
+    static int phys_dim;
+};
+
+void ReadCgnsGrid( const std::string & filename );
diff --git a/example/partition/struct/1d/01c/Partition.cpp b/example/partition/struct/1d/01c/Partition.cpp
new file mode 100644
index 00000000..5011f918
--- /dev/null
+++ b/example/partition/struct/1d/01c/Partition.cpp
@@ -0,0 +1,1248 @@
+#include "Partition.h"
+#include "CgnsGrid.h"
+#include "cgnslib.h"
+#include <string>
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox  )
+{
+    domainBox.start = zoneBox.start;
+    domainBox.end = zoneBox.end;
+
+    int axis = iDomain / 2;
+    int direction = iDomain % 2;
+
+    if ( direction == 0 )
+    {
+        domainBox.end[ axis ] = domainBox.start[ axis ];
+    }
+    else if ( direction == 1 )
+    {
+        domainBox.start[ axis ] = domainBox.end[ axis ];
+    }
+}
+
+DimInfo::DimInfo()
+{
+    this->dim = 1;
+    dimList.resize( this->dim, 1 );
+    oriPoint.resize( this->dim, 0 );
+}
+
+DimInfo::~DimInfo()
+{
+}
+
+DimInfo & DimInfo::operator = ( const DimInfo & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->dim = rhs.dim;
+    this->dimList = rhs.dimList;
+    this->oriPoint = rhs.oriPoint;
+
+    return * this;
+}
+
+int DimInfo::ComputeNumNodes()
+{
+    int nNodes = 1;
+    for ( int m = 0; m < this->dimList.size(); ++ m )
+    {
+        nNodes *= this->dimList[ m ];
+    }
+    return nNodes;
+}
+
+void DimInfo::ComputeISize()
+{
+    int index_dim = this->dimList.size();
+    this->isize.resize( index_dim * 3, 0 );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        isize[ m ] = this->dimList[ m ];
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 1;
+        isize[ start + m ] = this->dimList[ m ] - 1;
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 2;
+        isize[ start + m ] = 0;
+    }
+
+    for ( int i = 0; i < isize.size(); ++ i )
+    {
+        std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+    }
+}
+
+void DimInfo::ComputeRminmax( std::vector<int> & ref )
+{
+    int index_dim = this->dimList.size();
+    this->rmin.resize( index_dim );
+    this->rmax.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        rmin[ m ] = ref[ m ] + 1;
+        rmax[ m ] = ref[ m ] + this->dimList[ m ];
+    }
+
+    std::cout << "rmin, rmax = \n";
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        std::cout << rmin[ m ] << " " << rmax[ m ] << "\n";
+    }
+}
+
+void DimInfo::Init( std::vector<int> & dimList )
+{
+    this->dimList = dimList;
+    std::vector<int> zero( dimList.size(), 0 );
+    this->oriPoint = zero;
+}
+
+void DimInfo::SetNewDimension( int axis, int newStart, int newWidth )
+{
+    this->oriPoint[ axis ] = newStart;
+    this->dimList [ axis ] = newWidth;
+}
+
+void DimInfo::GetZoneGlobalBox( RangeRegion &zoneBox )
+{
+    int index_dim = this->dimList.size();
+    zoneBox.start.resize( index_dim );
+    zoneBox.end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        zoneBox.start[ m ] = this->oriPoint[ m ] + 1;
+        zoneBox.end[ m ] = this->oriPoint[ m ] + this->dimList[ m ];
+    }
+}
+
+void DimInfo::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    int index_dim = this->dimList.size();
+    localBox.start.resize( index_dim );
+    localBox.end.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        localBox.start[ m ] = globalBox.start[ m ] - this->oriPoint[ m ];
+        localBox.end[ m ] = globalBox.end[ m ] - this->oriPoint[ m ];
+    }
+}
+
+RangeRegion::RangeRegion( int nSize )
+{
+    this->start.resize( nSize );
+    this->end.resize( nSize );
+}
+
+RangeRegion::~RangeRegion()
+{
+}
+
+RangeRegion & RangeRegion::operator = ( const RangeRegion & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+    this->regionAxis = rhs.regionAxis;
+
+    return * this;
+}
+
+bool RangeRegion::operator == ( const RangeRegion & rhs ) const
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] != rhs.start[ m ] || 
+            this->end  [ m ] != rhs.end  [ m ] )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+    this->ComputeRegionAxis();
+}
+
+int RangeRegion::ComputeRegionAxis()
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] == this->end[ m ] )
+        {
+            this->regionAxis = m;
+            return this->regionAxis;
+        }
+    }
+    return this->regionAxis;
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion );
+
+bool ComputeOverlapRegion( RangeRegion & region1, RangeRegion & region2, RangeRegion & overlapRegion )
+{
+    int index_dim = region1.start.size();
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        overlapRegion.start[ m ] = std::max( region1.start[ m ], region2.start[ m ] );
+        overlapRegion.end  [ m ] = std::min( region1.end  [ m ], region2.end  [ m ] );
+    }
+
+    return CheckOverLapping( overlapRegion );
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion )
+{
+    int index_dim = overlapRegion.start.size();
+    int iCount = 0;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        if ( overlapRegion.start[ m ] == overlapRegion.end[ m ] )
+        {
+            ++ iCount;
+        }
+    }
+
+    return ( iCount == 1 );
+}
+
+SplitBc * CreateSplitBc( RangeRegion & bcRegion, RangeRegion & zoneDomainRegion )
+{
+    int sRegionAxis = bcRegion.ComputeRegionAxis();
+    int tRegionAxis = zoneDomainRegion.ComputeRegionAxis();
+
+    //Two regions in different directions
+    if ( sRegionAxis != tRegionAxis )
+    {
+        return 0;
+    }
+
+    //Although the two regions are in the same direction, the coordinates are inconsistent.
+    if ( bcRegion.start[ sRegionAxis ] != zoneDomainRegion.start[ sRegionAxis ] )
+    {
+        return 0;
+    }
+
+    RangeRegion overlapRegion;
+    ComputeOverlapRegion( bcRegion, zoneDomainRegion, overlapRegion );
+
+    if ( CheckOverLapping( overlapRegion ) )
+    {
+        SplitBc * splitBc = new SplitBc();
+        splitBc->SetRegion( overlapRegion );
+        return splitBc;
+    }
+
+    int kkk = 1;
+
+    return 0;
+}
+
+bool GetInterfaceRegion( RangeRegion & zoneBoxL, RangeRegion & zoneBoxR, RangeRegion & interfaceRegion )
+{
+    int index_dim = zoneBoxL.start.size();
+    int nDomains = 2 * index_dim;
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegionL;
+        GetDomainRegion( zoneBoxL, iDomain, domainRegionL );
+
+        for ( int jDomain = 0; jDomain < nDomains; ++ jDomain )
+        {
+            RangeRegion domainRegionR;
+            GetDomainRegion( zoneBoxR, jDomain, domainRegionR );
+
+            if ( domainRegionL == domainRegionR )
+            {
+                interfaceRegion = domainRegionL;
+                return true;
+            }
+        }
+    }
+    return false;
+}
+
+void CreateInterfaceBc( SplitZone * zoneL, SplitZone * zoneR )
+{
+    RangeRegion globalBoxL, globalBoxR, globalInterfaceRegion;
+
+    zoneL->GetZoneGlobalBox( globalBoxL );
+    zoneR->GetZoneGlobalBox( globalBoxR );
+
+    if ( ! GetInterfaceRegion( globalBoxL, globalBoxR, globalInterfaceRegion ) )
+    {
+        int kkk = 1;
+        return;
+    }
+
+    RangeRegion localInterfaceRegionL, localInterfaceRegionR;
+
+    zoneL->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionL );
+    zoneR->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionR );
+
+    int kkk = 1;
+
+    SplitBc * splitBcL = new SplitBc();
+    zoneL->AddSplitBc( splitBcL );
+
+    SplitBc * splitBcR = new SplitBc();
+    zoneR->AddSplitBc( splitBcR );
+
+    splitBcL->splitZone = zoneL;
+    splitBcL->SetRegion( localInterfaceRegionL );
+    splitBcL->bcType = BCTypeUserDefined;
+
+    splitBcR->splitZone = zoneR;
+    splitBcR->SetRegion( localInterfaceRegionR );
+    splitBcR->bcType = BCTypeUserDefined;
+
+    //localInterfaceRegionL.MarkPatchBc();
+    //localInterfaceRegionR.MarkPatchBc();
+
+    SplitBcPatch * splitBcPatchL = new SplitBcPatch();
+    splitBcL->patch = splitBcPatchL;
+    splitBcPatchL->region = localInterfaceRegionR;
+    splitBcPatchL->splitZone = zoneR;
+
+    SplitBcPatch * splitBcPatchR = new SplitBcPatch();
+    splitBcR->patch = splitBcPatchR;
+    splitBcPatchR->region = localInterfaceRegionL;
+    splitBcPatchR->splitZone = zoneL;
+
+    //splitBcL->Normalize();
+    //splitBcR->Normalize();
+}
+
+
+SplitBc::SplitBc()
+{
+}
+
+SplitBc::~SplitBc()
+{
+    delete this->patch;
+}
+
+void SplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void SplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+void SplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = splitZone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void SplitBc::SetZoneBcFromParentBc( SplitBc * parentSplitBc )
+{
+    this->bcType = parentSplitBc->bcType;
+    //this->LocalCoordinate();
+    this->region.regionAxis = parentSplitBc->region.regionAxis;
+    this->InheritPatchBc( parentSplitBc );
+}
+
+void SplitBc::InheritPatchBc( SplitBc * parentSplitBc )
+{
+    if ( ! ( this->bcType < 0 ) ) return;
+
+    this->patch = new SplitBcPatch();
+
+    this->patch->splitZone = parentSplitBc->patch->splitZone;
+    //this->patch->faceAxis = parentSplitBc->patch->faceAxis;
+
+    //( * this->patch->vertexMap ) = ( * parentBc->patch->vertexMap );
+
+    ////È»ºó½øÐÐÐÞÕý
+    ////block1->map 1, 33 -> block1 369, 337
+    ////block2->global -> map 1, 33 -> block1 369, 337
+    ////block2->local  -> map 1, 33 -> block1 369, 337
+    ////refOld + M * stold           = block1Startold
+    ////refOld + M * ( stnew + ref ) = block1Startold
+    ////refNew = refOld + M * ( ref )
+
+    //for ( int m = 0; m < 3; ++ m )
+    //{
+    //    for ( int n = 0; n < 3; ++ n )
+    //    {
+    //        this->patch->vertexMap->pt[ m ] += this->patch->vertexMap->vm[ m ][ n ] * ( this->splitZone->sdim->oriPoint )[ n ];
+    //    }
+    //}
+
+    //RangeBox tRangeBox;
+
+    //MappingPatchPoint( this->patch, this->rangeBox, tRangeBox );
+    //tRangeBox.SetOrder();
+
+    ////ÕÒµ½ºÍ±¾¶Ô½Ó±ß½çÏà¶ÔÓ¦µÄ¿é
+    ////´Ópatch->splitZone°´ÕÕoverlapµÄ´óСÕÒµ½¶ÔÓ¦µÄ¶Ô½Ó±ß½ç£¬ÕâÑùÖÁÉÙ¿ÉÒÔÕÒµ½
+    ////¶ÔÃæµÄ¶Ô½Ó±ß½çÌõ¼þÓÉÓÚ±¾¿éµÄsplit±ØȻҪ·¢Éú¸Ä±ä£¬ÕâÀｫÏà¹Ø±ß½ç¼ÓÈë×ӱ߽ç
+    //this->patch->splitZone->CreateChildPatchBc( tRangeBox, this->splitZone );
+}
+
+SplitBcPatch::SplitBcPatch()
+{
+}
+
+SplitBcPatch::~SplitBcPatch()
+{
+}
+
+SplitZone::SplitZone()
+{
+    this->parent  = 0;
+    this->zoneIndex = 0;
+    this->iProc = 0;
+}
+
+SplitZone::~SplitZone()
+{
+    ;
+}
+
+void SplitZone::GetZoneGlobalBox( RangeRegion & zoneBox )
+{
+    this->dimInfo.GetZoneGlobalBox( zoneBox );
+}
+
+void SplitZone::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    this->dimInfo.GetZoneLocalBox( globalBox, localBox );
+}
+
+
+void SplitZone::ComputeRminmax()
+{
+    int index_dim = this->dimInfo.dimList.size();
+    std::vector<int> ref( index_dim, 0 );
+
+    SplitZone * rootSplitZone = 0;
+    this->GetRootInfo( rootSplitZone, ref );
+
+    this->dimInfo.ComputeRminmax( ref );
+}
+
+SplitZone * SplitZone::GetRootZone()
+{
+    SplitZone * root = this;
+
+    while ( true )
+    {
+        if ( root->parent )
+        {
+            root = root->parent;
+        }
+        else
+        {
+            return root;
+        }
+    };
+}
+
+void SplitZone::GetRootInfo( SplitZone *& root, std::vector<int> & ref )
+{
+    for ( int i = 0; i < this->dimInfo.dimList.size(); ++ i )
+    {
+        ref[ i ] += this->dimInfo.oriPoint[ i ];
+    }
+
+    if ( this->parent )
+    {
+        this->parent->GetRootInfo( root, ref );
+    }
+    else
+    {
+        root = this;
+    }
+}
+
+
+int SplitZone::GetNCell()
+{
+    int numberOfCells = 1;
+    for ( int i = 0; i < this->dimInfo.dim; ++ i )
+    {
+        numberOfCells *= std::max( 1, ( this->dimInfo.dimList[ i ] - 1 ) );
+    }
+
+    return numberOfCells; 
+}
+
+void SplitZone::SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int leftStart = 0;
+    int leftWidth = iSplit - 0;
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, leftStart , leftWidth  );
+}
+
+void SplitZone::SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int rightStart = iSplit - 1;
+    int rightWidth = dimList[ axisNeedSplit ] - ( iSplit - 1 );
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, rightStart, rightWidth );
+}
+
+void SplitZone::Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell )
+{
+    //Find the longest axis
+    int axisNeedSplit = this->FindAxisNeedSplit();
+    int iSplit        = this->FindSplitPosition( axisNeedSplit, nCell );
+
+    zoneL = new SplitZone();
+    zoneL->SetParent( this );
+
+    zoneR = new SplitZone();
+    zoneR->SetParent( this );
+
+    zoneL->SetLeftDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+    zoneR->SetRightDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+
+    zoneL->CreateBcFromParent();
+    zoneR->CreateBcFromParent();
+
+    CreateInterfaceBc( zoneL, zoneR );
+}
+
+void SplitZone::CreateBcFromParent()
+{
+    std::vector< SplitBc * > & parentSplitBcList = this->parent->GetSplitBcList();
+
+    int nParentSplitBcs = parentSplitBcList.size();
+
+    for ( int iParentBc = 0; iParentBc < nParentSplitBcs; ++ iParentBc )
+    {
+        SplitBc * parentSplitBc = parentSplitBcList[ iParentBc ];
+
+        this->CreateSplitBc( parentSplitBc );
+    }
+}
+
+void SplitZone::AddSplitBc( SplitBc * splitBc )
+{
+    if ( ! splitBc ) return;
+    this->splitBcList.push_back( splitBc );
+}
+
+void SplitZone::CreateSplitBc( SplitBc * parentSplitBc )
+{
+    if ( ! parentSplitBc->child )
+    {
+        int index_dim = this->dimInfo.dimList.size();
+        int nDomains = 2 * index_dim;
+        RangeRegion zoneBoxRegion( index_dim );
+        this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+        for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+        {
+            RangeRegion domainRegion( index_dim );
+            GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+            RangeRegion overlapRegion;
+            bool overlap_flag = ComputeOverlapRegion( parentSplitBc->region, domainRegion, overlapRegion );
+            if ( ! overlap_flag ) continue;
+
+            SplitBc * splitBc = new SplitBc();
+            this->AddSplitBc( splitBc );
+
+            splitBc->SetRegion( overlapRegion );
+            splitBc->bcType = parentSplitBc->bcType;
+            splitBc->splitZone = this;
+            splitBc->ChangeRegionToLocalCoordinate();
+            //splitBc->CreatePatchBc( parentSplitBc );
+
+            int kkk = 1;
+        }
+    }
+    else
+    {
+        int nChilds = parentSplitBc->child->size();
+        for ( int iChild = 0; iChild < nChilds; ++ iChild )
+        {
+            this->CreateSplitBc( ( * parentSplitBc->child )[ iChild ] );
+        }
+    }
+}
+
+
+int SplitZone::FindAxisNeedSplit()
+{
+    //Find the longest axis
+    int axisNeedSplit = 0;
+    int maxN = this->dimInfo.dimList[ 0 ];
+
+    for ( int m = 1; m < this->dimInfo.dimList.size(); ++ m )
+    {
+        if ( this->IsPoleBc( m ) )
+        {
+            continue;
+        }
+        int Nm = this->dimInfo.dimList[ m ];
+        if ( maxN < Nm )
+        {
+            maxN = Nm;
+            axisNeedSplit = m;
+        }
+    }
+
+    return axisNeedSplit;
+}
+
+int SplitZone::GetCrossSection( int axis )
+{
+    int nDim = this->dimInfo.dimList.size();
+    int crossSection = 1;
+    int N = nDim - 1;
+    for ( int m = 0; m < N; ++ m )
+    {
+         int mm = ( axis + 1 ) % nDim;
+         int nLineElements = std::max( 1, ( this->dimInfo.dimList[ mm ] - 1 ) );
+         crossSection *= nLineElements;
+    }
+    return crossSection;
+}
+
+int SplitZone::FindSplitPosition( int axisNeedSplit, double nCell )
+{
+    int nDim = this->dimInfo.dimList.size();
+    std::vector<int> crossSections( nDim );
+    for ( int m = 0; m < nDim; ++ m )
+    {
+        crossSections[ m ] = this->GetCrossSection( m );
+    }
+
+    //guess the value
+    double dSplit = nCell / crossSections[ axisNeedSplit ];
+    int  iSplit = 1 + static_cast< int >( std::floor( dSplit + 0.5 ) );
+    return iSplit;
+}
+
+
+bool SplitZone::IsPoleBc( int splitDirection )
+{
+    return false;
+}
+
+
+double CalSumOfProcSpeed( std::vector<double> & procSpeed );
+double CalSumOfProcSpeed( std::vector<double> & procSpeed )
+{
+    int nProc = procSpeed.size();
+    double sumOfProcSpeed = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        sumOfProcSpeed += procSpeed[ iProc ];
+    }
+    return sumOfProcSpeed;
+}
+
+Partition::Partition()
+{
+    ;
+}
+
+Partition::~Partition()
+{
+    ;
+}
+
+int Partition::GetMinValueIndex( double * data, int numberOfData )
+{
+    double minValue = data[ 0 ];
+    int minimumValueIndex = 0;
+
+    for ( int iData = 1; iData < numberOfData; ++ iData )
+    {
+        if ( minValue > data[ iData ] )
+        {
+            minValue      = data[ iData ];
+            minimumValueIndex = iData;
+        }
+    }
+    return minimumValueIndex;
+}
+
+int Partition::GetMinLoadProc()
+{
+    return this->GetMinValueIndex( this->timeProc.data(), this->nProc );
+}
+
+SplitZone * Partition::GetLargestZone()
+{
+    SplitZone * largestZone = 0;
+
+    double nMaxCell = 0.0;
+
+    for ( std::set< SplitZone * >::iterator iter = unsignedZoneGroup.begin(); iter != unsignedZoneGroup.end(); ++ iter )
+    {
+        double nSize = ( * iter )->GetNCell();
+        if ( nMaxCell < nSize )
+        {
+            nMaxCell    = nSize;
+            largestZone = * iter;
+        }
+    }
+
+    return largestZone;
+}
+
+void Partition::Solve()
+{
+    std::cout << "Partition::Split()\n";
+    this->nProc = 2;
+    this->ReadGrid();
+    this->Split();
+    this->ModifyZoneIndex();
+    this->DumpPartitionedGridFile();
+    this->FreeAllZones();
+}
+
+void Partition::ReadGrid()
+{
+    ReadCgnsGrid( "../heat1dni81.cgns" );
+
+    this->nOriZone = ::Global::zones.size();
+
+    std::cout << "numberOfBlocks = " << nOriZone << "\n";
+
+    this->refZone.resize( nOriZone );
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = new SplitZone();
+        refZone[ iZone ] = splitZone;
+
+        splitZone->SetZoneIndex( iZone );
+        splitZone->SetProcId( 0 );
+        splitZone->SetParent( 0 );
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        Zone * zone = ::Global::zones[ iZone ];
+
+        splitZone->dimInfo.dimList = zone->nijk;
+
+        int nBcRegion = zone->bccos.size();
+        std::cout << "nBcRegion = " << nBcRegion << "\n";
+
+        std::vector< SplitBc * > & splitBcList = splitZone->splitBcList;
+
+        for ( int iBcRegion = 0; iBcRegion < nBcRegion; ++ iBcRegion )
+        {
+            SplitBc * splitBc = new SplitBc();
+            splitBcList.push_back( splitBc );
+
+            ZoneBc * zoneBc = zone->bccos[ iBcRegion ];
+
+            splitBc->splitZone = splitZone;
+            splitBc->bcType = zoneBc->bcType;
+            splitBc->SetRegion( zoneBc->pnts );
+        }
+
+        int kkk = 1;
+
+        //splitZone->NormalizeBc();
+    }
+}
+
+void Partition::Split()
+{
+    this->InitSplit();
+    this->BinarySplit();
+    //this->SetZoneIndex();
+}
+
+void Partition::InitSplit()
+{
+    //nZone is the number of zones in the original grid
+    //nProc is not the number of blocks in the end, but the number of processes that need to be divided.
+    //This difference occurs because the structure grid can have many blocks per process.
+
+    //this->nProc    = nProc;
+    //this->nPhyBlocks = referenceBlock.size();
+    //this->nZone  = this->nPhyBlocks;
+
+    //tj Computation time on processor j
+    //Nk Number of internal grid-cells for zone j
+    //aveFloatOp:  Number of Real operations per gridcell
+    //Gj The set of blocks allocated to process j
+    //Pj Real operations per second for process j
+
+    //The Greedy Load Balancing Algorithm
+    //1.Compute an "ideal" uniprocessor time, Tuni = sum ( Nk * aveFloatOp )/ sum( Pj ).
+    //2.Set the group of unassigned blocks, Gu, to contain all blocks. The number of blocks in Nu=M, where M is the total number of blocks in the mesh.
+    //3.Start all processors with a very small fictitious zone to get a start tj=delt aveFloatOp/Pj, where delt<<1 is the size of the very small fictious zone.
+    //This is used to find the fastest processor in a heterogeneous system, tj could otherwise be set to 0 in the homogeneous case.
+    this->aveFloatOp = 1.0;
+    this->delta      = 1.0e-5;
+    this->procSpeed.resize( nProc );
+    this->timeProc.resize( nProc );
+
+    this->nTZone = this->nOriZone;
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        procSpeed[ iProc ] = 1.0;
+    }
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        timeProc[ iProc ] = delta * aveFloatOp / procSpeed[ iProc ];
+    }
+
+    double sumProcSpeed = CalSumOfProcSpeed( procSpeed );
+
+    double sumProcOp = 0.0;
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        sumProcOp += refZone[ iZone ]->GetNCell() * aveFloatOp;
+    }
+
+    this->idealUniProcTime = sumProcOp / sumProcSpeed;
+
+    this->eps = 0.05;
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        unsignedZoneGroup.insert( refZone[ iZone ] );
+    }
+
+    //Init zoneStorage
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        zoneStorage.insert( refZone[ iZone ] );
+    }
+
+    //Assign procSplitZone to each process
+    procSplitZone.resize( nProc );
+
+    int index_dim = Global::cell_dim;
+    this->minNode = 1;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->minNode *= 2;
+    }
+
+    int kkk = 1;
+
+}
+
+void Partition::FreeAllZones()
+{
+    int iCount = 0;
+    for ( std::set < SplitZone * >::iterator iter = zoneStorage.begin(); iter != zoneStorage.end(); ++ iter )
+    {
+        //cout << "iCount = " << iCount << "\n";
+        ++ iCount;
+        delete * iter;
+    }
+}
+
+int Partition::GetNZones( int iProc )
+{
+    return this->procSplitZone[ iProc ].size();
+}
+
+SplitZone * Partition::GetSplitZone( int iProc, int zoneId )
+{
+    return this->procSplitZone[ iProc ][ zoneId ];
+}
+
+void Partition::AddZoneToUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.insert( zone );
+}
+
+void Partition::RemoveZoneFromUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.erase( zone );
+}
+
+void Partition::AddZoneToProcess( int iProc, SplitZone * zone )
+{
+    this->procSplitZone[ iProc ].push_back( zone );
+}
+
+void Partition::AddNewZone( SplitZone * zone )
+{
+    zone->SetZoneIndex( nTZone ++ );
+
+    this->AddZoneToUnsignedGroup( zone );
+
+    this->zoneStorage.insert( zone );
+}
+
+SplitZone * Partition::Split( SplitZone * zone, double nCell )
+{
+    SplitZone * zoneL = 0;
+    SplitZone * zoneR = 0;
+
+    zone->Split( zoneL, zoneR, nCell );
+
+    this->AddNewZone( zoneL );
+    this->AddNewZone( zoneR );
+    this->RemoveZoneFromUnsignedGroup( zone );
+
+    return zoneL;
+}
+
+void Partition::BinarySplit()
+{
+    while ( ! unsignedZoneGroup.empty() )
+    {
+        std::cout << "number of unsigned zone = " << unsignedZoneGroup.size() << "\n";
+        int iProc = this->GetMinLoadProc();
+
+        //Get the block with the largest number of grids and its size
+        SplitZone * largestZone = this->GetLargestZone();
+
+        double nMaxCell = largestZone->GetNCell();
+
+        double aveFloatOp = this->aveFloatOp;
+        double tau = timeProc[ iProc ] + nMaxCell * aveFloatOp / procSpeed[ iProc ];
+
+        int kkk = 1;
+
+        //It seems that EPS is still necessary
+        //The idea here is as follows. For the candidate blocks which can be divided into blocks, 
+        //if the difference between the target blocks and the candidate blocks is too wide, 
+        //the binarySplit method is adopted. The binarySplit blocks do not directly join the process,
+        //but enter the next round of screening.
+
+        if ( tau > idealUniProcTime * ( 1.0 + eps ) )
+        {
+            double nRest = ( tau - idealUniProcTime ) * procSpeed[ iProc ] / aveFloatOp;
+
+            double nTarget = nMaxCell - nRest;
+            if ( nRest > this->minNode && nTarget > this->minNode )
+            {
+                //It is necessary to divide blocks only when a certain number of points are satisfied.
+                double nHalf = nMaxCell / 2.0;
+                nMaxCell = nTarget;
+                double ratio = nMaxCell / nRest;
+                double oRatio = 1.0 / ratio;
+
+                if ( std::max( ratio, oRatio ) < 3.0 )
+                {
+                    int kkk = 1;
+                    largestZone = this->Split( largestZone, nMaxCell );
+                    timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                    this->RemoveZoneFromUnsignedGroup( largestZone );
+                    this->AddZoneToProcess( iProc, largestZone );
+                }
+                else
+                {
+                    this->Split( largestZone, nHalf );
+                }
+            }
+            else
+            {
+                //If the block is of the right size, join the process directly, and there is no need to split it.
+                timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                this->RemoveZoneFromUnsignedGroup( largestZone );
+                this->AddZoneToProcess( iProc, largestZone );
+            }
+        }
+        else
+        {
+            //If the block is of the right size, join the process directly, and there is no need to split it.
+            timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+            this->RemoveZoneFromUnsignedGroup( largestZone );
+            this->AddZoneToProcess( iProc, largestZone );
+        }
+    }
+}
+
+void Partition::ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord )
+{
+    SplitZone * rootSplitZone = splitZone->GetRootZone();
+    Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+    int nNodes = splitZone->dimInfo.ComputeNumNodes();
+    std::cout << "nNodes = " << nNodes << "\n";
+
+    coord.resize( nNodes * sizeof(double) );
+
+    int index_dim = splitZone->dimInfo.dimList.size();
+    Coor * coor = zone->coors[ icoord ];
+
+    double * xlocal = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    double * xglobal = reinterpret_cast<double *>( const_cast<char *>( coor->coord.data() ) );
+    if ( index_dim == 1 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        for ( int i = imin; i < imax; ++ i )
+        {
+            xlocal[ icount++ ] = xglobal[ i ];
+        }
+    }
+    else if ( index_dim == 2 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        int jmin = splitZone->dimInfo.rmin[ 1 ] - 1;
+        int jmax = splitZone->dimInfo.rmax[ 1 ];
+        int ni = rootSplitZone->dimInfo.dimList[ 0 ];
+        int nj = rootSplitZone->dimInfo.dimList[ 1 ];
+        for ( int j = jmin; j < jmax; ++ j )
+        {
+            int jstride = j * ni;
+            for ( int i = imin; i < imax; ++ i )
+            {
+                xlocal[ icount++ ] = xglobal[ jstride + i ];
+            }
+        }
+    }
+}
+
+void Partition::DumpBc( SplitZone * splitZone )
+{
+    //std::vector< ZoneBc * > leafZoneBc;
+
+    //std::vector< ZoneBc * > & zoneBcList = splitZone->GetZoneBcList();
+
+    //for ( int i = 0; i < zoneBcList.size(); ++ i )
+    //{
+    //    std::vector< ZoneBc * > cl = zoneBcList[ i ]->GetLeaves();
+    //    for ( int j = 0; j < cl.size(); ++ j )
+    //    {
+    //        leafZoneBc.push_back( cl[ j ] );
+    //    }
+    //}
+
+    //int nZoneBc = leafZoneBc.size();
+
+    //for ( int iZoneBc = 0; iZoneBc < nZoneBc; ++ iZoneBc )
+    //{
+    //    ZoneBc * zoneBc = leafZoneBc[ iZoneBc ];
+    //    zoneBc->DumpBc();
+    //}
+}
+
+void Partition::DumpPartitionedGridFile()
+{
+    int fileId = -1;
+    std::string filename = "split1d.cgns";
+    cg_open( filename.c_str(), CG_MODE_WRITE, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        int icelldim = 1;
+        int iphysdim = 1;
+        std::string basename = "Base" + std::to_string( iProc );
+
+        int baseId = -1;
+        cg_base_write( fileId, basename.c_str(), icelldim, iphysdim, &baseId );
+
+        std::cout << "baseId = " << baseId << "\n";
+
+        int nZones = this->GetNZones( iProc );
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            ZoneType_t zoneType = Structured;
+
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+
+            int index_dim = splitZone->dimInfo.dimList.size();
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            splitZone->dimInfo.ComputeISize();
+
+            int isize_dim = index_dim * 3;
+
+            std::vector<cgsize_t> isize( index_dim * 3, 0 );
+            for ( int m = 0; m < isize_dim; ++ m )
+            {
+                isize[ m ] = splitZone->dimInfo.isize[ m ];
+            }
+
+            int zoneId = -1;
+
+            std::string zonename = "B" + std::to_string( iProc ) + "Zone" + std::to_string( iZone );
+            cg_zone_write( fileId, baseId, zonename.c_str(), isize.data(), zoneType, &zoneId );
+
+            std::cout << "zoneId = " << zoneId << "\n";
+                
+            splitZone->ComputeRminmax();
+
+            SplitZone * rootSplitZone = splitZone->GetRootZone();
+
+            Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+            int ncoords = zone->coors.size();
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = -1;
+                DataType_t dataType = RealDouble;
+                std::string coordname = "X";
+                Coor * coor = zone->coors[ icoord ];
+
+                int nNodes = splitZone->dimInfo.ComputeNumNodes();
+                std::cout << "nNodes = " << nNodes << "\n";
+
+                std::vector<char> coord;
+                ComputeCoor( splitZone, icoord, coord );
+
+                cg_coord_write( fileId, baseId, zoneId, dataType, coordname.c_str(), coord.data(), &coorId );
+
+                std::cout << "cg_get_error() = " << cg_get_error() << "\n";
+                std::cout << "fileId = " << fileId  << " baseId = " << baseId << " zoneId = " << zoneId  << " coorId = " << coorId << "\n";
+            }
+
+            //std::vector<ZoneBc *> bccos;
+
+            //this->DumpBc( splitZone );
+
+            int nBcLists = splitZone->splitBcList.size();
+            std::vector<SplitBc * > bccoList;
+            std::vector<SplitBc * > bc1to1List;
+
+            for ( int ibc = 0; ibc < nBcLists; ++ ibc )
+            {
+                SplitBc * splitBc = splitZone->splitBcList[ ibc ];
+                if ( splitBc->bcType == BCTypeUserDefined )
+                {
+                    bc1to1List.push_back( splitBc );
+                }
+                else
+                {
+                    bccoList.push_back( splitBc );
+                }
+            }
+            int nbocos = bccoList.size();
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = -1;
+                GridLocation_t location = Vertex;
+
+                std::string boconame = "BC" + std::to_string( iboco + 1 );
+
+                SplitBc * splitBc = bccoList[ iboco ];
+                BCType_t bocotype = static_cast<BCType_t>( splitBc->bcType );
+                PointSetType_t ptset_type = PointRange;
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> pnts;
+                int nSize = splitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.end[ i ] );
+                }
+
+                cg_boco_write( fileId, baseId, zoneId, boconame.c_str(), bocotype, ptset_type, npnts, pnts.data(), & bccoId);
+            }
+
+            int n1to1 = bc1to1List.size();
+            std::cout << "n1to1 = " << n1to1 << "\n";
+
+            std::vector<int> itranfrm( index_dim );
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                itranfrm[ m ] = m + 1;
+            }
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int index_conn = -1;
+
+                SplitBc * splitBc = bc1to1List[ i1to1 ];
+                BCType_t bocotype = static_cast<BCType_t>( splitBc->bcType );
+
+                std::vector<cgsize_t> pnts;
+                std::vector<cgsize_t> pntsdonor;
+                int nSize = splitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.end[ i ] );
+                }
+
+                int nPatchSize = splitBc->patch->region.start.size();
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( splitBc->patch->region.start[ i ] );
+                }
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( splitBc->patch->region.end[ i ] );
+                }
+                int id = splitBc->patch->splitZone->zoneIndex;
+                std::string donorname ="Zone" + std::to_string( id );
+                std::string donorname1 ="ZZone" + std::to_string( id );
+
+                cg_1to1_write( fileId, baseId, zoneId, "Interface", donorname.c_str(), pnts.data(), pntsdonor.data(), itranfrm.data(), &index_conn);
+                std::cout << "index_conn = " << index_conn << "\n";
+                cg_1to1_write( fileId, baseId, zoneId, "Interface1", donorname1.c_str(), pnts.data(), pntsdonor.data(), itranfrm.data(), &index_conn );
+                std::cout << "index_conn = " << index_conn << "\n";
+            }
+        }
+    }
+    cg_close(fileId);
+}
+
+void Partition::ModifyZoneIndex()
+{
+    int globalZoneId = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        std::cout << "iProc = " << iProc << "\n";
+        int nZones = this->GetNZones( iProc );
+        std::cout << "nZones in Proc " << iProc << "  = " << nZones << "\n";
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+            splitZone->SetZoneIndex( globalZoneId++ );
+        }
+    }
+}
\ No newline at end of file
diff --git a/example/partition/struct/1d/01c/Partition.h b/example/partition/struct/1d/01c/Partition.h
new file mode 100644
index 00000000..55dc9cea
--- /dev/null
+++ b/example/partition/struct/1d/01c/Partition.h
@@ -0,0 +1,171 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class SplitZone;
+class RangeRegion;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox );
+
+class DimInfo
+{
+public:
+    DimInfo();
+    ~DimInfo();
+public:
+    int dim;
+    std::vector<int> dimList;
+    std::vector<int> oriPoint;
+    std::vector<int> isize;
+    std::vector<int> rmin;
+    std::vector<int> rmax;
+public:
+    int GetSize() const { return dim; }
+    DimInfo & operator = ( const DimInfo & rhs );
+public:
+    int ComputeNumNodes();
+    void ComputeISize();
+    void ComputeRminmax( std::vector<int> & ref );
+    void Init( std::vector<int> & dimList );
+    void SetNewDimension( int axis, int newStart, int newWidth );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+};
+
+class SplitZone;
+class SplitBcPatch;
+
+class RangeRegion
+{
+public:
+    RangeRegion( int nSize = 1 );
+    ~RangeRegion();
+public:
+    int regionAxis = -1;
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    RangeRegion & operator = ( const RangeRegion & rhs );
+    bool operator == ( const RangeRegion & rhs ) const;
+    void SetRegion( std::vector<int> &pnts );
+    int ComputeRegionAxis();
+};
+
+class SplitBc
+{
+public:
+    SplitBc();
+    ~SplitBc();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone = nullptr;
+    SplitBcPatch * patch = nullptr;
+    std::vector< SplitBc * > * child = nullptr;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+    void ChangeRegionToLocalCoordinate();
+public:
+    void SetZoneBcFromParentBc( SplitBc * parentSplitBc );
+    void InheritPatchBc( SplitBc * parentSplitBc );
+};
+
+class SplitBcPatch
+{
+public:
+    SplitBcPatch ();
+    ~SplitBcPatch();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone;
+};
+
+
+class SplitZone
+{
+public:
+    SplitZone();
+    ~SplitZone();
+public:
+    DimInfo dimInfo;
+    int zoneIndex, iProc;
+    //int oriZoneId;
+protected:
+    SplitZone * parent;
+public:
+    std::vector< SplitBc * > splitBcList;
+public:
+    int GetNCell();
+    void ComputeRminmax();
+    void GetRootInfo( SplitZone *& root, std::vector<int> & ref );
+    void SetZoneIndex( int zoneIndex ) { this->zoneIndex = zoneIndex; }
+    int  GetZoneIndex() { return zoneIndex; }
+    void SetProcId( int iProc ) { this->iProc = iProc; }
+    void SetParent( SplitZone * parent ) { this->parent = parent; };
+    std::vector< SplitBc * > & GetSplitBcList() { return this->splitBcList; };
+    void CreateBcFromParent();
+    void CreateSplitBc( SplitBc * parentSplitBc );
+    void AddSplitBc( SplitBc * splitBc );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+    SplitZone * GetRootZone();
+public:
+    void Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell );
+    void SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+    void SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+private:
+    int FindAxisNeedSplit();
+    int FindSplitPosition( int axisNeedSplit, double nCell );
+    bool IsPoleBc( int splitDirection );
+    int GetCrossSection( int axis );
+};
+
+class Partition
+{
+public:
+    Partition();
+    ~Partition();
+protected:
+    std::set < SplitZone * > zoneStorage;
+    std::set < SplitZone * > unsignedZoneGroup;
+    std::vector< SplitZone * > refZone;
+    std::vector< std::vector< SplitZone * > > procSplitZone;
+    std::vector<double> procSpeed;
+    std::vector<double> timeProc;
+    double aveFloatOp, delta;
+    double idealUniProcTime, eps;
+    int minNode;
+    int nTZone;
+    int nOriZone;
+    int nProc;
+public:
+    void Solve();
+    void ReadGrid();
+    void Split();
+    void InitSplit();
+    void BinarySplit();
+    //void GreedySplit();
+public:
+    void AddNewZone( SplitZone * zone );
+    void AddZoneToUnsignedGroup( SplitZone * zone );
+    void RemoveZoneFromUnsignedGroup( SplitZone * zone );
+    void AddZoneToProcess( int iProc, SplitZone * zone );
+    void DumpPartitionedGridFile();
+    void ModifyZoneIndex();
+    void FreeAllZones();
+    int GetNZones( int iProc );
+    SplitZone * GetSplitZone( int iProc, int zoneId );
+    void ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord );
+    void DumpBc( SplitZone * splitZone );
+private:
+    int GetMinValueIndex( double * data, int numberOfData );
+    int GetMinLoadProc();
+    SplitZone * GetLargestZone();
+    SplitZone * Split( SplitZone * zone, double nCell );
+};
+
diff --git a/example/partition/struct/1d/01c/README.txt b/example/partition/struct/1d/01c/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/partition/struct/1d/01c/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/partition/struct/1d/01c/heat1dni81.cgns b/example/partition/struct/1d/01c/heat1dni81.cgns
new file mode 100644
index 00000000..b7d4954a
Binary files /dev/null and b/example/partition/struct/1d/01c/heat1dni81.cgns differ
diff --git a/example/partition/struct/1d/01c/main.cpp b/example/partition/struct/1d/01c/main.cpp
new file mode 100644
index 00000000..5da1de7c
--- /dev/null
+++ b/example/partition/struct/1d/01c/main.cpp
@@ -0,0 +1,18 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include "Partition.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip>
+
+int main(int argc, char **argv)
+{
+    Partition * partition = new Partition();
+    partition->Solve();
+    delete partition;
+
+    return 0;
+}
diff --git a/example/partition/struct/1d/01d/CMakeLists.txt b/example/partition/struct/1d/01d/CMakeLists.txt
new file mode 100644
index 00000000..9fa577c8
--- /dev/null
+++ b/example/partition/struct/1d/01d/CMakeLists.txt
@@ -0,0 +1,77 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	Partition.h Partition.cpp
+	CgnsGrid.h CgnsGrid.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/partition/struct/1d/01d/CgnsGrid.cpp b/example/partition/struct/1d/01d/CgnsGrid.cpp
new file mode 100644
index 00000000..e58aa1ec
--- /dev/null
+++ b/example/partition/struct/1d/01d/CgnsGrid.cpp
@@ -0,0 +1,231 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+
+Grid::Grid()
+{
+    ;
+}
+
+Grid::~Grid()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if( (i+1)%5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+}
+
+std::vector<Zone *> Global::zones;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+Global::Global()
+{
+    ;
+}
+
+Global::~Global()
+{
+}
+
+void Global::FreeData()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+    zones.resize( 0 );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones(fileId, baseId, &nzones);
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize(index_dim*3);
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin(index_dim);
+            std::vector<cgsize_t> irmax(index_dim);
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[33];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                std::vector<char> coord( nNodes * sizeof(double) );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+                coor->DumpCoor();
+            }
+
+            int nbocos = -1;
+
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex(index_dim,-1);
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type, 
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset);
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[i] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[normalDataType] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList(nNodes*iphysdim*sizeof(double));
+
+                std::vector<cgsize_t> pnts(npnts*index_dim);
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double*>(const_cast<char *>(normalList.data()));
+
+                //std::cout << "normalList = ";
+                //for ( int i = 0; i < nNodes*iphysdim; ++ i )
+                //{
+                //    std::cout << normal_d[ i ] << " ";
+                //}
+                //std::cout << "\n";
+            }
+        }
+    }
+    cg_close(fileId);
+}
\ No newline at end of file
diff --git a/example/partition/struct/1d/01d/CgnsGrid.h b/example/partition/struct/1d/01d/CgnsGrid.h
new file mode 100644
index 00000000..b84abd1d
--- /dev/null
+++ b/example/partition/struct/1d/01d/CgnsGrid.h
@@ -0,0 +1,69 @@
+#pragma once
+#include <iostream>
+#include <vector>
+
+class Grid;
+
+class Zone;
+
+class Grid
+{
+public:
+    Grid();
+    ~Grid();
+public:
+    int nZone;
+    std::vector<double> x;
+    std::vector<Zone *> zones;
+};
+
+class ZoneBc;
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+};
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<Coor *> coors;
+};
+
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    std::vector<int> pnts;
+};
+
+class Global
+{
+public:
+    Global();
+    ~Global();
+public:
+    static std::vector<Zone *> zones;
+    static void FreeData();
+    static int cell_dim;
+    static int phys_dim;
+};
+
+void ReadCgnsGrid( const std::string & filename );
diff --git a/example/partition/struct/1d/01d/Partition.cpp b/example/partition/struct/1d/01d/Partition.cpp
new file mode 100644
index 00000000..aa40583c
--- /dev/null
+++ b/example/partition/struct/1d/01d/Partition.cpp
@@ -0,0 +1,1242 @@
+#include "Partition.h"
+#include "CgnsGrid.h"
+#include "cgnslib.h"
+#include <string>
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox  )
+{
+    domainBox.start = zoneBox.start;
+    domainBox.end = zoneBox.end;
+
+    int axis = iDomain / 2;
+    int direction = iDomain % 2;
+
+    if ( direction == 0 )
+    {
+        domainBox.end[ axis ] = domainBox.start[ axis ];
+    }
+    else if ( direction == 1 )
+    {
+        domainBox.start[ axis ] = domainBox.end[ axis ];
+    }
+}
+
+DimInfo::DimInfo()
+{
+    this->dim = 1;
+    dimList.resize( this->dim, 1 );
+    oriPoint.resize( this->dim, 0 );
+}
+
+DimInfo::~DimInfo()
+{
+}
+
+DimInfo & DimInfo::operator = ( const DimInfo & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->dim = rhs.dim;
+    this->dimList = rhs.dimList;
+    this->oriPoint = rhs.oriPoint;
+
+    return * this;
+}
+
+int DimInfo::ComputeNumNodes()
+{
+    int nNodes = 1;
+    for ( int m = 0; m < this->dimList.size(); ++ m )
+    {
+        nNodes *= this->dimList[ m ];
+    }
+    return nNodes;
+}
+
+void DimInfo::ComputeISize()
+{
+    int index_dim = this->dimList.size();
+    this->isize.resize( index_dim * 3, 0 );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        isize[ m ] = this->dimList[ m ];
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 1;
+        isize[ start + m ] = this->dimList[ m ] - 1;
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 2;
+        isize[ start + m ] = 0;
+    }
+
+    for ( int i = 0; i < isize.size(); ++ i )
+    {
+        std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+    }
+}
+
+void DimInfo::ComputeRminmax( std::vector<int> & ref )
+{
+    int index_dim = this->dimList.size();
+    this->rmin.resize( index_dim );
+    this->rmax.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        rmin[ m ] = ref[ m ] + 1;
+        rmax[ m ] = ref[ m ] + this->dimList[ m ];
+    }
+
+    std::cout << "rmin, rmax = \n";
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        std::cout << rmin[ m ] << " " << rmax[ m ] << "\n";
+    }
+}
+
+void DimInfo::Init( std::vector<int> & dimList )
+{
+    this->dimList = dimList;
+    std::vector<int> zero( dimList.size(), 0 );
+    this->oriPoint = zero;
+}
+
+void DimInfo::SetNewDimension( int axis, int newStart, int newWidth )
+{
+    this->oriPoint[ axis ] = newStart;
+    this->dimList [ axis ] = newWidth;
+}
+
+void DimInfo::GetZoneGlobalBox( RangeRegion &zoneBox )
+{
+    int index_dim = this->dimList.size();
+    zoneBox.start.resize( index_dim );
+    zoneBox.end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        zoneBox.start[ m ] = this->oriPoint[ m ] + 1;
+        zoneBox.end[ m ] = this->oriPoint[ m ] + this->dimList[ m ];
+    }
+}
+
+void DimInfo::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    int index_dim = this->dimList.size();
+    localBox.start.resize( index_dim );
+    localBox.end.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        localBox.start[ m ] = globalBox.start[ m ] - this->oriPoint[ m ];
+        localBox.end[ m ] = globalBox.end[ m ] - this->oriPoint[ m ];
+    }
+}
+
+RangeRegion::RangeRegion( int nSize )
+{
+    this->start.resize( nSize );
+    this->end.resize( nSize );
+}
+
+RangeRegion::~RangeRegion()
+{
+}
+
+RangeRegion & RangeRegion::operator = ( const RangeRegion & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+    this->regionAxis = rhs.regionAxis;
+
+    return * this;
+}
+
+bool RangeRegion::operator == ( const RangeRegion & rhs ) const
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] != rhs.start[ m ] || 
+            this->end  [ m ] != rhs.end  [ m ] )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+    this->ComputeRegionAxis();
+}
+
+int RangeRegion::ComputeRegionAxis()
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] == this->end[ m ] )
+        {
+            this->regionAxis = m;
+            return this->regionAxis;
+        }
+    }
+    return this->regionAxis;
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion );
+
+bool ComputeOverlapRegion( RangeRegion & region1, RangeRegion & region2, RangeRegion & overlapRegion )
+{
+    int index_dim = region1.start.size();
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        overlapRegion.start[ m ] = std::max( region1.start[ m ], region2.start[ m ] );
+        overlapRegion.end  [ m ] = std::min( region1.end  [ m ], region2.end  [ m ] );
+    }
+
+    return CheckOverLapping( overlapRegion );
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion )
+{
+    int index_dim = overlapRegion.start.size();
+    int iCount = 0;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        if ( overlapRegion.start[ m ] == overlapRegion.end[ m ] )
+        {
+            ++ iCount;
+        }
+    }
+
+    return ( iCount == 1 );
+}
+
+SplitBc * CreateSplitBc( RangeRegion & bcRegion, RangeRegion & zoneDomainRegion )
+{
+    int sRegionAxis = bcRegion.ComputeRegionAxis();
+    int tRegionAxis = zoneDomainRegion.ComputeRegionAxis();
+
+    //Two regions in different directions
+    if ( sRegionAxis != tRegionAxis )
+    {
+        return 0;
+    }
+
+    //Although the two regions are in the same direction, the coordinates are inconsistent.
+    if ( bcRegion.start[ sRegionAxis ] != zoneDomainRegion.start[ sRegionAxis ] )
+    {
+        return 0;
+    }
+
+    RangeRegion overlapRegion;
+    ComputeOverlapRegion( bcRegion, zoneDomainRegion, overlapRegion );
+
+    if ( CheckOverLapping( overlapRegion ) )
+    {
+        SplitBc * splitBc = new SplitBc();
+        splitBc->SetRegion( overlapRegion );
+        return splitBc;
+    }
+
+    int kkk = 1;
+
+    return 0;
+}
+
+bool GetInterfaceRegion( RangeRegion & zoneBoxL, RangeRegion & zoneBoxR, RangeRegion & interfaceRegion )
+{
+    int index_dim = zoneBoxL.start.size();
+    int nDomains = 2 * index_dim;
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegionL;
+        GetDomainRegion( zoneBoxL, iDomain, domainRegionL );
+
+        for ( int jDomain = 0; jDomain < nDomains; ++ jDomain )
+        {
+            RangeRegion domainRegionR;
+            GetDomainRegion( zoneBoxR, jDomain, domainRegionR );
+
+            if ( domainRegionL == domainRegionR )
+            {
+                interfaceRegion = domainRegionL;
+                return true;
+            }
+        }
+    }
+    return false;
+}
+
+void CreateInterfaceBc( SplitZone * zoneL, SplitZone * zoneR )
+{
+    RangeRegion globalBoxL, globalBoxR, globalInterfaceRegion;
+
+    zoneL->GetZoneGlobalBox( globalBoxL );
+    zoneR->GetZoneGlobalBox( globalBoxR );
+
+    if ( ! GetInterfaceRegion( globalBoxL, globalBoxR, globalInterfaceRegion ) )
+    {
+        int kkk = 1;
+        return;
+    }
+
+    RangeRegion localInterfaceRegionL, localInterfaceRegionR;
+
+    zoneL->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionL );
+    zoneR->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionR );
+
+    int kkk = 1;
+
+    SplitBc * splitBcL = new SplitBc();
+    zoneL->AddSplitBc( splitBcL );
+
+    SplitBc * splitBcR = new SplitBc();
+    zoneR->AddSplitBc( splitBcR );
+
+    splitBcL->splitZone = zoneL;
+    splitBcL->SetRegion( localInterfaceRegionL );
+    splitBcL->bcType = BCTypeUserDefined;
+
+    splitBcR->splitZone = zoneR;
+    splitBcR->SetRegion( localInterfaceRegionR );
+    splitBcR->bcType = BCTypeUserDefined;
+
+    //localInterfaceRegionL.MarkPatchBc();
+    //localInterfaceRegionR.MarkPatchBc();
+
+    SplitBcPatch * splitBcPatchL = new SplitBcPatch();
+    splitBcL->patch = splitBcPatchL;
+    splitBcPatchL->region = localInterfaceRegionR;
+    splitBcPatchL->splitZone = zoneR;
+
+    SplitBcPatch * splitBcPatchR = new SplitBcPatch();
+    splitBcR->patch = splitBcPatchR;
+    splitBcPatchR->region = localInterfaceRegionL;
+    splitBcPatchR->splitZone = zoneL;
+
+    //splitBcL->Normalize();
+    //splitBcR->Normalize();
+}
+
+
+SplitBc::SplitBc()
+{
+}
+
+SplitBc::~SplitBc()
+{
+    delete this->patch;
+}
+
+void SplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void SplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+void SplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = splitZone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void SplitBc::SetZoneBcFromParentBc( SplitBc * parentSplitBc )
+{
+    this->bcType = parentSplitBc->bcType;
+    //this->LocalCoordinate();
+    this->region.regionAxis = parentSplitBc->region.regionAxis;
+    this->InheritPatchBc( parentSplitBc );
+}
+
+void SplitBc::InheritPatchBc( SplitBc * parentSplitBc )
+{
+    if ( ! ( this->bcType < 0 ) ) return;
+
+    this->patch = new SplitBcPatch();
+
+    this->patch->splitZone = parentSplitBc->patch->splitZone;
+    //this->patch->faceAxis = parentSplitBc->patch->faceAxis;
+
+    //( * this->patch->vertexMap ) = ( * parentBc->patch->vertexMap );
+
+    ////È»ºó½øÐÐÐÞÕý
+    ////block1->map 1, 33 -> block1 369, 337
+    ////block2->global -> map 1, 33 -> block1 369, 337
+    ////block2->local  -> map 1, 33 -> block1 369, 337
+    ////refOld + M * stold           = block1Startold
+    ////refOld + M * ( stnew + ref ) = block1Startold
+    ////refNew = refOld + M * ( ref )
+
+    //for ( int m = 0; m < 3; ++ m )
+    //{
+    //    for ( int n = 0; n < 3; ++ n )
+    //    {
+    //        this->patch->vertexMap->pt[ m ] += this->patch->vertexMap->vm[ m ][ n ] * ( this->splitZone->sdim->oriPoint )[ n ];
+    //    }
+    //}
+
+    //RangeBox tRangeBox;
+
+    //MappingPatchPoint( this->patch, this->rangeBox, tRangeBox );
+    //tRangeBox.SetOrder();
+
+    ////ÕÒµ½ºÍ±¾¶Ô½Ó±ß½çÏà¶ÔÓ¦µÄ¿é
+    ////´Ópatch->splitZone°´ÕÕoverlapµÄ´óСÕÒµ½¶ÔÓ¦µÄ¶Ô½Ó±ß½ç£¬ÕâÑùÖÁÉÙ¿ÉÒÔÕÒµ½
+    ////¶ÔÃæµÄ¶Ô½Ó±ß½çÌõ¼þÓÉÓÚ±¾¿éµÄsplit±ØȻҪ·¢Éú¸Ä±ä£¬ÕâÀｫÏà¹Ø±ß½ç¼ÓÈë×ӱ߽ç
+    //this->patch->splitZone->CreateChildPatchBc( tRangeBox, this->splitZone );
+}
+
+SplitBcPatch::SplitBcPatch()
+{
+}
+
+SplitBcPatch::~SplitBcPatch()
+{
+}
+
+SplitZone::SplitZone()
+{
+    this->parent  = 0;
+    this->zoneIndex = 0;
+    this->iProc = 0;
+}
+
+SplitZone::~SplitZone()
+{
+    ;
+}
+
+void SplitZone::GetZoneGlobalBox( RangeRegion & zoneBox )
+{
+    this->dimInfo.GetZoneGlobalBox( zoneBox );
+}
+
+void SplitZone::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    this->dimInfo.GetZoneLocalBox( globalBox, localBox );
+}
+
+
+void SplitZone::ComputeRminmax()
+{
+    int index_dim = this->dimInfo.dimList.size();
+    std::vector<int> ref( index_dim, 0 );
+
+    SplitZone * rootSplitZone = 0;
+    this->GetRootInfo( rootSplitZone, ref );
+
+    this->dimInfo.ComputeRminmax( ref );
+}
+
+SplitZone * SplitZone::GetRootZone()
+{
+    SplitZone * root = this;
+
+    while ( true )
+    {
+        if ( root->parent )
+        {
+            root = root->parent;
+        }
+        else
+        {
+            return root;
+        }
+    };
+}
+
+void SplitZone::GetRootInfo( SplitZone *& root, std::vector<int> & ref )
+{
+    for ( int i = 0; i < this->dimInfo.dimList.size(); ++ i )
+    {
+        ref[ i ] += this->dimInfo.oriPoint[ i ];
+    }
+
+    if ( this->parent )
+    {
+        this->parent->GetRootInfo( root, ref );
+    }
+    else
+    {
+        root = this;
+    }
+}
+
+
+int SplitZone::GetNCell()
+{
+    int numberOfCells = 1;
+    for ( int i = 0; i < this->dimInfo.dim; ++ i )
+    {
+        numberOfCells *= std::max( 1, ( this->dimInfo.dimList[ i ] - 1 ) );
+    }
+
+    return numberOfCells; 
+}
+
+void SplitZone::SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int leftStart = 0;
+    int leftWidth = iSplit - 0;
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, leftStart , leftWidth  );
+}
+
+void SplitZone::SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int rightStart = iSplit - 1;
+    int rightWidth = dimList[ axisNeedSplit ] - ( iSplit - 1 );
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, rightStart, rightWidth );
+}
+
+void SplitZone::Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell )
+{
+    //Find the longest axis
+    int axisNeedSplit = this->FindAxisNeedSplit();
+    int iSplit        = this->FindSplitPosition( axisNeedSplit, nCell );
+
+    zoneL = new SplitZone();
+    zoneL->SetParent( this );
+
+    zoneR = new SplitZone();
+    zoneR->SetParent( this );
+
+    zoneL->SetLeftDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+    zoneR->SetRightDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+
+    zoneL->CreateBcFromParent();
+    zoneR->CreateBcFromParent();
+
+    CreateInterfaceBc( zoneL, zoneR );
+}
+
+void SplitZone::CreateBcFromParent()
+{
+    std::vector< SplitBc * > & parentSplitBcList = this->parent->GetSplitBcList();
+
+    int nParentSplitBcs = parentSplitBcList.size();
+
+    for ( int iParentBc = 0; iParentBc < nParentSplitBcs; ++ iParentBc )
+    {
+        SplitBc * parentSplitBc = parentSplitBcList[ iParentBc ];
+
+        this->CreateSplitBc( parentSplitBc );
+    }
+}
+
+void SplitZone::AddSplitBc( SplitBc * splitBc )
+{
+    if ( ! splitBc ) return;
+    this->splitBcList.push_back( splitBc );
+}
+
+void SplitZone::CreateSplitBc( SplitBc * parentSplitBc )
+{
+    if ( ! parentSplitBc->child )
+    {
+        int index_dim = this->dimInfo.dimList.size();
+        int nDomains = 2 * index_dim;
+        RangeRegion zoneBoxRegion( index_dim );
+        this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+        for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+        {
+            RangeRegion domainRegion( index_dim );
+            GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+            RangeRegion overlapRegion;
+            bool overlap_flag = ComputeOverlapRegion( parentSplitBc->region, domainRegion, overlapRegion );
+            if ( ! overlap_flag ) continue;
+
+            SplitBc * splitBc = new SplitBc();
+            this->AddSplitBc( splitBc );
+
+            splitBc->SetRegion( overlapRegion );
+            splitBc->bcType = parentSplitBc->bcType;
+            splitBc->splitZone = this;
+            splitBc->ChangeRegionToLocalCoordinate();
+            //splitBc->CreatePatchBc( parentSplitBc );
+
+            int kkk = 1;
+        }
+    }
+    else
+    {
+        int nChilds = parentSplitBc->child->size();
+        for ( int iChild = 0; iChild < nChilds; ++ iChild )
+        {
+            this->CreateSplitBc( ( * parentSplitBc->child )[ iChild ] );
+        }
+    }
+}
+
+
+int SplitZone::FindAxisNeedSplit()
+{
+    //Find the longest axis
+    int axisNeedSplit = 0;
+    int maxN = this->dimInfo.dimList[ 0 ];
+
+    for ( int m = 1; m < this->dimInfo.dimList.size(); ++ m )
+    {
+        if ( this->IsPoleBc( m ) )
+        {
+            continue;
+        }
+        int Nm = this->dimInfo.dimList[ m ];
+        if ( maxN < Nm )
+        {
+            maxN = Nm;
+            axisNeedSplit = m;
+        }
+    }
+
+    return axisNeedSplit;
+}
+
+int SplitZone::GetCrossSection( int axis )
+{
+    int nDim = this->dimInfo.dimList.size();
+    int crossSection = 1;
+    int N = nDim - 1;
+    for ( int m = 0; m < N; ++ m )
+    {
+         int mm = ( axis + 1 ) % nDim;
+         int nLineElements = std::max( 1, ( this->dimInfo.dimList[ mm ] - 1 ) );
+         crossSection *= nLineElements;
+    }
+    return crossSection;
+}
+
+int SplitZone::FindSplitPosition( int axisNeedSplit, double nCell )
+{
+    int nDim = this->dimInfo.dimList.size();
+    std::vector<int> crossSections( nDim );
+    for ( int m = 0; m < nDim; ++ m )
+    {
+        crossSections[ m ] = this->GetCrossSection( m );
+    }
+
+    //guess the value
+    double dSplit = nCell / crossSections[ axisNeedSplit ];
+    int  iSplit = 1 + static_cast< int >( std::floor( dSplit + 0.5 ) );
+    return iSplit;
+}
+
+
+bool SplitZone::IsPoleBc( int splitDirection )
+{
+    return false;
+}
+
+
+double CalSumOfProcSpeed( std::vector<double> & procSpeed );
+double CalSumOfProcSpeed( std::vector<double> & procSpeed )
+{
+    int nProc = procSpeed.size();
+    double sumOfProcSpeed = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        sumOfProcSpeed += procSpeed[ iProc ];
+    }
+    return sumOfProcSpeed;
+}
+
+Partition::Partition()
+{
+    ;
+}
+
+Partition::~Partition()
+{
+    ;
+}
+
+int Partition::GetMinValueIndex( double * data, int numberOfData )
+{
+    double minValue = data[ 0 ];
+    int minimumValueIndex = 0;
+
+    for ( int iData = 1; iData < numberOfData; ++ iData )
+    {
+        if ( minValue > data[ iData ] )
+        {
+            minValue      = data[ iData ];
+            minimumValueIndex = iData;
+        }
+    }
+    return minimumValueIndex;
+}
+
+int Partition::GetMinLoadProc()
+{
+    return this->GetMinValueIndex( this->timeProc.data(), this->nProc );
+}
+
+SplitZone * Partition::GetLargestZone()
+{
+    SplitZone * largestZone = 0;
+
+    double nMaxCell = 0.0;
+
+    for ( std::set< SplitZone * >::iterator iter = unsignedZoneGroup.begin(); iter != unsignedZoneGroup.end(); ++ iter )
+    {
+        double nSize = ( * iter )->GetNCell();
+        if ( nMaxCell < nSize )
+        {
+            nMaxCell    = nSize;
+            largestZone = * iter;
+        }
+    }
+
+    return largestZone;
+}
+
+void Partition::Solve()
+{
+    std::cout << "Partition::Split()\n";
+    this->nProc = 2;
+    this->ReadGrid();
+    this->Split();
+    this->ModifyZoneIndex();
+    this->DumpPartitionedGridFile();
+    this->FreeAllZones();
+}
+
+void Partition::ReadGrid()
+{
+    ReadCgnsGrid( "../heat1dni81.cgns" );
+
+    this->nOriZone = ::Global::zones.size();
+
+    std::cout << "numberOfBlocks = " << nOriZone << "\n";
+
+    this->refZone.resize( nOriZone );
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = new SplitZone();
+        refZone[ iZone ] = splitZone;
+
+        splitZone->SetZoneIndex( iZone );
+        splitZone->SetProcId( 0 );
+        splitZone->SetParent( 0 );
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        Zone * zone = ::Global::zones[ iZone ];
+
+        splitZone->dimInfo.dimList = zone->nijk;
+
+        int nBcRegion = zone->bccos.size();
+        std::cout << "nBcRegion = " << nBcRegion << "\n";
+
+        std::vector< SplitBc * > & splitBcList = splitZone->splitBcList;
+
+        for ( int iBcRegion = 0; iBcRegion < nBcRegion; ++ iBcRegion )
+        {
+            SplitBc * splitBc = new SplitBc();
+            splitBcList.push_back( splitBc );
+
+            ZoneBc * zoneBc = zone->bccos[ iBcRegion ];
+
+            splitBc->splitZone = splitZone;
+            splitBc->bcType = zoneBc->bcType;
+            splitBc->SetRegion( zoneBc->pnts );
+        }
+
+        int kkk = 1;
+
+        //splitZone->NormalizeBc();
+    }
+}
+
+void Partition::Split()
+{
+    this->InitSplit();
+    this->BinarySplit();
+    //this->SetZoneIndex();
+}
+
+void Partition::InitSplit()
+{
+    //nZone is the number of zones in the original grid
+    //nProc is not the number of blocks in the end, but the number of processes that need to be divided.
+    //This difference occurs because the structure grid can have many blocks per process.
+
+    //this->nProc    = nProc;
+    //this->nPhyBlocks = referenceBlock.size();
+    //this->nZone  = this->nPhyBlocks;
+
+    //tj Computation time on processor j
+    //Nk Number of internal grid-cells for zone j
+    //aveFloatOp:  Number of Real operations per gridcell
+    //Gj The set of blocks allocated to process j
+    //Pj Real operations per second for process j
+
+    //The Greedy Load Balancing Algorithm
+    //1.Compute an "ideal" uniprocessor time, Tuni = sum ( Nk * aveFloatOp )/ sum( Pj ).
+    //2.Set the group of unassigned blocks, Gu, to contain all blocks. The number of blocks in Nu=M, where M is the total number of blocks in the mesh.
+    //3.Start all processors with a very small fictitious zone to get a start tj=delt aveFloatOp/Pj, where delt<<1 is the size of the very small fictious zone.
+    //This is used to find the fastest processor in a heterogeneous system, tj could otherwise be set to 0 in the homogeneous case.
+    this->aveFloatOp = 1.0;
+    this->delta      = 1.0e-5;
+    this->procSpeed.resize( nProc );
+    this->timeProc.resize( nProc );
+
+    this->nTZone = this->nOriZone;
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        procSpeed[ iProc ] = 1.0;
+    }
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        timeProc[ iProc ] = delta * aveFloatOp / procSpeed[ iProc ];
+    }
+
+    double sumProcSpeed = CalSumOfProcSpeed( procSpeed );
+
+    double sumProcOp = 0.0;
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        sumProcOp += refZone[ iZone ]->GetNCell() * aveFloatOp;
+    }
+
+    this->idealUniProcTime = sumProcOp / sumProcSpeed;
+
+    this->eps = 0.05;
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        unsignedZoneGroup.insert( refZone[ iZone ] );
+    }
+
+    //Init zoneStorage
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        zoneStorage.insert( refZone[ iZone ] );
+    }
+
+    //Assign procSplitZone to each process
+    procSplitZone.resize( nProc );
+
+    int index_dim = Global::cell_dim;
+    this->minNode = 1;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->minNode *= 2;
+    }
+
+    int kkk = 1;
+
+}
+
+void Partition::FreeAllZones()
+{
+    int iCount = 0;
+    for ( std::set < SplitZone * >::iterator iter = zoneStorage.begin(); iter != zoneStorage.end(); ++ iter )
+    {
+        //cout << "iCount = " << iCount << "\n";
+        ++ iCount;
+        delete * iter;
+    }
+}
+
+int Partition::GetNZones( int iProc )
+{
+    return this->procSplitZone[ iProc ].size();
+}
+
+SplitZone * Partition::GetSplitZone( int iProc, int zoneId )
+{
+    return this->procSplitZone[ iProc ][ zoneId ];
+}
+
+void Partition::AddZoneToUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.insert( zone );
+}
+
+void Partition::RemoveZoneFromUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.erase( zone );
+}
+
+void Partition::AddZoneToProcess( int iProc, SplitZone * zone )
+{
+    this->procSplitZone[ iProc ].push_back( zone );
+}
+
+void Partition::AddNewZone( SplitZone * zone )
+{
+    zone->SetZoneIndex( nTZone ++ );
+
+    this->AddZoneToUnsignedGroup( zone );
+
+    this->zoneStorage.insert( zone );
+}
+
+SplitZone * Partition::Split( SplitZone * zone, double nCell )
+{
+    SplitZone * zoneL = 0;
+    SplitZone * zoneR = 0;
+
+    zone->Split( zoneL, zoneR, nCell );
+
+    this->AddNewZone( zoneL );
+    this->AddNewZone( zoneR );
+    this->RemoveZoneFromUnsignedGroup( zone );
+
+    return zoneL;
+}
+
+void Partition::BinarySplit()
+{
+    while ( ! unsignedZoneGroup.empty() )
+    {
+        std::cout << "number of unsigned zone = " << unsignedZoneGroup.size() << "\n";
+        int iProc = this->GetMinLoadProc();
+
+        //Get the block with the largest number of grids and its size
+        SplitZone * largestZone = this->GetLargestZone();
+
+        double nMaxCell = largestZone->GetNCell();
+
+        double aveFloatOp = this->aveFloatOp;
+        double tau = timeProc[ iProc ] + nMaxCell * aveFloatOp / procSpeed[ iProc ];
+
+        int kkk = 1;
+
+        //It seems that EPS is still necessary
+        //The idea here is as follows. For the candidate blocks which can be divided into blocks, 
+        //if the difference between the target blocks and the candidate blocks is too wide, 
+        //the binarySplit method is adopted. The binarySplit blocks do not directly join the process,
+        //but enter the next round of screening.
+
+        if ( tau > idealUniProcTime * ( 1.0 + eps ) )
+        {
+            double nRest = ( tau - idealUniProcTime ) * procSpeed[ iProc ] / aveFloatOp;
+
+            double nTarget = nMaxCell - nRest;
+            if ( nRest > this->minNode && nTarget > this->minNode )
+            {
+                //It is necessary to divide blocks only when a certain number of points are satisfied.
+                double nHalf = nMaxCell / 2.0;
+                nMaxCell = nTarget;
+                double ratio = nMaxCell / nRest;
+                double oRatio = 1.0 / ratio;
+
+                if ( std::max( ratio, oRatio ) < 3.0 )
+                {
+                    int kkk = 1;
+                    largestZone = this->Split( largestZone, nMaxCell );
+                    timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                    this->RemoveZoneFromUnsignedGroup( largestZone );
+                    this->AddZoneToProcess( iProc, largestZone );
+                }
+                else
+                {
+                    this->Split( largestZone, nHalf );
+                }
+            }
+            else
+            {
+                //If the block is of the right size, join the process directly, and there is no need to split it.
+                timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                this->RemoveZoneFromUnsignedGroup( largestZone );
+                this->AddZoneToProcess( iProc, largestZone );
+            }
+        }
+        else
+        {
+            //If the block is of the right size, join the process directly, and there is no need to split it.
+            timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+            this->RemoveZoneFromUnsignedGroup( largestZone );
+            this->AddZoneToProcess( iProc, largestZone );
+        }
+    }
+}
+
+void Partition::ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord )
+{
+    SplitZone * rootSplitZone = splitZone->GetRootZone();
+    Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+    int nNodes = splitZone->dimInfo.ComputeNumNodes();
+    std::cout << "nNodes = " << nNodes << "\n";
+
+    coord.resize( nNodes * sizeof(double) );
+
+    int index_dim = splitZone->dimInfo.dimList.size();
+    Coor * coor = zone->coors[ icoord ];
+
+    double * xlocal = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    double * xglobal = reinterpret_cast<double *>( const_cast<char *>( coor->coord.data() ) );
+    if ( index_dim == 1 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        for ( int i = imin; i < imax; ++ i )
+        {
+            xlocal[ icount++ ] = xglobal[ i ];
+        }
+    }
+    else if ( index_dim == 2 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        int jmin = splitZone->dimInfo.rmin[ 1 ] - 1;
+        int jmax = splitZone->dimInfo.rmax[ 1 ];
+        int ni = rootSplitZone->dimInfo.dimList[ 0 ];
+        int nj = rootSplitZone->dimInfo.dimList[ 1 ];
+        for ( int j = jmin; j < jmax; ++ j )
+        {
+            int jstride = j * ni;
+            for ( int i = imin; i < imax; ++ i )
+            {
+                xlocal[ icount++ ] = xglobal[ jstride + i ];
+            }
+        }
+    }
+}
+
+void Partition::DumpBc( SplitZone * splitZone )
+{
+    //std::vector< ZoneBc * > leafZoneBc;
+
+    //std::vector< ZoneBc * > & zoneBcList = splitZone->GetZoneBcList();
+
+    //for ( int i = 0; i < zoneBcList.size(); ++ i )
+    //{
+    //    std::vector< ZoneBc * > cl = zoneBcList[ i ]->GetLeaves();
+    //    for ( int j = 0; j < cl.size(); ++ j )
+    //    {
+    //        leafZoneBc.push_back( cl[ j ] );
+    //    }
+    //}
+
+    //int nZoneBc = leafZoneBc.size();
+
+    //for ( int iZoneBc = 0; iZoneBc < nZoneBc; ++ iZoneBc )
+    //{
+    //    ZoneBc * zoneBc = leafZoneBc[ iZoneBc ];
+    //    zoneBc->DumpBc();
+    //}
+}
+
+void Partition::DumpPartitionedGridFile()
+{
+    int fileId = -1;
+    std::string filename = "split1d.cgns";
+    cg_open( filename.c_str(), CG_MODE_WRITE, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        int icelldim = 1;
+        int iphysdim = 1;
+        std::string basename = "Base" + std::to_string( iProc );
+
+        int baseId = -1;
+        cg_base_write( fileId, basename.c_str(), icelldim, iphysdim, &baseId );
+
+        std::cout << "baseId = " << baseId << "\n";
+
+        int nZones = this->GetNZones( iProc );
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            ZoneType_t zoneType = Structured;
+
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+
+            int index_dim = splitZone->dimInfo.dimList.size();
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            splitZone->dimInfo.ComputeISize();
+
+            int isize_dim = index_dim * 3;
+
+            std::vector<cgsize_t> isize( index_dim * 3, 0 );
+            for ( int m = 0; m < isize_dim; ++ m )
+            {
+                isize[ m ] = splitZone->dimInfo.isize[ m ];
+            }
+
+            int zoneId = -1;
+
+            std::string zonename = "Zone" + std::to_string( splitZone->zoneIndex );
+
+            cg_zone_write( fileId, baseId, zonename.c_str(), isize.data(), zoneType, &zoneId );
+
+            std::cout << "zoneId = " << zoneId << "\n";
+                
+            splitZone->ComputeRminmax();
+
+            SplitZone * rootSplitZone = splitZone->GetRootZone();
+
+            Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+            int ncoords = zone->coors.size();
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = -1;
+                DataType_t dataType = RealDouble;
+                std::string coordname = "X";
+                Coor * coor = zone->coors[ icoord ];
+
+                int nNodes = splitZone->dimInfo.ComputeNumNodes();
+                std::cout << "nNodes = " << nNodes << "\n";
+
+                std::vector<char> coord;
+                ComputeCoor( splitZone, icoord, coord );
+
+                cg_coord_write( fileId, baseId, zoneId, dataType, coordname.c_str(), coord.data(), &coorId );
+
+                std::cout << "cg_get_error() = " << cg_get_error() << "\n";
+                std::cout << "fileId = " << fileId  << " baseId = " << baseId << " zoneId = " << zoneId  << " coorId = " << coorId << "\n";
+            }
+
+            int nBcLists = splitZone->splitBcList.size();
+            std::vector<SplitBc * > bccoList;
+            std::vector<SplitBc * > bc1to1List;
+
+            for ( int ibc = 0; ibc < nBcLists; ++ ibc )
+            {
+                SplitBc * splitBc = splitZone->splitBcList[ ibc ];
+                if ( splitBc->bcType == BCTypeUserDefined )
+                {
+                    bc1to1List.push_back( splitBc );
+                }
+                else
+                {
+                    bccoList.push_back( splitBc );
+                }
+            }
+            int nbocos = bccoList.size();
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = -1;
+                GridLocation_t location = Vertex;
+
+                std::string boconame = "BC" + std::to_string( iboco + 1 );
+
+                SplitBc * splitBc = bccoList[ iboco ];
+                BCType_t bocotype = static_cast<BCType_t>( splitBc->bcType );
+                PointSetType_t ptset_type = PointRange;
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> pnts;
+                int nSize = splitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.end[ i ] );
+                }
+
+                cg_boco_write( fileId, baseId, zoneId, boconame.c_str(), bocotype, ptset_type, npnts, pnts.data(), & bccoId );
+            }
+
+            int n1to1 = bc1to1List.size();
+            std::cout << "n1to1 = " << n1to1 << "\n";
+
+            std::vector<int> itranfrm( index_dim );
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                itranfrm[ m ] = m + 1;
+            }
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int index_conn = -1;
+
+                SplitBc * splitBc = bc1to1List[ i1to1 ];
+                BCType_t bocotype = static_cast<BCType_t>( splitBc->bcType );
+
+                std::vector<cgsize_t> pnts;
+                std::vector<cgsize_t> pntsdonor;
+                int nSize = splitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.end[ i ] );
+                }
+
+                int nPatchSize = splitBc->patch->region.start.size();
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( splitBc->patch->region.start[ i ] );
+                }
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( splitBc->patch->region.end[ i ] );
+                }
+                int id = splitBc->patch->splitZone->zoneIndex;
+                std::string donorname = "Zone" + std::to_string( id );
+
+                cg_1to1_write( fileId, baseId, zoneId, "Interface", donorname.c_str(), pnts.data(), pntsdonor.data(), itranfrm.data(), &index_conn);
+                std::cout << "index_conn = " << index_conn << "\n";
+            }
+        }
+    }
+    cg_close(fileId);
+}
+
+void Partition::ModifyZoneIndex()
+{
+    int globalZoneId = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        std::cout << "iProc = " << iProc << "\n";
+        int nZones = this->GetNZones( iProc );
+        std::cout << "nZones in Proc " << iProc << "  = " << nZones << "\n";
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+            splitZone->SetZoneIndex( globalZoneId++ );
+        }
+    }
+}
\ No newline at end of file
diff --git a/example/partition/struct/1d/01d/Partition.h b/example/partition/struct/1d/01d/Partition.h
new file mode 100644
index 00000000..55dc9cea
--- /dev/null
+++ b/example/partition/struct/1d/01d/Partition.h
@@ -0,0 +1,171 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class SplitZone;
+class RangeRegion;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox );
+
+class DimInfo
+{
+public:
+    DimInfo();
+    ~DimInfo();
+public:
+    int dim;
+    std::vector<int> dimList;
+    std::vector<int> oriPoint;
+    std::vector<int> isize;
+    std::vector<int> rmin;
+    std::vector<int> rmax;
+public:
+    int GetSize() const { return dim; }
+    DimInfo & operator = ( const DimInfo & rhs );
+public:
+    int ComputeNumNodes();
+    void ComputeISize();
+    void ComputeRminmax( std::vector<int> & ref );
+    void Init( std::vector<int> & dimList );
+    void SetNewDimension( int axis, int newStart, int newWidth );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+};
+
+class SplitZone;
+class SplitBcPatch;
+
+class RangeRegion
+{
+public:
+    RangeRegion( int nSize = 1 );
+    ~RangeRegion();
+public:
+    int regionAxis = -1;
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    RangeRegion & operator = ( const RangeRegion & rhs );
+    bool operator == ( const RangeRegion & rhs ) const;
+    void SetRegion( std::vector<int> &pnts );
+    int ComputeRegionAxis();
+};
+
+class SplitBc
+{
+public:
+    SplitBc();
+    ~SplitBc();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone = nullptr;
+    SplitBcPatch * patch = nullptr;
+    std::vector< SplitBc * > * child = nullptr;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+    void ChangeRegionToLocalCoordinate();
+public:
+    void SetZoneBcFromParentBc( SplitBc * parentSplitBc );
+    void InheritPatchBc( SplitBc * parentSplitBc );
+};
+
+class SplitBcPatch
+{
+public:
+    SplitBcPatch ();
+    ~SplitBcPatch();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone;
+};
+
+
+class SplitZone
+{
+public:
+    SplitZone();
+    ~SplitZone();
+public:
+    DimInfo dimInfo;
+    int zoneIndex, iProc;
+    //int oriZoneId;
+protected:
+    SplitZone * parent;
+public:
+    std::vector< SplitBc * > splitBcList;
+public:
+    int GetNCell();
+    void ComputeRminmax();
+    void GetRootInfo( SplitZone *& root, std::vector<int> & ref );
+    void SetZoneIndex( int zoneIndex ) { this->zoneIndex = zoneIndex; }
+    int  GetZoneIndex() { return zoneIndex; }
+    void SetProcId( int iProc ) { this->iProc = iProc; }
+    void SetParent( SplitZone * parent ) { this->parent = parent; };
+    std::vector< SplitBc * > & GetSplitBcList() { return this->splitBcList; };
+    void CreateBcFromParent();
+    void CreateSplitBc( SplitBc * parentSplitBc );
+    void AddSplitBc( SplitBc * splitBc );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+    SplitZone * GetRootZone();
+public:
+    void Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell );
+    void SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+    void SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+private:
+    int FindAxisNeedSplit();
+    int FindSplitPosition( int axisNeedSplit, double nCell );
+    bool IsPoleBc( int splitDirection );
+    int GetCrossSection( int axis );
+};
+
+class Partition
+{
+public:
+    Partition();
+    ~Partition();
+protected:
+    std::set < SplitZone * > zoneStorage;
+    std::set < SplitZone * > unsignedZoneGroup;
+    std::vector< SplitZone * > refZone;
+    std::vector< std::vector< SplitZone * > > procSplitZone;
+    std::vector<double> procSpeed;
+    std::vector<double> timeProc;
+    double aveFloatOp, delta;
+    double idealUniProcTime, eps;
+    int minNode;
+    int nTZone;
+    int nOriZone;
+    int nProc;
+public:
+    void Solve();
+    void ReadGrid();
+    void Split();
+    void InitSplit();
+    void BinarySplit();
+    //void GreedySplit();
+public:
+    void AddNewZone( SplitZone * zone );
+    void AddZoneToUnsignedGroup( SplitZone * zone );
+    void RemoveZoneFromUnsignedGroup( SplitZone * zone );
+    void AddZoneToProcess( int iProc, SplitZone * zone );
+    void DumpPartitionedGridFile();
+    void ModifyZoneIndex();
+    void FreeAllZones();
+    int GetNZones( int iProc );
+    SplitZone * GetSplitZone( int iProc, int zoneId );
+    void ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord );
+    void DumpBc( SplitZone * splitZone );
+private:
+    int GetMinValueIndex( double * data, int numberOfData );
+    int GetMinLoadProc();
+    SplitZone * GetLargestZone();
+    SplitZone * Split( SplitZone * zone, double nCell );
+};
+
diff --git a/example/partition/struct/1d/01d/README.txt b/example/partition/struct/1d/01d/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/partition/struct/1d/01d/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/partition/struct/1d/01d/heat1dni81.cgns b/example/partition/struct/1d/01d/heat1dni81.cgns
new file mode 100644
index 00000000..b7d4954a
Binary files /dev/null and b/example/partition/struct/1d/01d/heat1dni81.cgns differ
diff --git a/example/partition/struct/1d/01d/main.cpp b/example/partition/struct/1d/01d/main.cpp
new file mode 100644
index 00000000..5da1de7c
--- /dev/null
+++ b/example/partition/struct/1d/01d/main.cpp
@@ -0,0 +1,18 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include "Partition.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip>
+
+int main(int argc, char **argv)
+{
+    Partition * partition = new Partition();
+    partition->Solve();
+    delete partition;
+
+    return 0;
+}
diff --git a/example/partition/struct/1d/02/CMakeLists.txt b/example/partition/struct/1d/02/CMakeLists.txt
new file mode 100644
index 00000000..9fa577c8
--- /dev/null
+++ b/example/partition/struct/1d/02/CMakeLists.txt
@@ -0,0 +1,77 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	Partition.h Partition.cpp
+	CgnsGrid.h CgnsGrid.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/partition/struct/1d/02/CgnsGrid.cpp b/example/partition/struct/1d/02/CgnsGrid.cpp
new file mode 100644
index 00000000..269276f9
--- /dev/null
+++ b/example/partition/struct/1d/02/CgnsGrid.cpp
@@ -0,0 +1,345 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include <map>
+
+Grid::Grid()
+{
+    ;
+}
+
+Grid::~Grid()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if( (i+1)%5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+    delete this->patch;
+}
+
+ZoneBcPatch::ZoneBcPatch()
+{
+    ;
+}
+
+ZoneBcPatch::~ZoneBcPatch()
+{
+}
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+Global::Global()
+{
+    ;
+}
+
+Global::~Global()
+{
+}
+
+void Global::FreeData()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+    zones.resize( 0 );
+}
+
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            //baseZone.baseId = baseId;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones(fileId, baseId, &nzones);
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin( index_dim );
+            std::vector<cgsize_t> irmax( index_dim );
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[33];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                std::vector<char> coord( nNodes * sizeof(double) );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+                coor->DumpCoor();
+            }
+
+            int nbocos = -1;
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex(index_dim,-1);
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type, 
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset);
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[i] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[normalDataType] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList(nNodes*iphysdim*sizeof(double));
+
+                std::vector<cgsize_t> pnts(npnts*index_dim);
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc->pnts.push_back( range[ i ] );
+                }
+
+                zonebc->zoneid = gZoneId;
+                zonebc->bcType = BCTypeUserDefined;
+
+                ZoneBcPatch * patch = new ZoneBcPatch();
+                zonebc->patch = patch;
+
+                patch->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    patch->donor_pnts.push_back( donor_range[ i ] );
+                }
+                int kkk = 1;
+            }
+        }
+        int kkk = 1;
+    }
+    int kkk = 1;
+    cg_close(fileId);
+}
\ No newline at end of file
diff --git a/example/partition/struct/1d/02/CgnsGrid.h b/example/partition/struct/1d/02/CgnsGrid.h
new file mode 100644
index 00000000..af67a321
--- /dev/null
+++ b/example/partition/struct/1d/02/CgnsGrid.h
@@ -0,0 +1,123 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <map>
+
+class Grid;
+
+class Zone;
+
+class Grid
+{
+public:
+    Grid();
+    ~Grid();
+public:
+    int nZone;
+    std::vector<double> x;
+    std::vector<Zone *> zones;
+};
+
+class ZoneBc;
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+};
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<Coor *> coors;
+};
+
+class ZoneBcPatch;
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+    ZoneBcPatch * patch = nullptr;
+};
+
+class ZoneBcPatch
+{
+public:
+    ZoneBcPatch();
+    ~ZoneBcPatch();
+public:
+    int donor_zoneid;
+    std::vector<int> donor_pnts;
+};
+
+class BaseZone
+{
+public:
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Global
+{
+public:
+    Global();
+    ~Global();
+public:
+    static int cell_dim;
+    static int phys_dim;
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+public:
+    static void FreeData();
+};
+
+void ReadCgnsGrid( const std::string & filename );
+void ReadCgnsGridBaseZone( const std::string & filename );
\ No newline at end of file
diff --git a/example/partition/struct/1d/02/Partition.cpp b/example/partition/struct/1d/02/Partition.cpp
new file mode 100644
index 00000000..795cb892
--- /dev/null
+++ b/example/partition/struct/1d/02/Partition.cpp
@@ -0,0 +1,1267 @@
+#include "Partition.h"
+#include "CgnsGrid.h"
+#include "cgnslib.h"
+#include <string>
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox  )
+{
+    domainBox.start = zoneBox.start;
+    domainBox.end = zoneBox.end;
+
+    int axis = iDomain / 2;
+    int direction = iDomain % 2;
+
+    if ( direction == 0 )
+    {
+        domainBox.end[ axis ] = domainBox.start[ axis ];
+    }
+    else if ( direction == 1 )
+    {
+        domainBox.start[ axis ] = domainBox.end[ axis ];
+    }
+}
+
+DimInfo::DimInfo()
+{
+    this->dim = 1;
+    dimList.resize( this->dim, 1 );
+    oriPoint.resize( this->dim, 0 );
+}
+
+DimInfo::~DimInfo()
+{
+}
+
+DimInfo & DimInfo::operator = ( const DimInfo & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->dim = rhs.dim;
+    this->dimList = rhs.dimList;
+    this->oriPoint = rhs.oriPoint;
+
+    return * this;
+}
+
+int DimInfo::ComputeNumNodes()
+{
+    int nNodes = 1;
+    for ( int m = 0; m < this->dimList.size(); ++ m )
+    {
+        nNodes *= this->dimList[ m ];
+    }
+    return nNodes;
+}
+
+void DimInfo::ComputeISize()
+{
+    int index_dim = this->dimList.size();
+    this->isize.resize( index_dim * 3, 0 );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        isize[ m ] = this->dimList[ m ];
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 1;
+        isize[ start + m ] = this->dimList[ m ] - 1;
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 2;
+        isize[ start + m ] = 0;
+    }
+
+    for ( int i = 0; i < isize.size(); ++ i )
+    {
+        std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+    }
+}
+
+void DimInfo::ComputeRminmax( std::vector<int> & ref )
+{
+    int index_dim = this->dimList.size();
+    this->rmin.resize( index_dim );
+    this->rmax.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        rmin[ m ] = ref[ m ] + 1;
+        rmax[ m ] = ref[ m ] + this->dimList[ m ];
+    }
+
+    std::cout << "rmin, rmax = \n";
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        std::cout << rmin[ m ] << " " << rmax[ m ] << "\n";
+    }
+}
+
+void DimInfo::Init( std::vector<int> & dimList )
+{
+    this->dimList = dimList;
+    std::vector<int> zero( dimList.size(), 0 );
+    this->oriPoint = zero;
+}
+
+void DimInfo::SetNewDimension( int axis, int newStart, int newWidth )
+{
+    this->oriPoint[ axis ] = newStart;
+    this->dimList [ axis ] = newWidth;
+}
+
+void DimInfo::GetZoneGlobalBox( RangeRegion &zoneBox )
+{
+    int index_dim = this->dimList.size();
+    zoneBox.start.resize( index_dim );
+    zoneBox.end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        zoneBox.start[ m ] = this->oriPoint[ m ] + 1;
+        zoneBox.end[ m ] = this->oriPoint[ m ] + this->dimList[ m ];
+    }
+}
+
+void DimInfo::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    int index_dim = this->dimList.size();
+    localBox.start.resize( index_dim );
+    localBox.end.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        localBox.start[ m ] = globalBox.start[ m ] - this->oriPoint[ m ];
+        localBox.end[ m ] = globalBox.end[ m ] - this->oriPoint[ m ];
+    }
+}
+
+RangeRegion::RangeRegion( int nSize )
+{
+    this->start.resize( nSize );
+    this->end.resize( nSize );
+}
+
+RangeRegion::~RangeRegion()
+{
+}
+
+RangeRegion & RangeRegion::operator = ( const RangeRegion & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+    this->regionAxis = rhs.regionAxis;
+
+    return * this;
+}
+
+bool RangeRegion::operator == ( const RangeRegion & rhs ) const
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] != rhs.start[ m ] || 
+            this->end  [ m ] != rhs.end  [ m ] )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+    this->ComputeRegionAxis();
+}
+
+int RangeRegion::ComputeRegionAxis()
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] == this->end[ m ] )
+        {
+            this->regionAxis = m;
+            return this->regionAxis;
+        }
+    }
+    return this->regionAxis;
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion );
+
+bool ComputeOverlapRegion( RangeRegion & region1, RangeRegion & region2, RangeRegion & overlapRegion )
+{
+    int index_dim = region1.start.size();
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        overlapRegion.start[ m ] = std::max( region1.start[ m ], region2.start[ m ] );
+        overlapRegion.end  [ m ] = std::min( region1.end  [ m ], region2.end  [ m ] );
+    }
+
+    return CheckOverLapping( overlapRegion );
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion )
+{
+    int index_dim = overlapRegion.start.size();
+    int iCount = 0;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        if ( overlapRegion.start[ m ] == overlapRegion.end[ m ] )
+        {
+            ++ iCount;
+        }
+    }
+
+    return ( iCount == 1 );
+}
+
+SplitBc * CreateSplitBc( RangeRegion & bcRegion, RangeRegion & zoneDomainRegion )
+{
+    int sRegionAxis = bcRegion.ComputeRegionAxis();
+    int tRegionAxis = zoneDomainRegion.ComputeRegionAxis();
+
+    //Two regions in different directions
+    if ( sRegionAxis != tRegionAxis )
+    {
+        return 0;
+    }
+
+    //Although the two regions are in the same direction, the coordinates are inconsistent.
+    if ( bcRegion.start[ sRegionAxis ] != zoneDomainRegion.start[ sRegionAxis ] )
+    {
+        return 0;
+    }
+
+    RangeRegion overlapRegion;
+    ComputeOverlapRegion( bcRegion, zoneDomainRegion, overlapRegion );
+
+    if ( CheckOverLapping( overlapRegion ) )
+    {
+        SplitBc * splitBc = new SplitBc();
+        splitBc->SetRegion( overlapRegion );
+        return splitBc;
+    }
+
+    int kkk = 1;
+
+    return 0;
+}
+
+bool GetInterfaceRegion( RangeRegion & zoneBoxL, RangeRegion & zoneBoxR, RangeRegion & interfaceRegion )
+{
+    int index_dim = zoneBoxL.start.size();
+    int nDomains = 2 * index_dim;
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegionL;
+        GetDomainRegion( zoneBoxL, iDomain, domainRegionL );
+
+        for ( int jDomain = 0; jDomain < nDomains; ++ jDomain )
+        {
+            RangeRegion domainRegionR;
+            GetDomainRegion( zoneBoxR, jDomain, domainRegionR );
+
+            if ( domainRegionL == domainRegionR )
+            {
+                interfaceRegion = domainRegionL;
+                return true;
+            }
+        }
+    }
+    return false;
+}
+
+void CreateInterfaceBc( SplitZone * zoneL, SplitZone * zoneR )
+{
+    RangeRegion globalBoxL, globalBoxR, globalInterfaceRegion;
+
+    zoneL->GetZoneGlobalBox( globalBoxL );
+    zoneR->GetZoneGlobalBox( globalBoxR );
+
+    if ( ! GetInterfaceRegion( globalBoxL, globalBoxR, globalInterfaceRegion ) )
+    {
+        int kkk = 1;
+        return;
+    }
+
+    RangeRegion localInterfaceRegionL, localInterfaceRegionR;
+
+    zoneL->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionL );
+    zoneR->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionR );
+
+    int kkk = 1;
+
+    SplitBc * splitBcL = new SplitBc();
+    zoneL->AddSplitBc( splitBcL );
+
+    SplitBc * splitBcR = new SplitBc();
+    zoneR->AddSplitBc( splitBcR );
+
+    splitBcL->splitZone = zoneL;
+    splitBcL->SetRegion( localInterfaceRegionL );
+    splitBcL->bcType = BCTypeUserDefined;
+
+    splitBcR->splitZone = zoneR;
+    splitBcR->SetRegion( localInterfaceRegionR );
+    splitBcR->bcType = BCTypeUserDefined;
+
+    //localInterfaceRegionL.MarkPatchBc();
+    //localInterfaceRegionR.MarkPatchBc();
+
+    SplitBcPatch * splitBcPatchL = new SplitBcPatch();
+    splitBcL->patch = splitBcPatchL;
+    splitBcPatchL->region = localInterfaceRegionR;
+    splitBcPatchL->splitZone = zoneR;
+
+    SplitBcPatch * splitBcPatchR = new SplitBcPatch();
+    splitBcR->patch = splitBcPatchR;
+    splitBcPatchR->region = localInterfaceRegionL;
+    splitBcPatchR->splitZone = zoneL;
+
+    //splitBcL->Normalize();
+    //splitBcR->Normalize();
+}
+
+
+SplitBc::SplitBc()
+{
+}
+
+SplitBc::~SplitBc()
+{
+    delete this->patch;
+}
+
+void SplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void SplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+void SplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = splitZone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void SplitBc::SetZoneBcFromParentBc( SplitBc * parentSplitBc )
+{
+    this->bcType = parentSplitBc->bcType;
+    //this->LocalCoordinate();
+    this->region.regionAxis = parentSplitBc->region.regionAxis;
+    this->CreatePatchBc( parentSplitBc );
+}
+
+void SplitBc::CreatePatchBc( SplitBc * parentSplitBc )
+{
+    if ( parentSplitBc->bcType !=  BCTypeUserDefined ) return;
+
+    this->patch = new SplitBcPatch();
+    this->patch->splitZone = parentSplitBc->patch->splitZone;
+    this->patch->SetRegion( parentSplitBc->patch->region );
+    int kkk = 1;
+
+    //this->patch->faceAxis = parentSplitBc->patch->faceAxis;
+
+    //( * this->patch->vertexMap ) = ( * parentBc->patch->vertexMap );
+
+    ////È»ºó½øÐÐÐÞÕý
+    ////block1->map 1, 33 -> block1 369, 337
+    ////block2->global -> map 1, 33 -> block1 369, 337
+    ////block2->local  -> map 1, 33 -> block1 369, 337
+    ////refOld + M * stold           = block1Startold
+    ////refOld + M * ( stnew + ref ) = block1Startold
+    ////refNew = refOld + M * ( ref )
+
+    //for ( int m = 0; m < 3; ++ m )
+    //{
+    //    for ( int n = 0; n < 3; ++ n )
+    //    {
+    //        this->patch->vertexMap->pt[ m ] += this->patch->vertexMap->vm[ m ][ n ] * ( this->splitZone->sdim->oriPoint )[ n ];
+    //    }
+    //}
+
+    //RangeBox tRangeBox;
+
+    //MappingPatchPoint( this->patch, this->rangeBox, tRangeBox );
+    //tRangeBox.SetOrder();
+
+    ////ÕÒµ½ºÍ±¾¶Ô½Ó±ß½çÏà¶ÔÓ¦µÄ¿é
+    ////´Ópatch->splitZone°´ÕÕoverlapµÄ´óСÕÒµ½¶ÔÓ¦µÄ¶Ô½Ó±ß½ç£¬ÕâÑùÖÁÉÙ¿ÉÒÔÕÒµ½
+    ////¶ÔÃæµÄ¶Ô½Ó±ß½çÌõ¼þÓÉÓÚ±¾¿éµÄsplit±ØȻҪ·¢Éú¸Ä±ä£¬ÕâÀｫÏà¹Ø±ß½ç¼ÓÈë×ӱ߽ç
+    //this->patch->splitZone->CreateChildPatchBc( tRangeBox, this->splitZone );
+}
+
+SplitBcPatch::SplitBcPatch()
+{
+}
+
+SplitBcPatch::~SplitBcPatch()
+{
+}
+
+void SplitBcPatch::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void SplitBcPatch::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+SplitZone::SplitZone()
+{
+    this->parent  = 0;
+    this->zoneIndex = 0;
+    this->iProc = 0;
+}
+
+SplitZone::~SplitZone()
+{
+    ;
+}
+
+void SplitZone::GetZoneGlobalBox( RangeRegion & zoneBox )
+{
+    this->dimInfo.GetZoneGlobalBox( zoneBox );
+}
+
+void SplitZone::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    this->dimInfo.GetZoneLocalBox( globalBox, localBox );
+}
+
+
+void SplitZone::ComputeRminmax()
+{
+    int index_dim = this->dimInfo.dimList.size();
+    std::vector<int> ref( index_dim, 0 );
+
+    SplitZone * rootSplitZone = 0;
+    this->GetRootInfo( rootSplitZone, ref );
+
+    this->dimInfo.ComputeRminmax( ref );
+}
+
+SplitZone * SplitZone::GetRootZone()
+{
+    SplitZone * root = this;
+
+    while ( true )
+    {
+        if ( root->parent )
+        {
+            root = root->parent;
+        }
+        else
+        {
+            return root;
+        }
+    };
+}
+
+void SplitZone::GetRootInfo( SplitZone *& root, std::vector<int> & ref )
+{
+    for ( int i = 0; i < this->dimInfo.dimList.size(); ++ i )
+    {
+        ref[ i ] += this->dimInfo.oriPoint[ i ];
+    }
+
+    if ( this->parent )
+    {
+        this->parent->GetRootInfo( root, ref );
+    }
+    else
+    {
+        root = this;
+    }
+}
+
+
+int SplitZone::GetNCell()
+{
+    int numberOfCells = 1;
+    for ( int i = 0; i < this->dimInfo.dim; ++ i )
+    {
+        numberOfCells *= std::max( 1, ( this->dimInfo.dimList[ i ] - 1 ) );
+    }
+
+    return numberOfCells; 
+}
+
+void SplitZone::SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int leftStart = 0;
+    int leftWidth = iSplit - 0;
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, leftStart , leftWidth  );
+}
+
+void SplitZone::SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int rightStart = iSplit - 1;
+    int rightWidth = dimList[ axisNeedSplit ] - ( iSplit - 1 );
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, rightStart, rightWidth );
+}
+
+void SplitZone::Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell )
+{
+    //Find the longest axis
+    int axisNeedSplit = this->FindAxisNeedSplit();
+    int iSplit        = this->FindSplitPosition( axisNeedSplit, nCell );
+
+    zoneL = new SplitZone();
+    zoneL->SetParent( this );
+
+    zoneR = new SplitZone();
+    zoneR->SetParent( this );
+
+    zoneL->SetLeftDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+    zoneR->SetRightDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+
+    zoneL->CreateBcFromParent();
+    zoneR->CreateBcFromParent();
+
+    CreateInterfaceBc( zoneL, zoneR );
+}
+
+void SplitZone::CreateBcFromParent()
+{
+    std::vector< SplitBc * > & parentSplitBcList = this->parent->GetSplitBcList();
+
+    int nParentSplitBcs = parentSplitBcList.size();
+
+    for ( int iParentBc = 0; iParentBc < nParentSplitBcs; ++ iParentBc )
+    {
+        SplitBc * parentSplitBc = parentSplitBcList[ iParentBc ];
+
+        this->CreateSplitBc( parentSplitBc );
+    }
+}
+
+void SplitZone::AddSplitBc( SplitBc * splitBc )
+{
+    if ( ! splitBc ) return;
+    this->splitBcList.push_back( splitBc );
+}
+
+void SplitZone::CreateSplitBc( SplitBc * parentSplitBc )
+{
+    if ( ! parentSplitBc->child )
+    {
+        int index_dim = this->dimInfo.dimList.size();
+        int nDomains = 2 * index_dim;
+        RangeRegion zoneBoxRegion( index_dim );
+        this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+        for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+        {
+            RangeRegion domainRegion( index_dim );
+            GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+            RangeRegion overlapRegion;
+            bool overlap_flag = ComputeOverlapRegion( parentSplitBc->region, domainRegion, overlapRegion );
+            if ( ! overlap_flag ) continue;
+
+            SplitBc * splitBc = new SplitBc();
+            this->AddSplitBc( splitBc );
+
+            splitBc->SetRegion( overlapRegion );
+            splitBc->bcType = parentSplitBc->bcType;
+            splitBc->splitZone = this;
+            splitBc->ChangeRegionToLocalCoordinate();
+            splitBc->CreatePatchBc( parentSplitBc );
+            int kkk = 1;
+        }
+    }
+    else
+    {
+        int nChilds = parentSplitBc->child->size();
+        for ( int iChild = 0; iChild < nChilds; ++ iChild )
+        {
+            this->CreateSplitBc( ( * parentSplitBc->child )[ iChild ] );
+        }
+    }
+}
+
+
+int SplitZone::FindAxisNeedSplit()
+{
+    //Find the longest axis
+    int axisNeedSplit = 0;
+    int maxN = this->dimInfo.dimList[ 0 ];
+
+    for ( int m = 1; m < this->dimInfo.dimList.size(); ++ m )
+    {
+        if ( this->IsPoleBc( m ) )
+        {
+            continue;
+        }
+        int Nm = this->dimInfo.dimList[ m ];
+        if ( maxN < Nm )
+        {
+            maxN = Nm;
+            axisNeedSplit = m;
+        }
+    }
+
+    return axisNeedSplit;
+}
+
+int SplitZone::GetCrossSection( int axis )
+{
+    int nDim = this->dimInfo.dimList.size();
+    int crossSection = 1;
+    int N = nDim - 1;
+    for ( int m = 0; m < N; ++ m )
+    {
+         int mm = ( axis + 1 ) % nDim;
+         int nLineElements = std::max( 1, ( this->dimInfo.dimList[ mm ] - 1 ) );
+         crossSection *= nLineElements;
+    }
+    return crossSection;
+}
+
+int SplitZone::FindSplitPosition( int axisNeedSplit, double nCell )
+{
+    int nDim = this->dimInfo.dimList.size();
+    std::vector<int> crossSections( nDim );
+    for ( int m = 0; m < nDim; ++ m )
+    {
+        crossSections[ m ] = this->GetCrossSection( m );
+    }
+
+    //guess the value
+    double dSplit = nCell / crossSections[ axisNeedSplit ];
+    int  iSplit = 1 + static_cast< int >( std::floor( dSplit + 0.5 ) );
+    return iSplit;
+}
+
+
+bool SplitZone::IsPoleBc( int splitDirection )
+{
+    return false;
+}
+
+
+double CalSumOfProcSpeed( std::vector<double> & procSpeed );
+double CalSumOfProcSpeed( std::vector<double> & procSpeed )
+{
+    int nProc = procSpeed.size();
+    double sumOfProcSpeed = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        sumOfProcSpeed += procSpeed[ iProc ];
+    }
+    return sumOfProcSpeed;
+}
+
+Partition::Partition()
+{
+    this->inputName = "../heat1d2blocks.cgns";
+    this->outName =  "../heat1dpart.cgns";
+}
+
+Partition::~Partition()
+{
+    ;
+}
+
+int Partition::GetMinValueIndex( double * data, int numberOfData )
+{
+    double minValue = data[ 0 ];
+    int minimumValueIndex = 0;
+
+    for ( int iData = 1; iData < numberOfData; ++ iData )
+    {
+        if ( minValue > data[ iData ] )
+        {
+            minValue      = data[ iData ];
+            minimumValueIndex = iData;
+        }
+    }
+    return minimumValueIndex;
+}
+
+int Partition::GetMinLoadProc()
+{
+    return this->GetMinValueIndex( this->timeProc.data(), this->nProc );
+}
+
+SplitZone * Partition::GetLargestZone()
+{
+    SplitZone * largestZone = 0;
+
+    double nMaxCell = 0.0;
+
+    for ( std::set< SplitZone * >::iterator iter = unsignedZoneGroup.begin(); iter != unsignedZoneGroup.end(); ++ iter )
+    {
+        double nSize = ( * iter )->GetNCell();
+        if ( nMaxCell < nSize )
+        {
+            nMaxCell    = nSize;
+            largestZone = * iter;
+        }
+    }
+
+    return largestZone;
+}
+
+void Partition::Solve()
+{
+    std::cout << "Partition::Split()\n";
+    //this->nProc = 2;
+    this->nProc = 4;
+    this->ReadGrid();
+    this->Split();
+    this->ModifyZoneIndex();
+    this->DumpPartitionedGridFile();
+    this->FreeAllZones();
+}
+
+void Partition::ReadGrid()
+{
+    //ReadCgnsGrid( "../heat1dni81.cgns" );
+    ReadCgnsGridBaseZone( this->inputName );
+    ReadCgnsGrid( this->inputName );
+
+    this->nOriZone = ::Global::zones.size();
+
+    std::cout << "numberOfBlocks = " << nOriZone << "\n";
+
+    this->refZone.resize( nOriZone );
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = new SplitZone();
+        refZone[ iZone ] = splitZone;
+
+        splitZone->SetZoneIndex( iZone );
+        splitZone->SetProcId( 0 );
+        splitZone->SetParent( 0 );
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        Zone * zone = ::Global::zones[ iZone ];
+
+        splitZone->dimInfo.dimList = zone->nijk;
+
+        int nBcRegion = zone->bccos.size();
+        std::cout << "nBcRegion = " << nBcRegion << "\n";
+
+        std::vector< SplitBc * > & splitBcList = splitZone->splitBcList;
+
+        for ( int iBcRegion = 0; iBcRegion < nBcRegion; ++ iBcRegion )
+        {
+            SplitBc * splitBc = new SplitBc();
+            splitBcList.push_back( splitBc );
+
+            ZoneBc * zoneBc = zone->bccos[ iBcRegion ];
+
+            splitBc->splitZone = splitZone;
+            splitBc->bcType = zoneBc->bcType;
+            splitBc->SetRegion( zoneBc->pnts );
+            if ( zoneBc->patch )
+            {
+                SplitBcPatch * patch = new SplitBcPatch();
+                splitBc->patch = patch;
+
+                patch->splitZone = refZone[ zoneBc->patch->donor_zoneid ];
+                patch->SetRegion( zoneBc->patch->donor_pnts );
+            }
+        }
+
+        int kkk = 1;
+
+        //splitZone->NormalizeBc();
+    }
+    int kkk = 1;
+}
+
+void Partition::Split()
+{
+    this->InitSplit();
+    this->BinarySplit();
+    //this->SetZoneIndex();
+}
+
+void Partition::InitSplit()
+{
+    //nZone is the number of zones in the original grid
+    //nProc is not the number of blocks in the end, but the number of processes that need to be divided.
+    //This difference occurs because the structure grid can have many blocks per process.
+
+    //this->nProc    = nProc;
+    //this->nPhyBlocks = referenceBlock.size();
+    //this->nZone  = this->nPhyBlocks;
+
+    //tj Computation time on processor j
+    //Nk Number of internal grid-cells for zone j
+    //aveFloatOp:  Number of Real operations per gridcell
+    //Gj The set of blocks allocated to process j
+    //Pj Real operations per second for process j
+
+    //The Greedy Load Balancing Algorithm
+    //1.Compute an "ideal" uniprocessor time, Tuni = sum ( Nk * aveFloatOp )/ sum( Pj ).
+    //2.Set the group of unassigned blocks, Gu, to contain all blocks. The number of blocks in Nu=M, where M is the total number of blocks in the mesh.
+    //3.Start all processors with a very small fictitious zone to get a start tj=delt aveFloatOp/Pj, where delt<<1 is the size of the very small fictious zone.
+    //This is used to find the fastest processor in a heterogeneous system, tj could otherwise be set to 0 in the homogeneous case.
+    this->aveFloatOp = 1.0;
+    this->delta      = 1.0e-5;
+    this->procSpeed.resize( nProc );
+    this->timeProc.resize( nProc );
+
+    this->nTZone = this->nOriZone;
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        procSpeed[ iProc ] = 1.0;
+    }
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        timeProc[ iProc ] = delta * aveFloatOp / procSpeed[ iProc ];
+    }
+
+    double sumProcSpeed = CalSumOfProcSpeed( procSpeed );
+
+    double sumProcOp = 0.0;
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        sumProcOp += refZone[ iZone ]->GetNCell() * aveFloatOp;
+    }
+
+    this->idealUniProcTime = sumProcOp / sumProcSpeed;
+
+    this->eps = 0.05;
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        unsignedZoneGroup.insert( refZone[ iZone ] );
+    }
+
+    //Init zoneStorage
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        zoneStorage.insert( refZone[ iZone ] );
+    }
+
+    //Assign procSplitZone to each process
+    procSplitZone.resize( nProc );
+
+    int index_dim = Global::cell_dim;
+    this->minNode = 1;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->minNode *= 2;
+    }
+
+    int kkk = 1;
+
+}
+
+void Partition::FreeAllZones()
+{
+    int iCount = 0;
+    for ( std::set < SplitZone * >::iterator iter = zoneStorage.begin(); iter != zoneStorage.end(); ++ iter )
+    {
+        //cout << "iCount = " << iCount << "\n";
+        ++ iCount;
+        delete * iter;
+    }
+}
+
+int Partition::GetNZones( int iProc )
+{
+    return this->procSplitZone[ iProc ].size();
+}
+
+SplitZone * Partition::GetSplitZone( int iProc, int zoneId )
+{
+    return this->procSplitZone[ iProc ][ zoneId ];
+}
+
+void Partition::AddZoneToUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.insert( zone );
+}
+
+void Partition::RemoveZoneFromUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.erase( zone );
+}
+
+void Partition::AddZoneToProcess( int iProc, SplitZone * zone )
+{
+    this->procSplitZone[ iProc ].push_back( zone );
+}
+
+void Partition::AddNewZone( SplitZone * zone )
+{
+    zone->SetZoneIndex( nTZone ++ );
+
+    this->AddZoneToUnsignedGroup( zone );
+
+    this->zoneStorage.insert( zone );
+}
+
+SplitZone * Partition::Split( SplitZone * zone, double nCell )
+{
+    SplitZone * zoneL = 0;
+    SplitZone * zoneR = 0;
+
+    zone->Split( zoneL, zoneR, nCell );
+
+    this->AddNewZone( zoneL );
+    this->AddNewZone( zoneR );
+    this->RemoveZoneFromUnsignedGroup( zone );
+
+    return zoneL;
+}
+
+void Partition::BinarySplit()
+{
+    while ( ! unsignedZoneGroup.empty() )
+    {
+        std::cout << "number of unsigned zone = " << unsignedZoneGroup.size() << "\n";
+        int iProc = this->GetMinLoadProc();
+
+        //Get the block with the largest number of grids and its size
+        SplitZone * largestZone = this->GetLargestZone();
+
+        double nMaxCell = largestZone->GetNCell();
+
+        double aveFloatOp = this->aveFloatOp;
+        double tau = timeProc[ iProc ] + nMaxCell * aveFloatOp / procSpeed[ iProc ];
+
+        int kkk = 1;
+
+        //It seems that EPS is still necessary
+        //The idea here is as follows. For the candidate blocks which can be divided into blocks, 
+        //if the difference between the target blocks and the candidate blocks is too wide, 
+        //the binarySplit method is adopted. The binarySplit blocks do not directly join the process,
+        //but enter the next round of screening.
+
+        if ( tau > idealUniProcTime * ( 1.0 + eps ) )
+        {
+            double nRest = ( tau - idealUniProcTime ) * procSpeed[ iProc ] / aveFloatOp;
+
+            double nTarget = nMaxCell - nRest;
+            if ( nRest > this->minNode && nTarget > this->minNode )
+            {
+                //It is necessary to divide blocks only when a certain number of points are satisfied.
+                double nHalf = nMaxCell / 2.0;
+                nMaxCell = nTarget;
+                double ratio = nMaxCell / nRest;
+                double oRatio = 1.0 / ratio;
+
+                if ( std::max( ratio, oRatio ) < 3.0 )
+                {
+                    int kkk = 1;
+                    largestZone = this->Split( largestZone, nMaxCell );
+                    timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                    this->RemoveZoneFromUnsignedGroup( largestZone );
+                    this->AddZoneToProcess( iProc, largestZone );
+                }
+                else
+                {
+                    this->Split( largestZone, nHalf );
+                }
+            }
+            else
+            {
+                //If the block is of the right size, join the process directly, and there is no need to split it.
+                timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                this->RemoveZoneFromUnsignedGroup( largestZone );
+                this->AddZoneToProcess( iProc, largestZone );
+            }
+        }
+        else
+        {
+            //If the block is of the right size, join the process directly, and there is no need to split it.
+            timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+            this->RemoveZoneFromUnsignedGroup( largestZone );
+            this->AddZoneToProcess( iProc, largestZone );
+        }
+    }
+}
+
+void Partition::ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord )
+{
+    SplitZone * rootSplitZone = splitZone->GetRootZone();
+    Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+    int nNodes = splitZone->dimInfo.ComputeNumNodes();
+    std::cout << "nNodes = " << nNodes << "\n";
+
+    coord.resize( nNodes * sizeof(double) );
+
+    int index_dim = splitZone->dimInfo.dimList.size();
+    Coor * coor = zone->coors[ icoord ];
+
+    double * xlocal = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    double * xglobal = reinterpret_cast<double *>( const_cast<char *>( coor->coord.data() ) );
+    if ( index_dim == 1 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        for ( int i = imin; i < imax; ++ i )
+        {
+            xlocal[ icount++ ] = xglobal[ i ];
+        }
+    }
+    else if ( index_dim == 2 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        int jmin = splitZone->dimInfo.rmin[ 1 ] - 1;
+        int jmax = splitZone->dimInfo.rmax[ 1 ];
+        int ni = rootSplitZone->dimInfo.dimList[ 0 ];
+        int nj = rootSplitZone->dimInfo.dimList[ 1 ];
+        for ( int j = jmin; j < jmax; ++ j )
+        {
+            int jstride = j * ni;
+            for ( int i = imin; i < imax; ++ i )
+            {
+                xlocal[ icount++ ] = xglobal[ jstride + i ];
+            }
+        }
+    }
+}
+
+void Partition::DumpBc( SplitZone * splitZone )
+{
+    //std::vector< ZoneBc * > leafZoneBc;
+
+    //std::vector< ZoneBc * > & zoneBcList = splitZone->GetZoneBcList();
+
+    //for ( int i = 0; i < zoneBcList.size(); ++ i )
+    //{
+    //    std::vector< ZoneBc * > cl = zoneBcList[ i ]->GetLeaves();
+    //    for ( int j = 0; j < cl.size(); ++ j )
+    //    {
+    //        leafZoneBc.push_back( cl[ j ] );
+    //    }
+    //}
+
+    //int nZoneBc = leafZoneBc.size();
+
+    //for ( int iZoneBc = 0; iZoneBc < nZoneBc; ++ iZoneBc )
+    //{
+    //    ZoneBc * zoneBc = leafZoneBc[ iZoneBc ];
+    //    zoneBc->DumpBc();
+    //}
+}
+
+void Partition::DumpPartitionedGridFile()
+{
+    int fileId = -1;
+    std::string filename = this->outName;
+    cg_open( filename.c_str(), CG_MODE_WRITE, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        int icelldim = 1;
+        int iphysdim = 1;
+        std::string basename = "Base" + std::to_string( iProc );
+
+        int baseId = -1;
+        cg_base_write( fileId, basename.c_str(), icelldim, iphysdim, &baseId );
+
+        std::cout << "baseId = " << baseId << "\n";
+
+        int nZones = this->GetNZones( iProc );
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            ZoneType_t zoneType = Structured;
+
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+
+            int index_dim = splitZone->dimInfo.dimList.size();
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            splitZone->dimInfo.ComputeISize();
+
+            int isize_dim = index_dim * 3;
+
+            std::vector<cgsize_t> isize( index_dim * 3, 0 );
+            for ( int m = 0; m < isize_dim; ++ m )
+            {
+                isize[ m ] = splitZone->dimInfo.isize[ m ];
+            }
+
+            int zoneId = -1;
+
+            std::string zonename = "Zone" + std::to_string( splitZone->zoneIndex );
+
+            cg_zone_write( fileId, baseId, zonename.c_str(), isize.data(), zoneType, &zoneId );
+
+            std::cout << "zoneId = " << zoneId << "\n";
+                
+            splitZone->ComputeRminmax();
+
+            SplitZone * rootSplitZone = splitZone->GetRootZone();
+
+            Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+            int ncoords = zone->coors.size();
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = -1;
+                DataType_t dataType = RealDouble;
+                std::string coordname = "X";
+                Coor * coor = zone->coors[ icoord ];
+
+                int nNodes = splitZone->dimInfo.ComputeNumNodes();
+                std::cout << "nNodes = " << nNodes << "\n";
+
+                std::vector<char> coord;
+                ComputeCoor( splitZone, icoord, coord );
+
+                cg_coord_write( fileId, baseId, zoneId, dataType, coordname.c_str(), coord.data(), &coorId );
+
+                std::cout << "cg_get_error() = " << cg_get_error() << "\n";
+                std::cout << "fileId = " << fileId  << " baseId = " << baseId << " zoneId = " << zoneId  << " coorId = " << coorId << "\n";
+            }
+
+            int nBcLists = splitZone->splitBcList.size();
+            std::vector<SplitBc * > bccoList;
+            std::vector<SplitBc * > bc1to1List;
+
+            for ( int ibc = 0; ibc < nBcLists; ++ ibc )
+            {
+                SplitBc * splitBc = splitZone->splitBcList[ ibc ];
+                if ( splitBc->bcType == BCTypeUserDefined )
+                {
+                    bc1to1List.push_back( splitBc );
+                }
+                else
+                {
+                    bccoList.push_back( splitBc );
+                }
+            }
+            int nbocos = bccoList.size();
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = -1;
+                GridLocation_t location = Vertex;
+
+                std::string boconame = "BC" + std::to_string( iboco + 1 );
+
+                SplitBc * splitBc = bccoList[ iboco ];
+                BCType_t bocotype = static_cast<BCType_t>( splitBc->bcType );
+                PointSetType_t ptset_type = PointRange;
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> pnts;
+                int nSize = splitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.end[ i ] );
+                }
+
+                cg_boco_write( fileId, baseId, zoneId, boconame.c_str(), bocotype, ptset_type, npnts, pnts.data(), & bccoId );
+            }
+
+            int n1to1 = bc1to1List.size();
+            std::cout << "n1to1 = " << n1to1 << "\n";
+
+            std::vector<int> itranfrm( index_dim );
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                itranfrm[ m ] = m + 1;
+            }
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int index_conn = -1;
+
+                SplitBc * splitBc = bc1to1List[ i1to1 ];
+                BCType_t bocotype = static_cast<BCType_t>( splitBc->bcType );
+
+                std::vector<cgsize_t> pnts;
+                std::vector<cgsize_t> pntsdonor;
+                int nSize = splitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.end[ i ] );
+                }
+
+                int nPatchSize = splitBc->patch->region.start.size();
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( splitBc->patch->region.start[ i ] );
+                }
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( splitBc->patch->region.end[ i ] );
+                }
+                int id = splitBc->patch->splitZone->zoneIndex;
+                std::string donorname = "Zone" + std::to_string( id );
+                std::string connectname = "Interface" + std::to_string( i1to1 );
+
+                cg_1to1_write( fileId, baseId, zoneId, connectname.c_str(), donorname.c_str(), pnts.data(), pntsdonor.data(), itranfrm.data(), &index_conn);
+                std::cout << "index_conn = " << index_conn << "\n";
+            }
+        }
+    }
+    cg_close(fileId);
+}
+
+void Partition::ModifyZoneIndex()
+{
+    int globalZoneId = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        std::cout << "iProc = " << iProc << "\n";
+        int nZones = this->GetNZones( iProc );
+        std::cout << "nZones in Proc " << iProc << "  = " << nZones << "\n";
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+            splitZone->SetZoneIndex( globalZoneId++ );
+        }
+    }
+}
\ No newline at end of file
diff --git a/example/partition/struct/1d/02/Partition.h b/example/partition/struct/1d/02/Partition.h
new file mode 100644
index 00000000..b9c38c91
--- /dev/null
+++ b/example/partition/struct/1d/02/Partition.h
@@ -0,0 +1,177 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class SplitZone;
+class RangeRegion;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox );
+
+class DimInfo
+{
+public:
+    DimInfo();
+    ~DimInfo();
+public:
+    int dim;
+    std::vector<int> dimList;
+    std::vector<int> oriPoint;
+    std::vector<int> isize;
+    std::vector<int> rmin;
+    std::vector<int> rmax;
+public:
+    int GetSize() const { return dim; }
+    DimInfo & operator = ( const DimInfo & rhs );
+public:
+    int ComputeNumNodes();
+    void ComputeISize();
+    void ComputeRminmax( std::vector<int> & ref );
+    void Init( std::vector<int> & dimList );
+    void SetNewDimension( int axis, int newStart, int newWidth );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+};
+
+class SplitZone;
+class SplitBcPatch;
+
+class RangeRegion
+{
+public:
+    RangeRegion( int nSize = 1 );
+    ~RangeRegion();
+public:
+    int regionAxis = -1;
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    RangeRegion & operator = ( const RangeRegion & rhs );
+    bool operator == ( const RangeRegion & rhs ) const;
+    void SetRegion( std::vector<int> &pnts );
+    int ComputeRegionAxis();
+};
+
+class SplitBc
+{
+public:
+    SplitBc();
+    ~SplitBc();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone = nullptr;
+    SplitBcPatch * patch = nullptr;
+    std::vector< SplitBc * > * child = nullptr;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+    void ChangeRegionToLocalCoordinate();
+public:
+    void SetZoneBcFromParentBc( SplitBc * parentSplitBc );
+    void CreatePatchBc( SplitBc * parentSplitBc );
+};
+
+class SplitBcPatch
+{
+public:
+    SplitBcPatch ();
+    ~SplitBcPatch();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+};
+
+
+class SplitZone
+{
+public:
+    SplitZone();
+    ~SplitZone();
+public:
+    DimInfo dimInfo;
+    int zoneIndex, iProc;
+    //int oriZoneId;
+protected:
+    SplitZone * parent;
+public:
+    std::vector< SplitBc * > splitBcList;
+public:
+    int GetNCell();
+    void ComputeRminmax();
+    void GetRootInfo( SplitZone *& root, std::vector<int> & ref );
+    void SetZoneIndex( int zoneIndex ) { this->zoneIndex = zoneIndex; }
+    int  GetZoneIndex() { return zoneIndex; }
+    void SetProcId( int iProc ) { this->iProc = iProc; }
+    void SetParent( SplitZone * parent ) { this->parent = parent; };
+    std::vector< SplitBc * > & GetSplitBcList() { return this->splitBcList; };
+    void CreateBcFromParent();
+    void CreateSplitBc( SplitBc * parentSplitBc );
+    void AddSplitBc( SplitBc * splitBc );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+    SplitZone * GetRootZone();
+public:
+    void Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell );
+    void SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+    void SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+private:
+    int FindAxisNeedSplit();
+    int FindSplitPosition( int axisNeedSplit, double nCell );
+    bool IsPoleBc( int splitDirection );
+    int GetCrossSection( int axis );
+};
+
+class Partition
+{
+public:
+    Partition();
+    ~Partition();
+protected:
+    std::set < SplitZone * > zoneStorage;
+    std::set < SplitZone * > unsignedZoneGroup;
+    std::vector< SplitZone * > refZone;
+    std::vector< std::vector< SplitZone * > > procSplitZone;
+    std::vector<double> procSpeed;
+    std::vector<double> timeProc;
+    double aveFloatOp, delta;
+    double idealUniProcTime, eps;
+    int minNode;
+    int nTZone;
+    int nOriZone;
+    int nProc;
+public:
+    std::string inputName;
+    std::string outName;
+public:
+    void Solve();
+    void ReadGrid();
+    void Split();
+    void InitSplit();
+    void BinarySplit();
+    //void GreedySplit();
+public:
+    void AddNewZone( SplitZone * zone );
+    void AddZoneToUnsignedGroup( SplitZone * zone );
+    void RemoveZoneFromUnsignedGroup( SplitZone * zone );
+    void AddZoneToProcess( int iProc, SplitZone * zone );
+    void DumpPartitionedGridFile();
+    void ModifyZoneIndex();
+    void FreeAllZones();
+    int GetNZones( int iProc );
+    SplitZone * GetSplitZone( int iProc, int zoneId );
+    void ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord );
+    void DumpBc( SplitZone * splitZone );
+private:
+    int GetMinValueIndex( double * data, int numberOfData );
+    int GetMinLoadProc();
+    SplitZone * GetLargestZone();
+    SplitZone * Split( SplitZone * zone, double nCell );
+};
+
diff --git a/example/partition/struct/1d/02/README.txt b/example/partition/struct/1d/02/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/partition/struct/1d/02/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/partition/struct/1d/02/heat1d2blocks.cgns b/example/partition/struct/1d/02/heat1d2blocks.cgns
new file mode 100644
index 00000000..4f4441f0
Binary files /dev/null and b/example/partition/struct/1d/02/heat1d2blocks.cgns differ
diff --git a/example/partition/struct/1d/02/main.cpp b/example/partition/struct/1d/02/main.cpp
new file mode 100644
index 00000000..5da1de7c
--- /dev/null
+++ b/example/partition/struct/1d/02/main.cpp
@@ -0,0 +1,18 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include "Partition.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip>
+
+int main(int argc, char **argv)
+{
+    Partition * partition = new Partition();
+    partition->Solve();
+    delete partition;
+
+    return 0;
+}
diff --git a/example/partition/struct/1d/02a/CMakeLists.txt b/example/partition/struct/1d/02a/CMakeLists.txt
new file mode 100644
index 00000000..74ceea7d
--- /dev/null
+++ b/example/partition/struct/1d/02a/CMakeLists.txt
@@ -0,0 +1,78 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	Partition.h Partition.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	SplitZone.h SplitZone.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/partition/struct/1d/02a/CgnsGrid.cpp b/example/partition/struct/1d/02a/CgnsGrid.cpp
new file mode 100644
index 00000000..dfe750bd
--- /dev/null
+++ b/example/partition/struct/1d/02a/CgnsGrid.cpp
@@ -0,0 +1,349 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include <map>
+
+Grid::Grid()
+{
+    ;
+}
+
+Grid::~Grid()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if( (i+1)%5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+    delete this->patch;
+}
+
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+ZoneBcPatch::ZoneBcPatch()
+{
+    ;
+}
+
+ZoneBcPatch::~ZoneBcPatch()
+{
+}
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+Global::Global()
+{
+    ;
+}
+
+Global::~Global()
+{
+}
+
+void Global::FreeData()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+    zones.resize( 0 );
+}
+
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            //baseZone.baseId = baseId;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin( index_dim );
+            std::vector<cgsize_t> irmax( index_dim );
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                std::vector<char> coord( nNodes * sizeof(double) );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+                coor->DumpCoor();
+            }
+
+            int nbocos = -1;
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+                int kkk = 1;
+            }
+        }
+        int kkk = 1;
+    }
+    int kkk = 1;
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/partition/struct/1d/02a/CgnsGrid.h b/example/partition/struct/1d/02a/CgnsGrid.h
new file mode 100644
index 00000000..053c467b
--- /dev/null
+++ b/example/partition/struct/1d/02a/CgnsGrid.h
@@ -0,0 +1,140 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <map>
+
+class Grid;
+
+class Zone;
+
+class Grid
+{
+public:
+    Grid();
+    ~Grid();
+public:
+    int nZone;
+    std::vector<double> x;
+    std::vector<Zone *> zones;
+};
+
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+};
+
+class ZoneBc;
+class ZoneBc1To1;
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class ZoneBcPatch;
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+    ZoneBcPatch * patch = nullptr;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+class ZoneBcPatch
+{
+public:
+    ZoneBcPatch();
+    ~ZoneBcPatch();
+public:
+    int donor_zoneid;
+    std::vector<int> transform;
+    std::vector<int> donor_pnts;
+};
+
+class BaseZone
+{
+public:
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Global
+{
+public:
+    Global();
+    ~Global();
+public:
+    static int cell_dim;
+    static int phys_dim;
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+public:
+    static void FreeData();
+};
+
+void ReadCgnsGrid( const std::string & filename );
+void ReadCgnsGridBaseZone( const std::string & filename );
\ No newline at end of file
diff --git a/example/partition/struct/1d/02a/Partition.cpp b/example/partition/struct/1d/02a/Partition.cpp
new file mode 100644
index 00000000..e2e15648
--- /dev/null
+++ b/example/partition/struct/1d/02a/Partition.cpp
@@ -0,0 +1,619 @@
+#include "Partition.h"
+#include "CgnsGrid.h"
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+bool CmpSplitZone::operator() ( SplitZone * a, SplitZone * b ) const
+{
+    return a->zoneIndex < b->zoneIndex;
+};
+
+
+double CalSumOfProcSpeed( std::vector<double> & procSpeed );
+double CalSumOfProcSpeed( std::vector<double> & procSpeed )
+{
+    int nProc = procSpeed.size();
+    double sumOfProcSpeed = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        sumOfProcSpeed += procSpeed[ iProc ];
+    }
+    return sumOfProcSpeed;
+}
+
+Partition::Partition()
+{
+    this->inputName = "../heat1d2blocksv1.cgns";
+    this->outName =  "../heat1dpart.cgns";
+}
+
+Partition::~Partition()
+{
+    ;
+}
+
+int Partition::GetMinValueIndex( double * data, int numberOfData )
+{
+    double minValue = data[ 0 ];
+    int minimumValueIndex = 0;
+
+    for ( int iData = 1; iData < numberOfData; ++ iData )
+    {
+        if ( minValue > data[ iData ] )
+        {
+            minValue      = data[ iData ];
+            minimumValueIndex = iData;
+        }
+    }
+    return minimumValueIndex;
+}
+
+int Partition::GetMinLoadProc()
+{
+    return this->GetMinValueIndex( this->timeProc.data(), this->nProc );
+}
+
+SplitZone * Partition::GetLargestZone()
+{
+    SplitZone * largestZone = 0;
+
+    double nMaxCell = 0.0;
+
+    for ( std::set< SplitZone * >::iterator iter = unsignedZoneGroup.begin(); iter != unsignedZoneGroup.end(); ++ iter )
+    {
+        double nSize = ( * iter )->GetNCell();
+        if ( nMaxCell < nSize )
+        {
+            nMaxCell    = nSize;
+            largestZone = * iter;
+        }
+    }
+
+    return largestZone;
+}
+
+void Partition::Solve()
+{
+    std::cout << "Partition::Split()\n";
+    this->nProc = 2;
+    this->ReadGrid();
+    this->Split();
+    this->DumpPartitionedGridFile();
+    this->FreeAllZones();
+}
+
+void Partition::ReadGrid()
+{
+    ReadCgnsGridBaseZone( this->inputName );
+    ReadCgnsGrid( this->inputName );
+
+    this->nOriZone = ::Global::zones.size();
+    Dim::dim = Global::cell_dim;
+
+    std::cout << "numberOfBlocks = " << nOriZone << "\n";
+
+    this->refZone.resize( nOriZone );
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = new SplitZone();
+        refZone[ iZone ] = splitZone;
+
+        splitZone->SetZoneIndex( iZone );
+        splitZone->SetProcId( 0 );
+        splitZone->SetParentAndChild( 0 );
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        Zone * zone = ::Global::zones[ iZone ];
+
+        splitZone->dimInfo.dimList = zone->nijk;
+
+        int nbccos = zone->bccos.size();
+        std::cout << "nbccos = " << nbccos << "\n";
+
+        for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+        {
+            ZoneBc * zoneBc = zone->bccos[ ibcco ];
+
+            PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+            splitZone->physicalSplitBcList.push_back( physicalSplitBc );
+            physicalSplitBc->bcType = zoneBc->bcType;
+            physicalSplitBc->SetRegion( zoneBc->pnts );
+            physicalSplitBc->splitZone = splitZone;
+        }
+
+        int nbc1to1s = zone->bc1to1s.size();
+
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * zoneBc1To1 = zone->bc1to1s[ ibc1to1 ];
+
+            InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+            splitZone->interfaceSplitBcList.push_back( interfaceSplitBc );
+            interfaceSplitBc->zone = splitZone;
+            interfaceSplitBc->region.SetRegion( zoneBc1To1->pnts );
+
+            interfaceSplitBc->transform = zoneBc1To1->transform;
+            interfaceSplitBc->CalcTransformMatrix();
+
+            interfaceSplitBc->donor_zone = refZone[ zoneBc1To1->donor_zoneid ];
+            interfaceSplitBc->donor_region.SetRegion( zoneBc1To1->donor_pnts );
+        }
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        int nbc1to1s = splitZone->interfaceSplitBcList.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            InterfaceSplitBc * interfaceSplitBc = splitZone->interfaceSplitBcList[ ibc1to1 ];
+            InterfaceInfo interfaceInfo;
+            interfaceSplitBc->donor_zone->FindDonorInterface( interfaceSplitBc, interfaceInfo );
+            interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+            interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+        }
+    }
+}
+
+void Partition::Split()
+{
+    this->InitSplit();
+    this->BinarySplit();
+    this->ModifyZoneIndex();
+    int kkk = 1;
+}
+
+void Partition::InitSplit()
+{
+    //nZone is the number of zones in the original grid
+    //nProc is not the number of blocks in the end, but the number of processes that need to be divided.
+    //This difference occurs because the structure grid can have many blocks per process.
+
+    //this->nProc    = nProc;
+    //this->nPhyBlocks = referenceBlock.size();
+    //this->nZone  = this->nPhyBlocks;
+
+    //tj Computation time on processor j
+    //Nk Number of internal grid-cells for zone j
+    //aveFloatOp:  Number of Real operations per gridcell
+    //Gj The set of blocks allocated to process j
+    //Pj Real operations per second for process j
+
+    //The Greedy Load Balancing Algorithm
+    //1.Compute an "ideal" uniprocessor time, Tuni = sum ( Nk * aveFloatOp )/ sum( Pj ).
+    //2.Set the group of unassigned blocks, Gu, to contain all blocks. The number of blocks in Nu=M, where M is the total number of blocks in the mesh.
+    //3.Start all processors with a very small fictitious zone to get a start tj=delt aveFloatOp/Pj, where delt<<1 is the size of the very small fictious zone.
+    //This is used to find the fastest processor in a heterogeneous system, tj could otherwise be set to 0 in the homogeneous case.
+    this->aveFloatOp = 1.0;
+    this->delta      = 1.0e-5;
+    this->procSpeed.resize( nProc );
+    this->timeProc.resize( nProc );
+
+    this->nTZone = this->nOriZone;
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        procSpeed[ iProc ] = 1.0;
+    }
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        timeProc[ iProc ] = delta * aveFloatOp / procSpeed[ iProc ];
+    }
+
+    double sumProcSpeed = CalSumOfProcSpeed( procSpeed );
+
+    double sumProcOp = 0.0;
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        sumProcOp += refZone[ iZone ]->GetNCell() * aveFloatOp;
+    }
+
+    this->idealUniProcTime = sumProcOp / sumProcSpeed;
+
+    this->eps = 0.05;
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        unsignedZoneGroup.insert( refZone[ iZone ] );
+    }
+
+    //Init zoneStorage
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        zoneStorage.insert( refZone[ iZone ] );
+    }
+
+    //Assign procSplitZone to each process
+    procSplitZone.resize( nProc );
+
+    this->minNumberCell = 1;
+    for ( int m = 0; m < Dim::dim; ++ m )
+    {
+        this->minNumberCell *= 1;
+    }
+
+    int kkk = 1;
+
+}
+
+void Partition::FreeAllZones()
+{
+    int iCount = 0;
+    for ( std::set < SplitZone * >::iterator iter = zoneStorage.begin(); iter != zoneStorage.end(); ++ iter )
+    {
+        //cout << "iCount = " << iCount << "\n";
+        ++ iCount;
+        delete * iter;
+    }
+}
+
+int Partition::GetNZones( int iProc )
+{
+    return this->procSplitZone[ iProc ].size();
+}
+
+SplitZone * Partition::GetSplitZone( int iProc, int zoneId )
+{
+    return this->procSplitZone[ iProc ][ zoneId ];
+}
+
+void Partition::AddZoneToUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.insert( zone );
+}
+
+void Partition::RemoveZoneFromUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.erase( zone );
+}
+
+void Partition::AddZoneToProcess( int iProc, SplitZone * zone )
+{
+    this->procSplitZone[ iProc ].push_back( zone );
+}
+
+void Partition::AddNewZone( SplitZone * zone )
+{
+    zone->SetZoneIndex( nTZone ++ );
+
+    this->AddZoneToUnsignedGroup( zone );
+
+    this->zoneStorage.insert( zone );
+}
+
+SplitZone * Partition::Split( SplitZone * zone, double nCell )
+{
+    SplitZone * zoneL = new SplitZone();
+    zoneL->SetParentAndChild( zone );
+
+    SplitZone * zoneR = new SplitZone();
+    zoneR->SetParentAndChild( zone );
+
+    //Remove the original block from the UnsignedGroup
+    this->RemoveZoneFromUnsignedGroup( zone );
+
+    this->AddNewZone( zoneL );
+    this->AddNewZone( zoneR );
+
+    zone->Split( zoneL, zoneR, nCell );
+
+    return zoneL;
+}
+
+void Partition::BinarySplit()
+{
+    while ( ! unsignedZoneGroup.empty() )
+    {
+        std::cout << "number of unsigned zone = " << unsignedZoneGroup.size() << "\n";
+        int iProc = this->GetMinLoadProc();
+
+        //Get the block with the largest number of grids and its size
+        SplitZone * largestZone = this->GetLargestZone();
+
+        double nMaxCell = largestZone->GetNCell();
+
+        double aveFloatOp = this->aveFloatOp;
+        double tau = timeProc[ iProc ] + nMaxCell * aveFloatOp / procSpeed[ iProc ];
+
+        //It seems that EPS is still necessary
+        //The idea here is as follows. For the candidate blocks which can be divided into blocks, 
+        //if the difference between the target blocks and the candidate blocks is too wide, 
+        //the binarySplit method is adopted. The binarySplit blocks do not directly join the process,
+        //but enter the next round of screening.
+
+        if ( tau > idealUniProcTime * ( 1.0 + eps ) )
+        {
+            double nRest = ( tau - idealUniProcTime ) * procSpeed[ iProc ] / aveFloatOp;
+
+            double nTarget = nMaxCell - nRest;
+            if ( nRest > this->minNumberCell && nTarget > this->minNumberCell )
+            {
+                //It is necessary to divide blocks only when a certain number of points are satisfied.
+                double nHalf = nMaxCell / 2.0;
+                nMaxCell = nTarget;
+                double ratio = nMaxCell / nRest;
+                double oRatio = 1.0 / ratio;
+
+                if ( std::max( ratio, oRatio ) < 3.0 )
+                {
+                    int kkk = 1;
+                    largestZone = this->Split( largestZone, nMaxCell );
+                    timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                    this->RemoveZoneFromUnsignedGroup( largestZone );
+                    this->AddZoneToProcess( iProc, largestZone );
+                }
+                else
+                {
+                    this->Split( largestZone, nHalf );
+                }
+            }
+            else
+            {
+                //If the block is of the right size, join the process directly, and there is no need to split it.
+                timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                this->RemoveZoneFromUnsignedGroup( largestZone );
+                this->AddZoneToProcess( iProc, largestZone );
+            }
+        }
+        else
+        {
+            //If the block is of the right size, join the process directly, and there is no need to split it.
+            timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+            this->RemoveZoneFromUnsignedGroup( largestZone );
+            this->AddZoneToProcess( iProc, largestZone );
+        }
+    }
+}
+
+void Partition::ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord )
+{
+    SplitZone * rootSplitZone = splitZone->GetRootZone();
+    Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+    int nNodes = splitZone->dimInfo.ComputeNumNodes();
+    std::cout << "nNodes = " << nNodes << "\n";
+
+    coord.resize( nNodes * sizeof(double) );
+
+    int index_dim = splitZone->dimInfo.dimList.size();
+    Coor * coor = zone->coors[ icoord ];
+
+    double * xlocal = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    double * xglobal = reinterpret_cast<double *>( const_cast<char *>( coor->coord.data() ) );
+    if ( index_dim == 1 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        for ( int i = imin; i < imax; ++ i )
+        {
+            xlocal[ icount++ ] = xglobal[ i ];
+        }
+    }
+    else if ( index_dim == 2 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        int jmin = splitZone->dimInfo.rmin[ 1 ] - 1;
+        int jmax = splitZone->dimInfo.rmax[ 1 ];
+        int ni = rootSplitZone->dimInfo.dimList[ 0 ];
+        int nj = rootSplitZone->dimInfo.dimList[ 1 ];
+        for ( int j = jmin; j < jmax; ++ j )
+        {
+            int jstride = j * ni;
+            for ( int i = imin; i < imax; ++ i )
+            {
+                xlocal[ icount++ ] = xglobal[ jstride + i ];
+            }
+        }
+    }
+}
+
+void Partition::DumpBc( SplitZone * splitZone )
+{
+}
+
+void Partition::DumpPartitionedGridFile()
+{
+    std::cout << "\n";
+    std::cout << "DumpPartitionedGridFile -------------------------------" << "\n";
+    std::cout << "\n";
+    int fileId = -1;
+    std::string filename = this->outName;
+    int ierr = cg_open( filename.c_str(), CG_MODE_WRITE, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+
+    std::vector<std::string> coordnames;
+    coordnames.push_back( "CoordinateX" );
+    coordnames.push_back( "CoordinateY" );
+    coordnames.push_back( "CoordinateZ" );
+
+    std::string basename = "Base";
+    int baseId = -1;
+    int icelldim = Global::cell_dim;
+    int iphysdim = Global::phys_dim;
+    cg_base_write( fileId, basename.c_str(), icelldim, iphysdim, &baseId );
+
+    std::cout << "baseId = " << baseId << "\n";
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        int nZones = this->GetNZones( iProc );
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            ZoneType_t zoneType = Structured;
+
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+
+            int index_dim = splitZone->dimInfo.dimList.size();
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            splitZone->dimInfo.ComputeISize();
+
+            int isize_dim = index_dim * 3;
+
+            std::vector<cgsize_t> isize( index_dim * 3, 0 );
+            for ( int m = 0; m < isize_dim; ++ m )
+            {
+                isize[ m ] = splitZone->dimInfo.isize[ m ];
+            }
+
+            int zoneId = -1;
+
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+
+            std::string zonename = "Zone" + std::to_string( splitZone->newIndex );
+
+            cg_zone_write( fileId, baseId, zonename.c_str(), isize.data(), zoneType, &zoneId );
+
+            std::cout << "zoneId = " << zoneId << "\n";
+            std::cout << "zonename = " << zonename << "\n";
+                
+            splitZone->ComputeRminmax();
+
+            SplitZone * rootSplitZone = splitZone->GetRootZone();
+
+            Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+            int ncoords = zone->coors.size();
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = -1;
+                DataType_t dataType = RealDouble;
+                std::string coordname = coordnames[ icoord ];
+                Coor * coor = zone->coors[ icoord ];
+
+                int nNodes = splitZone->dimInfo.ComputeNumNodes();
+                std::cout << "nNodes = " << nNodes << "\n";
+
+                std::vector<char> coord;
+                ComputeCoor( splitZone, icoord, coord );
+
+                cg_coord_write( fileId, baseId, zoneId, dataType, coordname.c_str(), coord.data(), &coorId );
+
+                std::cout << "fileId = " << fileId  << " baseId = " << baseId << " zoneId = " << zoneId  << " coorId = " << coorId << "\n";
+            }
+
+            std::vector< PhysicalSplitBc * > &bccoList = splitZone->physicalSplitBcList;
+
+            int nbocos = bccoList.size();
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = -1;
+                GridLocation_t location = Vertex;
+
+                std::string boconame = "BC" + std::to_string( iboco + 1 );
+
+                PhysicalSplitBc * physicalSplitBc = bccoList[ iboco ];
+                BCType_t bocotype = static_cast<BCType_t>( physicalSplitBc->bcType );
+                PointSetType_t ptset_type = PointRange;
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> pnts;
+                int nSize = physicalSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.end[ i ] );
+                }
+
+                cg_boco_write( fileId, baseId, zoneId, boconame.c_str(), bocotype, ptset_type, npnts, pnts.data(), & bccoId );
+            }
+
+            //std::vector< InterfaceSplitBc * > & bc1to1List = splitZone->interfaceSplitBcList;
+            std::vector< InterfaceSplitBc * > bc1to1List;
+            splitZone->GetLeafInterfaceBc( bc1to1List );
+
+            int n1to1 = bc1to1List.size();
+            std::cout << "n1to1 = " << n1to1 << "\n";
+
+            std::vector<int> itranfrm( index_dim );
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                itranfrm[ m ] = m + 1;
+            }
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int index_conn = -1;
+
+                InterfaceSplitBc * interfaceSplitBc = bc1to1List[ i1to1 ];
+
+                std::vector<cgsize_t> pnts;
+                std::vector<cgsize_t> pntsdonor;
+                int nSize = interfaceSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.end[ i ] );
+                }
+
+                int nPatchSize = interfaceSplitBc->donor_region.start.size();
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.start[ i ] );
+                }
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.end[ i ] );
+                }
+                int id = interfaceSplitBc->donor_zone->newIndex;
+                int oldZoneIndex = interfaceSplitBc->donor_zone->zoneIndex;
+                std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+                std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+                std::cout << "donor zone id = " << id << "\n";
+                std::cout << "donor zone oldZoneIndex = " << oldZoneIndex << "\n";
+                std::string donorname = "Zone" + std::to_string( id );
+                std::string connectname = "Interface" + std::to_string( i1to1 );
+
+                std::cout << "donorname = " << donorname << "\n";
+                std::cout << "connectname = " << connectname << "\n";
+
+                std::vector<int> & itranfrm = interfaceSplitBc->transform;
+
+                cg_1to1_write( fileId, baseId, zoneId, connectname.c_str(), donorname.c_str(), pnts.data(), pntsdonor.data(), itranfrm.data(), &index_conn );
+                std::cout << "index_conn = " << index_conn << "\n";
+            }
+        }
+    }
+    cg_close( fileId );
+}
+
+void Partition::ModifyZoneIndex()
+{
+    std::cout << "ModifyZoneIndex +++++++++++++++++++++++++ " << "\n";
+    int globalZoneId = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        std::cout << "iProc = " << iProc << "\n";
+        int nZones = this->GetNZones( iProc );
+        std::cout << "nZones in Proc " << iProc << "  = " << nZones << "\n";
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+            //splitZone->SetZoneIndex( globalZoneId++ );
+            splitZone->newIndex = ( globalZoneId++ );
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+        }
+    }
+}
\ No newline at end of file
diff --git a/example/partition/struct/1d/02a/Partition.h b/example/partition/struct/1d/02a/Partition.h
new file mode 100644
index 00000000..8a4a9731
--- /dev/null
+++ b/example/partition/struct/1d/02a/Partition.h
@@ -0,0 +1,59 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class SplitZone;
+
+struct CmpSplitZone 
+{
+    bool operator() ( SplitZone * a, SplitZone * b ) const;
+};
+
+class Partition
+{
+public:
+    Partition();
+    ~Partition();
+protected:
+    std::set < SplitZone * > zoneStorage;
+    std::set < SplitZone *, CmpSplitZone > unsignedZoneGroup;
+    std::vector< SplitZone * > refZone;
+    std::vector< std::vector< SplitZone * > > procSplitZone;
+    std::vector<double> procSpeed;
+    std::vector<double> timeProc;
+    double aveFloatOp, delta;
+    double idealUniProcTime, eps;
+    int minNumberCell;
+    int nTZone;
+    int nOriZone;
+    int nProc;
+public:
+    std::string inputName;
+    std::string outName;
+public:
+    void Solve();
+    void ReadGrid();
+    void Split();
+    void InitSplit();
+    void BinarySplit();
+    //void GreedySplit();
+public:
+    void AddNewZone( SplitZone * zone );
+    void AddZoneToUnsignedGroup( SplitZone * zone );
+    void RemoveZoneFromUnsignedGroup( SplitZone * zone );
+    void AddZoneToProcess( int iProc, SplitZone * zone );
+    void DumpPartitionedGridFile();
+    void ModifyZoneIndex();
+    void FreeAllZones();
+    int GetNZones( int iProc );
+    SplitZone * GetSplitZone( int iProc, int zoneId );
+    void ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord );
+    void DumpBc( SplitZone * splitZone );
+private:
+    int GetMinValueIndex( double * data, int numberOfData );
+    int GetMinLoadProc();
+    SplitZone * GetLargestZone();
+    SplitZone * Split( SplitZone * zone, double nCell );
+};
+
diff --git a/example/partition/struct/1d/02a/README.txt b/example/partition/struct/1d/02a/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/partition/struct/1d/02a/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/partition/struct/1d/02a/SplitZone.cpp b/example/partition/struct/1d/02a/SplitZone.cpp
new file mode 100644
index 00000000..aef70754
--- /dev/null
+++ b/example/partition/struct/1d/02a/SplitZone.cpp
@@ -0,0 +1,1091 @@
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+int Dim::dim = -1;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox  )
+{
+    domainBox.start = zoneBox.start;
+    domainBox.end = zoneBox.end;
+
+    int axis = iDomain / 2;
+    int direction = iDomain % 2;
+
+    if ( direction == 0 )
+    {
+        domainBox.end[ axis ] = domainBox.start[ axis ];
+    }
+    else if ( direction == 1 )
+    {
+        domainBox.start[ axis ] = domainBox.end[ axis ];
+    }
+}
+
+DimInfo::DimInfo()
+{
+    this->Init( 1 );
+}
+
+DimInfo::~DimInfo()
+{
+}
+
+void DimInfo::Init( int dim )
+{
+    this->dim = dim;
+    dimList.resize( this->dim, 1 );
+    oriPoint.resize( this->dim, 0 );
+}
+
+DimInfo & DimInfo::operator = ( const DimInfo & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->dim = rhs.dim;
+    this->dimList = rhs.dimList;
+    this->oriPoint = rhs.oriPoint;
+
+    return * this;
+}
+
+int DimInfo::ComputeNumNodes()
+{
+    int nNodes = 1;
+    for ( int m = 0; m < this->dimList.size(); ++ m )
+    {
+        nNodes *= this->dimList[ m ];
+    }
+    return nNodes;
+}
+
+void DimInfo::ComputeISize()
+{
+    int index_dim = this->dimList.size();
+    this->isize.resize( index_dim * 3, 0 );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        isize[ m ] = this->dimList[ m ];
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 1;
+        isize[ start + m ] = this->dimList[ m ] - 1;
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 2;
+        isize[ start + m ] = 0;
+    }
+
+    for ( int i = 0; i < isize.size(); ++ i )
+    {
+        std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+    }
+}
+
+void DimInfo::ComputeRminmax( std::vector<int> & ref )
+{
+    int index_dim = this->dimList.size();
+    this->rmin.resize( index_dim );
+    this->rmax.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        rmin[ m ] = ref[ m ] + 1;
+        rmax[ m ] = ref[ m ] + this->dimList[ m ];
+    }
+
+    std::cout << "rmin, rmax = \n";
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        std::cout << rmin[ m ] << " " << rmax[ m ] << "\n";
+    }
+}
+
+void DimInfo::Init( std::vector<int> & dimList )
+{
+    this->dim = dimList.size();
+    this->dimList = dimList;
+    std::vector<int> zero( dimList.size(), 0 );
+    this->oriPoint = zero;
+}
+
+void DimInfo::SetNewDimension( int axis, int newStart, int newWidth )
+{
+    this->oriPoint[ axis ] = newStart;
+    this->dimList [ axis ] = newWidth;
+}
+
+void DimInfo::GetZoneGlobalBox( RangeRegion &zoneBox )
+{
+    int index_dim = this->dimList.size();
+    zoneBox.start.resize( index_dim );
+    zoneBox.end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        zoneBox.start[ m ] = this->oriPoint[ m ] + 1;
+        zoneBox.end[ m ] = this->oriPoint[ m ] + this->dimList[ m ];
+    }
+}
+
+void DimInfo::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    int index_dim = this->dimList.size();
+    localBox.start.resize( index_dim );
+    localBox.end.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        localBox.start[ m ] = globalBox.start[ m ] - this->oriPoint[ m ];
+        localBox.end[ m ] = globalBox.end[ m ] - this->oriPoint[ m ];
+    }
+}
+
+RangeRegion::RangeRegion( int nSize )
+{
+    this->Init( nSize );
+}
+
+RangeRegion::~RangeRegion()
+{
+}
+
+void RangeRegion::Init( int nSize )
+{
+    this->start.resize( nSize );
+    this->end.resize( nSize );
+}
+
+RangeRegion & RangeRegion::operator = ( const RangeRegion & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+bool RangeRegion::operator == ( const RangeRegion & rhs ) const
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] != rhs.start[ m ] || 
+            this->end  [ m ] != rhs.end  [ m ] )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+bool RangeRegion::InRegion( const RangeRegion & region )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( ( this->start[ m ] < region.start[ m ] ) || ( this->end[ m ] > region.end[ m ] ) )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::Normalize()
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        int minv = std::min( this->start[ m ], this->end[ m ] );
+        int maxv = std::max( this->start[ m ], this->end[ m ] );
+        this->start[ m ] = minv;
+        this->end[ m ] = maxv;
+    }
+}
+
+void RangeRegion::Localize( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] -= oriPoint[ m ];
+        this->end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void RangeRegion::ToGlobal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] += oriPoint[ m ];
+        this->end[ m ] += oriPoint[ m ];
+    }
+}
+
+void RangeRegion::ToLocal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] -= oriPoint[ m ];
+        this->end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void RangeRegion::PrintGlobal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    std::cout << "global start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ] + oriPoint[m];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "global end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ] + oriPoint[m];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+void RangeRegion::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion );
+
+bool ComputeOverlapRegion( RangeRegion & region1, RangeRegion & region2, RangeRegion & overlapRegion )
+{
+    int index_dim = region1.start.size();
+    overlapRegion.Init( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int ijkmin1 = std::min( region1.start[ m ], region1.end[ m ] );
+        int ijkmax1 = std::max( region1.start[ m ], region1.end[ m ] );
+        int ijkmin2 = std::min( region2.start[ m ], region2.end[ m ] );
+        int ijkmax2 = std::max( region2.start[ m ], region2.end[ m ] );
+        if ( ( ijkmax1 < ijkmin2 ) || ( ijkmin1 > ijkmax2 ) )
+        {
+            return false;
+        }
+
+        int ijkmin = std::max( ijkmin1, ijkmin2 );
+        int ijkmax = std::min( ijkmax1, ijkmax2 );
+
+        overlapRegion.start[ m ] = ijkmin;
+        overlapRegion.end  [ m ] = ijkmax;
+    }
+
+    return CheckOverLapping( overlapRegion );
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion )
+{
+    int index_dim = overlapRegion.start.size();
+    int iCount = 0;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        if ( overlapRegion.start[ m ] == overlapRegion.end[ m ] )
+        {
+            ++ iCount;
+        }
+    }
+
+    return ( iCount == 1 );
+}
+
+bool GetInterfaceRegion( RangeRegion & zoneBoxL, RangeRegion & zoneBoxR, RangeRegion & interfaceRegion )
+{
+    int index_dim = zoneBoxL.start.size();
+    int nDomains = 2 * index_dim;
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegionL;
+        GetDomainRegion( zoneBoxL, iDomain, domainRegionL );
+
+        for ( int jDomain = 0; jDomain < nDomains; ++ jDomain )
+        {
+            RangeRegion domainRegionR;
+            GetDomainRegion( zoneBoxR, jDomain, domainRegionR );
+
+            if ( domainRegionL == domainRegionR )
+            {
+                interfaceRegion = domainRegionL;
+                return true;
+            }
+        }
+    }
+    return false;
+}
+
+void CreateInterfaceBc( SplitZone * zoneL, SplitZone * zoneR )
+{
+    RangeRegion globalBoxL, globalBoxR, globalInterfaceRegion;
+
+    zoneL->GetZoneGlobalBox( globalBoxL );
+    zoneR->GetZoneGlobalBox( globalBoxR );
+
+    if ( ! GetInterfaceRegion( globalBoxL, globalBoxR, globalInterfaceRegion ) )
+    {
+        return;
+    }
+
+    RangeRegion localInterfaceRegionL, localInterfaceRegionR;
+
+    zoneL->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionL );
+    zoneR->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionR );
+
+    int kkk = 1;
+
+    InterfaceSplitBc * interfaceSplitBcL = new InterfaceSplitBc();
+    zoneL->interfaceSplitBcList.push_back( interfaceSplitBcL );
+    interfaceSplitBcL->zone = zoneL;
+    interfaceSplitBcL->region = localInterfaceRegionL;
+
+    int nSize = localInterfaceRegionL.start.size();
+
+    std::vector<int> transform;
+
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        transform.push_back( m + 1 );
+    }
+
+    interfaceSplitBcL->transform = transform;
+    interfaceSplitBcL->CalcTransformMatrix();
+
+    interfaceSplitBcL->donor_zone = zoneR;
+    interfaceSplitBcL->donor_region = localInterfaceRegionR;
+
+    InterfaceSplitBc * interfaceSplitBcR = new InterfaceSplitBc();
+    zoneR->interfaceSplitBcList.push_back( interfaceSplitBcR );
+
+    interfaceSplitBcR->zone = zoneR;
+    interfaceSplitBcR->region = localInterfaceRegionR;
+
+    interfaceSplitBcR->transform = transform;
+    interfaceSplitBcR->CalcTransformMatrix();
+
+    interfaceSplitBcR->donor_zone = zoneL;
+    interfaceSplitBcR->donor_region = localInterfaceRegionL;
+}
+
+
+PhysicalSplitBc::PhysicalSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+PhysicalSplitBc::~PhysicalSplitBc()
+{
+}
+
+void PhysicalSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void PhysicalSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+void PhysicalSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = splitZone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+BasicSplitBc::BasicSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+BasicSplitBc::~BasicSplitBc()
+{
+    ;
+}
+
+void BasicSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void BasicSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+int trans::M[ 3 ][ 3 ];
+std::vector<int> trans::transform;
+
+int trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void trans::CalcTransformMatrix()
+{
+    int dim = trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = trans::transform[ 0 ];
+        int sgna = trans::sgn( a );
+        int a1 = trans::del( a, 1 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int c = trans::transform[ 2 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int sgnc = trans::sgn( c );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int a3 = trans::del( a, 3 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        int b3 = trans::del( b, 3 );
+        int c1 = trans::del( c, 1 );
+        int c2 = trans::del( c, 2 );
+        int c3 = trans::del( c, 3 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 2 ][ 0 ] = sgna * a3;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+        trans::M[ 2 ][ 1 ] = sgnb * b3;
+        trans::M[ 0 ][ 2 ] = sgnc * c1;
+        trans::M[ 1 ][ 2 ] = sgnc * c2;
+        trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+InterfaceInfo::InterfaceInfo()
+{
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceInfo::~InterfaceInfo()
+{
+}
+
+InterfaceSplitBc::InterfaceSplitBc()
+{
+    this->region.Init( Dim::dim );
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceSplitBc::~InterfaceSplitBc()
+{
+}
+
+void InterfaceSplitBc::GetLeafInterfaceBc( std::vector< InterfaceSplitBc * > & leafInterfaceBcList )
+{
+    int nChild = this->child.size();
+    if ( nChild == 0 )
+    {
+        leafInterfaceBcList.push_back( this );
+    }
+    else
+    {
+        for ( int iChild = 0; iChild < nChild; ++ iChild )
+        {
+            InterfaceSplitBc * interfaceSplitBc = this->child[ iChild ];
+            interfaceSplitBc->GetLeafInterfaceBc( leafInterfaceBcList );
+        }
+    }
+}
+
+void InterfaceSplitBc::CopyMatrix( InterfaceSplitBc * interfaceSplitBc )
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = interfaceSplitBc->Mt[ i ][ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::CalcTransformMatrix()
+{
+    trans::ZeroMatrix();
+    trans::transform = this->transform;
+    trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = trans::M[ i ][ j ];
+        }
+    }
+
+}
+
+void InterfaceSplitBc::mapindex( std::vector<int> & begin1, std::vector<int> & begin2,  std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = Dim::dim;
+    std::vector<int> diff( dim );
+    for ( int m = 0; m < dim; ++ m )
+    {
+        diff[ m ] = index1[ m ] - begin1[ m ];
+    }
+
+    std::vector<int> mul( dim );
+
+    Multiply( Mt, diff, mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = mul[ m ] + begin2[ m ];
+    }
+}
+
+void InterfaceSplitBc::Multiply( int Mt[][3], std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = Dim::dim;
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = this->zone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void InterfaceSplitBc::CalcSubDonorRegion( RangeRegion &subRegion, RangeRegion &subDonorRegion )
+{
+    std::vector<int> begin1 = this->region.start;
+    std::vector<int> end1 = this->region.end;
+    std::vector<int> begin2 = this->donor_region.start;
+    std::vector<int> end2 = this->donor_region.end;
+
+    std::vector<int> new_begin1 = subRegion.start;
+    std::vector<int> new_end1 = subRegion.end;
+
+    int dim = Dim::dim;
+    std::vector<int> new_begin2( dim );
+    std::vector<int> new_end2( dim );
+
+    mapindex( begin1, begin2, new_begin1, new_begin2 );
+    mapindex( begin1, begin2, new_end1, new_end2 );
+
+    subDonorRegion.start = new_begin2;
+    subDonorRegion.end = new_end2;
+}
+
+SplitZone::SplitZone()
+{
+    this->parent  = 0;
+    this->zoneIndex = 0;
+    this->iProc = 0;
+    dimInfo.Init( Dim::dim );
+    int kk = 1;
+}
+
+SplitZone::~SplitZone()
+{
+    ;
+}
+
+void SplitZone::GetZoneGlobalBox( RangeRegion & zoneBox )
+{
+    this->dimInfo.GetZoneGlobalBox( zoneBox );
+}
+
+void SplitZone::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    this->dimInfo.GetZoneLocalBox( globalBox, localBox );
+}
+
+
+void SplitZone::ComputeRminmax()
+{
+    int index_dim = this->dimInfo.dimList.size();
+    std::vector<int> ref( index_dim, 0 );
+
+    SplitZone * rootSplitZone = 0;
+    this->GetRootInfo( rootSplitZone, ref );
+
+    this->dimInfo.ComputeRminmax( ref );
+}
+
+SplitZone * SplitZone::GetRootZone()
+{
+    SplitZone * root = this;
+
+    while ( true )
+    {
+        if ( root->parent )
+        {
+            root = root->parent;
+        }
+        else
+        {
+            return root;
+        }
+    };
+}
+
+void SplitZone::GetRootInfo( SplitZone *& root, std::vector<int> & ref )
+{
+    for ( int i = 0; i < this->dimInfo.dimList.size(); ++ i )
+    {
+        ref[ i ] += this->dimInfo.oriPoint[ i ];
+    }
+
+    if ( this->parent )
+    {
+        this->parent->GetRootInfo( root, ref );
+    }
+    else
+    {
+        root = this;
+    }
+}
+
+void SplitZone::SetParentAndChild( SplitZone * parent )
+{
+    this->parent = parent;
+    if ( parent )
+    {
+        parent->child.push_back( this );
+    }
+}
+
+void SplitZone::GetLeafInterfaceBc( std::vector< InterfaceSplitBc * > & leafInterfaceBcList )
+{
+    int nInterfaceBcs = this->interfaceSplitBcList.size();
+    for ( int i = 0; i < nInterfaceBcs; ++ i )
+    {
+        InterfaceSplitBc * interfaceSplitBc = this->interfaceSplitBcList[ i ];
+        interfaceSplitBc->GetLeafInterfaceBc( leafInterfaceBcList );
+    }
+}
+
+int SplitZone::GetNCell()
+{
+    int numberOfCells = 1;
+    for ( int i = 0; i < this->dimInfo.dim; ++ i )
+    {
+        numberOfCells *= std::max( 1, ( this->dimInfo.dimList[ i ] - 1 ) );
+    }
+
+    return numberOfCells; 
+}
+
+void SplitZone::SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int leftStart = 0;
+    int leftWidth = iSplit - 0;
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, leftStart , leftWidth  );
+}
+
+void SplitZone::SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int rightStart = iSplit - 1;
+    int rightWidth = dimList[ axisNeedSplit ] - ( iSplit - 1 );
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, rightStart, rightWidth );
+}
+
+void SplitZone::Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell )
+{
+    //Find the longest axis
+    int axisNeedSplit = this->FindAxisNeedSplit();
+    int iSplit        = this->FindSplitPosition( axisNeedSplit, nCell );
+
+    zoneL->SetLeftDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+    zoneR->SetRightDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+
+    zoneL->CreateBcFromParent();
+    zoneR->CreateBcFromParent();
+    
+    CreateInterfaceBc( zoneL, zoneR );
+}
+
+void SplitZone::CreateBcFromParent()
+{
+    this->CreatePhysicalBcFromParent();
+    this->CreateInterfaceBcFromParent();
+}
+
+void SplitZone::CreatePhysicalBcFromParent()
+{
+    int nParentPhysicalBcs = this->parent->physicalSplitBcList.size();
+
+    for ( int iParentPhysicalBcs = 0; iParentPhysicalBcs < nParentPhysicalBcs; ++ iParentPhysicalBcs )
+    {
+        PhysicalSplitBc * parentPhysicalSplitBc = this->parent->physicalSplitBcList[ iParentPhysicalBcs ];
+
+        this->CreatePhysicalBcFromParent( parentPhysicalSplitBc );
+    }
+}
+
+void SplitZone::CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentPhysicalSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreatePhysicalBc( overlapRegion, parentPhysicalSplitBc->bcType );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent()
+{
+    int nInterfaceSplitBcs = this->parent->interfaceSplitBcList.size();
+
+    for ( int iInterfaceSplitBcs = 0; iInterfaceSplitBcs < nInterfaceSplitBcs; ++ iInterfaceSplitBcs )
+    {
+        InterfaceSplitBc * parentInterfaceSplitBc = this->parent->interfaceSplitBcList[ iInterfaceSplitBcs ];
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc );
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentInterfaceSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc, overlapRegion );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::FindDonorInterface( InterfaceSplitBc * interfaceSplitBc, InterfaceInfo & interfaceInfo )
+{
+    RangeRegion donor_region = interfaceSplitBc->donor_region;
+    donor_region.Normalize();
+    interfaceInfo.donor_zone = this;
+    for ( int iInterface = 0; iInterface < interfaceSplitBcList.size(); ++ iInterface )
+    {
+        InterfaceSplitBc * candidateDonorBc = interfaceSplitBcList[ iInterface ];
+        bool flag = donor_region.InRegion( candidateDonorBc->region );
+        if ( flag )
+        {
+            if ( donor_region == candidateDonorBc->region )
+            {
+                interfaceInfo.donor_interface = candidateDonorBc;
+                return;
+            }
+            else
+            {
+                InterfaceSplitBc * donorBc = new InterfaceSplitBc();
+                candidateDonorBc->child.push_back( donorBc );
+                donorBc->region = donor_region;
+                donorBc->zone = candidateDonorBc->zone;
+                donorBc->donor_zone = interfaceSplitBc->zone;
+                donorBc->transform = candidateDonorBc->transform;
+                donorBc->CopyMatrix( candidateDonorBc );
+                RangeRegion subDonorRegion( Dim::dim );
+                candidateDonorBc->CalcSubDonorRegion( donorBc->region, subDonorRegion );
+                std::vector<int> & oriPoint = interfaceSplitBc->zone->dimInfo.oriPoint;
+                subDonorRegion.Localize( oriPoint );
+                donorBc->donor_region = subDonorRegion;
+                donorBc->donor_bc = interfaceSplitBc;
+                interfaceInfo.donor_interface = donorBc;
+                return;
+            }
+        }
+    }
+    return;
+}
+
+void SplitZone::GetChildDonorRegion( RangeRegion & subDonorRegion, InterfaceInfo & interfaceInfo )
+{
+    std::cout << "subDonorRegion = \n";
+    //subDonorRegion.Print();
+    RangeRegion normalizedDonorRegion = subDonorRegion;
+    normalizedDonorRegion.Normalize();
+    int nChild = this->child.size();
+    for ( int ichild = 0; ichild < nChild; ++ ichild )
+    {
+        std::cout << " iChild = " << ichild << " nChild = " << nChild << "\n";
+        SplitZone * sub_zone = this->child[ ichild ];
+        std::cout << " zoneIndex = " << sub_zone->zoneIndex << "\n";
+        int nInters = sub_zone->interfaceSplitBcList.size();
+        for ( int iInter = 0; iInter < nInters; ++ iInter )
+        {
+            std::cout << " iInter = " << iInter << "\n";
+            InterfaceSplitBc * interfaceSplitBc = sub_zone->interfaceSplitBcList[ iInter ];
+            std::cout << "interfaceSplitBc local = \n";
+            interfaceSplitBc->region.Print();
+            std::cout << "interfaceSplitBc global = \n";
+            interfaceSplitBc->region.PrintGlobal( sub_zone->dimInfo.oriPoint );
+            RangeRegion g_region = interfaceSplitBc->region;
+            g_region.ToGlobal( sub_zone->dimInfo.oriPoint );
+            if ( g_region == normalizedDonorRegion )
+            {
+                RangeRegion donorRegion = subDonorRegion;
+                donorRegion.ToLocal( sub_zone->dimInfo.oriPoint );
+
+                interfaceInfo.donor_zone = sub_zone;
+                interfaceInfo.donor_interface = interfaceSplitBc;
+                interfaceInfo.donor_region = donorRegion;
+                return;
+            }
+        }
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion )
+{
+    InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+    this->interfaceSplitBcList.push_back( interfaceSplitBc );
+
+    interfaceSplitBc->region = overlapRegion;
+    interfaceSplitBc->zone = this;
+    interfaceSplitBc->transform = parentInterfaceSplitBc->transform;
+    interfaceSplitBc->CopyMatrix( parentInterfaceSplitBc );
+    RangeRegion subDonorRegion( Dim::dim );
+    parentInterfaceSplitBc->CalcSubDonorRegion( overlapRegion, subDonorRegion );
+    interfaceSplitBc->ChangeRegionToLocalCoordinate();
+    interfaceSplitBc->donor_region = subDonorRegion;
+    SplitZone * parent_donor_zone = parentInterfaceSplitBc->donor_zone;
+    std::cout << " parentInterfaceSplitBc->zone->zoneIndex " << parentInterfaceSplitBc->zone->zoneIndex << "\n";
+    std::cout << " parentInterfaceSplitBc->donor_zone->zoneIndex " << parent_donor_zone->zoneIndex << "\n";
+    if ( parent_donor_zone->child.size() > 0 )
+    {
+        InterfaceInfo interfaceInfo;
+        parent_donor_zone->GetChildDonorRegion( subDonorRegion, interfaceInfo );
+        interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+        interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+        interfaceSplitBc->donor_region = interfaceInfo.donor_region;
+        //compatibility
+        InterfaceSplitBc * donor_bc = interfaceSplitBc->donor_bc;
+        SplitZone * donor_zone = interfaceSplitBc->donor_zone;
+        if ( interfaceSplitBc->zone != donor_bc->donor_zone )
+        {
+            if ( interfaceSplitBc->zone->parent == donor_bc->donor_zone )
+            {
+                RangeRegion d_region = donor_bc->donor_region;
+                d_region.ToLocal( interfaceSplitBc->zone->dimInfo.oriPoint );
+                donor_bc->donor_region = d_region;
+            }
+            donor_bc->donor_zone = interfaceSplitBc->zone;
+         
+            int kkk = 1;
+        }
+        int kkk = 1;
+    }
+    else
+    {
+        InterfaceInfo interfaceInfo;
+        parent_donor_zone->FindDonorInterface( interfaceSplitBc, interfaceInfo );
+        interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+        interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+    }
+    
+    int kkk = 1;
+}
+
+void SplitZone::CreatePhysicalBc( RangeRegion & overlapRegion, int bcType )
+{
+    PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+    this->physicalSplitBcList.push_back( physicalSplitBc );
+    physicalSplitBc->SetRegion( overlapRegion );
+    physicalSplitBc->bcType = bcType;
+    physicalSplitBc->splitZone = this;
+    physicalSplitBc->ChangeRegionToLocalCoordinate();
+}
+
+int SplitZone::FindAxisNeedSplit()
+{
+    //Find the longest axis
+    int axisNeedSplit = 0;
+    int maxN = this->dimInfo.dimList[ 0 ];
+
+    for ( int m = 1; m < this->dimInfo.dimList.size(); ++ m )
+    {
+        if ( this->IsPoleBc( m ) )
+        {
+            continue;
+        }
+        int Nm = this->dimInfo.dimList[ m ];
+        if ( maxN < Nm )
+        {
+            maxN = Nm;
+            axisNeedSplit = m;
+        }
+    }
+
+    return axisNeedSplit;
+}
+
+int SplitZone::GetCrossSection( int axis )
+{
+    int nDim = this->dimInfo.dimList.size();
+    int crossSection = 1;
+    int N = nDim - 1;
+    for ( int m = 0; m < N; ++ m )
+    {
+         int mm = ( axis + 1 ) % nDim;
+         int nLineElements = std::max( 1, ( this->dimInfo.dimList[ mm ] - 1 ) );
+         crossSection *= nLineElements;
+    }
+    return crossSection;
+}
+
+int SplitZone::FindSplitPosition( int axisNeedSplit, double nCell )
+{
+    int nDim = this->dimInfo.dimList.size();
+    std::vector<int> crossSections( nDim );
+    for ( int m = 0; m < nDim; ++ m )
+    {
+        crossSections[ m ] = this->GetCrossSection( m );
+    }
+
+    //guess the value
+    double dSplit = nCell / crossSections[ axisNeedSplit ];
+    int  iSplit = 1 + static_cast< int >( std::floor( dSplit + 0.5 ) );
+    return iSplit;
+}
+
+
+bool SplitZone::IsPoleBc( int splitDirection )
+{
+    return false;
+}
+
diff --git a/example/partition/struct/1d/02a/SplitZone.h b/example/partition/struct/1d/02a/SplitZone.h
new file mode 100644
index 00000000..ffe1e306
--- /dev/null
+++ b/example/partition/struct/1d/02a/SplitZone.h
@@ -0,0 +1,196 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class Dim
+{
+public:
+    static int dim;
+};
+
+class SplitZone;
+class RangeRegion;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox );
+
+class DimInfo
+{
+public:
+    DimInfo();
+    ~DimInfo();
+public:
+    int dim;
+    std::vector<int> dimList;
+    std::vector<int> oriPoint;
+    std::vector<int> isize;
+    std::vector<int> rmin;
+    std::vector<int> rmax;
+public:
+    int GetSize() const { return dim; }
+    DimInfo & operator = ( const DimInfo & rhs );
+public:
+    int ComputeNumNodes();
+    void ComputeISize();
+    void ComputeRminmax( std::vector<int> & ref );
+    void Init( int dim );
+    void Init( std::vector<int> & dimList );
+    void SetNewDimension( int axis, int newStart, int newWidth );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+};
+
+class SplitZone;
+class SplitBcPatch;
+
+class RangeRegion
+{
+public:
+    RangeRegion( int nSize = 1 );
+    ~RangeRegion();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    void Init( int nSize );
+    RangeRegion & operator = ( const RangeRegion & rhs );
+    bool operator == ( const RangeRegion & rhs ) const;
+    bool InRegion( const RangeRegion & region );
+    void SetRegion( std::vector<int> &pnts );
+    void Normalize();
+    void Localize( std::vector<int> & oriPoint );
+    void ToGlobal( std::vector<int> & oriPoint );
+    void ToLocal( std::vector<int> & oriPoint );
+    void PrintGlobal( std::vector<int> & oriPoint );
+    void Print();
+};
+
+class PhysicalSplitBc
+{
+public:
+    PhysicalSplitBc();
+    ~PhysicalSplitBc();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class BasicSplitBc
+{
+public:
+    BasicSplitBc();
+    ~BasicSplitBc();
+public:
+    RangeRegion region;
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> & pnts );
+    void SetRegion( RangeRegion & region );
+};
+
+class trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class InterfaceSplitBc;
+class SplitZone;
+
+class InterfaceInfo
+{
+public:
+    InterfaceInfo();
+    ~InterfaceInfo();
+public:
+    InterfaceSplitBc * donor_interface = nullptr;
+    SplitZone * donor_zone = nullptr;
+    RangeRegion donor_region;
+};
+
+class InterfaceSplitBc
+{
+public:
+    InterfaceSplitBc();
+    ~InterfaceSplitBc();
+public:
+    std::vector<int> transform;
+    int Mt[ 3 ][ 3 ];
+    RangeRegion region;
+    SplitZone * zone = nullptr;
+    RangeRegion donor_region;
+    SplitZone * donor_zone = nullptr;
+    InterfaceSplitBc * donor_bc = nullptr;
+public:
+    std::vector<InterfaceSplitBc *> child;
+    void GetLeafInterfaceBc( std::vector< InterfaceSplitBc * > & leafInterfaceBcList );
+public:
+    void CopyMatrix( InterfaceSplitBc * interfaceSplitBc );
+    void CalcTransformMatrix();
+    void CalcSubDonorRegion( RangeRegion & subRegion, RangeRegion & subDonorRegion );
+    void mapindex( std::vector<int> & begin1, std::vector<int> & begin2, std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( int Mt[][ 3 ], std::vector<int> & a, std::vector<int> & b );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class SplitZone
+{
+public:
+    SplitZone();
+    ~SplitZone();
+public:
+    DimInfo dimInfo;
+    int zoneIndex, iProc;
+    int newIndex;
+protected:
+    SplitZone * parent;
+    std::vector<SplitZone *> child;
+public:
+    std::vector< PhysicalSplitBc * > physicalSplitBcList;
+    std::vector< InterfaceSplitBc * > interfaceSplitBcList;
+    void GetLeafInterfaceBc( std::vector< InterfaceSplitBc * > & leafInterfaceBcList );
+public:
+    int GetNCell();
+    void ComputeRminmax();
+    void GetRootInfo( SplitZone *& root, std::vector<int> & ref );
+    void SetZoneIndex( int zoneIndex ) { this->zoneIndex = zoneIndex; }
+    int  GetZoneIndex() { return zoneIndex; }
+    void SetProcId( int iProc ) { this->iProc = iProc; }
+    void SetParent( SplitZone * parent ) { this->parent = parent; };
+    void SetParentAndChild( SplitZone * parent );
+    void FindDonorInterface( InterfaceSplitBc * interfaceSplitBc, InterfaceInfo & interfaceInfo );
+    void GetChildDonorRegion( RangeRegion & subDonorRegion, InterfaceInfo & interfaceInfo );
+public:
+    void CreateBcFromParent();
+    void CreatePhysicalBcFromParent();
+    void CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc );
+    void CreatePhysicalBc( RangeRegion & overlapRegion, int bcType );
+    void CreateInterfaceBcFromParent();
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc );
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion );
+
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+    SplitZone * GetRootZone();
+public:
+    void Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell );
+    void SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+    void SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+private:
+    int FindAxisNeedSplit();
+    int FindSplitPosition( int axisNeedSplit, double nCell );
+    bool IsPoleBc( int splitDirection );
+    int GetCrossSection( int axis );
+};
+
diff --git a/example/partition/struct/1d/02a/heat1d2blocksv1.cgns b/example/partition/struct/1d/02a/heat1d2blocksv1.cgns
new file mode 100644
index 00000000..4c9c4994
Binary files /dev/null and b/example/partition/struct/1d/02a/heat1d2blocksv1.cgns differ
diff --git a/example/partition/struct/1d/02a/heat1dpart.cgns b/example/partition/struct/1d/02a/heat1dpart.cgns
new file mode 100644
index 00000000..a51b966c
Binary files /dev/null and b/example/partition/struct/1d/02a/heat1dpart.cgns differ
diff --git a/example/partition/struct/1d/02a/main.cpp b/example/partition/struct/1d/02a/main.cpp
new file mode 100644
index 00000000..5da1de7c
--- /dev/null
+++ b/example/partition/struct/1d/02a/main.cpp
@@ -0,0 +1,18 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include "Partition.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip>
+
+int main(int argc, char **argv)
+{
+    Partition * partition = new Partition();
+    partition->Solve();
+    delete partition;
+
+    return 0;
+}
diff --git a/example/partition/struct/1d/02b/CMakeLists.txt b/example/partition/struct/1d/02b/CMakeLists.txt
new file mode 100644
index 00000000..74ceea7d
--- /dev/null
+++ b/example/partition/struct/1d/02b/CMakeLists.txt
@@ -0,0 +1,78 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	Partition.h Partition.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	SplitZone.h SplitZone.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/partition/struct/1d/02b/CgnsGrid.cpp b/example/partition/struct/1d/02b/CgnsGrid.cpp
new file mode 100644
index 00000000..dfe750bd
--- /dev/null
+++ b/example/partition/struct/1d/02b/CgnsGrid.cpp
@@ -0,0 +1,349 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include <map>
+
+Grid::Grid()
+{
+    ;
+}
+
+Grid::~Grid()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if( (i+1)%5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+    delete this->patch;
+}
+
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+ZoneBcPatch::ZoneBcPatch()
+{
+    ;
+}
+
+ZoneBcPatch::~ZoneBcPatch()
+{
+}
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+Global::Global()
+{
+    ;
+}
+
+Global::~Global()
+{
+}
+
+void Global::FreeData()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+    zones.resize( 0 );
+}
+
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            //baseZone.baseId = baseId;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin( index_dim );
+            std::vector<cgsize_t> irmax( index_dim );
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                std::vector<char> coord( nNodes * sizeof(double) );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+                coor->DumpCoor();
+            }
+
+            int nbocos = -1;
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+                int kkk = 1;
+            }
+        }
+        int kkk = 1;
+    }
+    int kkk = 1;
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/partition/struct/1d/02b/CgnsGrid.h b/example/partition/struct/1d/02b/CgnsGrid.h
new file mode 100644
index 00000000..053c467b
--- /dev/null
+++ b/example/partition/struct/1d/02b/CgnsGrid.h
@@ -0,0 +1,140 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <map>
+
+class Grid;
+
+class Zone;
+
+class Grid
+{
+public:
+    Grid();
+    ~Grid();
+public:
+    int nZone;
+    std::vector<double> x;
+    std::vector<Zone *> zones;
+};
+
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+};
+
+class ZoneBc;
+class ZoneBc1To1;
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class ZoneBcPatch;
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+    ZoneBcPatch * patch = nullptr;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+class ZoneBcPatch
+{
+public:
+    ZoneBcPatch();
+    ~ZoneBcPatch();
+public:
+    int donor_zoneid;
+    std::vector<int> transform;
+    std::vector<int> donor_pnts;
+};
+
+class BaseZone
+{
+public:
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Global
+{
+public:
+    Global();
+    ~Global();
+public:
+    static int cell_dim;
+    static int phys_dim;
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+public:
+    static void FreeData();
+};
+
+void ReadCgnsGrid( const std::string & filename );
+void ReadCgnsGridBaseZone( const std::string & filename );
\ No newline at end of file
diff --git a/example/partition/struct/1d/02b/Partition.cpp b/example/partition/struct/1d/02b/Partition.cpp
new file mode 100644
index 00000000..291c15e4
--- /dev/null
+++ b/example/partition/struct/1d/02b/Partition.cpp
@@ -0,0 +1,619 @@
+#include "Partition.h"
+#include "CgnsGrid.h"
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+bool CmpSplitZone::operator() ( SplitZone * a, SplitZone * b ) const
+{
+    return a->zoneIndex < b->zoneIndex;
+};
+
+
+double CalSumOfProcSpeed( std::vector<double> & procSpeed );
+double CalSumOfProcSpeed( std::vector<double> & procSpeed )
+{
+    int nProc = procSpeed.size();
+    double sumOfProcSpeed = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        sumOfProcSpeed += procSpeed[ iProc ];
+    }
+    return sumOfProcSpeed;
+}
+
+Partition::Partition()
+{
+    this->inputName = "../heat1d2blocksv1.cgns";
+    this->outName =  "../heat1dpart.cgns";
+}
+
+Partition::~Partition()
+{
+    ;
+}
+
+int Partition::GetMinValueIndex( double * data, int numberOfData )
+{
+    double minValue = data[ 0 ];
+    int minimumValueIndex = 0;
+
+    for ( int iData = 1; iData < numberOfData; ++ iData )
+    {
+        if ( minValue > data[ iData ] )
+        {
+            minValue      = data[ iData ];
+            minimumValueIndex = iData;
+        }
+    }
+    return minimumValueIndex;
+}
+
+int Partition::GetMinLoadProc()
+{
+    return this->GetMinValueIndex( this->timeProc.data(), this->nProc );
+}
+
+SplitZone * Partition::GetLargestZone()
+{
+    SplitZone * largestZone = 0;
+
+    double nMaxCell = 0.0;
+
+    for ( std::set< SplitZone * >::iterator iter = unsignedZoneGroup.begin(); iter != unsignedZoneGroup.end(); ++ iter )
+    {
+        double nSize = ( * iter )->GetNCell();
+        if ( nMaxCell < nSize )
+        {
+            nMaxCell    = nSize;
+            largestZone = * iter;
+        }
+    }
+
+    return largestZone;
+}
+
+void Partition::Solve()
+{
+    std::cout << "Partition::Split()\n";
+    this->nProc = 4;
+    this->ReadGrid();
+    this->Split();
+    this->DumpPartitionedGridFile();
+    this->FreeAllZones();
+}
+
+void Partition::ReadGrid()
+{
+    ReadCgnsGridBaseZone( this->inputName );
+    ReadCgnsGrid( this->inputName );
+
+    this->nOriZone = ::Global::zones.size();
+    Dim::dim = Global::cell_dim;
+
+    std::cout << "numberOfBlocks = " << nOriZone << "\n";
+
+    this->refZone.resize( nOriZone );
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = new SplitZone();
+        refZone[ iZone ] = splitZone;
+
+        splitZone->SetZoneIndex( iZone );
+        splitZone->SetProcId( 0 );
+        splitZone->SetParentAndChild( 0 );
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        Zone * zone = ::Global::zones[ iZone ];
+
+        splitZone->dimInfo.dimList = zone->nijk;
+
+        int nbccos = zone->bccos.size();
+        std::cout << "nbccos = " << nbccos << "\n";
+
+        for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+        {
+            ZoneBc * zoneBc = zone->bccos[ ibcco ];
+
+            PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+            splitZone->physicalSplitBcList.push_back( physicalSplitBc );
+            physicalSplitBc->bcType = zoneBc->bcType;
+            physicalSplitBc->SetRegion( zoneBc->pnts );
+            physicalSplitBc->splitZone = splitZone;
+        }
+
+        int nbc1to1s = zone->bc1to1s.size();
+
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * zoneBc1To1 = zone->bc1to1s[ ibc1to1 ];
+
+            InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+            splitZone->interfaceSplitBcList.push_back( interfaceSplitBc );
+            interfaceSplitBc->zone = splitZone;
+            interfaceSplitBc->region.SetRegion( zoneBc1To1->pnts );
+
+            interfaceSplitBc->transform = zoneBc1To1->transform;
+            interfaceSplitBc->CalcTransformMatrix();
+
+            interfaceSplitBc->donor_zone = refZone[ zoneBc1To1->donor_zoneid ];
+            interfaceSplitBc->donor_region.SetRegion( zoneBc1To1->donor_pnts );
+        }
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        int nbc1to1s = splitZone->interfaceSplitBcList.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            InterfaceSplitBc * interfaceSplitBc = splitZone->interfaceSplitBcList[ ibc1to1 ];
+            InterfaceInfo interfaceInfo;
+            interfaceSplitBc->donor_zone->FindDonorInterface( interfaceSplitBc, interfaceInfo );
+            interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+            interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+        }
+    }
+}
+
+void Partition::Split()
+{
+    this->InitSplit();
+    this->BinarySplit();
+    this->ModifyZoneIndex();
+    int kkk = 1;
+}
+
+void Partition::InitSplit()
+{
+    //nZone is the number of zones in the original grid
+    //nProc is not the number of blocks in the end, but the number of processes that need to be divided.
+    //This difference occurs because the structure grid can have many blocks per process.
+
+    //this->nProc    = nProc;
+    //this->nPhyBlocks = referenceBlock.size();
+    //this->nZone  = this->nPhyBlocks;
+
+    //tj Computation time on processor j
+    //Nk Number of internal grid-cells for zone j
+    //aveFloatOp:  Number of Real operations per gridcell
+    //Gj The set of blocks allocated to process j
+    //Pj Real operations per second for process j
+
+    //The Greedy Load Balancing Algorithm
+    //1.Compute an "ideal" uniprocessor time, Tuni = sum ( Nk * aveFloatOp )/ sum( Pj ).
+    //2.Set the group of unassigned blocks, Gu, to contain all blocks. The number of blocks in Nu=M, where M is the total number of blocks in the mesh.
+    //3.Start all processors with a very small fictitious zone to get a start tj=delt aveFloatOp/Pj, where delt<<1 is the size of the very small fictious zone.
+    //This is used to find the fastest processor in a heterogeneous system, tj could otherwise be set to 0 in the homogeneous case.
+    this->aveFloatOp = 1.0;
+    this->delta      = 1.0e-5;
+    this->procSpeed.resize( nProc );
+    this->timeProc.resize( nProc );
+
+    this->nTZone = this->nOriZone;
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        procSpeed[ iProc ] = 1.0;
+    }
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        timeProc[ iProc ] = delta * aveFloatOp / procSpeed[ iProc ];
+    }
+
+    double sumProcSpeed = CalSumOfProcSpeed( procSpeed );
+
+    double sumProcOp = 0.0;
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        sumProcOp += refZone[ iZone ]->GetNCell() * aveFloatOp;
+    }
+
+    this->idealUniProcTime = sumProcOp / sumProcSpeed;
+
+    this->eps = 0.05;
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        unsignedZoneGroup.insert( refZone[ iZone ] );
+    }
+
+    //Init zoneStorage
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        zoneStorage.insert( refZone[ iZone ] );
+    }
+
+    //Assign procSplitZone to each process
+    procSplitZone.resize( nProc );
+
+    this->minNumberCell = 1;
+    for ( int m = 0; m < Dim::dim; ++ m )
+    {
+        this->minNumberCell *= 1;
+    }
+
+    int kkk = 1;
+
+}
+
+void Partition::FreeAllZones()
+{
+    int iCount = 0;
+    for ( std::set < SplitZone * >::iterator iter = zoneStorage.begin(); iter != zoneStorage.end(); ++ iter )
+    {
+        //cout << "iCount = " << iCount << "\n";
+        ++ iCount;
+        delete * iter;
+    }
+}
+
+int Partition::GetNZones( int iProc )
+{
+    return this->procSplitZone[ iProc ].size();
+}
+
+SplitZone * Partition::GetSplitZone( int iProc, int zoneId )
+{
+    return this->procSplitZone[ iProc ][ zoneId ];
+}
+
+void Partition::AddZoneToUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.insert( zone );
+}
+
+void Partition::RemoveZoneFromUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.erase( zone );
+}
+
+void Partition::AddZoneToProcess( int iProc, SplitZone * zone )
+{
+    this->procSplitZone[ iProc ].push_back( zone );
+}
+
+void Partition::AddNewZone( SplitZone * zone )
+{
+    zone->SetZoneIndex( nTZone ++ );
+
+    this->AddZoneToUnsignedGroup( zone );
+
+    this->zoneStorage.insert( zone );
+}
+
+SplitZone * Partition::Split( SplitZone * zone, double nCell )
+{
+    SplitZone * zoneL = new SplitZone();
+    zoneL->SetParentAndChild( zone );
+
+    SplitZone * zoneR = new SplitZone();
+    zoneR->SetParentAndChild( zone );
+
+    //Remove the original block from the UnsignedGroup
+    this->RemoveZoneFromUnsignedGroup( zone );
+
+    this->AddNewZone( zoneL );
+    this->AddNewZone( zoneR );
+
+    zone->Split( zoneL, zoneR, nCell );
+
+    return zoneL;
+}
+
+void Partition::BinarySplit()
+{
+    while ( ! unsignedZoneGroup.empty() )
+    {
+        std::cout << "number of unsigned zone = " << unsignedZoneGroup.size() << "\n";
+        int iProc = this->GetMinLoadProc();
+
+        //Get the block with the largest number of grids and its size
+        SplitZone * largestZone = this->GetLargestZone();
+
+        double nMaxCell = largestZone->GetNCell();
+
+        double aveFloatOp = this->aveFloatOp;
+        double tau = timeProc[ iProc ] + nMaxCell * aveFloatOp / procSpeed[ iProc ];
+
+        //It seems that EPS is still necessary
+        //The idea here is as follows. For the candidate blocks which can be divided into blocks, 
+        //if the difference between the target blocks and the candidate blocks is too wide, 
+        //the binarySplit method is adopted. The binarySplit blocks do not directly join the process,
+        //but enter the next round of screening.
+
+        if ( tau > idealUniProcTime * ( 1.0 + eps ) )
+        {
+            double nRest = ( tau - idealUniProcTime ) * procSpeed[ iProc ] / aveFloatOp;
+
+            double nTarget = nMaxCell - nRest;
+            if ( nRest > this->minNumberCell && nTarget > this->minNumberCell )
+            {
+                //It is necessary to divide blocks only when a certain number of points are satisfied.
+                double nHalf = nMaxCell / 2.0;
+                nMaxCell = nTarget;
+                double ratio = nMaxCell / nRest;
+                double oRatio = 1.0 / ratio;
+
+                if ( std::max( ratio, oRatio ) < 3.0 )
+                {
+                    int kkk = 1;
+                    largestZone = this->Split( largestZone, nMaxCell );
+                    timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                    this->RemoveZoneFromUnsignedGroup( largestZone );
+                    this->AddZoneToProcess( iProc, largestZone );
+                }
+                else
+                {
+                    this->Split( largestZone, nHalf );
+                }
+            }
+            else
+            {
+                //If the block is of the right size, join the process directly, and there is no need to split it.
+                timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                this->RemoveZoneFromUnsignedGroup( largestZone );
+                this->AddZoneToProcess( iProc, largestZone );
+            }
+        }
+        else
+        {
+            //If the block is of the right size, join the process directly, and there is no need to split it.
+            timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+            this->RemoveZoneFromUnsignedGroup( largestZone );
+            this->AddZoneToProcess( iProc, largestZone );
+        }
+    }
+}
+
+void Partition::ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord )
+{
+    SplitZone * rootSplitZone = splitZone->GetRootZone();
+    Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+    int nNodes = splitZone->dimInfo.ComputeNumNodes();
+    std::cout << "nNodes = " << nNodes << "\n";
+
+    coord.resize( nNodes * sizeof(double) );
+
+    int index_dim = splitZone->dimInfo.dimList.size();
+    Coor * coor = zone->coors[ icoord ];
+
+    double * xlocal = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    double * xglobal = reinterpret_cast<double *>( const_cast<char *>( coor->coord.data() ) );
+    if ( index_dim == 1 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        for ( int i = imin; i < imax; ++ i )
+        {
+            xlocal[ icount++ ] = xglobal[ i ];
+        }
+    }
+    else if ( index_dim == 2 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        int jmin = splitZone->dimInfo.rmin[ 1 ] - 1;
+        int jmax = splitZone->dimInfo.rmax[ 1 ];
+        int ni = rootSplitZone->dimInfo.dimList[ 0 ];
+        int nj = rootSplitZone->dimInfo.dimList[ 1 ];
+        for ( int j = jmin; j < jmax; ++ j )
+        {
+            int jstride = j * ni;
+            for ( int i = imin; i < imax; ++ i )
+            {
+                xlocal[ icount++ ] = xglobal[ jstride + i ];
+            }
+        }
+    }
+}
+
+void Partition::DumpBc( SplitZone * splitZone )
+{
+}
+
+void Partition::DumpPartitionedGridFile()
+{
+    std::cout << "\n";
+    std::cout << "DumpPartitionedGridFile -------------------------------" << "\n";
+    std::cout << "\n";
+    int fileId = -1;
+    std::string filename = this->outName;
+    int ierr = cg_open( filename.c_str(), CG_MODE_WRITE, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+
+    std::vector<std::string> coordnames;
+    coordnames.push_back( "CoordinateX" );
+    coordnames.push_back( "CoordinateY" );
+    coordnames.push_back( "CoordinateZ" );
+
+    std::string basename = "Base";
+    int baseId = -1;
+    int icelldim = Global::cell_dim;
+    int iphysdim = Global::phys_dim;
+    cg_base_write( fileId, basename.c_str(), icelldim, iphysdim, &baseId );
+
+    std::cout << "baseId = " << baseId << "\n";
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        int nZones = this->GetNZones( iProc );
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            ZoneType_t zoneType = Structured;
+
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+
+            int index_dim = splitZone->dimInfo.dimList.size();
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            splitZone->dimInfo.ComputeISize();
+
+            int isize_dim = index_dim * 3;
+
+            std::vector<cgsize_t> isize( index_dim * 3, 0 );
+            for ( int m = 0; m < isize_dim; ++ m )
+            {
+                isize[ m ] = splitZone->dimInfo.isize[ m ];
+            }
+
+            int zoneId = -1;
+
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+
+            std::string zonename = "Zone" + std::to_string( splitZone->newIndex );
+
+            cg_zone_write( fileId, baseId, zonename.c_str(), isize.data(), zoneType, &zoneId );
+
+            std::cout << "zoneId = " << zoneId << "\n";
+            std::cout << "zonename = " << zonename << "\n";
+                
+            splitZone->ComputeRminmax();
+
+            SplitZone * rootSplitZone = splitZone->GetRootZone();
+
+            Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+            int ncoords = zone->coors.size();
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = -1;
+                DataType_t dataType = RealDouble;
+                std::string coordname = coordnames[ icoord ];
+                Coor * coor = zone->coors[ icoord ];
+
+                int nNodes = splitZone->dimInfo.ComputeNumNodes();
+                std::cout << "nNodes = " << nNodes << "\n";
+
+                std::vector<char> coord;
+                ComputeCoor( splitZone, icoord, coord );
+
+                cg_coord_write( fileId, baseId, zoneId, dataType, coordname.c_str(), coord.data(), &coorId );
+
+                std::cout << "fileId = " << fileId  << " baseId = " << baseId << " zoneId = " << zoneId  << " coorId = " << coorId << "\n";
+            }
+
+            std::vector< PhysicalSplitBc * > &bccoList = splitZone->physicalSplitBcList;
+
+            int nbocos = bccoList.size();
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = -1;
+                GridLocation_t location = Vertex;
+
+                std::string boconame = "BC" + std::to_string( iboco + 1 );
+
+                PhysicalSplitBc * physicalSplitBc = bccoList[ iboco ];
+                BCType_t bocotype = static_cast<BCType_t>( physicalSplitBc->bcType );
+                PointSetType_t ptset_type = PointRange;
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> pnts;
+                int nSize = physicalSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.end[ i ] );
+                }
+
+                cg_boco_write( fileId, baseId, zoneId, boconame.c_str(), bocotype, ptset_type, npnts, pnts.data(), & bccoId );
+            }
+
+            //std::vector< InterfaceSplitBc * > & bc1to1List = splitZone->interfaceSplitBcList;
+            std::vector< InterfaceSplitBc * > bc1to1List;
+            splitZone->GetLeafInterfaceBc( bc1to1List );
+
+            int n1to1 = bc1to1List.size();
+            std::cout << "n1to1 = " << n1to1 << "\n";
+
+            std::vector<int> itranfrm( index_dim );
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                itranfrm[ m ] = m + 1;
+            }
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int index_conn = -1;
+
+                InterfaceSplitBc * interfaceSplitBc = bc1to1List[ i1to1 ];
+
+                std::vector<cgsize_t> pnts;
+                std::vector<cgsize_t> pntsdonor;
+                int nSize = interfaceSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.end[ i ] );
+                }
+
+                int nPatchSize = interfaceSplitBc->donor_region.start.size();
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.start[ i ] );
+                }
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.end[ i ] );
+                }
+                int id = interfaceSplitBc->donor_zone->newIndex;
+                int oldZoneIndex = interfaceSplitBc->donor_zone->zoneIndex;
+                std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+                std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+                std::cout << "donor zone id = " << id << "\n";
+                std::cout << "donor zone oldZoneIndex = " << oldZoneIndex << "\n";
+                std::string donorname = "Zone" + std::to_string( id );
+                std::string connectname = "Interface" + std::to_string( i1to1 );
+
+                std::cout << "donorname = " << donorname << "\n";
+                std::cout << "connectname = " << connectname << "\n";
+
+                std::vector<int> & itranfrm = interfaceSplitBc->transform;
+
+                cg_1to1_write( fileId, baseId, zoneId, connectname.c_str(), donorname.c_str(), pnts.data(), pntsdonor.data(), itranfrm.data(), &index_conn );
+                std::cout << "index_conn = " << index_conn << "\n";
+            }
+        }
+    }
+    cg_close( fileId );
+}
+
+void Partition::ModifyZoneIndex()
+{
+    std::cout << "ModifyZoneIndex +++++++++++++++++++++++++ " << "\n";
+    int globalZoneId = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        std::cout << "iProc = " << iProc << "\n";
+        int nZones = this->GetNZones( iProc );
+        std::cout << "nZones in Proc " << iProc << "  = " << nZones << "\n";
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+            //splitZone->SetZoneIndex( globalZoneId++ );
+            splitZone->newIndex = ( globalZoneId++ );
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+        }
+    }
+}
\ No newline at end of file
diff --git a/example/partition/struct/1d/02b/Partition.h b/example/partition/struct/1d/02b/Partition.h
new file mode 100644
index 00000000..8a4a9731
--- /dev/null
+++ b/example/partition/struct/1d/02b/Partition.h
@@ -0,0 +1,59 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class SplitZone;
+
+struct CmpSplitZone 
+{
+    bool operator() ( SplitZone * a, SplitZone * b ) const;
+};
+
+class Partition
+{
+public:
+    Partition();
+    ~Partition();
+protected:
+    std::set < SplitZone * > zoneStorage;
+    std::set < SplitZone *, CmpSplitZone > unsignedZoneGroup;
+    std::vector< SplitZone * > refZone;
+    std::vector< std::vector< SplitZone * > > procSplitZone;
+    std::vector<double> procSpeed;
+    std::vector<double> timeProc;
+    double aveFloatOp, delta;
+    double idealUniProcTime, eps;
+    int minNumberCell;
+    int nTZone;
+    int nOriZone;
+    int nProc;
+public:
+    std::string inputName;
+    std::string outName;
+public:
+    void Solve();
+    void ReadGrid();
+    void Split();
+    void InitSplit();
+    void BinarySplit();
+    //void GreedySplit();
+public:
+    void AddNewZone( SplitZone * zone );
+    void AddZoneToUnsignedGroup( SplitZone * zone );
+    void RemoveZoneFromUnsignedGroup( SplitZone * zone );
+    void AddZoneToProcess( int iProc, SplitZone * zone );
+    void DumpPartitionedGridFile();
+    void ModifyZoneIndex();
+    void FreeAllZones();
+    int GetNZones( int iProc );
+    SplitZone * GetSplitZone( int iProc, int zoneId );
+    void ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord );
+    void DumpBc( SplitZone * splitZone );
+private:
+    int GetMinValueIndex( double * data, int numberOfData );
+    int GetMinLoadProc();
+    SplitZone * GetLargestZone();
+    SplitZone * Split( SplitZone * zone, double nCell );
+};
+
diff --git a/example/partition/struct/1d/02b/README.txt b/example/partition/struct/1d/02b/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/partition/struct/1d/02b/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/partition/struct/1d/02b/SplitZone.cpp b/example/partition/struct/1d/02b/SplitZone.cpp
new file mode 100644
index 00000000..aef70754
--- /dev/null
+++ b/example/partition/struct/1d/02b/SplitZone.cpp
@@ -0,0 +1,1091 @@
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+int Dim::dim = -1;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox  )
+{
+    domainBox.start = zoneBox.start;
+    domainBox.end = zoneBox.end;
+
+    int axis = iDomain / 2;
+    int direction = iDomain % 2;
+
+    if ( direction == 0 )
+    {
+        domainBox.end[ axis ] = domainBox.start[ axis ];
+    }
+    else if ( direction == 1 )
+    {
+        domainBox.start[ axis ] = domainBox.end[ axis ];
+    }
+}
+
+DimInfo::DimInfo()
+{
+    this->Init( 1 );
+}
+
+DimInfo::~DimInfo()
+{
+}
+
+void DimInfo::Init( int dim )
+{
+    this->dim = dim;
+    dimList.resize( this->dim, 1 );
+    oriPoint.resize( this->dim, 0 );
+}
+
+DimInfo & DimInfo::operator = ( const DimInfo & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->dim = rhs.dim;
+    this->dimList = rhs.dimList;
+    this->oriPoint = rhs.oriPoint;
+
+    return * this;
+}
+
+int DimInfo::ComputeNumNodes()
+{
+    int nNodes = 1;
+    for ( int m = 0; m < this->dimList.size(); ++ m )
+    {
+        nNodes *= this->dimList[ m ];
+    }
+    return nNodes;
+}
+
+void DimInfo::ComputeISize()
+{
+    int index_dim = this->dimList.size();
+    this->isize.resize( index_dim * 3, 0 );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        isize[ m ] = this->dimList[ m ];
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 1;
+        isize[ start + m ] = this->dimList[ m ] - 1;
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 2;
+        isize[ start + m ] = 0;
+    }
+
+    for ( int i = 0; i < isize.size(); ++ i )
+    {
+        std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+    }
+}
+
+void DimInfo::ComputeRminmax( std::vector<int> & ref )
+{
+    int index_dim = this->dimList.size();
+    this->rmin.resize( index_dim );
+    this->rmax.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        rmin[ m ] = ref[ m ] + 1;
+        rmax[ m ] = ref[ m ] + this->dimList[ m ];
+    }
+
+    std::cout << "rmin, rmax = \n";
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        std::cout << rmin[ m ] << " " << rmax[ m ] << "\n";
+    }
+}
+
+void DimInfo::Init( std::vector<int> & dimList )
+{
+    this->dim = dimList.size();
+    this->dimList = dimList;
+    std::vector<int> zero( dimList.size(), 0 );
+    this->oriPoint = zero;
+}
+
+void DimInfo::SetNewDimension( int axis, int newStart, int newWidth )
+{
+    this->oriPoint[ axis ] = newStart;
+    this->dimList [ axis ] = newWidth;
+}
+
+void DimInfo::GetZoneGlobalBox( RangeRegion &zoneBox )
+{
+    int index_dim = this->dimList.size();
+    zoneBox.start.resize( index_dim );
+    zoneBox.end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        zoneBox.start[ m ] = this->oriPoint[ m ] + 1;
+        zoneBox.end[ m ] = this->oriPoint[ m ] + this->dimList[ m ];
+    }
+}
+
+void DimInfo::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    int index_dim = this->dimList.size();
+    localBox.start.resize( index_dim );
+    localBox.end.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        localBox.start[ m ] = globalBox.start[ m ] - this->oriPoint[ m ];
+        localBox.end[ m ] = globalBox.end[ m ] - this->oriPoint[ m ];
+    }
+}
+
+RangeRegion::RangeRegion( int nSize )
+{
+    this->Init( nSize );
+}
+
+RangeRegion::~RangeRegion()
+{
+}
+
+void RangeRegion::Init( int nSize )
+{
+    this->start.resize( nSize );
+    this->end.resize( nSize );
+}
+
+RangeRegion & RangeRegion::operator = ( const RangeRegion & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+bool RangeRegion::operator == ( const RangeRegion & rhs ) const
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] != rhs.start[ m ] || 
+            this->end  [ m ] != rhs.end  [ m ] )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+bool RangeRegion::InRegion( const RangeRegion & region )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( ( this->start[ m ] < region.start[ m ] ) || ( this->end[ m ] > region.end[ m ] ) )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::Normalize()
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        int minv = std::min( this->start[ m ], this->end[ m ] );
+        int maxv = std::max( this->start[ m ], this->end[ m ] );
+        this->start[ m ] = minv;
+        this->end[ m ] = maxv;
+    }
+}
+
+void RangeRegion::Localize( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] -= oriPoint[ m ];
+        this->end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void RangeRegion::ToGlobal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] += oriPoint[ m ];
+        this->end[ m ] += oriPoint[ m ];
+    }
+}
+
+void RangeRegion::ToLocal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] -= oriPoint[ m ];
+        this->end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void RangeRegion::PrintGlobal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    std::cout << "global start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ] + oriPoint[m];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "global end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ] + oriPoint[m];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+void RangeRegion::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion );
+
+bool ComputeOverlapRegion( RangeRegion & region1, RangeRegion & region2, RangeRegion & overlapRegion )
+{
+    int index_dim = region1.start.size();
+    overlapRegion.Init( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int ijkmin1 = std::min( region1.start[ m ], region1.end[ m ] );
+        int ijkmax1 = std::max( region1.start[ m ], region1.end[ m ] );
+        int ijkmin2 = std::min( region2.start[ m ], region2.end[ m ] );
+        int ijkmax2 = std::max( region2.start[ m ], region2.end[ m ] );
+        if ( ( ijkmax1 < ijkmin2 ) || ( ijkmin1 > ijkmax2 ) )
+        {
+            return false;
+        }
+
+        int ijkmin = std::max( ijkmin1, ijkmin2 );
+        int ijkmax = std::min( ijkmax1, ijkmax2 );
+
+        overlapRegion.start[ m ] = ijkmin;
+        overlapRegion.end  [ m ] = ijkmax;
+    }
+
+    return CheckOverLapping( overlapRegion );
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion )
+{
+    int index_dim = overlapRegion.start.size();
+    int iCount = 0;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        if ( overlapRegion.start[ m ] == overlapRegion.end[ m ] )
+        {
+            ++ iCount;
+        }
+    }
+
+    return ( iCount == 1 );
+}
+
+bool GetInterfaceRegion( RangeRegion & zoneBoxL, RangeRegion & zoneBoxR, RangeRegion & interfaceRegion )
+{
+    int index_dim = zoneBoxL.start.size();
+    int nDomains = 2 * index_dim;
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegionL;
+        GetDomainRegion( zoneBoxL, iDomain, domainRegionL );
+
+        for ( int jDomain = 0; jDomain < nDomains; ++ jDomain )
+        {
+            RangeRegion domainRegionR;
+            GetDomainRegion( zoneBoxR, jDomain, domainRegionR );
+
+            if ( domainRegionL == domainRegionR )
+            {
+                interfaceRegion = domainRegionL;
+                return true;
+            }
+        }
+    }
+    return false;
+}
+
+void CreateInterfaceBc( SplitZone * zoneL, SplitZone * zoneR )
+{
+    RangeRegion globalBoxL, globalBoxR, globalInterfaceRegion;
+
+    zoneL->GetZoneGlobalBox( globalBoxL );
+    zoneR->GetZoneGlobalBox( globalBoxR );
+
+    if ( ! GetInterfaceRegion( globalBoxL, globalBoxR, globalInterfaceRegion ) )
+    {
+        return;
+    }
+
+    RangeRegion localInterfaceRegionL, localInterfaceRegionR;
+
+    zoneL->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionL );
+    zoneR->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionR );
+
+    int kkk = 1;
+
+    InterfaceSplitBc * interfaceSplitBcL = new InterfaceSplitBc();
+    zoneL->interfaceSplitBcList.push_back( interfaceSplitBcL );
+    interfaceSplitBcL->zone = zoneL;
+    interfaceSplitBcL->region = localInterfaceRegionL;
+
+    int nSize = localInterfaceRegionL.start.size();
+
+    std::vector<int> transform;
+
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        transform.push_back( m + 1 );
+    }
+
+    interfaceSplitBcL->transform = transform;
+    interfaceSplitBcL->CalcTransformMatrix();
+
+    interfaceSplitBcL->donor_zone = zoneR;
+    interfaceSplitBcL->donor_region = localInterfaceRegionR;
+
+    InterfaceSplitBc * interfaceSplitBcR = new InterfaceSplitBc();
+    zoneR->interfaceSplitBcList.push_back( interfaceSplitBcR );
+
+    interfaceSplitBcR->zone = zoneR;
+    interfaceSplitBcR->region = localInterfaceRegionR;
+
+    interfaceSplitBcR->transform = transform;
+    interfaceSplitBcR->CalcTransformMatrix();
+
+    interfaceSplitBcR->donor_zone = zoneL;
+    interfaceSplitBcR->donor_region = localInterfaceRegionL;
+}
+
+
+PhysicalSplitBc::PhysicalSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+PhysicalSplitBc::~PhysicalSplitBc()
+{
+}
+
+void PhysicalSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void PhysicalSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+void PhysicalSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = splitZone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+BasicSplitBc::BasicSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+BasicSplitBc::~BasicSplitBc()
+{
+    ;
+}
+
+void BasicSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void BasicSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+int trans::M[ 3 ][ 3 ];
+std::vector<int> trans::transform;
+
+int trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void trans::CalcTransformMatrix()
+{
+    int dim = trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = trans::transform[ 0 ];
+        int sgna = trans::sgn( a );
+        int a1 = trans::del( a, 1 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int c = trans::transform[ 2 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int sgnc = trans::sgn( c );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int a3 = trans::del( a, 3 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        int b3 = trans::del( b, 3 );
+        int c1 = trans::del( c, 1 );
+        int c2 = trans::del( c, 2 );
+        int c3 = trans::del( c, 3 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 2 ][ 0 ] = sgna * a3;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+        trans::M[ 2 ][ 1 ] = sgnb * b3;
+        trans::M[ 0 ][ 2 ] = sgnc * c1;
+        trans::M[ 1 ][ 2 ] = sgnc * c2;
+        trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+InterfaceInfo::InterfaceInfo()
+{
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceInfo::~InterfaceInfo()
+{
+}
+
+InterfaceSplitBc::InterfaceSplitBc()
+{
+    this->region.Init( Dim::dim );
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceSplitBc::~InterfaceSplitBc()
+{
+}
+
+void InterfaceSplitBc::GetLeafInterfaceBc( std::vector< InterfaceSplitBc * > & leafInterfaceBcList )
+{
+    int nChild = this->child.size();
+    if ( nChild == 0 )
+    {
+        leafInterfaceBcList.push_back( this );
+    }
+    else
+    {
+        for ( int iChild = 0; iChild < nChild; ++ iChild )
+        {
+            InterfaceSplitBc * interfaceSplitBc = this->child[ iChild ];
+            interfaceSplitBc->GetLeafInterfaceBc( leafInterfaceBcList );
+        }
+    }
+}
+
+void InterfaceSplitBc::CopyMatrix( InterfaceSplitBc * interfaceSplitBc )
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = interfaceSplitBc->Mt[ i ][ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::CalcTransformMatrix()
+{
+    trans::ZeroMatrix();
+    trans::transform = this->transform;
+    trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = trans::M[ i ][ j ];
+        }
+    }
+
+}
+
+void InterfaceSplitBc::mapindex( std::vector<int> & begin1, std::vector<int> & begin2,  std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = Dim::dim;
+    std::vector<int> diff( dim );
+    for ( int m = 0; m < dim; ++ m )
+    {
+        diff[ m ] = index1[ m ] - begin1[ m ];
+    }
+
+    std::vector<int> mul( dim );
+
+    Multiply( Mt, diff, mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = mul[ m ] + begin2[ m ];
+    }
+}
+
+void InterfaceSplitBc::Multiply( int Mt[][3], std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = Dim::dim;
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = this->zone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void InterfaceSplitBc::CalcSubDonorRegion( RangeRegion &subRegion, RangeRegion &subDonorRegion )
+{
+    std::vector<int> begin1 = this->region.start;
+    std::vector<int> end1 = this->region.end;
+    std::vector<int> begin2 = this->donor_region.start;
+    std::vector<int> end2 = this->donor_region.end;
+
+    std::vector<int> new_begin1 = subRegion.start;
+    std::vector<int> new_end1 = subRegion.end;
+
+    int dim = Dim::dim;
+    std::vector<int> new_begin2( dim );
+    std::vector<int> new_end2( dim );
+
+    mapindex( begin1, begin2, new_begin1, new_begin2 );
+    mapindex( begin1, begin2, new_end1, new_end2 );
+
+    subDonorRegion.start = new_begin2;
+    subDonorRegion.end = new_end2;
+}
+
+SplitZone::SplitZone()
+{
+    this->parent  = 0;
+    this->zoneIndex = 0;
+    this->iProc = 0;
+    dimInfo.Init( Dim::dim );
+    int kk = 1;
+}
+
+SplitZone::~SplitZone()
+{
+    ;
+}
+
+void SplitZone::GetZoneGlobalBox( RangeRegion & zoneBox )
+{
+    this->dimInfo.GetZoneGlobalBox( zoneBox );
+}
+
+void SplitZone::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    this->dimInfo.GetZoneLocalBox( globalBox, localBox );
+}
+
+
+void SplitZone::ComputeRminmax()
+{
+    int index_dim = this->dimInfo.dimList.size();
+    std::vector<int> ref( index_dim, 0 );
+
+    SplitZone * rootSplitZone = 0;
+    this->GetRootInfo( rootSplitZone, ref );
+
+    this->dimInfo.ComputeRminmax( ref );
+}
+
+SplitZone * SplitZone::GetRootZone()
+{
+    SplitZone * root = this;
+
+    while ( true )
+    {
+        if ( root->parent )
+        {
+            root = root->parent;
+        }
+        else
+        {
+            return root;
+        }
+    };
+}
+
+void SplitZone::GetRootInfo( SplitZone *& root, std::vector<int> & ref )
+{
+    for ( int i = 0; i < this->dimInfo.dimList.size(); ++ i )
+    {
+        ref[ i ] += this->dimInfo.oriPoint[ i ];
+    }
+
+    if ( this->parent )
+    {
+        this->parent->GetRootInfo( root, ref );
+    }
+    else
+    {
+        root = this;
+    }
+}
+
+void SplitZone::SetParentAndChild( SplitZone * parent )
+{
+    this->parent = parent;
+    if ( parent )
+    {
+        parent->child.push_back( this );
+    }
+}
+
+void SplitZone::GetLeafInterfaceBc( std::vector< InterfaceSplitBc * > & leafInterfaceBcList )
+{
+    int nInterfaceBcs = this->interfaceSplitBcList.size();
+    for ( int i = 0; i < nInterfaceBcs; ++ i )
+    {
+        InterfaceSplitBc * interfaceSplitBc = this->interfaceSplitBcList[ i ];
+        interfaceSplitBc->GetLeafInterfaceBc( leafInterfaceBcList );
+    }
+}
+
+int SplitZone::GetNCell()
+{
+    int numberOfCells = 1;
+    for ( int i = 0; i < this->dimInfo.dim; ++ i )
+    {
+        numberOfCells *= std::max( 1, ( this->dimInfo.dimList[ i ] - 1 ) );
+    }
+
+    return numberOfCells; 
+}
+
+void SplitZone::SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int leftStart = 0;
+    int leftWidth = iSplit - 0;
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, leftStart , leftWidth  );
+}
+
+void SplitZone::SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int rightStart = iSplit - 1;
+    int rightWidth = dimList[ axisNeedSplit ] - ( iSplit - 1 );
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, rightStart, rightWidth );
+}
+
+void SplitZone::Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell )
+{
+    //Find the longest axis
+    int axisNeedSplit = this->FindAxisNeedSplit();
+    int iSplit        = this->FindSplitPosition( axisNeedSplit, nCell );
+
+    zoneL->SetLeftDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+    zoneR->SetRightDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+
+    zoneL->CreateBcFromParent();
+    zoneR->CreateBcFromParent();
+    
+    CreateInterfaceBc( zoneL, zoneR );
+}
+
+void SplitZone::CreateBcFromParent()
+{
+    this->CreatePhysicalBcFromParent();
+    this->CreateInterfaceBcFromParent();
+}
+
+void SplitZone::CreatePhysicalBcFromParent()
+{
+    int nParentPhysicalBcs = this->parent->physicalSplitBcList.size();
+
+    for ( int iParentPhysicalBcs = 0; iParentPhysicalBcs < nParentPhysicalBcs; ++ iParentPhysicalBcs )
+    {
+        PhysicalSplitBc * parentPhysicalSplitBc = this->parent->physicalSplitBcList[ iParentPhysicalBcs ];
+
+        this->CreatePhysicalBcFromParent( parentPhysicalSplitBc );
+    }
+}
+
+void SplitZone::CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentPhysicalSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreatePhysicalBc( overlapRegion, parentPhysicalSplitBc->bcType );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent()
+{
+    int nInterfaceSplitBcs = this->parent->interfaceSplitBcList.size();
+
+    for ( int iInterfaceSplitBcs = 0; iInterfaceSplitBcs < nInterfaceSplitBcs; ++ iInterfaceSplitBcs )
+    {
+        InterfaceSplitBc * parentInterfaceSplitBc = this->parent->interfaceSplitBcList[ iInterfaceSplitBcs ];
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc );
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentInterfaceSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc, overlapRegion );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::FindDonorInterface( InterfaceSplitBc * interfaceSplitBc, InterfaceInfo & interfaceInfo )
+{
+    RangeRegion donor_region = interfaceSplitBc->donor_region;
+    donor_region.Normalize();
+    interfaceInfo.donor_zone = this;
+    for ( int iInterface = 0; iInterface < interfaceSplitBcList.size(); ++ iInterface )
+    {
+        InterfaceSplitBc * candidateDonorBc = interfaceSplitBcList[ iInterface ];
+        bool flag = donor_region.InRegion( candidateDonorBc->region );
+        if ( flag )
+        {
+            if ( donor_region == candidateDonorBc->region )
+            {
+                interfaceInfo.donor_interface = candidateDonorBc;
+                return;
+            }
+            else
+            {
+                InterfaceSplitBc * donorBc = new InterfaceSplitBc();
+                candidateDonorBc->child.push_back( donorBc );
+                donorBc->region = donor_region;
+                donorBc->zone = candidateDonorBc->zone;
+                donorBc->donor_zone = interfaceSplitBc->zone;
+                donorBc->transform = candidateDonorBc->transform;
+                donorBc->CopyMatrix( candidateDonorBc );
+                RangeRegion subDonorRegion( Dim::dim );
+                candidateDonorBc->CalcSubDonorRegion( donorBc->region, subDonorRegion );
+                std::vector<int> & oriPoint = interfaceSplitBc->zone->dimInfo.oriPoint;
+                subDonorRegion.Localize( oriPoint );
+                donorBc->donor_region = subDonorRegion;
+                donorBc->donor_bc = interfaceSplitBc;
+                interfaceInfo.donor_interface = donorBc;
+                return;
+            }
+        }
+    }
+    return;
+}
+
+void SplitZone::GetChildDonorRegion( RangeRegion & subDonorRegion, InterfaceInfo & interfaceInfo )
+{
+    std::cout << "subDonorRegion = \n";
+    //subDonorRegion.Print();
+    RangeRegion normalizedDonorRegion = subDonorRegion;
+    normalizedDonorRegion.Normalize();
+    int nChild = this->child.size();
+    for ( int ichild = 0; ichild < nChild; ++ ichild )
+    {
+        std::cout << " iChild = " << ichild << " nChild = " << nChild << "\n";
+        SplitZone * sub_zone = this->child[ ichild ];
+        std::cout << " zoneIndex = " << sub_zone->zoneIndex << "\n";
+        int nInters = sub_zone->interfaceSplitBcList.size();
+        for ( int iInter = 0; iInter < nInters; ++ iInter )
+        {
+            std::cout << " iInter = " << iInter << "\n";
+            InterfaceSplitBc * interfaceSplitBc = sub_zone->interfaceSplitBcList[ iInter ];
+            std::cout << "interfaceSplitBc local = \n";
+            interfaceSplitBc->region.Print();
+            std::cout << "interfaceSplitBc global = \n";
+            interfaceSplitBc->region.PrintGlobal( sub_zone->dimInfo.oriPoint );
+            RangeRegion g_region = interfaceSplitBc->region;
+            g_region.ToGlobal( sub_zone->dimInfo.oriPoint );
+            if ( g_region == normalizedDonorRegion )
+            {
+                RangeRegion donorRegion = subDonorRegion;
+                donorRegion.ToLocal( sub_zone->dimInfo.oriPoint );
+
+                interfaceInfo.donor_zone = sub_zone;
+                interfaceInfo.donor_interface = interfaceSplitBc;
+                interfaceInfo.donor_region = donorRegion;
+                return;
+            }
+        }
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion )
+{
+    InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+    this->interfaceSplitBcList.push_back( interfaceSplitBc );
+
+    interfaceSplitBc->region = overlapRegion;
+    interfaceSplitBc->zone = this;
+    interfaceSplitBc->transform = parentInterfaceSplitBc->transform;
+    interfaceSplitBc->CopyMatrix( parentInterfaceSplitBc );
+    RangeRegion subDonorRegion( Dim::dim );
+    parentInterfaceSplitBc->CalcSubDonorRegion( overlapRegion, subDonorRegion );
+    interfaceSplitBc->ChangeRegionToLocalCoordinate();
+    interfaceSplitBc->donor_region = subDonorRegion;
+    SplitZone * parent_donor_zone = parentInterfaceSplitBc->donor_zone;
+    std::cout << " parentInterfaceSplitBc->zone->zoneIndex " << parentInterfaceSplitBc->zone->zoneIndex << "\n";
+    std::cout << " parentInterfaceSplitBc->donor_zone->zoneIndex " << parent_donor_zone->zoneIndex << "\n";
+    if ( parent_donor_zone->child.size() > 0 )
+    {
+        InterfaceInfo interfaceInfo;
+        parent_donor_zone->GetChildDonorRegion( subDonorRegion, interfaceInfo );
+        interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+        interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+        interfaceSplitBc->donor_region = interfaceInfo.donor_region;
+        //compatibility
+        InterfaceSplitBc * donor_bc = interfaceSplitBc->donor_bc;
+        SplitZone * donor_zone = interfaceSplitBc->donor_zone;
+        if ( interfaceSplitBc->zone != donor_bc->donor_zone )
+        {
+            if ( interfaceSplitBc->zone->parent == donor_bc->donor_zone )
+            {
+                RangeRegion d_region = donor_bc->donor_region;
+                d_region.ToLocal( interfaceSplitBc->zone->dimInfo.oriPoint );
+                donor_bc->donor_region = d_region;
+            }
+            donor_bc->donor_zone = interfaceSplitBc->zone;
+         
+            int kkk = 1;
+        }
+        int kkk = 1;
+    }
+    else
+    {
+        InterfaceInfo interfaceInfo;
+        parent_donor_zone->FindDonorInterface( interfaceSplitBc, interfaceInfo );
+        interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+        interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+    }
+    
+    int kkk = 1;
+}
+
+void SplitZone::CreatePhysicalBc( RangeRegion & overlapRegion, int bcType )
+{
+    PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+    this->physicalSplitBcList.push_back( physicalSplitBc );
+    physicalSplitBc->SetRegion( overlapRegion );
+    physicalSplitBc->bcType = bcType;
+    physicalSplitBc->splitZone = this;
+    physicalSplitBc->ChangeRegionToLocalCoordinate();
+}
+
+int SplitZone::FindAxisNeedSplit()
+{
+    //Find the longest axis
+    int axisNeedSplit = 0;
+    int maxN = this->dimInfo.dimList[ 0 ];
+
+    for ( int m = 1; m < this->dimInfo.dimList.size(); ++ m )
+    {
+        if ( this->IsPoleBc( m ) )
+        {
+            continue;
+        }
+        int Nm = this->dimInfo.dimList[ m ];
+        if ( maxN < Nm )
+        {
+            maxN = Nm;
+            axisNeedSplit = m;
+        }
+    }
+
+    return axisNeedSplit;
+}
+
+int SplitZone::GetCrossSection( int axis )
+{
+    int nDim = this->dimInfo.dimList.size();
+    int crossSection = 1;
+    int N = nDim - 1;
+    for ( int m = 0; m < N; ++ m )
+    {
+         int mm = ( axis + 1 ) % nDim;
+         int nLineElements = std::max( 1, ( this->dimInfo.dimList[ mm ] - 1 ) );
+         crossSection *= nLineElements;
+    }
+    return crossSection;
+}
+
+int SplitZone::FindSplitPosition( int axisNeedSplit, double nCell )
+{
+    int nDim = this->dimInfo.dimList.size();
+    std::vector<int> crossSections( nDim );
+    for ( int m = 0; m < nDim; ++ m )
+    {
+        crossSections[ m ] = this->GetCrossSection( m );
+    }
+
+    //guess the value
+    double dSplit = nCell / crossSections[ axisNeedSplit ];
+    int  iSplit = 1 + static_cast< int >( std::floor( dSplit + 0.5 ) );
+    return iSplit;
+}
+
+
+bool SplitZone::IsPoleBc( int splitDirection )
+{
+    return false;
+}
+
diff --git a/example/partition/struct/1d/02b/SplitZone.h b/example/partition/struct/1d/02b/SplitZone.h
new file mode 100644
index 00000000..ffe1e306
--- /dev/null
+++ b/example/partition/struct/1d/02b/SplitZone.h
@@ -0,0 +1,196 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class Dim
+{
+public:
+    static int dim;
+};
+
+class SplitZone;
+class RangeRegion;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox );
+
+class DimInfo
+{
+public:
+    DimInfo();
+    ~DimInfo();
+public:
+    int dim;
+    std::vector<int> dimList;
+    std::vector<int> oriPoint;
+    std::vector<int> isize;
+    std::vector<int> rmin;
+    std::vector<int> rmax;
+public:
+    int GetSize() const { return dim; }
+    DimInfo & operator = ( const DimInfo & rhs );
+public:
+    int ComputeNumNodes();
+    void ComputeISize();
+    void ComputeRminmax( std::vector<int> & ref );
+    void Init( int dim );
+    void Init( std::vector<int> & dimList );
+    void SetNewDimension( int axis, int newStart, int newWidth );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+};
+
+class SplitZone;
+class SplitBcPatch;
+
+class RangeRegion
+{
+public:
+    RangeRegion( int nSize = 1 );
+    ~RangeRegion();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    void Init( int nSize );
+    RangeRegion & operator = ( const RangeRegion & rhs );
+    bool operator == ( const RangeRegion & rhs ) const;
+    bool InRegion( const RangeRegion & region );
+    void SetRegion( std::vector<int> &pnts );
+    void Normalize();
+    void Localize( std::vector<int> & oriPoint );
+    void ToGlobal( std::vector<int> & oriPoint );
+    void ToLocal( std::vector<int> & oriPoint );
+    void PrintGlobal( std::vector<int> & oriPoint );
+    void Print();
+};
+
+class PhysicalSplitBc
+{
+public:
+    PhysicalSplitBc();
+    ~PhysicalSplitBc();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class BasicSplitBc
+{
+public:
+    BasicSplitBc();
+    ~BasicSplitBc();
+public:
+    RangeRegion region;
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> & pnts );
+    void SetRegion( RangeRegion & region );
+};
+
+class trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class InterfaceSplitBc;
+class SplitZone;
+
+class InterfaceInfo
+{
+public:
+    InterfaceInfo();
+    ~InterfaceInfo();
+public:
+    InterfaceSplitBc * donor_interface = nullptr;
+    SplitZone * donor_zone = nullptr;
+    RangeRegion donor_region;
+};
+
+class InterfaceSplitBc
+{
+public:
+    InterfaceSplitBc();
+    ~InterfaceSplitBc();
+public:
+    std::vector<int> transform;
+    int Mt[ 3 ][ 3 ];
+    RangeRegion region;
+    SplitZone * zone = nullptr;
+    RangeRegion donor_region;
+    SplitZone * donor_zone = nullptr;
+    InterfaceSplitBc * donor_bc = nullptr;
+public:
+    std::vector<InterfaceSplitBc *> child;
+    void GetLeafInterfaceBc( std::vector< InterfaceSplitBc * > & leafInterfaceBcList );
+public:
+    void CopyMatrix( InterfaceSplitBc * interfaceSplitBc );
+    void CalcTransformMatrix();
+    void CalcSubDonorRegion( RangeRegion & subRegion, RangeRegion & subDonorRegion );
+    void mapindex( std::vector<int> & begin1, std::vector<int> & begin2, std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( int Mt[][ 3 ], std::vector<int> & a, std::vector<int> & b );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class SplitZone
+{
+public:
+    SplitZone();
+    ~SplitZone();
+public:
+    DimInfo dimInfo;
+    int zoneIndex, iProc;
+    int newIndex;
+protected:
+    SplitZone * parent;
+    std::vector<SplitZone *> child;
+public:
+    std::vector< PhysicalSplitBc * > physicalSplitBcList;
+    std::vector< InterfaceSplitBc * > interfaceSplitBcList;
+    void GetLeafInterfaceBc( std::vector< InterfaceSplitBc * > & leafInterfaceBcList );
+public:
+    int GetNCell();
+    void ComputeRminmax();
+    void GetRootInfo( SplitZone *& root, std::vector<int> & ref );
+    void SetZoneIndex( int zoneIndex ) { this->zoneIndex = zoneIndex; }
+    int  GetZoneIndex() { return zoneIndex; }
+    void SetProcId( int iProc ) { this->iProc = iProc; }
+    void SetParent( SplitZone * parent ) { this->parent = parent; };
+    void SetParentAndChild( SplitZone * parent );
+    void FindDonorInterface( InterfaceSplitBc * interfaceSplitBc, InterfaceInfo & interfaceInfo );
+    void GetChildDonorRegion( RangeRegion & subDonorRegion, InterfaceInfo & interfaceInfo );
+public:
+    void CreateBcFromParent();
+    void CreatePhysicalBcFromParent();
+    void CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc );
+    void CreatePhysicalBc( RangeRegion & overlapRegion, int bcType );
+    void CreateInterfaceBcFromParent();
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc );
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion );
+
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+    SplitZone * GetRootZone();
+public:
+    void Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell );
+    void SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+    void SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+private:
+    int FindAxisNeedSplit();
+    int FindSplitPosition( int axisNeedSplit, double nCell );
+    bool IsPoleBc( int splitDirection );
+    int GetCrossSection( int axis );
+};
+
diff --git a/example/partition/struct/1d/02b/heat1d2blocksv1.cgns b/example/partition/struct/1d/02b/heat1d2blocksv1.cgns
new file mode 100644
index 00000000..4c9c4994
Binary files /dev/null and b/example/partition/struct/1d/02b/heat1d2blocksv1.cgns differ
diff --git a/example/partition/struct/1d/02b/heat1dpart.cgns b/example/partition/struct/1d/02b/heat1dpart.cgns
new file mode 100644
index 00000000..ad02ab7e
Binary files /dev/null and b/example/partition/struct/1d/02b/heat1dpart.cgns differ
diff --git a/example/partition/struct/1d/02b/main.cpp b/example/partition/struct/1d/02b/main.cpp
new file mode 100644
index 00000000..5da1de7c
--- /dev/null
+++ b/example/partition/struct/1d/02b/main.cpp
@@ -0,0 +1,18 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include "Partition.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip>
+
+int main(int argc, char **argv)
+{
+    Partition * partition = new Partition();
+    partition->Solve();
+    delete partition;
+
+    return 0;
+}
diff --git a/example/partition/struct/1d/03/CMakeLists.txt b/example/partition/struct/1d/03/CMakeLists.txt
new file mode 100644
index 00000000..74ceea7d
--- /dev/null
+++ b/example/partition/struct/1d/03/CMakeLists.txt
@@ -0,0 +1,78 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	Partition.h Partition.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	SplitZone.h SplitZone.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/partition/struct/1d/03/CgnsGrid.cpp b/example/partition/struct/1d/03/CgnsGrid.cpp
new file mode 100644
index 00000000..dfe750bd
--- /dev/null
+++ b/example/partition/struct/1d/03/CgnsGrid.cpp
@@ -0,0 +1,349 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include <map>
+
+Grid::Grid()
+{
+    ;
+}
+
+Grid::~Grid()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if( (i+1)%5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+    delete this->patch;
+}
+
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+ZoneBcPatch::ZoneBcPatch()
+{
+    ;
+}
+
+ZoneBcPatch::~ZoneBcPatch()
+{
+}
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+Global::Global()
+{
+    ;
+}
+
+Global::~Global()
+{
+}
+
+void Global::FreeData()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+    zones.resize( 0 );
+}
+
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            //baseZone.baseId = baseId;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin( index_dim );
+            std::vector<cgsize_t> irmax( index_dim );
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                std::vector<char> coord( nNodes * sizeof(double) );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+                coor->DumpCoor();
+            }
+
+            int nbocos = -1;
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+                int kkk = 1;
+            }
+        }
+        int kkk = 1;
+    }
+    int kkk = 1;
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/partition/struct/1d/03/CgnsGrid.h b/example/partition/struct/1d/03/CgnsGrid.h
new file mode 100644
index 00000000..053c467b
--- /dev/null
+++ b/example/partition/struct/1d/03/CgnsGrid.h
@@ -0,0 +1,140 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <map>
+
+class Grid;
+
+class Zone;
+
+class Grid
+{
+public:
+    Grid();
+    ~Grid();
+public:
+    int nZone;
+    std::vector<double> x;
+    std::vector<Zone *> zones;
+};
+
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+};
+
+class ZoneBc;
+class ZoneBc1To1;
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class ZoneBcPatch;
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+    ZoneBcPatch * patch = nullptr;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+class ZoneBcPatch
+{
+public:
+    ZoneBcPatch();
+    ~ZoneBcPatch();
+public:
+    int donor_zoneid;
+    std::vector<int> transform;
+    std::vector<int> donor_pnts;
+};
+
+class BaseZone
+{
+public:
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Global
+{
+public:
+    Global();
+    ~Global();
+public:
+    static int cell_dim;
+    static int phys_dim;
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+public:
+    static void FreeData();
+};
+
+void ReadCgnsGrid( const std::string & filename );
+void ReadCgnsGridBaseZone( const std::string & filename );
\ No newline at end of file
diff --git a/example/partition/struct/1d/03/Partition.cpp b/example/partition/struct/1d/03/Partition.cpp
new file mode 100644
index 00000000..ae983863
--- /dev/null
+++ b/example/partition/struct/1d/03/Partition.cpp
@@ -0,0 +1,619 @@
+#include "Partition.h"
+#include "CgnsGrid.h"
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+bool CmpSplitZone::operator() ( SplitZone * a, SplitZone * b ) const
+{
+    return a->zoneIndex < b->zoneIndex;
+};
+
+
+double CalSumOfProcSpeed( std::vector<double> & procSpeed );
+double CalSumOfProcSpeed( std::vector<double> & procSpeed )
+{
+    int nProc = procSpeed.size();
+    double sumOfProcSpeed = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        sumOfProcSpeed += procSpeed[ iProc ];
+    }
+    return sumOfProcSpeed;
+}
+
+Partition::Partition()
+{
+    this->inputName = "../heat1d2blocksv2.cgns";
+    this->outName =  "../heat1dpart.cgns";
+}
+
+Partition::~Partition()
+{
+    ;
+}
+
+int Partition::GetMinValueIndex( double * data, int numberOfData )
+{
+    double minValue = data[ 0 ];
+    int minimumValueIndex = 0;
+
+    for ( int iData = 1; iData < numberOfData; ++ iData )
+    {
+        if ( minValue > data[ iData ] )
+        {
+            minValue      = data[ iData ];
+            minimumValueIndex = iData;
+        }
+    }
+    return minimumValueIndex;
+}
+
+int Partition::GetMinLoadProc()
+{
+    return this->GetMinValueIndex( this->timeProc.data(), this->nProc );
+}
+
+SplitZone * Partition::GetLargestZone()
+{
+    SplitZone * largestZone = 0;
+
+    double nMaxCell = 0.0;
+
+    for ( std::set< SplitZone * >::iterator iter = unsignedZoneGroup.begin(); iter != unsignedZoneGroup.end(); ++ iter )
+    {
+        double nSize = ( * iter )->GetNCell();
+        if ( nMaxCell < nSize )
+        {
+            nMaxCell    = nSize;
+            largestZone = * iter;
+        }
+    }
+
+    return largestZone;
+}
+
+void Partition::Solve()
+{
+    std::cout << "Partition::Split()\n";
+    this->nProc = 2;
+    this->ReadGrid();
+    this->Split();
+    this->DumpPartitionedGridFile();
+    this->FreeAllZones();
+}
+
+void Partition::ReadGrid()
+{
+    ReadCgnsGridBaseZone( this->inputName );
+    ReadCgnsGrid( this->inputName );
+
+    this->nOriZone = ::Global::zones.size();
+    Dim::dim = Global::cell_dim;
+
+    std::cout << "numberOfBlocks = " << nOriZone << "\n";
+
+    this->refZone.resize( nOriZone );
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = new SplitZone();
+        refZone[ iZone ] = splitZone;
+
+        splitZone->SetZoneIndex( iZone );
+        splitZone->SetProcId( 0 );
+        splitZone->SetParentAndChild( 0 );
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        Zone * zone = ::Global::zones[ iZone ];
+
+        splitZone->dimInfo.dimList = zone->nijk;
+
+        int nbccos = zone->bccos.size();
+        std::cout << "nbccos = " << nbccos << "\n";
+
+        for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+        {
+            ZoneBc * zoneBc = zone->bccos[ ibcco ];
+
+            PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+            splitZone->physicalSplitBcList.push_back( physicalSplitBc );
+            physicalSplitBc->bcType = zoneBc->bcType;
+            physicalSplitBc->SetRegion( zoneBc->pnts );
+            physicalSplitBc->splitZone = splitZone;
+        }
+
+        int nbc1to1s = zone->bc1to1s.size();
+
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * zoneBc1To1 = zone->bc1to1s[ ibc1to1 ];
+
+            InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+            splitZone->interfaceSplitBcList.push_back( interfaceSplitBc );
+            interfaceSplitBc->zone = splitZone;
+            interfaceSplitBc->region.SetRegion( zoneBc1To1->pnts );
+
+            interfaceSplitBc->transform = zoneBc1To1->transform;
+            interfaceSplitBc->CalcTransformMatrix();
+
+            interfaceSplitBc->donor_zone = refZone[ zoneBc1To1->donor_zoneid ];
+            interfaceSplitBc->donor_region.SetRegion( zoneBc1To1->donor_pnts );
+        }
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        int nbc1to1s = splitZone->interfaceSplitBcList.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            InterfaceSplitBc * interfaceSplitBc = splitZone->interfaceSplitBcList[ ibc1to1 ];
+            InterfaceInfo interfaceInfo;
+            interfaceSplitBc->donor_zone->FindDonorInterface( interfaceSplitBc, interfaceInfo );
+            interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+            interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+        }
+    }
+}
+
+void Partition::Split()
+{
+    this->InitSplit();
+    this->BinarySplit();
+    this->ModifyZoneIndex();
+    int kkk = 1;
+}
+
+void Partition::InitSplit()
+{
+    //nZone is the number of zones in the original grid
+    //nProc is not the number of blocks in the end, but the number of processes that need to be divided.
+    //This difference occurs because the structure grid can have many blocks per process.
+
+    //this->nProc    = nProc;
+    //this->nPhyBlocks = referenceBlock.size();
+    //this->nZone  = this->nPhyBlocks;
+
+    //tj Computation time on processor j
+    //Nk Number of internal grid-cells for zone j
+    //aveFloatOp:  Number of Real operations per gridcell
+    //Gj The set of blocks allocated to process j
+    //Pj Real operations per second for process j
+
+    //The Greedy Load Balancing Algorithm
+    //1.Compute an "ideal" uniprocessor time, Tuni = sum ( Nk * aveFloatOp )/ sum( Pj ).
+    //2.Set the group of unassigned blocks, Gu, to contain all blocks. The number of blocks in Nu=M, where M is the total number of blocks in the mesh.
+    //3.Start all processors with a very small fictitious zone to get a start tj=delt aveFloatOp/Pj, where delt<<1 is the size of the very small fictious zone.
+    //This is used to find the fastest processor in a heterogeneous system, tj could otherwise be set to 0 in the homogeneous case.
+    this->aveFloatOp = 1.0;
+    this->delta      = 1.0e-5;
+    this->procSpeed.resize( nProc );
+    this->timeProc.resize( nProc );
+
+    this->nTZone = this->nOriZone;
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        procSpeed[ iProc ] = 1.0;
+    }
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        timeProc[ iProc ] = delta * aveFloatOp / procSpeed[ iProc ];
+    }
+
+    double sumProcSpeed = CalSumOfProcSpeed( procSpeed );
+
+    double sumProcOp = 0.0;
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        sumProcOp += refZone[ iZone ]->GetNCell() * aveFloatOp;
+    }
+
+    this->idealUniProcTime = sumProcOp / sumProcSpeed;
+
+    this->eps = 0.05;
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        unsignedZoneGroup.insert( refZone[ iZone ] );
+    }
+
+    //Init zoneStorage
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        zoneStorage.insert( refZone[ iZone ] );
+    }
+
+    //Assign procSplitZone to each process
+    procSplitZone.resize( nProc );
+
+    this->minNumberCell = 1;
+    for ( int m = 0; m < Dim::dim; ++ m )
+    {
+        this->minNumberCell *= 1;
+    }
+
+    int kkk = 1;
+
+}
+
+void Partition::FreeAllZones()
+{
+    int iCount = 0;
+    for ( std::set < SplitZone * >::iterator iter = zoneStorage.begin(); iter != zoneStorage.end(); ++ iter )
+    {
+        //cout << "iCount = " << iCount << "\n";
+        ++ iCount;
+        delete * iter;
+    }
+}
+
+int Partition::GetNZones( int iProc )
+{
+    return this->procSplitZone[ iProc ].size();
+}
+
+SplitZone * Partition::GetSplitZone( int iProc, int zoneId )
+{
+    return this->procSplitZone[ iProc ][ zoneId ];
+}
+
+void Partition::AddZoneToUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.insert( zone );
+}
+
+void Partition::RemoveZoneFromUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.erase( zone );
+}
+
+void Partition::AddZoneToProcess( int iProc, SplitZone * zone )
+{
+    this->procSplitZone[ iProc ].push_back( zone );
+}
+
+void Partition::AddNewZone( SplitZone * zone )
+{
+    zone->SetZoneIndex( nTZone ++ );
+
+    this->AddZoneToUnsignedGroup( zone );
+
+    this->zoneStorage.insert( zone );
+}
+
+SplitZone * Partition::Split( SplitZone * zone, double nCell )
+{
+    SplitZone * zoneL = new SplitZone();
+    zoneL->SetParentAndChild( zone );
+
+    SplitZone * zoneR = new SplitZone();
+    zoneR->SetParentAndChild( zone );
+
+    //Remove the original block from the UnsignedGroup
+    this->RemoveZoneFromUnsignedGroup( zone );
+
+    this->AddNewZone( zoneL );
+    this->AddNewZone( zoneR );
+
+    zone->Split( zoneL, zoneR, nCell );
+
+    return zoneL;
+}
+
+void Partition::BinarySplit()
+{
+    while ( ! unsignedZoneGroup.empty() )
+    {
+        std::cout << "number of unsigned zone = " << unsignedZoneGroup.size() << "\n";
+        int iProc = this->GetMinLoadProc();
+
+        //Get the block with the largest number of grids and its size
+        SplitZone * largestZone = this->GetLargestZone();
+
+        double nMaxCell = largestZone->GetNCell();
+
+        double aveFloatOp = this->aveFloatOp;
+        double tau = timeProc[ iProc ] + nMaxCell * aveFloatOp / procSpeed[ iProc ];
+
+        //It seems that EPS is still necessary
+        //The idea here is as follows. For the candidate blocks which can be divided into blocks, 
+        //if the difference between the target blocks and the candidate blocks is too wide, 
+        //the binarySplit method is adopted. The binarySplit blocks do not directly join the process,
+        //but enter the next round of screening.
+
+        if ( tau > idealUniProcTime * ( 1.0 + eps ) )
+        {
+            double nRest = ( tau - idealUniProcTime ) * procSpeed[ iProc ] / aveFloatOp;
+
+            double nTarget = nMaxCell - nRest;
+            if ( nRest > this->minNumberCell && nTarget > this->minNumberCell )
+            {
+                //It is necessary to divide blocks only when a certain number of points are satisfied.
+                double nHalf = nMaxCell / 2.0;
+                nMaxCell = nTarget;
+                double ratio = nMaxCell / nRest;
+                double oRatio = 1.0 / ratio;
+
+                if ( std::max( ratio, oRatio ) < 3.0 )
+                {
+                    int kkk = 1;
+                    largestZone = this->Split( largestZone, nMaxCell );
+                    timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                    this->RemoveZoneFromUnsignedGroup( largestZone );
+                    this->AddZoneToProcess( iProc, largestZone );
+                }
+                else
+                {
+                    this->Split( largestZone, nHalf );
+                }
+            }
+            else
+            {
+                //If the block is of the right size, join the process directly, and there is no need to split it.
+                timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                this->RemoveZoneFromUnsignedGroup( largestZone );
+                this->AddZoneToProcess( iProc, largestZone );
+            }
+        }
+        else
+        {
+            //If the block is of the right size, join the process directly, and there is no need to split it.
+            timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+            this->RemoveZoneFromUnsignedGroup( largestZone );
+            this->AddZoneToProcess( iProc, largestZone );
+        }
+    }
+}
+
+void Partition::ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord )
+{
+    SplitZone * rootSplitZone = splitZone->GetRootZone();
+    Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+    int nNodes = splitZone->dimInfo.ComputeNumNodes();
+    std::cout << "nNodes = " << nNodes << "\n";
+
+    coord.resize( nNodes * sizeof(double) );
+
+    int index_dim = splitZone->dimInfo.dimList.size();
+    Coor * coor = zone->coors[ icoord ];
+
+    double * xlocal = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    double * xglobal = reinterpret_cast<double *>( const_cast<char *>( coor->coord.data() ) );
+    if ( index_dim == 1 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        for ( int i = imin; i < imax; ++ i )
+        {
+            xlocal[ icount++ ] = xglobal[ i ];
+        }
+    }
+    else if ( index_dim == 2 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        int jmin = splitZone->dimInfo.rmin[ 1 ] - 1;
+        int jmax = splitZone->dimInfo.rmax[ 1 ];
+        int ni = rootSplitZone->dimInfo.dimList[ 0 ];
+        int nj = rootSplitZone->dimInfo.dimList[ 1 ];
+        for ( int j = jmin; j < jmax; ++ j )
+        {
+            int jstride = j * ni;
+            for ( int i = imin; i < imax; ++ i )
+            {
+                xlocal[ icount++ ] = xglobal[ jstride + i ];
+            }
+        }
+    }
+}
+
+void Partition::DumpBc( SplitZone * splitZone )
+{
+}
+
+void Partition::DumpPartitionedGridFile()
+{
+    std::cout << "\n";
+    std::cout << "DumpPartitionedGridFile -------------------------------" << "\n";
+    std::cout << "\n";
+    int fileId = -1;
+    std::string filename = this->outName;
+    int ierr = cg_open( filename.c_str(), CG_MODE_WRITE, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+
+    std::vector<std::string> coordnames;
+    coordnames.push_back( "CoordinateX" );
+    coordnames.push_back( "CoordinateY" );
+    coordnames.push_back( "CoordinateZ" );
+
+    std::string basename = "Base";
+    int baseId = -1;
+    int icelldim = Global::cell_dim;
+    int iphysdim = Global::phys_dim;
+    cg_base_write( fileId, basename.c_str(), icelldim, iphysdim, &baseId );
+
+    std::cout << "baseId = " << baseId << "\n";
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        int nZones = this->GetNZones( iProc );
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            ZoneType_t zoneType = Structured;
+
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+
+            int index_dim = splitZone->dimInfo.dimList.size();
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            splitZone->dimInfo.ComputeISize();
+
+            int isize_dim = index_dim * 3;
+
+            std::vector<cgsize_t> isize( index_dim * 3, 0 );
+            for ( int m = 0; m < isize_dim; ++ m )
+            {
+                isize[ m ] = splitZone->dimInfo.isize[ m ];
+            }
+
+            int zoneId = -1;
+
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+
+            std::string zonename = "Zone" + std::to_string( splitZone->newIndex );
+
+            cg_zone_write( fileId, baseId, zonename.c_str(), isize.data(), zoneType, &zoneId );
+
+            std::cout << "zoneId = " << zoneId << "\n";
+            std::cout << "zonename = " << zonename << "\n";
+                
+            splitZone->ComputeRminmax();
+
+            SplitZone * rootSplitZone = splitZone->GetRootZone();
+
+            Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+            int ncoords = zone->coors.size();
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = -1;
+                DataType_t dataType = RealDouble;
+                std::string coordname = coordnames[ icoord ];
+                Coor * coor = zone->coors[ icoord ];
+
+                int nNodes = splitZone->dimInfo.ComputeNumNodes();
+                std::cout << "nNodes = " << nNodes << "\n";
+
+                std::vector<char> coord;
+                ComputeCoor( splitZone, icoord, coord );
+
+                cg_coord_write( fileId, baseId, zoneId, dataType, coordname.c_str(), coord.data(), &coorId );
+
+                std::cout << "fileId = " << fileId  << " baseId = " << baseId << " zoneId = " << zoneId  << " coorId = " << coorId << "\n";
+            }
+
+            std::vector< PhysicalSplitBc * > &bccoList = splitZone->physicalSplitBcList;
+
+            int nbocos = bccoList.size();
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = -1;
+                GridLocation_t location = Vertex;
+
+                std::string boconame = "BC" + std::to_string( iboco + 1 );
+
+                PhysicalSplitBc * physicalSplitBc = bccoList[ iboco ];
+                BCType_t bocotype = static_cast<BCType_t>( physicalSplitBc->bcType );
+                PointSetType_t ptset_type = PointRange;
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> pnts;
+                int nSize = physicalSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.end[ i ] );
+                }
+
+                cg_boco_write( fileId, baseId, zoneId, boconame.c_str(), bocotype, ptset_type, npnts, pnts.data(), & bccoId );
+            }
+
+            //std::vector< InterfaceSplitBc * > & bc1to1List = splitZone->interfaceSplitBcList;
+            std::vector< InterfaceSplitBc * > bc1to1List;
+            splitZone->GetLeafInterfaceBc( bc1to1List );
+
+            int n1to1 = bc1to1List.size();
+            std::cout << "n1to1 = " << n1to1 << "\n";
+
+            std::vector<int> itranfrm( index_dim );
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                itranfrm[ m ] = m + 1;
+            }
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int index_conn = -1;
+
+                InterfaceSplitBc * interfaceSplitBc = bc1to1List[ i1to1 ];
+
+                std::vector<cgsize_t> pnts;
+                std::vector<cgsize_t> pntsdonor;
+                int nSize = interfaceSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.end[ i ] );
+                }
+
+                int nPatchSize = interfaceSplitBc->donor_region.start.size();
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.start[ i ] );
+                }
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.end[ i ] );
+                }
+                int id = interfaceSplitBc->donor_zone->newIndex;
+                int oldZoneIndex = interfaceSplitBc->donor_zone->zoneIndex;
+                std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+                std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+                std::cout << "donor zone id = " << id << "\n";
+                std::cout << "donor zone oldZoneIndex = " << oldZoneIndex << "\n";
+                std::string donorname = "Zone" + std::to_string( id );
+                std::string connectname = "Interface" + std::to_string( i1to1 );
+
+                std::cout << "donorname = " << donorname << "\n";
+                std::cout << "connectname = " << connectname << "\n";
+
+                std::vector<int> & itranfrm = interfaceSplitBc->transform;
+
+                cg_1to1_write( fileId, baseId, zoneId, connectname.c_str(), donorname.c_str(), pnts.data(), pntsdonor.data(), itranfrm.data(), &index_conn );
+                std::cout << "index_conn = " << index_conn << "\n";
+            }
+        }
+    }
+    cg_close( fileId );
+}
+
+void Partition::ModifyZoneIndex()
+{
+    std::cout << "ModifyZoneIndex +++++++++++++++++++++++++ " << "\n";
+    int globalZoneId = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        std::cout << "iProc = " << iProc << "\n";
+        int nZones = this->GetNZones( iProc );
+        std::cout << "nZones in Proc " << iProc << "  = " << nZones << "\n";
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+            //splitZone->SetZoneIndex( globalZoneId++ );
+            splitZone->newIndex = ( globalZoneId++ );
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+        }
+    }
+}
\ No newline at end of file
diff --git a/example/partition/struct/1d/03/Partition.h b/example/partition/struct/1d/03/Partition.h
new file mode 100644
index 00000000..8a4a9731
--- /dev/null
+++ b/example/partition/struct/1d/03/Partition.h
@@ -0,0 +1,59 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class SplitZone;
+
+struct CmpSplitZone 
+{
+    bool operator() ( SplitZone * a, SplitZone * b ) const;
+};
+
+class Partition
+{
+public:
+    Partition();
+    ~Partition();
+protected:
+    std::set < SplitZone * > zoneStorage;
+    std::set < SplitZone *, CmpSplitZone > unsignedZoneGroup;
+    std::vector< SplitZone * > refZone;
+    std::vector< std::vector< SplitZone * > > procSplitZone;
+    std::vector<double> procSpeed;
+    std::vector<double> timeProc;
+    double aveFloatOp, delta;
+    double idealUniProcTime, eps;
+    int minNumberCell;
+    int nTZone;
+    int nOriZone;
+    int nProc;
+public:
+    std::string inputName;
+    std::string outName;
+public:
+    void Solve();
+    void ReadGrid();
+    void Split();
+    void InitSplit();
+    void BinarySplit();
+    //void GreedySplit();
+public:
+    void AddNewZone( SplitZone * zone );
+    void AddZoneToUnsignedGroup( SplitZone * zone );
+    void RemoveZoneFromUnsignedGroup( SplitZone * zone );
+    void AddZoneToProcess( int iProc, SplitZone * zone );
+    void DumpPartitionedGridFile();
+    void ModifyZoneIndex();
+    void FreeAllZones();
+    int GetNZones( int iProc );
+    SplitZone * GetSplitZone( int iProc, int zoneId );
+    void ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord );
+    void DumpBc( SplitZone * splitZone );
+private:
+    int GetMinValueIndex( double * data, int numberOfData );
+    int GetMinLoadProc();
+    SplitZone * GetLargestZone();
+    SplitZone * Split( SplitZone * zone, double nCell );
+};
+
diff --git a/example/partition/struct/1d/03/README.txt b/example/partition/struct/1d/03/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/partition/struct/1d/03/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/partition/struct/1d/03/SplitZone.cpp b/example/partition/struct/1d/03/SplitZone.cpp
new file mode 100644
index 00000000..aef70754
--- /dev/null
+++ b/example/partition/struct/1d/03/SplitZone.cpp
@@ -0,0 +1,1091 @@
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+int Dim::dim = -1;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox  )
+{
+    domainBox.start = zoneBox.start;
+    domainBox.end = zoneBox.end;
+
+    int axis = iDomain / 2;
+    int direction = iDomain % 2;
+
+    if ( direction == 0 )
+    {
+        domainBox.end[ axis ] = domainBox.start[ axis ];
+    }
+    else if ( direction == 1 )
+    {
+        domainBox.start[ axis ] = domainBox.end[ axis ];
+    }
+}
+
+DimInfo::DimInfo()
+{
+    this->Init( 1 );
+}
+
+DimInfo::~DimInfo()
+{
+}
+
+void DimInfo::Init( int dim )
+{
+    this->dim = dim;
+    dimList.resize( this->dim, 1 );
+    oriPoint.resize( this->dim, 0 );
+}
+
+DimInfo & DimInfo::operator = ( const DimInfo & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->dim = rhs.dim;
+    this->dimList = rhs.dimList;
+    this->oriPoint = rhs.oriPoint;
+
+    return * this;
+}
+
+int DimInfo::ComputeNumNodes()
+{
+    int nNodes = 1;
+    for ( int m = 0; m < this->dimList.size(); ++ m )
+    {
+        nNodes *= this->dimList[ m ];
+    }
+    return nNodes;
+}
+
+void DimInfo::ComputeISize()
+{
+    int index_dim = this->dimList.size();
+    this->isize.resize( index_dim * 3, 0 );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        isize[ m ] = this->dimList[ m ];
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 1;
+        isize[ start + m ] = this->dimList[ m ] - 1;
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 2;
+        isize[ start + m ] = 0;
+    }
+
+    for ( int i = 0; i < isize.size(); ++ i )
+    {
+        std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+    }
+}
+
+void DimInfo::ComputeRminmax( std::vector<int> & ref )
+{
+    int index_dim = this->dimList.size();
+    this->rmin.resize( index_dim );
+    this->rmax.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        rmin[ m ] = ref[ m ] + 1;
+        rmax[ m ] = ref[ m ] + this->dimList[ m ];
+    }
+
+    std::cout << "rmin, rmax = \n";
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        std::cout << rmin[ m ] << " " << rmax[ m ] << "\n";
+    }
+}
+
+void DimInfo::Init( std::vector<int> & dimList )
+{
+    this->dim = dimList.size();
+    this->dimList = dimList;
+    std::vector<int> zero( dimList.size(), 0 );
+    this->oriPoint = zero;
+}
+
+void DimInfo::SetNewDimension( int axis, int newStart, int newWidth )
+{
+    this->oriPoint[ axis ] = newStart;
+    this->dimList [ axis ] = newWidth;
+}
+
+void DimInfo::GetZoneGlobalBox( RangeRegion &zoneBox )
+{
+    int index_dim = this->dimList.size();
+    zoneBox.start.resize( index_dim );
+    zoneBox.end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        zoneBox.start[ m ] = this->oriPoint[ m ] + 1;
+        zoneBox.end[ m ] = this->oriPoint[ m ] + this->dimList[ m ];
+    }
+}
+
+void DimInfo::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    int index_dim = this->dimList.size();
+    localBox.start.resize( index_dim );
+    localBox.end.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        localBox.start[ m ] = globalBox.start[ m ] - this->oriPoint[ m ];
+        localBox.end[ m ] = globalBox.end[ m ] - this->oriPoint[ m ];
+    }
+}
+
+RangeRegion::RangeRegion( int nSize )
+{
+    this->Init( nSize );
+}
+
+RangeRegion::~RangeRegion()
+{
+}
+
+void RangeRegion::Init( int nSize )
+{
+    this->start.resize( nSize );
+    this->end.resize( nSize );
+}
+
+RangeRegion & RangeRegion::operator = ( const RangeRegion & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+bool RangeRegion::operator == ( const RangeRegion & rhs ) const
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] != rhs.start[ m ] || 
+            this->end  [ m ] != rhs.end  [ m ] )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+bool RangeRegion::InRegion( const RangeRegion & region )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( ( this->start[ m ] < region.start[ m ] ) || ( this->end[ m ] > region.end[ m ] ) )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::Normalize()
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        int minv = std::min( this->start[ m ], this->end[ m ] );
+        int maxv = std::max( this->start[ m ], this->end[ m ] );
+        this->start[ m ] = minv;
+        this->end[ m ] = maxv;
+    }
+}
+
+void RangeRegion::Localize( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] -= oriPoint[ m ];
+        this->end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void RangeRegion::ToGlobal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] += oriPoint[ m ];
+        this->end[ m ] += oriPoint[ m ];
+    }
+}
+
+void RangeRegion::ToLocal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] -= oriPoint[ m ];
+        this->end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void RangeRegion::PrintGlobal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    std::cout << "global start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ] + oriPoint[m];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "global end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ] + oriPoint[m];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+void RangeRegion::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion );
+
+bool ComputeOverlapRegion( RangeRegion & region1, RangeRegion & region2, RangeRegion & overlapRegion )
+{
+    int index_dim = region1.start.size();
+    overlapRegion.Init( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int ijkmin1 = std::min( region1.start[ m ], region1.end[ m ] );
+        int ijkmax1 = std::max( region1.start[ m ], region1.end[ m ] );
+        int ijkmin2 = std::min( region2.start[ m ], region2.end[ m ] );
+        int ijkmax2 = std::max( region2.start[ m ], region2.end[ m ] );
+        if ( ( ijkmax1 < ijkmin2 ) || ( ijkmin1 > ijkmax2 ) )
+        {
+            return false;
+        }
+
+        int ijkmin = std::max( ijkmin1, ijkmin2 );
+        int ijkmax = std::min( ijkmax1, ijkmax2 );
+
+        overlapRegion.start[ m ] = ijkmin;
+        overlapRegion.end  [ m ] = ijkmax;
+    }
+
+    return CheckOverLapping( overlapRegion );
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion )
+{
+    int index_dim = overlapRegion.start.size();
+    int iCount = 0;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        if ( overlapRegion.start[ m ] == overlapRegion.end[ m ] )
+        {
+            ++ iCount;
+        }
+    }
+
+    return ( iCount == 1 );
+}
+
+bool GetInterfaceRegion( RangeRegion & zoneBoxL, RangeRegion & zoneBoxR, RangeRegion & interfaceRegion )
+{
+    int index_dim = zoneBoxL.start.size();
+    int nDomains = 2 * index_dim;
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegionL;
+        GetDomainRegion( zoneBoxL, iDomain, domainRegionL );
+
+        for ( int jDomain = 0; jDomain < nDomains; ++ jDomain )
+        {
+            RangeRegion domainRegionR;
+            GetDomainRegion( zoneBoxR, jDomain, domainRegionR );
+
+            if ( domainRegionL == domainRegionR )
+            {
+                interfaceRegion = domainRegionL;
+                return true;
+            }
+        }
+    }
+    return false;
+}
+
+void CreateInterfaceBc( SplitZone * zoneL, SplitZone * zoneR )
+{
+    RangeRegion globalBoxL, globalBoxR, globalInterfaceRegion;
+
+    zoneL->GetZoneGlobalBox( globalBoxL );
+    zoneR->GetZoneGlobalBox( globalBoxR );
+
+    if ( ! GetInterfaceRegion( globalBoxL, globalBoxR, globalInterfaceRegion ) )
+    {
+        return;
+    }
+
+    RangeRegion localInterfaceRegionL, localInterfaceRegionR;
+
+    zoneL->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionL );
+    zoneR->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionR );
+
+    int kkk = 1;
+
+    InterfaceSplitBc * interfaceSplitBcL = new InterfaceSplitBc();
+    zoneL->interfaceSplitBcList.push_back( interfaceSplitBcL );
+    interfaceSplitBcL->zone = zoneL;
+    interfaceSplitBcL->region = localInterfaceRegionL;
+
+    int nSize = localInterfaceRegionL.start.size();
+
+    std::vector<int> transform;
+
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        transform.push_back( m + 1 );
+    }
+
+    interfaceSplitBcL->transform = transform;
+    interfaceSplitBcL->CalcTransformMatrix();
+
+    interfaceSplitBcL->donor_zone = zoneR;
+    interfaceSplitBcL->donor_region = localInterfaceRegionR;
+
+    InterfaceSplitBc * interfaceSplitBcR = new InterfaceSplitBc();
+    zoneR->interfaceSplitBcList.push_back( interfaceSplitBcR );
+
+    interfaceSplitBcR->zone = zoneR;
+    interfaceSplitBcR->region = localInterfaceRegionR;
+
+    interfaceSplitBcR->transform = transform;
+    interfaceSplitBcR->CalcTransformMatrix();
+
+    interfaceSplitBcR->donor_zone = zoneL;
+    interfaceSplitBcR->donor_region = localInterfaceRegionL;
+}
+
+
+PhysicalSplitBc::PhysicalSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+PhysicalSplitBc::~PhysicalSplitBc()
+{
+}
+
+void PhysicalSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void PhysicalSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+void PhysicalSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = splitZone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+BasicSplitBc::BasicSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+BasicSplitBc::~BasicSplitBc()
+{
+    ;
+}
+
+void BasicSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void BasicSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+int trans::M[ 3 ][ 3 ];
+std::vector<int> trans::transform;
+
+int trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void trans::CalcTransformMatrix()
+{
+    int dim = trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = trans::transform[ 0 ];
+        int sgna = trans::sgn( a );
+        int a1 = trans::del( a, 1 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int c = trans::transform[ 2 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int sgnc = trans::sgn( c );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int a3 = trans::del( a, 3 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        int b3 = trans::del( b, 3 );
+        int c1 = trans::del( c, 1 );
+        int c2 = trans::del( c, 2 );
+        int c3 = trans::del( c, 3 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 2 ][ 0 ] = sgna * a3;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+        trans::M[ 2 ][ 1 ] = sgnb * b3;
+        trans::M[ 0 ][ 2 ] = sgnc * c1;
+        trans::M[ 1 ][ 2 ] = sgnc * c2;
+        trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+InterfaceInfo::InterfaceInfo()
+{
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceInfo::~InterfaceInfo()
+{
+}
+
+InterfaceSplitBc::InterfaceSplitBc()
+{
+    this->region.Init( Dim::dim );
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceSplitBc::~InterfaceSplitBc()
+{
+}
+
+void InterfaceSplitBc::GetLeafInterfaceBc( std::vector< InterfaceSplitBc * > & leafInterfaceBcList )
+{
+    int nChild = this->child.size();
+    if ( nChild == 0 )
+    {
+        leafInterfaceBcList.push_back( this );
+    }
+    else
+    {
+        for ( int iChild = 0; iChild < nChild; ++ iChild )
+        {
+            InterfaceSplitBc * interfaceSplitBc = this->child[ iChild ];
+            interfaceSplitBc->GetLeafInterfaceBc( leafInterfaceBcList );
+        }
+    }
+}
+
+void InterfaceSplitBc::CopyMatrix( InterfaceSplitBc * interfaceSplitBc )
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = interfaceSplitBc->Mt[ i ][ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::CalcTransformMatrix()
+{
+    trans::ZeroMatrix();
+    trans::transform = this->transform;
+    trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = trans::M[ i ][ j ];
+        }
+    }
+
+}
+
+void InterfaceSplitBc::mapindex( std::vector<int> & begin1, std::vector<int> & begin2,  std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = Dim::dim;
+    std::vector<int> diff( dim );
+    for ( int m = 0; m < dim; ++ m )
+    {
+        diff[ m ] = index1[ m ] - begin1[ m ];
+    }
+
+    std::vector<int> mul( dim );
+
+    Multiply( Mt, diff, mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = mul[ m ] + begin2[ m ];
+    }
+}
+
+void InterfaceSplitBc::Multiply( int Mt[][3], std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = Dim::dim;
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = this->zone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void InterfaceSplitBc::CalcSubDonorRegion( RangeRegion &subRegion, RangeRegion &subDonorRegion )
+{
+    std::vector<int> begin1 = this->region.start;
+    std::vector<int> end1 = this->region.end;
+    std::vector<int> begin2 = this->donor_region.start;
+    std::vector<int> end2 = this->donor_region.end;
+
+    std::vector<int> new_begin1 = subRegion.start;
+    std::vector<int> new_end1 = subRegion.end;
+
+    int dim = Dim::dim;
+    std::vector<int> new_begin2( dim );
+    std::vector<int> new_end2( dim );
+
+    mapindex( begin1, begin2, new_begin1, new_begin2 );
+    mapindex( begin1, begin2, new_end1, new_end2 );
+
+    subDonorRegion.start = new_begin2;
+    subDonorRegion.end = new_end2;
+}
+
+SplitZone::SplitZone()
+{
+    this->parent  = 0;
+    this->zoneIndex = 0;
+    this->iProc = 0;
+    dimInfo.Init( Dim::dim );
+    int kk = 1;
+}
+
+SplitZone::~SplitZone()
+{
+    ;
+}
+
+void SplitZone::GetZoneGlobalBox( RangeRegion & zoneBox )
+{
+    this->dimInfo.GetZoneGlobalBox( zoneBox );
+}
+
+void SplitZone::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    this->dimInfo.GetZoneLocalBox( globalBox, localBox );
+}
+
+
+void SplitZone::ComputeRminmax()
+{
+    int index_dim = this->dimInfo.dimList.size();
+    std::vector<int> ref( index_dim, 0 );
+
+    SplitZone * rootSplitZone = 0;
+    this->GetRootInfo( rootSplitZone, ref );
+
+    this->dimInfo.ComputeRminmax( ref );
+}
+
+SplitZone * SplitZone::GetRootZone()
+{
+    SplitZone * root = this;
+
+    while ( true )
+    {
+        if ( root->parent )
+        {
+            root = root->parent;
+        }
+        else
+        {
+            return root;
+        }
+    };
+}
+
+void SplitZone::GetRootInfo( SplitZone *& root, std::vector<int> & ref )
+{
+    for ( int i = 0; i < this->dimInfo.dimList.size(); ++ i )
+    {
+        ref[ i ] += this->dimInfo.oriPoint[ i ];
+    }
+
+    if ( this->parent )
+    {
+        this->parent->GetRootInfo( root, ref );
+    }
+    else
+    {
+        root = this;
+    }
+}
+
+void SplitZone::SetParentAndChild( SplitZone * parent )
+{
+    this->parent = parent;
+    if ( parent )
+    {
+        parent->child.push_back( this );
+    }
+}
+
+void SplitZone::GetLeafInterfaceBc( std::vector< InterfaceSplitBc * > & leafInterfaceBcList )
+{
+    int nInterfaceBcs = this->interfaceSplitBcList.size();
+    for ( int i = 0; i < nInterfaceBcs; ++ i )
+    {
+        InterfaceSplitBc * interfaceSplitBc = this->interfaceSplitBcList[ i ];
+        interfaceSplitBc->GetLeafInterfaceBc( leafInterfaceBcList );
+    }
+}
+
+int SplitZone::GetNCell()
+{
+    int numberOfCells = 1;
+    for ( int i = 0; i < this->dimInfo.dim; ++ i )
+    {
+        numberOfCells *= std::max( 1, ( this->dimInfo.dimList[ i ] - 1 ) );
+    }
+
+    return numberOfCells; 
+}
+
+void SplitZone::SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int leftStart = 0;
+    int leftWidth = iSplit - 0;
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, leftStart , leftWidth  );
+}
+
+void SplitZone::SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int rightStart = iSplit - 1;
+    int rightWidth = dimList[ axisNeedSplit ] - ( iSplit - 1 );
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, rightStart, rightWidth );
+}
+
+void SplitZone::Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell )
+{
+    //Find the longest axis
+    int axisNeedSplit = this->FindAxisNeedSplit();
+    int iSplit        = this->FindSplitPosition( axisNeedSplit, nCell );
+
+    zoneL->SetLeftDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+    zoneR->SetRightDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+
+    zoneL->CreateBcFromParent();
+    zoneR->CreateBcFromParent();
+    
+    CreateInterfaceBc( zoneL, zoneR );
+}
+
+void SplitZone::CreateBcFromParent()
+{
+    this->CreatePhysicalBcFromParent();
+    this->CreateInterfaceBcFromParent();
+}
+
+void SplitZone::CreatePhysicalBcFromParent()
+{
+    int nParentPhysicalBcs = this->parent->physicalSplitBcList.size();
+
+    for ( int iParentPhysicalBcs = 0; iParentPhysicalBcs < nParentPhysicalBcs; ++ iParentPhysicalBcs )
+    {
+        PhysicalSplitBc * parentPhysicalSplitBc = this->parent->physicalSplitBcList[ iParentPhysicalBcs ];
+
+        this->CreatePhysicalBcFromParent( parentPhysicalSplitBc );
+    }
+}
+
+void SplitZone::CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentPhysicalSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreatePhysicalBc( overlapRegion, parentPhysicalSplitBc->bcType );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent()
+{
+    int nInterfaceSplitBcs = this->parent->interfaceSplitBcList.size();
+
+    for ( int iInterfaceSplitBcs = 0; iInterfaceSplitBcs < nInterfaceSplitBcs; ++ iInterfaceSplitBcs )
+    {
+        InterfaceSplitBc * parentInterfaceSplitBc = this->parent->interfaceSplitBcList[ iInterfaceSplitBcs ];
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc );
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentInterfaceSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc, overlapRegion );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::FindDonorInterface( InterfaceSplitBc * interfaceSplitBc, InterfaceInfo & interfaceInfo )
+{
+    RangeRegion donor_region = interfaceSplitBc->donor_region;
+    donor_region.Normalize();
+    interfaceInfo.donor_zone = this;
+    for ( int iInterface = 0; iInterface < interfaceSplitBcList.size(); ++ iInterface )
+    {
+        InterfaceSplitBc * candidateDonorBc = interfaceSplitBcList[ iInterface ];
+        bool flag = donor_region.InRegion( candidateDonorBc->region );
+        if ( flag )
+        {
+            if ( donor_region == candidateDonorBc->region )
+            {
+                interfaceInfo.donor_interface = candidateDonorBc;
+                return;
+            }
+            else
+            {
+                InterfaceSplitBc * donorBc = new InterfaceSplitBc();
+                candidateDonorBc->child.push_back( donorBc );
+                donorBc->region = donor_region;
+                donorBc->zone = candidateDonorBc->zone;
+                donorBc->donor_zone = interfaceSplitBc->zone;
+                donorBc->transform = candidateDonorBc->transform;
+                donorBc->CopyMatrix( candidateDonorBc );
+                RangeRegion subDonorRegion( Dim::dim );
+                candidateDonorBc->CalcSubDonorRegion( donorBc->region, subDonorRegion );
+                std::vector<int> & oriPoint = interfaceSplitBc->zone->dimInfo.oriPoint;
+                subDonorRegion.Localize( oriPoint );
+                donorBc->donor_region = subDonorRegion;
+                donorBc->donor_bc = interfaceSplitBc;
+                interfaceInfo.donor_interface = donorBc;
+                return;
+            }
+        }
+    }
+    return;
+}
+
+void SplitZone::GetChildDonorRegion( RangeRegion & subDonorRegion, InterfaceInfo & interfaceInfo )
+{
+    std::cout << "subDonorRegion = \n";
+    //subDonorRegion.Print();
+    RangeRegion normalizedDonorRegion = subDonorRegion;
+    normalizedDonorRegion.Normalize();
+    int nChild = this->child.size();
+    for ( int ichild = 0; ichild < nChild; ++ ichild )
+    {
+        std::cout << " iChild = " << ichild << " nChild = " << nChild << "\n";
+        SplitZone * sub_zone = this->child[ ichild ];
+        std::cout << " zoneIndex = " << sub_zone->zoneIndex << "\n";
+        int nInters = sub_zone->interfaceSplitBcList.size();
+        for ( int iInter = 0; iInter < nInters; ++ iInter )
+        {
+            std::cout << " iInter = " << iInter << "\n";
+            InterfaceSplitBc * interfaceSplitBc = sub_zone->interfaceSplitBcList[ iInter ];
+            std::cout << "interfaceSplitBc local = \n";
+            interfaceSplitBc->region.Print();
+            std::cout << "interfaceSplitBc global = \n";
+            interfaceSplitBc->region.PrintGlobal( sub_zone->dimInfo.oriPoint );
+            RangeRegion g_region = interfaceSplitBc->region;
+            g_region.ToGlobal( sub_zone->dimInfo.oriPoint );
+            if ( g_region == normalizedDonorRegion )
+            {
+                RangeRegion donorRegion = subDonorRegion;
+                donorRegion.ToLocal( sub_zone->dimInfo.oriPoint );
+
+                interfaceInfo.donor_zone = sub_zone;
+                interfaceInfo.donor_interface = interfaceSplitBc;
+                interfaceInfo.donor_region = donorRegion;
+                return;
+            }
+        }
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion )
+{
+    InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+    this->interfaceSplitBcList.push_back( interfaceSplitBc );
+
+    interfaceSplitBc->region = overlapRegion;
+    interfaceSplitBc->zone = this;
+    interfaceSplitBc->transform = parentInterfaceSplitBc->transform;
+    interfaceSplitBc->CopyMatrix( parentInterfaceSplitBc );
+    RangeRegion subDonorRegion( Dim::dim );
+    parentInterfaceSplitBc->CalcSubDonorRegion( overlapRegion, subDonorRegion );
+    interfaceSplitBc->ChangeRegionToLocalCoordinate();
+    interfaceSplitBc->donor_region = subDonorRegion;
+    SplitZone * parent_donor_zone = parentInterfaceSplitBc->donor_zone;
+    std::cout << " parentInterfaceSplitBc->zone->zoneIndex " << parentInterfaceSplitBc->zone->zoneIndex << "\n";
+    std::cout << " parentInterfaceSplitBc->donor_zone->zoneIndex " << parent_donor_zone->zoneIndex << "\n";
+    if ( parent_donor_zone->child.size() > 0 )
+    {
+        InterfaceInfo interfaceInfo;
+        parent_donor_zone->GetChildDonorRegion( subDonorRegion, interfaceInfo );
+        interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+        interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+        interfaceSplitBc->donor_region = interfaceInfo.donor_region;
+        //compatibility
+        InterfaceSplitBc * donor_bc = interfaceSplitBc->donor_bc;
+        SplitZone * donor_zone = interfaceSplitBc->donor_zone;
+        if ( interfaceSplitBc->zone != donor_bc->donor_zone )
+        {
+            if ( interfaceSplitBc->zone->parent == donor_bc->donor_zone )
+            {
+                RangeRegion d_region = donor_bc->donor_region;
+                d_region.ToLocal( interfaceSplitBc->zone->dimInfo.oriPoint );
+                donor_bc->donor_region = d_region;
+            }
+            donor_bc->donor_zone = interfaceSplitBc->zone;
+         
+            int kkk = 1;
+        }
+        int kkk = 1;
+    }
+    else
+    {
+        InterfaceInfo interfaceInfo;
+        parent_donor_zone->FindDonorInterface( interfaceSplitBc, interfaceInfo );
+        interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+        interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+    }
+    
+    int kkk = 1;
+}
+
+void SplitZone::CreatePhysicalBc( RangeRegion & overlapRegion, int bcType )
+{
+    PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+    this->physicalSplitBcList.push_back( physicalSplitBc );
+    physicalSplitBc->SetRegion( overlapRegion );
+    physicalSplitBc->bcType = bcType;
+    physicalSplitBc->splitZone = this;
+    physicalSplitBc->ChangeRegionToLocalCoordinate();
+}
+
+int SplitZone::FindAxisNeedSplit()
+{
+    //Find the longest axis
+    int axisNeedSplit = 0;
+    int maxN = this->dimInfo.dimList[ 0 ];
+
+    for ( int m = 1; m < this->dimInfo.dimList.size(); ++ m )
+    {
+        if ( this->IsPoleBc( m ) )
+        {
+            continue;
+        }
+        int Nm = this->dimInfo.dimList[ m ];
+        if ( maxN < Nm )
+        {
+            maxN = Nm;
+            axisNeedSplit = m;
+        }
+    }
+
+    return axisNeedSplit;
+}
+
+int SplitZone::GetCrossSection( int axis )
+{
+    int nDim = this->dimInfo.dimList.size();
+    int crossSection = 1;
+    int N = nDim - 1;
+    for ( int m = 0; m < N; ++ m )
+    {
+         int mm = ( axis + 1 ) % nDim;
+         int nLineElements = std::max( 1, ( this->dimInfo.dimList[ mm ] - 1 ) );
+         crossSection *= nLineElements;
+    }
+    return crossSection;
+}
+
+int SplitZone::FindSplitPosition( int axisNeedSplit, double nCell )
+{
+    int nDim = this->dimInfo.dimList.size();
+    std::vector<int> crossSections( nDim );
+    for ( int m = 0; m < nDim; ++ m )
+    {
+        crossSections[ m ] = this->GetCrossSection( m );
+    }
+
+    //guess the value
+    double dSplit = nCell / crossSections[ axisNeedSplit ];
+    int  iSplit = 1 + static_cast< int >( std::floor( dSplit + 0.5 ) );
+    return iSplit;
+}
+
+
+bool SplitZone::IsPoleBc( int splitDirection )
+{
+    return false;
+}
+
diff --git a/example/partition/struct/1d/03/SplitZone.h b/example/partition/struct/1d/03/SplitZone.h
new file mode 100644
index 00000000..ffe1e306
--- /dev/null
+++ b/example/partition/struct/1d/03/SplitZone.h
@@ -0,0 +1,196 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class Dim
+{
+public:
+    static int dim;
+};
+
+class SplitZone;
+class RangeRegion;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox );
+
+class DimInfo
+{
+public:
+    DimInfo();
+    ~DimInfo();
+public:
+    int dim;
+    std::vector<int> dimList;
+    std::vector<int> oriPoint;
+    std::vector<int> isize;
+    std::vector<int> rmin;
+    std::vector<int> rmax;
+public:
+    int GetSize() const { return dim; }
+    DimInfo & operator = ( const DimInfo & rhs );
+public:
+    int ComputeNumNodes();
+    void ComputeISize();
+    void ComputeRminmax( std::vector<int> & ref );
+    void Init( int dim );
+    void Init( std::vector<int> & dimList );
+    void SetNewDimension( int axis, int newStart, int newWidth );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+};
+
+class SplitZone;
+class SplitBcPatch;
+
+class RangeRegion
+{
+public:
+    RangeRegion( int nSize = 1 );
+    ~RangeRegion();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    void Init( int nSize );
+    RangeRegion & operator = ( const RangeRegion & rhs );
+    bool operator == ( const RangeRegion & rhs ) const;
+    bool InRegion( const RangeRegion & region );
+    void SetRegion( std::vector<int> &pnts );
+    void Normalize();
+    void Localize( std::vector<int> & oriPoint );
+    void ToGlobal( std::vector<int> & oriPoint );
+    void ToLocal( std::vector<int> & oriPoint );
+    void PrintGlobal( std::vector<int> & oriPoint );
+    void Print();
+};
+
+class PhysicalSplitBc
+{
+public:
+    PhysicalSplitBc();
+    ~PhysicalSplitBc();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class BasicSplitBc
+{
+public:
+    BasicSplitBc();
+    ~BasicSplitBc();
+public:
+    RangeRegion region;
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> & pnts );
+    void SetRegion( RangeRegion & region );
+};
+
+class trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class InterfaceSplitBc;
+class SplitZone;
+
+class InterfaceInfo
+{
+public:
+    InterfaceInfo();
+    ~InterfaceInfo();
+public:
+    InterfaceSplitBc * donor_interface = nullptr;
+    SplitZone * donor_zone = nullptr;
+    RangeRegion donor_region;
+};
+
+class InterfaceSplitBc
+{
+public:
+    InterfaceSplitBc();
+    ~InterfaceSplitBc();
+public:
+    std::vector<int> transform;
+    int Mt[ 3 ][ 3 ];
+    RangeRegion region;
+    SplitZone * zone = nullptr;
+    RangeRegion donor_region;
+    SplitZone * donor_zone = nullptr;
+    InterfaceSplitBc * donor_bc = nullptr;
+public:
+    std::vector<InterfaceSplitBc *> child;
+    void GetLeafInterfaceBc( std::vector< InterfaceSplitBc * > & leafInterfaceBcList );
+public:
+    void CopyMatrix( InterfaceSplitBc * interfaceSplitBc );
+    void CalcTransformMatrix();
+    void CalcSubDonorRegion( RangeRegion & subRegion, RangeRegion & subDonorRegion );
+    void mapindex( std::vector<int> & begin1, std::vector<int> & begin2, std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( int Mt[][ 3 ], std::vector<int> & a, std::vector<int> & b );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class SplitZone
+{
+public:
+    SplitZone();
+    ~SplitZone();
+public:
+    DimInfo dimInfo;
+    int zoneIndex, iProc;
+    int newIndex;
+protected:
+    SplitZone * parent;
+    std::vector<SplitZone *> child;
+public:
+    std::vector< PhysicalSplitBc * > physicalSplitBcList;
+    std::vector< InterfaceSplitBc * > interfaceSplitBcList;
+    void GetLeafInterfaceBc( std::vector< InterfaceSplitBc * > & leafInterfaceBcList );
+public:
+    int GetNCell();
+    void ComputeRminmax();
+    void GetRootInfo( SplitZone *& root, std::vector<int> & ref );
+    void SetZoneIndex( int zoneIndex ) { this->zoneIndex = zoneIndex; }
+    int  GetZoneIndex() { return zoneIndex; }
+    void SetProcId( int iProc ) { this->iProc = iProc; }
+    void SetParent( SplitZone * parent ) { this->parent = parent; };
+    void SetParentAndChild( SplitZone * parent );
+    void FindDonorInterface( InterfaceSplitBc * interfaceSplitBc, InterfaceInfo & interfaceInfo );
+    void GetChildDonorRegion( RangeRegion & subDonorRegion, InterfaceInfo & interfaceInfo );
+public:
+    void CreateBcFromParent();
+    void CreatePhysicalBcFromParent();
+    void CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc );
+    void CreatePhysicalBc( RangeRegion & overlapRegion, int bcType );
+    void CreateInterfaceBcFromParent();
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc );
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion );
+
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+    SplitZone * GetRootZone();
+public:
+    void Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell );
+    void SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+    void SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+private:
+    int FindAxisNeedSplit();
+    int FindSplitPosition( int axisNeedSplit, double nCell );
+    bool IsPoleBc( int splitDirection );
+    int GetCrossSection( int axis );
+};
+
diff --git a/example/partition/struct/1d/03/heat1d2blocksv2.cgns b/example/partition/struct/1d/03/heat1d2blocksv2.cgns
new file mode 100644
index 00000000..de6cfb78
Binary files /dev/null and b/example/partition/struct/1d/03/heat1d2blocksv2.cgns differ
diff --git a/example/partition/struct/1d/03/heat1dpart.cgns b/example/partition/struct/1d/03/heat1dpart.cgns
new file mode 100644
index 00000000..cd6c8473
Binary files /dev/null and b/example/partition/struct/1d/03/heat1dpart.cgns differ
diff --git a/example/partition/struct/1d/03/main.cpp b/example/partition/struct/1d/03/main.cpp
new file mode 100644
index 00000000..5da1de7c
--- /dev/null
+++ b/example/partition/struct/1d/03/main.cpp
@@ -0,0 +1,18 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include "Partition.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip>
+
+int main(int argc, char **argv)
+{
+    Partition * partition = new Partition();
+    partition->Solve();
+    delete partition;
+
+    return 0;
+}
diff --git a/example/partition/struct/1d/1to4blocks/01/CMakeLists.txt b/example/partition/struct/1d/1to4blocks/01/CMakeLists.txt
new file mode 100644
index 00000000..74ceea7d
--- /dev/null
+++ b/example/partition/struct/1d/1to4blocks/01/CMakeLists.txt
@@ -0,0 +1,78 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	Partition.h Partition.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	SplitZone.h SplitZone.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/partition/struct/1d/1to4blocks/01/CgnsGrid.cpp b/example/partition/struct/1d/1to4blocks/01/CgnsGrid.cpp
new file mode 100644
index 00000000..dfe750bd
--- /dev/null
+++ b/example/partition/struct/1d/1to4blocks/01/CgnsGrid.cpp
@@ -0,0 +1,349 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include <map>
+
+Grid::Grid()
+{
+    ;
+}
+
+Grid::~Grid()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if( (i+1)%5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+    delete this->patch;
+}
+
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+ZoneBcPatch::ZoneBcPatch()
+{
+    ;
+}
+
+ZoneBcPatch::~ZoneBcPatch()
+{
+}
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+Global::Global()
+{
+    ;
+}
+
+Global::~Global()
+{
+}
+
+void Global::FreeData()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+    zones.resize( 0 );
+}
+
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            //baseZone.baseId = baseId;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin( index_dim );
+            std::vector<cgsize_t> irmax( index_dim );
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                std::vector<char> coord( nNodes * sizeof(double) );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+                coor->DumpCoor();
+            }
+
+            int nbocos = -1;
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+                int kkk = 1;
+            }
+        }
+        int kkk = 1;
+    }
+    int kkk = 1;
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/partition/struct/1d/1to4blocks/01/CgnsGrid.h b/example/partition/struct/1d/1to4blocks/01/CgnsGrid.h
new file mode 100644
index 00000000..053c467b
--- /dev/null
+++ b/example/partition/struct/1d/1to4blocks/01/CgnsGrid.h
@@ -0,0 +1,140 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <map>
+
+class Grid;
+
+class Zone;
+
+class Grid
+{
+public:
+    Grid();
+    ~Grid();
+public:
+    int nZone;
+    std::vector<double> x;
+    std::vector<Zone *> zones;
+};
+
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+};
+
+class ZoneBc;
+class ZoneBc1To1;
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class ZoneBcPatch;
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+    ZoneBcPatch * patch = nullptr;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+class ZoneBcPatch
+{
+public:
+    ZoneBcPatch();
+    ~ZoneBcPatch();
+public:
+    int donor_zoneid;
+    std::vector<int> transform;
+    std::vector<int> donor_pnts;
+};
+
+class BaseZone
+{
+public:
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Global
+{
+public:
+    Global();
+    ~Global();
+public:
+    static int cell_dim;
+    static int phys_dim;
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+public:
+    static void FreeData();
+};
+
+void ReadCgnsGrid( const std::string & filename );
+void ReadCgnsGridBaseZone( const std::string & filename );
\ No newline at end of file
diff --git a/example/partition/struct/1d/1to4blocks/01/Partition.cpp b/example/partition/struct/1d/1to4blocks/01/Partition.cpp
new file mode 100644
index 00000000..c262d5dc
--- /dev/null
+++ b/example/partition/struct/1d/1to4blocks/01/Partition.cpp
@@ -0,0 +1,619 @@
+#include "Partition.h"
+#include "CgnsGrid.h"
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+bool CmpSplitZone::operator() ( SplitZone * a, SplitZone * b ) const
+{
+    return a->zoneIndex < b->zoneIndex;
+};
+
+
+double CalSumOfProcSpeed( std::vector<double> & procSpeed );
+double CalSumOfProcSpeed( std::vector<double> & procSpeed )
+{
+    int nProc = procSpeed.size();
+    double sumOfProcSpeed = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        sumOfProcSpeed += procSpeed[ iProc ];
+    }
+    return sumOfProcSpeed;
+}
+
+Partition::Partition()
+{
+    this->inputName = "../heat1d1blocksv1.cgns";
+    this->outName =  "../heat1dpart.cgns";
+}
+
+Partition::~Partition()
+{
+    ;
+}
+
+int Partition::GetMinValueIndex( double * data, int numberOfData )
+{
+    double minValue = data[ 0 ];
+    int minimumValueIndex = 0;
+
+    for ( int iData = 1; iData < numberOfData; ++ iData )
+    {
+        if ( minValue > data[ iData ] )
+        {
+            minValue      = data[ iData ];
+            minimumValueIndex = iData;
+        }
+    }
+    return minimumValueIndex;
+}
+
+int Partition::GetMinLoadProc()
+{
+    return this->GetMinValueIndex( this->timeProc.data(), this->nProc );
+}
+
+SplitZone * Partition::GetLargestZone()
+{
+    SplitZone * largestZone = 0;
+
+    double nMaxCell = 0.0;
+
+    for ( std::set< SplitZone * >::iterator iter = unsignedZoneGroup.begin(); iter != unsignedZoneGroup.end(); ++ iter )
+    {
+        double nSize = ( * iter )->GetNCell();
+        if ( nMaxCell < nSize )
+        {
+            nMaxCell    = nSize;
+            largestZone = * iter;
+        }
+    }
+
+    return largestZone;
+}
+
+void Partition::Solve()
+{
+    std::cout << "Partition::Split()\n";
+    this->nProc = 4;
+    this->ReadGrid();
+    this->Split();
+    this->DumpPartitionedGridFile();
+    this->FreeAllZones();
+}
+
+void Partition::ReadGrid()
+{
+    ReadCgnsGridBaseZone( this->inputName );
+    ReadCgnsGrid( this->inputName );
+
+    this->nOriZone = ::Global::zones.size();
+    Dim::dim = Global::cell_dim;
+
+    std::cout << "numberOfBlocks = " << nOriZone << "\n";
+
+    this->refZone.resize( nOriZone );
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = new SplitZone();
+        refZone[ iZone ] = splitZone;
+
+        splitZone->SetZoneIndex( iZone );
+        splitZone->SetProcId( 0 );
+        splitZone->SetParentAndChild( 0 );
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        Zone * zone = ::Global::zones[ iZone ];
+
+        splitZone->dimInfo.dimList = zone->nijk;
+
+        int nbccos = zone->bccos.size();
+        std::cout << "nbccos = " << nbccos << "\n";
+
+        for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+        {
+            ZoneBc * zoneBc = zone->bccos[ ibcco ];
+
+            PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+            splitZone->physicalSplitBcList.push_back( physicalSplitBc );
+            physicalSplitBc->bcType = zoneBc->bcType;
+            physicalSplitBc->SetRegion( zoneBc->pnts );
+            physicalSplitBc->splitZone = splitZone;
+        }
+
+        int nbc1to1s = zone->bc1to1s.size();
+
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * zoneBc1To1 = zone->bc1to1s[ ibc1to1 ];
+
+            InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+            splitZone->interfaceSplitBcList.push_back( interfaceSplitBc );
+            interfaceSplitBc->zone = splitZone;
+            interfaceSplitBc->region.SetRegion( zoneBc1To1->pnts );
+
+            interfaceSplitBc->transform = zoneBc1To1->transform;
+            interfaceSplitBc->CalcTransformMatrix();
+
+            interfaceSplitBc->donor_zone = refZone[ zoneBc1To1->donor_zoneid ];
+            interfaceSplitBc->donor_region.SetRegion( zoneBc1To1->donor_pnts );
+        }
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        int nbc1to1s = splitZone->interfaceSplitBcList.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            InterfaceSplitBc * interfaceSplitBc = splitZone->interfaceSplitBcList[ ibc1to1 ];
+            InterfaceInfo interfaceInfo;
+            interfaceSplitBc->donor_zone->FindDonorInterface( interfaceSplitBc, interfaceInfo );
+            interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+            interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+        }
+    }
+}
+
+void Partition::Split()
+{
+    this->InitSplit();
+    this->BinarySplit();
+    this->ModifyZoneIndex();
+    int kkk = 1;
+}
+
+void Partition::InitSplit()
+{
+    //nZone is the number of zones in the original grid
+    //nProc is not the number of blocks in the end, but the number of processes that need to be divided.
+    //This difference occurs because the structure grid can have many blocks per process.
+
+    //this->nProc    = nProc;
+    //this->nPhyBlocks = referenceBlock.size();
+    //this->nZone  = this->nPhyBlocks;
+
+    //tj Computation time on processor j
+    //Nk Number of internal grid-cells for zone j
+    //aveFloatOp:  Number of Real operations per gridcell
+    //Gj The set of blocks allocated to process j
+    //Pj Real operations per second for process j
+
+    //The Greedy Load Balancing Algorithm
+    //1.Compute an "ideal" uniprocessor time, Tuni = sum ( Nk * aveFloatOp )/ sum( Pj ).
+    //2.Set the group of unassigned blocks, Gu, to contain all blocks. The number of blocks in Nu=M, where M is the total number of blocks in the mesh.
+    //3.Start all processors with a very small fictitious zone to get a start tj=delt aveFloatOp/Pj, where delt<<1 is the size of the very small fictious zone.
+    //This is used to find the fastest processor in a heterogeneous system, tj could otherwise be set to 0 in the homogeneous case.
+    this->aveFloatOp = 1.0;
+    this->delta      = 1.0e-5;
+    this->procSpeed.resize( nProc );
+    this->timeProc.resize( nProc );
+
+    this->nTZone = this->nOriZone;
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        procSpeed[ iProc ] = 1.0;
+    }
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        timeProc[ iProc ] = delta * aveFloatOp / procSpeed[ iProc ];
+    }
+
+    double sumProcSpeed = CalSumOfProcSpeed( procSpeed );
+
+    double sumProcOp = 0.0;
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        sumProcOp += refZone[ iZone ]->GetNCell() * aveFloatOp;
+    }
+
+    this->idealUniProcTime = sumProcOp / sumProcSpeed;
+
+    this->eps = 0.05;
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        unsignedZoneGroup.insert( refZone[ iZone ] );
+    }
+
+    //Init zoneStorage
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        zoneStorage.insert( refZone[ iZone ] );
+    }
+
+    //Assign procSplitZone to each process
+    procSplitZone.resize( nProc );
+
+    this->minNumberCell = 1;
+    for ( int m = 0; m < Dim::dim; ++ m )
+    {
+        this->minNumberCell *= 1;
+    }
+
+    int kkk = 1;
+
+}
+
+void Partition::FreeAllZones()
+{
+    int iCount = 0;
+    for ( std::set < SplitZone * >::iterator iter = zoneStorage.begin(); iter != zoneStorage.end(); ++ iter )
+    {
+        //cout << "iCount = " << iCount << "\n";
+        ++ iCount;
+        delete * iter;
+    }
+}
+
+int Partition::GetNZones( int iProc )
+{
+    return this->procSplitZone[ iProc ].size();
+}
+
+SplitZone * Partition::GetSplitZone( int iProc, int zoneId )
+{
+    return this->procSplitZone[ iProc ][ zoneId ];
+}
+
+void Partition::AddZoneToUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.insert( zone );
+}
+
+void Partition::RemoveZoneFromUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.erase( zone );
+}
+
+void Partition::AddZoneToProcess( int iProc, SplitZone * zone )
+{
+    this->procSplitZone[ iProc ].push_back( zone );
+}
+
+void Partition::AddNewZone( SplitZone * zone )
+{
+    zone->SetZoneIndex( nTZone ++ );
+
+    this->AddZoneToUnsignedGroup( zone );
+
+    this->zoneStorage.insert( zone );
+}
+
+SplitZone * Partition::Split( SplitZone * zone, double nCell )
+{
+    SplitZone * zoneL = new SplitZone();
+    zoneL->SetParentAndChild( zone );
+
+    SplitZone * zoneR = new SplitZone();
+    zoneR->SetParentAndChild( zone );
+
+    //Remove the original block from the UnsignedGroup
+    this->RemoveZoneFromUnsignedGroup( zone );
+
+    this->AddNewZone( zoneL );
+    this->AddNewZone( zoneR );
+
+    zone->Split( zoneL, zoneR, nCell );
+
+    return zoneL;
+}
+
+void Partition::BinarySplit()
+{
+    while ( ! unsignedZoneGroup.empty() )
+    {
+        std::cout << "number of unsigned zone = " << unsignedZoneGroup.size() << "\n";
+        int iProc = this->GetMinLoadProc();
+
+        //Get the block with the largest number of grids and its size
+        SplitZone * largestZone = this->GetLargestZone();
+
+        double nMaxCell = largestZone->GetNCell();
+
+        double aveFloatOp = this->aveFloatOp;
+        double tau = timeProc[ iProc ] + nMaxCell * aveFloatOp / procSpeed[ iProc ];
+
+        //It seems that EPS is still necessary
+        //The idea here is as follows. For the candidate blocks which can be divided into blocks, 
+        //if the difference between the target blocks and the candidate blocks is too wide, 
+        //the binarySplit method is adopted. The binarySplit blocks do not directly join the process,
+        //but enter the next round of screening.
+
+        if ( tau > idealUniProcTime * ( 1.0 + eps ) )
+        {
+            double nRest = ( tau - idealUniProcTime ) * procSpeed[ iProc ] / aveFloatOp;
+
+            double nTarget = nMaxCell - nRest;
+            if ( nRest > this->minNumberCell && nTarget > this->minNumberCell )
+            {
+                //It is necessary to divide blocks only when a certain number of points are satisfied.
+                double nHalf = nMaxCell / 2.0;
+                nMaxCell = nTarget;
+                double ratio = nMaxCell / nRest;
+                double oRatio = 1.0 / ratio;
+
+                if ( std::max( ratio, oRatio ) < 3.0 )
+                {
+                    int kkk = 1;
+                    largestZone = this->Split( largestZone, nMaxCell );
+                    timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                    this->RemoveZoneFromUnsignedGroup( largestZone );
+                    this->AddZoneToProcess( iProc, largestZone );
+                }
+                else
+                {
+                    this->Split( largestZone, nHalf );
+                }
+            }
+            else
+            {
+                //If the block is of the right size, join the process directly, and there is no need to split it.
+                timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                this->RemoveZoneFromUnsignedGroup( largestZone );
+                this->AddZoneToProcess( iProc, largestZone );
+            }
+        }
+        else
+        {
+            //If the block is of the right size, join the process directly, and there is no need to split it.
+            timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+            this->RemoveZoneFromUnsignedGroup( largestZone );
+            this->AddZoneToProcess( iProc, largestZone );
+        }
+    }
+}
+
+void Partition::ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord )
+{
+    SplitZone * rootSplitZone = splitZone->GetRootZone();
+    Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+    int nNodes = splitZone->dimInfo.ComputeNumNodes();
+    std::cout << "nNodes = " << nNodes << "\n";
+
+    coord.resize( nNodes * sizeof(double) );
+
+    int index_dim = splitZone->dimInfo.dimList.size();
+    Coor * coor = zone->coors[ icoord ];
+
+    double * xlocal = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    double * xglobal = reinterpret_cast<double *>( const_cast<char *>( coor->coord.data() ) );
+    if ( index_dim == 1 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        for ( int i = imin; i < imax; ++ i )
+        {
+            xlocal[ icount++ ] = xglobal[ i ];
+        }
+    }
+    else if ( index_dim == 2 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        int jmin = splitZone->dimInfo.rmin[ 1 ] - 1;
+        int jmax = splitZone->dimInfo.rmax[ 1 ];
+        int ni = rootSplitZone->dimInfo.dimList[ 0 ];
+        int nj = rootSplitZone->dimInfo.dimList[ 1 ];
+        for ( int j = jmin; j < jmax; ++ j )
+        {
+            int jstride = j * ni;
+            for ( int i = imin; i < imax; ++ i )
+            {
+                xlocal[ icount++ ] = xglobal[ jstride + i ];
+            }
+        }
+    }
+}
+
+void Partition::DumpBc( SplitZone * splitZone )
+{
+}
+
+void Partition::DumpPartitionedGridFile()
+{
+    std::cout << "\n";
+    std::cout << "DumpPartitionedGridFile -------------------------------" << "\n";
+    std::cout << "\n";
+    int fileId = -1;
+    std::string filename = this->outName;
+    int ierr = cg_open( filename.c_str(), CG_MODE_WRITE, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+
+    std::vector<std::string> coordnames;
+    coordnames.push_back( "CoordinateX" );
+    coordnames.push_back( "CoordinateY" );
+    coordnames.push_back( "CoordinateZ" );
+
+    std::string basename = "Base";
+    int baseId = -1;
+    int icelldim = Global::cell_dim;
+    int iphysdim = Global::phys_dim;
+    cg_base_write( fileId, basename.c_str(), icelldim, iphysdim, &baseId );
+
+    std::cout << "baseId = " << baseId << "\n";
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        int nZones = this->GetNZones( iProc );
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            ZoneType_t zoneType = Structured;
+
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+
+            int index_dim = splitZone->dimInfo.dimList.size();
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            splitZone->dimInfo.ComputeISize();
+
+            int isize_dim = index_dim * 3;
+
+            std::vector<cgsize_t> isize( index_dim * 3, 0 );
+            for ( int m = 0; m < isize_dim; ++ m )
+            {
+                isize[ m ] = splitZone->dimInfo.isize[ m ];
+            }
+
+            int zoneId = -1;
+
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+
+            std::string zonename = "Zone" + std::to_string( splitZone->newIndex );
+
+            cg_zone_write( fileId, baseId, zonename.c_str(), isize.data(), zoneType, &zoneId );
+
+            std::cout << "zoneId = " << zoneId << "\n";
+            std::cout << "zonename = " << zonename << "\n";
+                
+            splitZone->ComputeRminmax();
+
+            SplitZone * rootSplitZone = splitZone->GetRootZone();
+
+            Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+            int ncoords = zone->coors.size();
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = -1;
+                DataType_t dataType = RealDouble;
+                std::string coordname = coordnames[ icoord ];
+                Coor * coor = zone->coors[ icoord ];
+
+                int nNodes = splitZone->dimInfo.ComputeNumNodes();
+                std::cout << "nNodes = " << nNodes << "\n";
+
+                std::vector<char> coord;
+                ComputeCoor( splitZone, icoord, coord );
+
+                cg_coord_write( fileId, baseId, zoneId, dataType, coordname.c_str(), coord.data(), &coorId );
+
+                std::cout << "fileId = " << fileId  << " baseId = " << baseId << " zoneId = " << zoneId  << " coorId = " << coorId << "\n";
+            }
+
+            std::vector< PhysicalSplitBc * > &bccoList = splitZone->physicalSplitBcList;
+
+            int nbocos = bccoList.size();
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = -1;
+                GridLocation_t location = Vertex;
+
+                std::string boconame = "BC" + std::to_string( iboco + 1 );
+
+                PhysicalSplitBc * physicalSplitBc = bccoList[ iboco ];
+                BCType_t bocotype = static_cast<BCType_t>( physicalSplitBc->bcType );
+                PointSetType_t ptset_type = PointRange;
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> pnts;
+                int nSize = physicalSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.end[ i ] );
+                }
+
+                cg_boco_write( fileId, baseId, zoneId, boconame.c_str(), bocotype, ptset_type, npnts, pnts.data(), & bccoId );
+            }
+
+            //std::vector< InterfaceSplitBc * > & bc1to1List = splitZone->interfaceSplitBcList;
+            std::vector< InterfaceSplitBc * > bc1to1List;
+            splitZone->GetLeafInterfaceBc( bc1to1List );
+
+            int n1to1 = bc1to1List.size();
+            std::cout << "n1to1 = " << n1to1 << "\n";
+
+            std::vector<int> itranfrm( index_dim );
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                itranfrm[ m ] = m + 1;
+            }
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int index_conn = -1;
+
+                InterfaceSplitBc * interfaceSplitBc = bc1to1List[ i1to1 ];
+
+                std::vector<cgsize_t> pnts;
+                std::vector<cgsize_t> pntsdonor;
+                int nSize = interfaceSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.end[ i ] );
+                }
+
+                int nPatchSize = interfaceSplitBc->donor_region.start.size();
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.start[ i ] );
+                }
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.end[ i ] );
+                }
+                int id = interfaceSplitBc->donor_zone->newIndex;
+                int oldZoneIndex = interfaceSplitBc->donor_zone->zoneIndex;
+                std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+                std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+                std::cout << "donor zone id = " << id << "\n";
+                std::cout << "donor zone oldZoneIndex = " << oldZoneIndex << "\n";
+                std::string donorname = "Zone" + std::to_string( id );
+                std::string connectname = "Interface" + std::to_string( i1to1 );
+
+                std::cout << "donorname = " << donorname << "\n";
+                std::cout << "connectname = " << connectname << "\n";
+
+                std::vector<int> & itranfrm = interfaceSplitBc->transform;
+
+                cg_1to1_write( fileId, baseId, zoneId, connectname.c_str(), donorname.c_str(), pnts.data(), pntsdonor.data(), itranfrm.data(), &index_conn );
+                std::cout << "index_conn = " << index_conn << "\n";
+            }
+        }
+    }
+    cg_close( fileId );
+}
+
+void Partition::ModifyZoneIndex()
+{
+    std::cout << "ModifyZoneIndex +++++++++++++++++++++++++ " << "\n";
+    int globalZoneId = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        std::cout << "iProc = " << iProc << "\n";
+        int nZones = this->GetNZones( iProc );
+        std::cout << "nZones in Proc " << iProc << "  = " << nZones << "\n";
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+            //splitZone->SetZoneIndex( globalZoneId++ );
+            splitZone->newIndex = ( globalZoneId++ );
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+        }
+    }
+}
\ No newline at end of file
diff --git a/example/partition/struct/1d/1to4blocks/01/Partition.h b/example/partition/struct/1d/1to4blocks/01/Partition.h
new file mode 100644
index 00000000..8a4a9731
--- /dev/null
+++ b/example/partition/struct/1d/1to4blocks/01/Partition.h
@@ -0,0 +1,59 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class SplitZone;
+
+struct CmpSplitZone 
+{
+    bool operator() ( SplitZone * a, SplitZone * b ) const;
+};
+
+class Partition
+{
+public:
+    Partition();
+    ~Partition();
+protected:
+    std::set < SplitZone * > zoneStorage;
+    std::set < SplitZone *, CmpSplitZone > unsignedZoneGroup;
+    std::vector< SplitZone * > refZone;
+    std::vector< std::vector< SplitZone * > > procSplitZone;
+    std::vector<double> procSpeed;
+    std::vector<double> timeProc;
+    double aveFloatOp, delta;
+    double idealUniProcTime, eps;
+    int minNumberCell;
+    int nTZone;
+    int nOriZone;
+    int nProc;
+public:
+    std::string inputName;
+    std::string outName;
+public:
+    void Solve();
+    void ReadGrid();
+    void Split();
+    void InitSplit();
+    void BinarySplit();
+    //void GreedySplit();
+public:
+    void AddNewZone( SplitZone * zone );
+    void AddZoneToUnsignedGroup( SplitZone * zone );
+    void RemoveZoneFromUnsignedGroup( SplitZone * zone );
+    void AddZoneToProcess( int iProc, SplitZone * zone );
+    void DumpPartitionedGridFile();
+    void ModifyZoneIndex();
+    void FreeAllZones();
+    int GetNZones( int iProc );
+    SplitZone * GetSplitZone( int iProc, int zoneId );
+    void ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord );
+    void DumpBc( SplitZone * splitZone );
+private:
+    int GetMinValueIndex( double * data, int numberOfData );
+    int GetMinLoadProc();
+    SplitZone * GetLargestZone();
+    SplitZone * Split( SplitZone * zone, double nCell );
+};
+
diff --git a/example/partition/struct/1d/1to4blocks/01/README.txt b/example/partition/struct/1d/1to4blocks/01/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/partition/struct/1d/1to4blocks/01/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/partition/struct/1d/1to4blocks/01/SplitZone.cpp b/example/partition/struct/1d/1to4blocks/01/SplitZone.cpp
new file mode 100644
index 00000000..aef70754
--- /dev/null
+++ b/example/partition/struct/1d/1to4blocks/01/SplitZone.cpp
@@ -0,0 +1,1091 @@
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+int Dim::dim = -1;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox  )
+{
+    domainBox.start = zoneBox.start;
+    domainBox.end = zoneBox.end;
+
+    int axis = iDomain / 2;
+    int direction = iDomain % 2;
+
+    if ( direction == 0 )
+    {
+        domainBox.end[ axis ] = domainBox.start[ axis ];
+    }
+    else if ( direction == 1 )
+    {
+        domainBox.start[ axis ] = domainBox.end[ axis ];
+    }
+}
+
+DimInfo::DimInfo()
+{
+    this->Init( 1 );
+}
+
+DimInfo::~DimInfo()
+{
+}
+
+void DimInfo::Init( int dim )
+{
+    this->dim = dim;
+    dimList.resize( this->dim, 1 );
+    oriPoint.resize( this->dim, 0 );
+}
+
+DimInfo & DimInfo::operator = ( const DimInfo & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->dim = rhs.dim;
+    this->dimList = rhs.dimList;
+    this->oriPoint = rhs.oriPoint;
+
+    return * this;
+}
+
+int DimInfo::ComputeNumNodes()
+{
+    int nNodes = 1;
+    for ( int m = 0; m < this->dimList.size(); ++ m )
+    {
+        nNodes *= this->dimList[ m ];
+    }
+    return nNodes;
+}
+
+void DimInfo::ComputeISize()
+{
+    int index_dim = this->dimList.size();
+    this->isize.resize( index_dim * 3, 0 );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        isize[ m ] = this->dimList[ m ];
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 1;
+        isize[ start + m ] = this->dimList[ m ] - 1;
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 2;
+        isize[ start + m ] = 0;
+    }
+
+    for ( int i = 0; i < isize.size(); ++ i )
+    {
+        std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+    }
+}
+
+void DimInfo::ComputeRminmax( std::vector<int> & ref )
+{
+    int index_dim = this->dimList.size();
+    this->rmin.resize( index_dim );
+    this->rmax.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        rmin[ m ] = ref[ m ] + 1;
+        rmax[ m ] = ref[ m ] + this->dimList[ m ];
+    }
+
+    std::cout << "rmin, rmax = \n";
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        std::cout << rmin[ m ] << " " << rmax[ m ] << "\n";
+    }
+}
+
+void DimInfo::Init( std::vector<int> & dimList )
+{
+    this->dim = dimList.size();
+    this->dimList = dimList;
+    std::vector<int> zero( dimList.size(), 0 );
+    this->oriPoint = zero;
+}
+
+void DimInfo::SetNewDimension( int axis, int newStart, int newWidth )
+{
+    this->oriPoint[ axis ] = newStart;
+    this->dimList [ axis ] = newWidth;
+}
+
+void DimInfo::GetZoneGlobalBox( RangeRegion &zoneBox )
+{
+    int index_dim = this->dimList.size();
+    zoneBox.start.resize( index_dim );
+    zoneBox.end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        zoneBox.start[ m ] = this->oriPoint[ m ] + 1;
+        zoneBox.end[ m ] = this->oriPoint[ m ] + this->dimList[ m ];
+    }
+}
+
+void DimInfo::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    int index_dim = this->dimList.size();
+    localBox.start.resize( index_dim );
+    localBox.end.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        localBox.start[ m ] = globalBox.start[ m ] - this->oriPoint[ m ];
+        localBox.end[ m ] = globalBox.end[ m ] - this->oriPoint[ m ];
+    }
+}
+
+RangeRegion::RangeRegion( int nSize )
+{
+    this->Init( nSize );
+}
+
+RangeRegion::~RangeRegion()
+{
+}
+
+void RangeRegion::Init( int nSize )
+{
+    this->start.resize( nSize );
+    this->end.resize( nSize );
+}
+
+RangeRegion & RangeRegion::operator = ( const RangeRegion & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+bool RangeRegion::operator == ( const RangeRegion & rhs ) const
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] != rhs.start[ m ] || 
+            this->end  [ m ] != rhs.end  [ m ] )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+bool RangeRegion::InRegion( const RangeRegion & region )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( ( this->start[ m ] < region.start[ m ] ) || ( this->end[ m ] > region.end[ m ] ) )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::Normalize()
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        int minv = std::min( this->start[ m ], this->end[ m ] );
+        int maxv = std::max( this->start[ m ], this->end[ m ] );
+        this->start[ m ] = minv;
+        this->end[ m ] = maxv;
+    }
+}
+
+void RangeRegion::Localize( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] -= oriPoint[ m ];
+        this->end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void RangeRegion::ToGlobal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] += oriPoint[ m ];
+        this->end[ m ] += oriPoint[ m ];
+    }
+}
+
+void RangeRegion::ToLocal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] -= oriPoint[ m ];
+        this->end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void RangeRegion::PrintGlobal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    std::cout << "global start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ] + oriPoint[m];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "global end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ] + oriPoint[m];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+void RangeRegion::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion );
+
+bool ComputeOverlapRegion( RangeRegion & region1, RangeRegion & region2, RangeRegion & overlapRegion )
+{
+    int index_dim = region1.start.size();
+    overlapRegion.Init( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int ijkmin1 = std::min( region1.start[ m ], region1.end[ m ] );
+        int ijkmax1 = std::max( region1.start[ m ], region1.end[ m ] );
+        int ijkmin2 = std::min( region2.start[ m ], region2.end[ m ] );
+        int ijkmax2 = std::max( region2.start[ m ], region2.end[ m ] );
+        if ( ( ijkmax1 < ijkmin2 ) || ( ijkmin1 > ijkmax2 ) )
+        {
+            return false;
+        }
+
+        int ijkmin = std::max( ijkmin1, ijkmin2 );
+        int ijkmax = std::min( ijkmax1, ijkmax2 );
+
+        overlapRegion.start[ m ] = ijkmin;
+        overlapRegion.end  [ m ] = ijkmax;
+    }
+
+    return CheckOverLapping( overlapRegion );
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion )
+{
+    int index_dim = overlapRegion.start.size();
+    int iCount = 0;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        if ( overlapRegion.start[ m ] == overlapRegion.end[ m ] )
+        {
+            ++ iCount;
+        }
+    }
+
+    return ( iCount == 1 );
+}
+
+bool GetInterfaceRegion( RangeRegion & zoneBoxL, RangeRegion & zoneBoxR, RangeRegion & interfaceRegion )
+{
+    int index_dim = zoneBoxL.start.size();
+    int nDomains = 2 * index_dim;
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegionL;
+        GetDomainRegion( zoneBoxL, iDomain, domainRegionL );
+
+        for ( int jDomain = 0; jDomain < nDomains; ++ jDomain )
+        {
+            RangeRegion domainRegionR;
+            GetDomainRegion( zoneBoxR, jDomain, domainRegionR );
+
+            if ( domainRegionL == domainRegionR )
+            {
+                interfaceRegion = domainRegionL;
+                return true;
+            }
+        }
+    }
+    return false;
+}
+
+void CreateInterfaceBc( SplitZone * zoneL, SplitZone * zoneR )
+{
+    RangeRegion globalBoxL, globalBoxR, globalInterfaceRegion;
+
+    zoneL->GetZoneGlobalBox( globalBoxL );
+    zoneR->GetZoneGlobalBox( globalBoxR );
+
+    if ( ! GetInterfaceRegion( globalBoxL, globalBoxR, globalInterfaceRegion ) )
+    {
+        return;
+    }
+
+    RangeRegion localInterfaceRegionL, localInterfaceRegionR;
+
+    zoneL->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionL );
+    zoneR->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionR );
+
+    int kkk = 1;
+
+    InterfaceSplitBc * interfaceSplitBcL = new InterfaceSplitBc();
+    zoneL->interfaceSplitBcList.push_back( interfaceSplitBcL );
+    interfaceSplitBcL->zone = zoneL;
+    interfaceSplitBcL->region = localInterfaceRegionL;
+
+    int nSize = localInterfaceRegionL.start.size();
+
+    std::vector<int> transform;
+
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        transform.push_back( m + 1 );
+    }
+
+    interfaceSplitBcL->transform = transform;
+    interfaceSplitBcL->CalcTransformMatrix();
+
+    interfaceSplitBcL->donor_zone = zoneR;
+    interfaceSplitBcL->donor_region = localInterfaceRegionR;
+
+    InterfaceSplitBc * interfaceSplitBcR = new InterfaceSplitBc();
+    zoneR->interfaceSplitBcList.push_back( interfaceSplitBcR );
+
+    interfaceSplitBcR->zone = zoneR;
+    interfaceSplitBcR->region = localInterfaceRegionR;
+
+    interfaceSplitBcR->transform = transform;
+    interfaceSplitBcR->CalcTransformMatrix();
+
+    interfaceSplitBcR->donor_zone = zoneL;
+    interfaceSplitBcR->donor_region = localInterfaceRegionL;
+}
+
+
+PhysicalSplitBc::PhysicalSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+PhysicalSplitBc::~PhysicalSplitBc()
+{
+}
+
+void PhysicalSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void PhysicalSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+void PhysicalSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = splitZone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+BasicSplitBc::BasicSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+BasicSplitBc::~BasicSplitBc()
+{
+    ;
+}
+
+void BasicSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void BasicSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+int trans::M[ 3 ][ 3 ];
+std::vector<int> trans::transform;
+
+int trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void trans::CalcTransformMatrix()
+{
+    int dim = trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = trans::transform[ 0 ];
+        int sgna = trans::sgn( a );
+        int a1 = trans::del( a, 1 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int c = trans::transform[ 2 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int sgnc = trans::sgn( c );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int a3 = trans::del( a, 3 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        int b3 = trans::del( b, 3 );
+        int c1 = trans::del( c, 1 );
+        int c2 = trans::del( c, 2 );
+        int c3 = trans::del( c, 3 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 2 ][ 0 ] = sgna * a3;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+        trans::M[ 2 ][ 1 ] = sgnb * b3;
+        trans::M[ 0 ][ 2 ] = sgnc * c1;
+        trans::M[ 1 ][ 2 ] = sgnc * c2;
+        trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+InterfaceInfo::InterfaceInfo()
+{
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceInfo::~InterfaceInfo()
+{
+}
+
+InterfaceSplitBc::InterfaceSplitBc()
+{
+    this->region.Init( Dim::dim );
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceSplitBc::~InterfaceSplitBc()
+{
+}
+
+void InterfaceSplitBc::GetLeafInterfaceBc( std::vector< InterfaceSplitBc * > & leafInterfaceBcList )
+{
+    int nChild = this->child.size();
+    if ( nChild == 0 )
+    {
+        leafInterfaceBcList.push_back( this );
+    }
+    else
+    {
+        for ( int iChild = 0; iChild < nChild; ++ iChild )
+        {
+            InterfaceSplitBc * interfaceSplitBc = this->child[ iChild ];
+            interfaceSplitBc->GetLeafInterfaceBc( leafInterfaceBcList );
+        }
+    }
+}
+
+void InterfaceSplitBc::CopyMatrix( InterfaceSplitBc * interfaceSplitBc )
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = interfaceSplitBc->Mt[ i ][ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::CalcTransformMatrix()
+{
+    trans::ZeroMatrix();
+    trans::transform = this->transform;
+    trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = trans::M[ i ][ j ];
+        }
+    }
+
+}
+
+void InterfaceSplitBc::mapindex( std::vector<int> & begin1, std::vector<int> & begin2,  std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = Dim::dim;
+    std::vector<int> diff( dim );
+    for ( int m = 0; m < dim; ++ m )
+    {
+        diff[ m ] = index1[ m ] - begin1[ m ];
+    }
+
+    std::vector<int> mul( dim );
+
+    Multiply( Mt, diff, mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = mul[ m ] + begin2[ m ];
+    }
+}
+
+void InterfaceSplitBc::Multiply( int Mt[][3], std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = Dim::dim;
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = this->zone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void InterfaceSplitBc::CalcSubDonorRegion( RangeRegion &subRegion, RangeRegion &subDonorRegion )
+{
+    std::vector<int> begin1 = this->region.start;
+    std::vector<int> end1 = this->region.end;
+    std::vector<int> begin2 = this->donor_region.start;
+    std::vector<int> end2 = this->donor_region.end;
+
+    std::vector<int> new_begin1 = subRegion.start;
+    std::vector<int> new_end1 = subRegion.end;
+
+    int dim = Dim::dim;
+    std::vector<int> new_begin2( dim );
+    std::vector<int> new_end2( dim );
+
+    mapindex( begin1, begin2, new_begin1, new_begin2 );
+    mapindex( begin1, begin2, new_end1, new_end2 );
+
+    subDonorRegion.start = new_begin2;
+    subDonorRegion.end = new_end2;
+}
+
+SplitZone::SplitZone()
+{
+    this->parent  = 0;
+    this->zoneIndex = 0;
+    this->iProc = 0;
+    dimInfo.Init( Dim::dim );
+    int kk = 1;
+}
+
+SplitZone::~SplitZone()
+{
+    ;
+}
+
+void SplitZone::GetZoneGlobalBox( RangeRegion & zoneBox )
+{
+    this->dimInfo.GetZoneGlobalBox( zoneBox );
+}
+
+void SplitZone::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    this->dimInfo.GetZoneLocalBox( globalBox, localBox );
+}
+
+
+void SplitZone::ComputeRminmax()
+{
+    int index_dim = this->dimInfo.dimList.size();
+    std::vector<int> ref( index_dim, 0 );
+
+    SplitZone * rootSplitZone = 0;
+    this->GetRootInfo( rootSplitZone, ref );
+
+    this->dimInfo.ComputeRminmax( ref );
+}
+
+SplitZone * SplitZone::GetRootZone()
+{
+    SplitZone * root = this;
+
+    while ( true )
+    {
+        if ( root->parent )
+        {
+            root = root->parent;
+        }
+        else
+        {
+            return root;
+        }
+    };
+}
+
+void SplitZone::GetRootInfo( SplitZone *& root, std::vector<int> & ref )
+{
+    for ( int i = 0; i < this->dimInfo.dimList.size(); ++ i )
+    {
+        ref[ i ] += this->dimInfo.oriPoint[ i ];
+    }
+
+    if ( this->parent )
+    {
+        this->parent->GetRootInfo( root, ref );
+    }
+    else
+    {
+        root = this;
+    }
+}
+
+void SplitZone::SetParentAndChild( SplitZone * parent )
+{
+    this->parent = parent;
+    if ( parent )
+    {
+        parent->child.push_back( this );
+    }
+}
+
+void SplitZone::GetLeafInterfaceBc( std::vector< InterfaceSplitBc * > & leafInterfaceBcList )
+{
+    int nInterfaceBcs = this->interfaceSplitBcList.size();
+    for ( int i = 0; i < nInterfaceBcs; ++ i )
+    {
+        InterfaceSplitBc * interfaceSplitBc = this->interfaceSplitBcList[ i ];
+        interfaceSplitBc->GetLeafInterfaceBc( leafInterfaceBcList );
+    }
+}
+
+int SplitZone::GetNCell()
+{
+    int numberOfCells = 1;
+    for ( int i = 0; i < this->dimInfo.dim; ++ i )
+    {
+        numberOfCells *= std::max( 1, ( this->dimInfo.dimList[ i ] - 1 ) );
+    }
+
+    return numberOfCells; 
+}
+
+void SplitZone::SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int leftStart = 0;
+    int leftWidth = iSplit - 0;
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, leftStart , leftWidth  );
+}
+
+void SplitZone::SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int rightStart = iSplit - 1;
+    int rightWidth = dimList[ axisNeedSplit ] - ( iSplit - 1 );
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, rightStart, rightWidth );
+}
+
+void SplitZone::Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell )
+{
+    //Find the longest axis
+    int axisNeedSplit = this->FindAxisNeedSplit();
+    int iSplit        = this->FindSplitPosition( axisNeedSplit, nCell );
+
+    zoneL->SetLeftDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+    zoneR->SetRightDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+
+    zoneL->CreateBcFromParent();
+    zoneR->CreateBcFromParent();
+    
+    CreateInterfaceBc( zoneL, zoneR );
+}
+
+void SplitZone::CreateBcFromParent()
+{
+    this->CreatePhysicalBcFromParent();
+    this->CreateInterfaceBcFromParent();
+}
+
+void SplitZone::CreatePhysicalBcFromParent()
+{
+    int nParentPhysicalBcs = this->parent->physicalSplitBcList.size();
+
+    for ( int iParentPhysicalBcs = 0; iParentPhysicalBcs < nParentPhysicalBcs; ++ iParentPhysicalBcs )
+    {
+        PhysicalSplitBc * parentPhysicalSplitBc = this->parent->physicalSplitBcList[ iParentPhysicalBcs ];
+
+        this->CreatePhysicalBcFromParent( parentPhysicalSplitBc );
+    }
+}
+
+void SplitZone::CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentPhysicalSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreatePhysicalBc( overlapRegion, parentPhysicalSplitBc->bcType );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent()
+{
+    int nInterfaceSplitBcs = this->parent->interfaceSplitBcList.size();
+
+    for ( int iInterfaceSplitBcs = 0; iInterfaceSplitBcs < nInterfaceSplitBcs; ++ iInterfaceSplitBcs )
+    {
+        InterfaceSplitBc * parentInterfaceSplitBc = this->parent->interfaceSplitBcList[ iInterfaceSplitBcs ];
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc );
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentInterfaceSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc, overlapRegion );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::FindDonorInterface( InterfaceSplitBc * interfaceSplitBc, InterfaceInfo & interfaceInfo )
+{
+    RangeRegion donor_region = interfaceSplitBc->donor_region;
+    donor_region.Normalize();
+    interfaceInfo.donor_zone = this;
+    for ( int iInterface = 0; iInterface < interfaceSplitBcList.size(); ++ iInterface )
+    {
+        InterfaceSplitBc * candidateDonorBc = interfaceSplitBcList[ iInterface ];
+        bool flag = donor_region.InRegion( candidateDonorBc->region );
+        if ( flag )
+        {
+            if ( donor_region == candidateDonorBc->region )
+            {
+                interfaceInfo.donor_interface = candidateDonorBc;
+                return;
+            }
+            else
+            {
+                InterfaceSplitBc * donorBc = new InterfaceSplitBc();
+                candidateDonorBc->child.push_back( donorBc );
+                donorBc->region = donor_region;
+                donorBc->zone = candidateDonorBc->zone;
+                donorBc->donor_zone = interfaceSplitBc->zone;
+                donorBc->transform = candidateDonorBc->transform;
+                donorBc->CopyMatrix( candidateDonorBc );
+                RangeRegion subDonorRegion( Dim::dim );
+                candidateDonorBc->CalcSubDonorRegion( donorBc->region, subDonorRegion );
+                std::vector<int> & oriPoint = interfaceSplitBc->zone->dimInfo.oriPoint;
+                subDonorRegion.Localize( oriPoint );
+                donorBc->donor_region = subDonorRegion;
+                donorBc->donor_bc = interfaceSplitBc;
+                interfaceInfo.donor_interface = donorBc;
+                return;
+            }
+        }
+    }
+    return;
+}
+
+void SplitZone::GetChildDonorRegion( RangeRegion & subDonorRegion, InterfaceInfo & interfaceInfo )
+{
+    std::cout << "subDonorRegion = \n";
+    //subDonorRegion.Print();
+    RangeRegion normalizedDonorRegion = subDonorRegion;
+    normalizedDonorRegion.Normalize();
+    int nChild = this->child.size();
+    for ( int ichild = 0; ichild < nChild; ++ ichild )
+    {
+        std::cout << " iChild = " << ichild << " nChild = " << nChild << "\n";
+        SplitZone * sub_zone = this->child[ ichild ];
+        std::cout << " zoneIndex = " << sub_zone->zoneIndex << "\n";
+        int nInters = sub_zone->interfaceSplitBcList.size();
+        for ( int iInter = 0; iInter < nInters; ++ iInter )
+        {
+            std::cout << " iInter = " << iInter << "\n";
+            InterfaceSplitBc * interfaceSplitBc = sub_zone->interfaceSplitBcList[ iInter ];
+            std::cout << "interfaceSplitBc local = \n";
+            interfaceSplitBc->region.Print();
+            std::cout << "interfaceSplitBc global = \n";
+            interfaceSplitBc->region.PrintGlobal( sub_zone->dimInfo.oriPoint );
+            RangeRegion g_region = interfaceSplitBc->region;
+            g_region.ToGlobal( sub_zone->dimInfo.oriPoint );
+            if ( g_region == normalizedDonorRegion )
+            {
+                RangeRegion donorRegion = subDonorRegion;
+                donorRegion.ToLocal( sub_zone->dimInfo.oriPoint );
+
+                interfaceInfo.donor_zone = sub_zone;
+                interfaceInfo.donor_interface = interfaceSplitBc;
+                interfaceInfo.donor_region = donorRegion;
+                return;
+            }
+        }
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion )
+{
+    InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+    this->interfaceSplitBcList.push_back( interfaceSplitBc );
+
+    interfaceSplitBc->region = overlapRegion;
+    interfaceSplitBc->zone = this;
+    interfaceSplitBc->transform = parentInterfaceSplitBc->transform;
+    interfaceSplitBc->CopyMatrix( parentInterfaceSplitBc );
+    RangeRegion subDonorRegion( Dim::dim );
+    parentInterfaceSplitBc->CalcSubDonorRegion( overlapRegion, subDonorRegion );
+    interfaceSplitBc->ChangeRegionToLocalCoordinate();
+    interfaceSplitBc->donor_region = subDonorRegion;
+    SplitZone * parent_donor_zone = parentInterfaceSplitBc->donor_zone;
+    std::cout << " parentInterfaceSplitBc->zone->zoneIndex " << parentInterfaceSplitBc->zone->zoneIndex << "\n";
+    std::cout << " parentInterfaceSplitBc->donor_zone->zoneIndex " << parent_donor_zone->zoneIndex << "\n";
+    if ( parent_donor_zone->child.size() > 0 )
+    {
+        InterfaceInfo interfaceInfo;
+        parent_donor_zone->GetChildDonorRegion( subDonorRegion, interfaceInfo );
+        interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+        interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+        interfaceSplitBc->donor_region = interfaceInfo.donor_region;
+        //compatibility
+        InterfaceSplitBc * donor_bc = interfaceSplitBc->donor_bc;
+        SplitZone * donor_zone = interfaceSplitBc->donor_zone;
+        if ( interfaceSplitBc->zone != donor_bc->donor_zone )
+        {
+            if ( interfaceSplitBc->zone->parent == donor_bc->donor_zone )
+            {
+                RangeRegion d_region = donor_bc->donor_region;
+                d_region.ToLocal( interfaceSplitBc->zone->dimInfo.oriPoint );
+                donor_bc->donor_region = d_region;
+            }
+            donor_bc->donor_zone = interfaceSplitBc->zone;
+         
+            int kkk = 1;
+        }
+        int kkk = 1;
+    }
+    else
+    {
+        InterfaceInfo interfaceInfo;
+        parent_donor_zone->FindDonorInterface( interfaceSplitBc, interfaceInfo );
+        interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+        interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+    }
+    
+    int kkk = 1;
+}
+
+void SplitZone::CreatePhysicalBc( RangeRegion & overlapRegion, int bcType )
+{
+    PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+    this->physicalSplitBcList.push_back( physicalSplitBc );
+    physicalSplitBc->SetRegion( overlapRegion );
+    physicalSplitBc->bcType = bcType;
+    physicalSplitBc->splitZone = this;
+    physicalSplitBc->ChangeRegionToLocalCoordinate();
+}
+
+int SplitZone::FindAxisNeedSplit()
+{
+    //Find the longest axis
+    int axisNeedSplit = 0;
+    int maxN = this->dimInfo.dimList[ 0 ];
+
+    for ( int m = 1; m < this->dimInfo.dimList.size(); ++ m )
+    {
+        if ( this->IsPoleBc( m ) )
+        {
+            continue;
+        }
+        int Nm = this->dimInfo.dimList[ m ];
+        if ( maxN < Nm )
+        {
+            maxN = Nm;
+            axisNeedSplit = m;
+        }
+    }
+
+    return axisNeedSplit;
+}
+
+int SplitZone::GetCrossSection( int axis )
+{
+    int nDim = this->dimInfo.dimList.size();
+    int crossSection = 1;
+    int N = nDim - 1;
+    for ( int m = 0; m < N; ++ m )
+    {
+         int mm = ( axis + 1 ) % nDim;
+         int nLineElements = std::max( 1, ( this->dimInfo.dimList[ mm ] - 1 ) );
+         crossSection *= nLineElements;
+    }
+    return crossSection;
+}
+
+int SplitZone::FindSplitPosition( int axisNeedSplit, double nCell )
+{
+    int nDim = this->dimInfo.dimList.size();
+    std::vector<int> crossSections( nDim );
+    for ( int m = 0; m < nDim; ++ m )
+    {
+        crossSections[ m ] = this->GetCrossSection( m );
+    }
+
+    //guess the value
+    double dSplit = nCell / crossSections[ axisNeedSplit ];
+    int  iSplit = 1 + static_cast< int >( std::floor( dSplit + 0.5 ) );
+    return iSplit;
+}
+
+
+bool SplitZone::IsPoleBc( int splitDirection )
+{
+    return false;
+}
+
diff --git a/example/partition/struct/1d/1to4blocks/01/SplitZone.h b/example/partition/struct/1d/1to4blocks/01/SplitZone.h
new file mode 100644
index 00000000..ffe1e306
--- /dev/null
+++ b/example/partition/struct/1d/1to4blocks/01/SplitZone.h
@@ -0,0 +1,196 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class Dim
+{
+public:
+    static int dim;
+};
+
+class SplitZone;
+class RangeRegion;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox );
+
+class DimInfo
+{
+public:
+    DimInfo();
+    ~DimInfo();
+public:
+    int dim;
+    std::vector<int> dimList;
+    std::vector<int> oriPoint;
+    std::vector<int> isize;
+    std::vector<int> rmin;
+    std::vector<int> rmax;
+public:
+    int GetSize() const { return dim; }
+    DimInfo & operator = ( const DimInfo & rhs );
+public:
+    int ComputeNumNodes();
+    void ComputeISize();
+    void ComputeRminmax( std::vector<int> & ref );
+    void Init( int dim );
+    void Init( std::vector<int> & dimList );
+    void SetNewDimension( int axis, int newStart, int newWidth );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+};
+
+class SplitZone;
+class SplitBcPatch;
+
+class RangeRegion
+{
+public:
+    RangeRegion( int nSize = 1 );
+    ~RangeRegion();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    void Init( int nSize );
+    RangeRegion & operator = ( const RangeRegion & rhs );
+    bool operator == ( const RangeRegion & rhs ) const;
+    bool InRegion( const RangeRegion & region );
+    void SetRegion( std::vector<int> &pnts );
+    void Normalize();
+    void Localize( std::vector<int> & oriPoint );
+    void ToGlobal( std::vector<int> & oriPoint );
+    void ToLocal( std::vector<int> & oriPoint );
+    void PrintGlobal( std::vector<int> & oriPoint );
+    void Print();
+};
+
+class PhysicalSplitBc
+{
+public:
+    PhysicalSplitBc();
+    ~PhysicalSplitBc();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class BasicSplitBc
+{
+public:
+    BasicSplitBc();
+    ~BasicSplitBc();
+public:
+    RangeRegion region;
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> & pnts );
+    void SetRegion( RangeRegion & region );
+};
+
+class trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class InterfaceSplitBc;
+class SplitZone;
+
+class InterfaceInfo
+{
+public:
+    InterfaceInfo();
+    ~InterfaceInfo();
+public:
+    InterfaceSplitBc * donor_interface = nullptr;
+    SplitZone * donor_zone = nullptr;
+    RangeRegion donor_region;
+};
+
+class InterfaceSplitBc
+{
+public:
+    InterfaceSplitBc();
+    ~InterfaceSplitBc();
+public:
+    std::vector<int> transform;
+    int Mt[ 3 ][ 3 ];
+    RangeRegion region;
+    SplitZone * zone = nullptr;
+    RangeRegion donor_region;
+    SplitZone * donor_zone = nullptr;
+    InterfaceSplitBc * donor_bc = nullptr;
+public:
+    std::vector<InterfaceSplitBc *> child;
+    void GetLeafInterfaceBc( std::vector< InterfaceSplitBc * > & leafInterfaceBcList );
+public:
+    void CopyMatrix( InterfaceSplitBc * interfaceSplitBc );
+    void CalcTransformMatrix();
+    void CalcSubDonorRegion( RangeRegion & subRegion, RangeRegion & subDonorRegion );
+    void mapindex( std::vector<int> & begin1, std::vector<int> & begin2, std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( int Mt[][ 3 ], std::vector<int> & a, std::vector<int> & b );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class SplitZone
+{
+public:
+    SplitZone();
+    ~SplitZone();
+public:
+    DimInfo dimInfo;
+    int zoneIndex, iProc;
+    int newIndex;
+protected:
+    SplitZone * parent;
+    std::vector<SplitZone *> child;
+public:
+    std::vector< PhysicalSplitBc * > physicalSplitBcList;
+    std::vector< InterfaceSplitBc * > interfaceSplitBcList;
+    void GetLeafInterfaceBc( std::vector< InterfaceSplitBc * > & leafInterfaceBcList );
+public:
+    int GetNCell();
+    void ComputeRminmax();
+    void GetRootInfo( SplitZone *& root, std::vector<int> & ref );
+    void SetZoneIndex( int zoneIndex ) { this->zoneIndex = zoneIndex; }
+    int  GetZoneIndex() { return zoneIndex; }
+    void SetProcId( int iProc ) { this->iProc = iProc; }
+    void SetParent( SplitZone * parent ) { this->parent = parent; };
+    void SetParentAndChild( SplitZone * parent );
+    void FindDonorInterface( InterfaceSplitBc * interfaceSplitBc, InterfaceInfo & interfaceInfo );
+    void GetChildDonorRegion( RangeRegion & subDonorRegion, InterfaceInfo & interfaceInfo );
+public:
+    void CreateBcFromParent();
+    void CreatePhysicalBcFromParent();
+    void CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc );
+    void CreatePhysicalBc( RangeRegion & overlapRegion, int bcType );
+    void CreateInterfaceBcFromParent();
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc );
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion );
+
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+    SplitZone * GetRootZone();
+public:
+    void Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell );
+    void SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+    void SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+private:
+    int FindAxisNeedSplit();
+    int FindSplitPosition( int axisNeedSplit, double nCell );
+    bool IsPoleBc( int splitDirection );
+    int GetCrossSection( int axis );
+};
+
diff --git a/example/partition/struct/1d/1to4blocks/01/heat1d1blocksv1.cgns b/example/partition/struct/1d/1to4blocks/01/heat1d1blocksv1.cgns
new file mode 100644
index 00000000..1d0a3fb2
Binary files /dev/null and b/example/partition/struct/1d/1to4blocks/01/heat1d1blocksv1.cgns differ
diff --git a/example/partition/struct/1d/1to4blocks/01/heat1dpart.cgns b/example/partition/struct/1d/1to4blocks/01/heat1dpart.cgns
new file mode 100644
index 00000000..df5ffc5f
Binary files /dev/null and b/example/partition/struct/1d/1to4blocks/01/heat1dpart.cgns differ
diff --git a/example/partition/struct/1d/1to4blocks/01/main.cpp b/example/partition/struct/1d/1to4blocks/01/main.cpp
new file mode 100644
index 00000000..5da1de7c
--- /dev/null
+++ b/example/partition/struct/1d/1to4blocks/01/main.cpp
@@ -0,0 +1,18 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include "Partition.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip>
+
+int main(int argc, char **argv)
+{
+    Partition * partition = new Partition();
+    partition->Solve();
+    delete partition;
+
+    return 0;
+}
diff --git a/example/partition/struct/1d/1to8blocks/01/CMakeLists.txt b/example/partition/struct/1d/1to8blocks/01/CMakeLists.txt
new file mode 100644
index 00000000..74ceea7d
--- /dev/null
+++ b/example/partition/struct/1d/1to8blocks/01/CMakeLists.txt
@@ -0,0 +1,78 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	Partition.h Partition.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	SplitZone.h SplitZone.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/partition/struct/1d/1to8blocks/01/CgnsGrid.cpp b/example/partition/struct/1d/1to8blocks/01/CgnsGrid.cpp
new file mode 100644
index 00000000..dfe750bd
--- /dev/null
+++ b/example/partition/struct/1d/1to8blocks/01/CgnsGrid.cpp
@@ -0,0 +1,349 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include <map>
+
+Grid::Grid()
+{
+    ;
+}
+
+Grid::~Grid()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if( (i+1)%5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+    delete this->patch;
+}
+
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+ZoneBcPatch::ZoneBcPatch()
+{
+    ;
+}
+
+ZoneBcPatch::~ZoneBcPatch()
+{
+}
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+Global::Global()
+{
+    ;
+}
+
+Global::~Global()
+{
+}
+
+void Global::FreeData()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+    zones.resize( 0 );
+}
+
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            //baseZone.baseId = baseId;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin( index_dim );
+            std::vector<cgsize_t> irmax( index_dim );
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                std::vector<char> coord( nNodes * sizeof(double) );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+                coor->DumpCoor();
+            }
+
+            int nbocos = -1;
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+                int kkk = 1;
+            }
+        }
+        int kkk = 1;
+    }
+    int kkk = 1;
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/partition/struct/1d/1to8blocks/01/CgnsGrid.h b/example/partition/struct/1d/1to8blocks/01/CgnsGrid.h
new file mode 100644
index 00000000..053c467b
--- /dev/null
+++ b/example/partition/struct/1d/1to8blocks/01/CgnsGrid.h
@@ -0,0 +1,140 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <map>
+
+class Grid;
+
+class Zone;
+
+class Grid
+{
+public:
+    Grid();
+    ~Grid();
+public:
+    int nZone;
+    std::vector<double> x;
+    std::vector<Zone *> zones;
+};
+
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+};
+
+class ZoneBc;
+class ZoneBc1To1;
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class ZoneBcPatch;
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+    ZoneBcPatch * patch = nullptr;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+class ZoneBcPatch
+{
+public:
+    ZoneBcPatch();
+    ~ZoneBcPatch();
+public:
+    int donor_zoneid;
+    std::vector<int> transform;
+    std::vector<int> donor_pnts;
+};
+
+class BaseZone
+{
+public:
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Global
+{
+public:
+    Global();
+    ~Global();
+public:
+    static int cell_dim;
+    static int phys_dim;
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+public:
+    static void FreeData();
+};
+
+void ReadCgnsGrid( const std::string & filename );
+void ReadCgnsGridBaseZone( const std::string & filename );
\ No newline at end of file
diff --git a/example/partition/struct/1d/1to8blocks/01/Partition.cpp b/example/partition/struct/1d/1to8blocks/01/Partition.cpp
new file mode 100644
index 00000000..93c40c99
--- /dev/null
+++ b/example/partition/struct/1d/1to8blocks/01/Partition.cpp
@@ -0,0 +1,619 @@
+#include "Partition.h"
+#include "CgnsGrid.h"
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+bool CmpSplitZone::operator() ( SplitZone * a, SplitZone * b ) const
+{
+    return a->zoneIndex < b->zoneIndex;
+};
+
+
+double CalSumOfProcSpeed( std::vector<double> & procSpeed );
+double CalSumOfProcSpeed( std::vector<double> & procSpeed )
+{
+    int nProc = procSpeed.size();
+    double sumOfProcSpeed = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        sumOfProcSpeed += procSpeed[ iProc ];
+    }
+    return sumOfProcSpeed;
+}
+
+Partition::Partition()
+{
+    this->inputName = "../heat1d1blocksv1.cgns";
+    this->outName =  "../heat1dpart.cgns";
+}
+
+Partition::~Partition()
+{
+    ;
+}
+
+int Partition::GetMinValueIndex( double * data, int numberOfData )
+{
+    double minValue = data[ 0 ];
+    int minimumValueIndex = 0;
+
+    for ( int iData = 1; iData < numberOfData; ++ iData )
+    {
+        if ( minValue > data[ iData ] )
+        {
+            minValue      = data[ iData ];
+            minimumValueIndex = iData;
+        }
+    }
+    return minimumValueIndex;
+}
+
+int Partition::GetMinLoadProc()
+{
+    return this->GetMinValueIndex( this->timeProc.data(), this->nProc );
+}
+
+SplitZone * Partition::GetLargestZone()
+{
+    SplitZone * largestZone = 0;
+
+    double nMaxCell = 0.0;
+
+    for ( std::set< SplitZone * >::iterator iter = unsignedZoneGroup.begin(); iter != unsignedZoneGroup.end(); ++ iter )
+    {
+        double nSize = ( * iter )->GetNCell();
+        if ( nMaxCell < nSize )
+        {
+            nMaxCell    = nSize;
+            largestZone = * iter;
+        }
+    }
+
+    return largestZone;
+}
+
+void Partition::Solve()
+{
+    std::cout << "Partition::Split()\n";
+    this->nProc = 8;
+    this->ReadGrid();
+    this->Split();
+    this->DumpPartitionedGridFile();
+    this->FreeAllZones();
+}
+
+void Partition::ReadGrid()
+{
+    ReadCgnsGridBaseZone( this->inputName );
+    ReadCgnsGrid( this->inputName );
+
+    this->nOriZone = ::Global::zones.size();
+    Dim::dim = Global::cell_dim;
+
+    std::cout << "numberOfBlocks = " << nOriZone << "\n";
+
+    this->refZone.resize( nOriZone );
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = new SplitZone();
+        refZone[ iZone ] = splitZone;
+
+        splitZone->SetZoneIndex( iZone );
+        splitZone->SetProcId( 0 );
+        splitZone->SetParentAndChild( 0 );
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        Zone * zone = ::Global::zones[ iZone ];
+
+        splitZone->dimInfo.dimList = zone->nijk;
+
+        int nbccos = zone->bccos.size();
+        std::cout << "nbccos = " << nbccos << "\n";
+
+        for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+        {
+            ZoneBc * zoneBc = zone->bccos[ ibcco ];
+
+            PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+            splitZone->physicalSplitBcList.push_back( physicalSplitBc );
+            physicalSplitBc->bcType = zoneBc->bcType;
+            physicalSplitBc->SetRegion( zoneBc->pnts );
+            physicalSplitBc->splitZone = splitZone;
+        }
+
+        int nbc1to1s = zone->bc1to1s.size();
+
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * zoneBc1To1 = zone->bc1to1s[ ibc1to1 ];
+
+            InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+            splitZone->interfaceSplitBcList.push_back( interfaceSplitBc );
+            interfaceSplitBc->zone = splitZone;
+            interfaceSplitBc->region.SetRegion( zoneBc1To1->pnts );
+
+            interfaceSplitBc->transform = zoneBc1To1->transform;
+            interfaceSplitBc->CalcTransformMatrix();
+
+            interfaceSplitBc->donor_zone = refZone[ zoneBc1To1->donor_zoneid ];
+            interfaceSplitBc->donor_region.SetRegion( zoneBc1To1->donor_pnts );
+        }
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        int nbc1to1s = splitZone->interfaceSplitBcList.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            InterfaceSplitBc * interfaceSplitBc = splitZone->interfaceSplitBcList[ ibc1to1 ];
+            InterfaceInfo interfaceInfo;
+            interfaceSplitBc->donor_zone->FindDonorInterface( interfaceSplitBc, interfaceInfo );
+            interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+            interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+        }
+    }
+}
+
+void Partition::Split()
+{
+    this->InitSplit();
+    this->BinarySplit();
+    this->ModifyZoneIndex();
+    int kkk = 1;
+}
+
+void Partition::InitSplit()
+{
+    //nZone is the number of zones in the original grid
+    //nProc is not the number of blocks in the end, but the number of processes that need to be divided.
+    //This difference occurs because the structure grid can have many blocks per process.
+
+    //this->nProc    = nProc;
+    //this->nPhyBlocks = referenceBlock.size();
+    //this->nZone  = this->nPhyBlocks;
+
+    //tj Computation time on processor j
+    //Nk Number of internal grid-cells for zone j
+    //aveFloatOp:  Number of Real operations per gridcell
+    //Gj The set of blocks allocated to process j
+    //Pj Real operations per second for process j
+
+    //The Greedy Load Balancing Algorithm
+    //1.Compute an "ideal" uniprocessor time, Tuni = sum ( Nk * aveFloatOp )/ sum( Pj ).
+    //2.Set the group of unassigned blocks, Gu, to contain all blocks. The number of blocks in Nu=M, where M is the total number of blocks in the mesh.
+    //3.Start all processors with a very small fictitious zone to get a start tj=delt aveFloatOp/Pj, where delt<<1 is the size of the very small fictious zone.
+    //This is used to find the fastest processor in a heterogeneous system, tj could otherwise be set to 0 in the homogeneous case.
+    this->aveFloatOp = 1.0;
+    this->delta      = 1.0e-5;
+    this->procSpeed.resize( nProc );
+    this->timeProc.resize( nProc );
+
+    this->nTZone = this->nOriZone;
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        procSpeed[ iProc ] = 1.0;
+    }
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        timeProc[ iProc ] = delta * aveFloatOp / procSpeed[ iProc ];
+    }
+
+    double sumProcSpeed = CalSumOfProcSpeed( procSpeed );
+
+    double sumProcOp = 0.0;
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        sumProcOp += refZone[ iZone ]->GetNCell() * aveFloatOp;
+    }
+
+    this->idealUniProcTime = sumProcOp / sumProcSpeed;
+
+    this->eps = 0.05;
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        unsignedZoneGroup.insert( refZone[ iZone ] );
+    }
+
+    //Init zoneStorage
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        zoneStorage.insert( refZone[ iZone ] );
+    }
+
+    //Assign procSplitZone to each process
+    procSplitZone.resize( nProc );
+
+    this->minNumberCell = 1;
+    for ( int m = 0; m < Dim::dim; ++ m )
+    {
+        this->minNumberCell *= 1;
+    }
+
+    int kkk = 1;
+
+}
+
+void Partition::FreeAllZones()
+{
+    int iCount = 0;
+    for ( std::set < SplitZone * >::iterator iter = zoneStorage.begin(); iter != zoneStorage.end(); ++ iter )
+    {
+        //cout << "iCount = " << iCount << "\n";
+        ++ iCount;
+        delete * iter;
+    }
+}
+
+int Partition::GetNZones( int iProc )
+{
+    return this->procSplitZone[ iProc ].size();
+}
+
+SplitZone * Partition::GetSplitZone( int iProc, int zoneId )
+{
+    return this->procSplitZone[ iProc ][ zoneId ];
+}
+
+void Partition::AddZoneToUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.insert( zone );
+}
+
+void Partition::RemoveZoneFromUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.erase( zone );
+}
+
+void Partition::AddZoneToProcess( int iProc, SplitZone * zone )
+{
+    this->procSplitZone[ iProc ].push_back( zone );
+}
+
+void Partition::AddNewZone( SplitZone * zone )
+{
+    zone->SetZoneIndex( nTZone ++ );
+
+    this->AddZoneToUnsignedGroup( zone );
+
+    this->zoneStorage.insert( zone );
+}
+
+SplitZone * Partition::Split( SplitZone * zone, double nCell )
+{
+    SplitZone * zoneL = new SplitZone();
+    zoneL->SetParentAndChild( zone );
+
+    SplitZone * zoneR = new SplitZone();
+    zoneR->SetParentAndChild( zone );
+
+    //Remove the original block from the UnsignedGroup
+    this->RemoveZoneFromUnsignedGroup( zone );
+
+    this->AddNewZone( zoneL );
+    this->AddNewZone( zoneR );
+
+    zone->Split( zoneL, zoneR, nCell );
+
+    return zoneL;
+}
+
+void Partition::BinarySplit()
+{
+    while ( ! unsignedZoneGroup.empty() )
+    {
+        std::cout << "number of unsigned zone = " << unsignedZoneGroup.size() << "\n";
+        int iProc = this->GetMinLoadProc();
+
+        //Get the block with the largest number of grids and its size
+        SplitZone * largestZone = this->GetLargestZone();
+
+        double nMaxCell = largestZone->GetNCell();
+
+        double aveFloatOp = this->aveFloatOp;
+        double tau = timeProc[ iProc ] + nMaxCell * aveFloatOp / procSpeed[ iProc ];
+
+        //It seems that EPS is still necessary
+        //The idea here is as follows. For the candidate blocks which can be divided into blocks, 
+        //if the difference between the target blocks and the candidate blocks is too wide, 
+        //the binarySplit method is adopted. The binarySplit blocks do not directly join the process,
+        //but enter the next round of screening.
+
+        if ( tau > idealUniProcTime * ( 1.0 + eps ) )
+        {
+            double nRest = ( tau - idealUniProcTime ) * procSpeed[ iProc ] / aveFloatOp;
+
+            double nTarget = nMaxCell - nRest;
+            if ( nRest > this->minNumberCell && nTarget > this->minNumberCell )
+            {
+                //It is necessary to divide blocks only when a certain number of points are satisfied.
+                double nHalf = nMaxCell / 2.0;
+                nMaxCell = nTarget;
+                double ratio = nMaxCell / nRest;
+                double oRatio = 1.0 / ratio;
+
+                if ( std::max( ratio, oRatio ) < 3.0 )
+                {
+                    int kkk = 1;
+                    largestZone = this->Split( largestZone, nMaxCell );
+                    timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                    this->RemoveZoneFromUnsignedGroup( largestZone );
+                    this->AddZoneToProcess( iProc, largestZone );
+                }
+                else
+                {
+                    this->Split( largestZone, nHalf );
+                }
+            }
+            else
+            {
+                //If the block is of the right size, join the process directly, and there is no need to split it.
+                timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                this->RemoveZoneFromUnsignedGroup( largestZone );
+                this->AddZoneToProcess( iProc, largestZone );
+            }
+        }
+        else
+        {
+            //If the block is of the right size, join the process directly, and there is no need to split it.
+            timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+            this->RemoveZoneFromUnsignedGroup( largestZone );
+            this->AddZoneToProcess( iProc, largestZone );
+        }
+    }
+}
+
+void Partition::ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord )
+{
+    SplitZone * rootSplitZone = splitZone->GetRootZone();
+    Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+    int nNodes = splitZone->dimInfo.ComputeNumNodes();
+    std::cout << "nNodes = " << nNodes << "\n";
+
+    coord.resize( nNodes * sizeof(double) );
+
+    int index_dim = splitZone->dimInfo.dimList.size();
+    Coor * coor = zone->coors[ icoord ];
+
+    double * xlocal = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    double * xglobal = reinterpret_cast<double *>( const_cast<char *>( coor->coord.data() ) );
+    if ( index_dim == 1 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        for ( int i = imin; i < imax; ++ i )
+        {
+            xlocal[ icount++ ] = xglobal[ i ];
+        }
+    }
+    else if ( index_dim == 2 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        int jmin = splitZone->dimInfo.rmin[ 1 ] - 1;
+        int jmax = splitZone->dimInfo.rmax[ 1 ];
+        int ni = rootSplitZone->dimInfo.dimList[ 0 ];
+        int nj = rootSplitZone->dimInfo.dimList[ 1 ];
+        for ( int j = jmin; j < jmax; ++ j )
+        {
+            int jstride = j * ni;
+            for ( int i = imin; i < imax; ++ i )
+            {
+                xlocal[ icount++ ] = xglobal[ jstride + i ];
+            }
+        }
+    }
+}
+
+void Partition::DumpBc( SplitZone * splitZone )
+{
+}
+
+void Partition::DumpPartitionedGridFile()
+{
+    std::cout << "\n";
+    std::cout << "DumpPartitionedGridFile -------------------------------" << "\n";
+    std::cout << "\n";
+    int fileId = -1;
+    std::string filename = this->outName;
+    int ierr = cg_open( filename.c_str(), CG_MODE_WRITE, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+
+    std::vector<std::string> coordnames;
+    coordnames.push_back( "CoordinateX" );
+    coordnames.push_back( "CoordinateY" );
+    coordnames.push_back( "CoordinateZ" );
+
+    std::string basename = "Base";
+    int baseId = -1;
+    int icelldim = Global::cell_dim;
+    int iphysdim = Global::phys_dim;
+    cg_base_write( fileId, basename.c_str(), icelldim, iphysdim, &baseId );
+
+    std::cout << "baseId = " << baseId << "\n";
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        int nZones = this->GetNZones( iProc );
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            ZoneType_t zoneType = Structured;
+
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+
+            int index_dim = splitZone->dimInfo.dimList.size();
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            splitZone->dimInfo.ComputeISize();
+
+            int isize_dim = index_dim * 3;
+
+            std::vector<cgsize_t> isize( index_dim * 3, 0 );
+            for ( int m = 0; m < isize_dim; ++ m )
+            {
+                isize[ m ] = splitZone->dimInfo.isize[ m ];
+            }
+
+            int zoneId = -1;
+
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+
+            std::string zonename = "Zone" + std::to_string( splitZone->newIndex );
+
+            cg_zone_write( fileId, baseId, zonename.c_str(), isize.data(), zoneType, &zoneId );
+
+            std::cout << "zoneId = " << zoneId << "\n";
+            std::cout << "zonename = " << zonename << "\n";
+                
+            splitZone->ComputeRminmax();
+
+            SplitZone * rootSplitZone = splitZone->GetRootZone();
+
+            Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+            int ncoords = zone->coors.size();
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = -1;
+                DataType_t dataType = RealDouble;
+                std::string coordname = coordnames[ icoord ];
+                Coor * coor = zone->coors[ icoord ];
+
+                int nNodes = splitZone->dimInfo.ComputeNumNodes();
+                std::cout << "nNodes = " << nNodes << "\n";
+
+                std::vector<char> coord;
+                ComputeCoor( splitZone, icoord, coord );
+
+                cg_coord_write( fileId, baseId, zoneId, dataType, coordname.c_str(), coord.data(), &coorId );
+
+                std::cout << "fileId = " << fileId  << " baseId = " << baseId << " zoneId = " << zoneId  << " coorId = " << coorId << "\n";
+            }
+
+            std::vector< PhysicalSplitBc * > &bccoList = splitZone->physicalSplitBcList;
+
+            int nbocos = bccoList.size();
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = -1;
+                GridLocation_t location = Vertex;
+
+                std::string boconame = "BC" + std::to_string( iboco + 1 );
+
+                PhysicalSplitBc * physicalSplitBc = bccoList[ iboco ];
+                BCType_t bocotype = static_cast<BCType_t>( physicalSplitBc->bcType );
+                PointSetType_t ptset_type = PointRange;
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> pnts;
+                int nSize = physicalSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.end[ i ] );
+                }
+
+                cg_boco_write( fileId, baseId, zoneId, boconame.c_str(), bocotype, ptset_type, npnts, pnts.data(), & bccoId );
+            }
+
+            //std::vector< InterfaceSplitBc * > & bc1to1List = splitZone->interfaceSplitBcList;
+            std::vector< InterfaceSplitBc * > bc1to1List;
+            splitZone->GetLeafInterfaceBc( bc1to1List );
+
+            int n1to1 = bc1to1List.size();
+            std::cout << "n1to1 = " << n1to1 << "\n";
+
+            std::vector<int> itranfrm( index_dim );
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                itranfrm[ m ] = m + 1;
+            }
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int index_conn = -1;
+
+                InterfaceSplitBc * interfaceSplitBc = bc1to1List[ i1to1 ];
+
+                std::vector<cgsize_t> pnts;
+                std::vector<cgsize_t> pntsdonor;
+                int nSize = interfaceSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.end[ i ] );
+                }
+
+                int nPatchSize = interfaceSplitBc->donor_region.start.size();
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.start[ i ] );
+                }
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.end[ i ] );
+                }
+                int id = interfaceSplitBc->donor_zone->newIndex;
+                int oldZoneIndex = interfaceSplitBc->donor_zone->zoneIndex;
+                std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+                std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+                std::cout << "donor zone id = " << id << "\n";
+                std::cout << "donor zone oldZoneIndex = " << oldZoneIndex << "\n";
+                std::string donorname = "Zone" + std::to_string( id );
+                std::string connectname = "Interface" + std::to_string( i1to1 );
+
+                std::cout << "donorname = " << donorname << "\n";
+                std::cout << "connectname = " << connectname << "\n";
+
+                std::vector<int> & itranfrm = interfaceSplitBc->transform;
+
+                cg_1to1_write( fileId, baseId, zoneId, connectname.c_str(), donorname.c_str(), pnts.data(), pntsdonor.data(), itranfrm.data(), &index_conn );
+                std::cout << "index_conn = " << index_conn << "\n";
+            }
+        }
+    }
+    cg_close( fileId );
+}
+
+void Partition::ModifyZoneIndex()
+{
+    std::cout << "ModifyZoneIndex +++++++++++++++++++++++++ " << "\n";
+    int globalZoneId = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        std::cout << "iProc = " << iProc << "\n";
+        int nZones = this->GetNZones( iProc );
+        std::cout << "nZones in Proc " << iProc << "  = " << nZones << "\n";
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+            //splitZone->SetZoneIndex( globalZoneId++ );
+            splitZone->newIndex = ( globalZoneId++ );
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+        }
+    }
+}
\ No newline at end of file
diff --git a/example/partition/struct/1d/1to8blocks/01/Partition.h b/example/partition/struct/1d/1to8blocks/01/Partition.h
new file mode 100644
index 00000000..8a4a9731
--- /dev/null
+++ b/example/partition/struct/1d/1to8blocks/01/Partition.h
@@ -0,0 +1,59 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class SplitZone;
+
+struct CmpSplitZone 
+{
+    bool operator() ( SplitZone * a, SplitZone * b ) const;
+};
+
+class Partition
+{
+public:
+    Partition();
+    ~Partition();
+protected:
+    std::set < SplitZone * > zoneStorage;
+    std::set < SplitZone *, CmpSplitZone > unsignedZoneGroup;
+    std::vector< SplitZone * > refZone;
+    std::vector< std::vector< SplitZone * > > procSplitZone;
+    std::vector<double> procSpeed;
+    std::vector<double> timeProc;
+    double aveFloatOp, delta;
+    double idealUniProcTime, eps;
+    int minNumberCell;
+    int nTZone;
+    int nOriZone;
+    int nProc;
+public:
+    std::string inputName;
+    std::string outName;
+public:
+    void Solve();
+    void ReadGrid();
+    void Split();
+    void InitSplit();
+    void BinarySplit();
+    //void GreedySplit();
+public:
+    void AddNewZone( SplitZone * zone );
+    void AddZoneToUnsignedGroup( SplitZone * zone );
+    void RemoveZoneFromUnsignedGroup( SplitZone * zone );
+    void AddZoneToProcess( int iProc, SplitZone * zone );
+    void DumpPartitionedGridFile();
+    void ModifyZoneIndex();
+    void FreeAllZones();
+    int GetNZones( int iProc );
+    SplitZone * GetSplitZone( int iProc, int zoneId );
+    void ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord );
+    void DumpBc( SplitZone * splitZone );
+private:
+    int GetMinValueIndex( double * data, int numberOfData );
+    int GetMinLoadProc();
+    SplitZone * GetLargestZone();
+    SplitZone * Split( SplitZone * zone, double nCell );
+};
+
diff --git a/example/partition/struct/1d/1to8blocks/01/README.txt b/example/partition/struct/1d/1to8blocks/01/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/partition/struct/1d/1to8blocks/01/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/partition/struct/1d/1to8blocks/01/SplitZone.cpp b/example/partition/struct/1d/1to8blocks/01/SplitZone.cpp
new file mode 100644
index 00000000..aef70754
--- /dev/null
+++ b/example/partition/struct/1d/1to8blocks/01/SplitZone.cpp
@@ -0,0 +1,1091 @@
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+int Dim::dim = -1;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox  )
+{
+    domainBox.start = zoneBox.start;
+    domainBox.end = zoneBox.end;
+
+    int axis = iDomain / 2;
+    int direction = iDomain % 2;
+
+    if ( direction == 0 )
+    {
+        domainBox.end[ axis ] = domainBox.start[ axis ];
+    }
+    else if ( direction == 1 )
+    {
+        domainBox.start[ axis ] = domainBox.end[ axis ];
+    }
+}
+
+DimInfo::DimInfo()
+{
+    this->Init( 1 );
+}
+
+DimInfo::~DimInfo()
+{
+}
+
+void DimInfo::Init( int dim )
+{
+    this->dim = dim;
+    dimList.resize( this->dim, 1 );
+    oriPoint.resize( this->dim, 0 );
+}
+
+DimInfo & DimInfo::operator = ( const DimInfo & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->dim = rhs.dim;
+    this->dimList = rhs.dimList;
+    this->oriPoint = rhs.oriPoint;
+
+    return * this;
+}
+
+int DimInfo::ComputeNumNodes()
+{
+    int nNodes = 1;
+    for ( int m = 0; m < this->dimList.size(); ++ m )
+    {
+        nNodes *= this->dimList[ m ];
+    }
+    return nNodes;
+}
+
+void DimInfo::ComputeISize()
+{
+    int index_dim = this->dimList.size();
+    this->isize.resize( index_dim * 3, 0 );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        isize[ m ] = this->dimList[ m ];
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 1;
+        isize[ start + m ] = this->dimList[ m ] - 1;
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 2;
+        isize[ start + m ] = 0;
+    }
+
+    for ( int i = 0; i < isize.size(); ++ i )
+    {
+        std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+    }
+}
+
+void DimInfo::ComputeRminmax( std::vector<int> & ref )
+{
+    int index_dim = this->dimList.size();
+    this->rmin.resize( index_dim );
+    this->rmax.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        rmin[ m ] = ref[ m ] + 1;
+        rmax[ m ] = ref[ m ] + this->dimList[ m ];
+    }
+
+    std::cout << "rmin, rmax = \n";
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        std::cout << rmin[ m ] << " " << rmax[ m ] << "\n";
+    }
+}
+
+void DimInfo::Init( std::vector<int> & dimList )
+{
+    this->dim = dimList.size();
+    this->dimList = dimList;
+    std::vector<int> zero( dimList.size(), 0 );
+    this->oriPoint = zero;
+}
+
+void DimInfo::SetNewDimension( int axis, int newStart, int newWidth )
+{
+    this->oriPoint[ axis ] = newStart;
+    this->dimList [ axis ] = newWidth;
+}
+
+void DimInfo::GetZoneGlobalBox( RangeRegion &zoneBox )
+{
+    int index_dim = this->dimList.size();
+    zoneBox.start.resize( index_dim );
+    zoneBox.end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        zoneBox.start[ m ] = this->oriPoint[ m ] + 1;
+        zoneBox.end[ m ] = this->oriPoint[ m ] + this->dimList[ m ];
+    }
+}
+
+void DimInfo::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    int index_dim = this->dimList.size();
+    localBox.start.resize( index_dim );
+    localBox.end.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        localBox.start[ m ] = globalBox.start[ m ] - this->oriPoint[ m ];
+        localBox.end[ m ] = globalBox.end[ m ] - this->oriPoint[ m ];
+    }
+}
+
+RangeRegion::RangeRegion( int nSize )
+{
+    this->Init( nSize );
+}
+
+RangeRegion::~RangeRegion()
+{
+}
+
+void RangeRegion::Init( int nSize )
+{
+    this->start.resize( nSize );
+    this->end.resize( nSize );
+}
+
+RangeRegion & RangeRegion::operator = ( const RangeRegion & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+bool RangeRegion::operator == ( const RangeRegion & rhs ) const
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] != rhs.start[ m ] || 
+            this->end  [ m ] != rhs.end  [ m ] )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+bool RangeRegion::InRegion( const RangeRegion & region )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( ( this->start[ m ] < region.start[ m ] ) || ( this->end[ m ] > region.end[ m ] ) )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::Normalize()
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        int minv = std::min( this->start[ m ], this->end[ m ] );
+        int maxv = std::max( this->start[ m ], this->end[ m ] );
+        this->start[ m ] = minv;
+        this->end[ m ] = maxv;
+    }
+}
+
+void RangeRegion::Localize( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] -= oriPoint[ m ];
+        this->end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void RangeRegion::ToGlobal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] += oriPoint[ m ];
+        this->end[ m ] += oriPoint[ m ];
+    }
+}
+
+void RangeRegion::ToLocal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] -= oriPoint[ m ];
+        this->end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void RangeRegion::PrintGlobal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    std::cout << "global start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ] + oriPoint[m];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "global end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ] + oriPoint[m];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+void RangeRegion::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion );
+
+bool ComputeOverlapRegion( RangeRegion & region1, RangeRegion & region2, RangeRegion & overlapRegion )
+{
+    int index_dim = region1.start.size();
+    overlapRegion.Init( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int ijkmin1 = std::min( region1.start[ m ], region1.end[ m ] );
+        int ijkmax1 = std::max( region1.start[ m ], region1.end[ m ] );
+        int ijkmin2 = std::min( region2.start[ m ], region2.end[ m ] );
+        int ijkmax2 = std::max( region2.start[ m ], region2.end[ m ] );
+        if ( ( ijkmax1 < ijkmin2 ) || ( ijkmin1 > ijkmax2 ) )
+        {
+            return false;
+        }
+
+        int ijkmin = std::max( ijkmin1, ijkmin2 );
+        int ijkmax = std::min( ijkmax1, ijkmax2 );
+
+        overlapRegion.start[ m ] = ijkmin;
+        overlapRegion.end  [ m ] = ijkmax;
+    }
+
+    return CheckOverLapping( overlapRegion );
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion )
+{
+    int index_dim = overlapRegion.start.size();
+    int iCount = 0;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        if ( overlapRegion.start[ m ] == overlapRegion.end[ m ] )
+        {
+            ++ iCount;
+        }
+    }
+
+    return ( iCount == 1 );
+}
+
+bool GetInterfaceRegion( RangeRegion & zoneBoxL, RangeRegion & zoneBoxR, RangeRegion & interfaceRegion )
+{
+    int index_dim = zoneBoxL.start.size();
+    int nDomains = 2 * index_dim;
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegionL;
+        GetDomainRegion( zoneBoxL, iDomain, domainRegionL );
+
+        for ( int jDomain = 0; jDomain < nDomains; ++ jDomain )
+        {
+            RangeRegion domainRegionR;
+            GetDomainRegion( zoneBoxR, jDomain, domainRegionR );
+
+            if ( domainRegionL == domainRegionR )
+            {
+                interfaceRegion = domainRegionL;
+                return true;
+            }
+        }
+    }
+    return false;
+}
+
+void CreateInterfaceBc( SplitZone * zoneL, SplitZone * zoneR )
+{
+    RangeRegion globalBoxL, globalBoxR, globalInterfaceRegion;
+
+    zoneL->GetZoneGlobalBox( globalBoxL );
+    zoneR->GetZoneGlobalBox( globalBoxR );
+
+    if ( ! GetInterfaceRegion( globalBoxL, globalBoxR, globalInterfaceRegion ) )
+    {
+        return;
+    }
+
+    RangeRegion localInterfaceRegionL, localInterfaceRegionR;
+
+    zoneL->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionL );
+    zoneR->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionR );
+
+    int kkk = 1;
+
+    InterfaceSplitBc * interfaceSplitBcL = new InterfaceSplitBc();
+    zoneL->interfaceSplitBcList.push_back( interfaceSplitBcL );
+    interfaceSplitBcL->zone = zoneL;
+    interfaceSplitBcL->region = localInterfaceRegionL;
+
+    int nSize = localInterfaceRegionL.start.size();
+
+    std::vector<int> transform;
+
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        transform.push_back( m + 1 );
+    }
+
+    interfaceSplitBcL->transform = transform;
+    interfaceSplitBcL->CalcTransformMatrix();
+
+    interfaceSplitBcL->donor_zone = zoneR;
+    interfaceSplitBcL->donor_region = localInterfaceRegionR;
+
+    InterfaceSplitBc * interfaceSplitBcR = new InterfaceSplitBc();
+    zoneR->interfaceSplitBcList.push_back( interfaceSplitBcR );
+
+    interfaceSplitBcR->zone = zoneR;
+    interfaceSplitBcR->region = localInterfaceRegionR;
+
+    interfaceSplitBcR->transform = transform;
+    interfaceSplitBcR->CalcTransformMatrix();
+
+    interfaceSplitBcR->donor_zone = zoneL;
+    interfaceSplitBcR->donor_region = localInterfaceRegionL;
+}
+
+
+PhysicalSplitBc::PhysicalSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+PhysicalSplitBc::~PhysicalSplitBc()
+{
+}
+
+void PhysicalSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void PhysicalSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+void PhysicalSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = splitZone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+BasicSplitBc::BasicSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+BasicSplitBc::~BasicSplitBc()
+{
+    ;
+}
+
+void BasicSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void BasicSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+int trans::M[ 3 ][ 3 ];
+std::vector<int> trans::transform;
+
+int trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void trans::CalcTransformMatrix()
+{
+    int dim = trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = trans::transform[ 0 ];
+        int sgna = trans::sgn( a );
+        int a1 = trans::del( a, 1 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int c = trans::transform[ 2 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int sgnc = trans::sgn( c );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int a3 = trans::del( a, 3 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        int b3 = trans::del( b, 3 );
+        int c1 = trans::del( c, 1 );
+        int c2 = trans::del( c, 2 );
+        int c3 = trans::del( c, 3 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 2 ][ 0 ] = sgna * a3;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+        trans::M[ 2 ][ 1 ] = sgnb * b3;
+        trans::M[ 0 ][ 2 ] = sgnc * c1;
+        trans::M[ 1 ][ 2 ] = sgnc * c2;
+        trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+InterfaceInfo::InterfaceInfo()
+{
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceInfo::~InterfaceInfo()
+{
+}
+
+InterfaceSplitBc::InterfaceSplitBc()
+{
+    this->region.Init( Dim::dim );
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceSplitBc::~InterfaceSplitBc()
+{
+}
+
+void InterfaceSplitBc::GetLeafInterfaceBc( std::vector< InterfaceSplitBc * > & leafInterfaceBcList )
+{
+    int nChild = this->child.size();
+    if ( nChild == 0 )
+    {
+        leafInterfaceBcList.push_back( this );
+    }
+    else
+    {
+        for ( int iChild = 0; iChild < nChild; ++ iChild )
+        {
+            InterfaceSplitBc * interfaceSplitBc = this->child[ iChild ];
+            interfaceSplitBc->GetLeafInterfaceBc( leafInterfaceBcList );
+        }
+    }
+}
+
+void InterfaceSplitBc::CopyMatrix( InterfaceSplitBc * interfaceSplitBc )
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = interfaceSplitBc->Mt[ i ][ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::CalcTransformMatrix()
+{
+    trans::ZeroMatrix();
+    trans::transform = this->transform;
+    trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = trans::M[ i ][ j ];
+        }
+    }
+
+}
+
+void InterfaceSplitBc::mapindex( std::vector<int> & begin1, std::vector<int> & begin2,  std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = Dim::dim;
+    std::vector<int> diff( dim );
+    for ( int m = 0; m < dim; ++ m )
+    {
+        diff[ m ] = index1[ m ] - begin1[ m ];
+    }
+
+    std::vector<int> mul( dim );
+
+    Multiply( Mt, diff, mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = mul[ m ] + begin2[ m ];
+    }
+}
+
+void InterfaceSplitBc::Multiply( int Mt[][3], std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = Dim::dim;
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = this->zone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void InterfaceSplitBc::CalcSubDonorRegion( RangeRegion &subRegion, RangeRegion &subDonorRegion )
+{
+    std::vector<int> begin1 = this->region.start;
+    std::vector<int> end1 = this->region.end;
+    std::vector<int> begin2 = this->donor_region.start;
+    std::vector<int> end2 = this->donor_region.end;
+
+    std::vector<int> new_begin1 = subRegion.start;
+    std::vector<int> new_end1 = subRegion.end;
+
+    int dim = Dim::dim;
+    std::vector<int> new_begin2( dim );
+    std::vector<int> new_end2( dim );
+
+    mapindex( begin1, begin2, new_begin1, new_begin2 );
+    mapindex( begin1, begin2, new_end1, new_end2 );
+
+    subDonorRegion.start = new_begin2;
+    subDonorRegion.end = new_end2;
+}
+
+SplitZone::SplitZone()
+{
+    this->parent  = 0;
+    this->zoneIndex = 0;
+    this->iProc = 0;
+    dimInfo.Init( Dim::dim );
+    int kk = 1;
+}
+
+SplitZone::~SplitZone()
+{
+    ;
+}
+
+void SplitZone::GetZoneGlobalBox( RangeRegion & zoneBox )
+{
+    this->dimInfo.GetZoneGlobalBox( zoneBox );
+}
+
+void SplitZone::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    this->dimInfo.GetZoneLocalBox( globalBox, localBox );
+}
+
+
+void SplitZone::ComputeRminmax()
+{
+    int index_dim = this->dimInfo.dimList.size();
+    std::vector<int> ref( index_dim, 0 );
+
+    SplitZone * rootSplitZone = 0;
+    this->GetRootInfo( rootSplitZone, ref );
+
+    this->dimInfo.ComputeRminmax( ref );
+}
+
+SplitZone * SplitZone::GetRootZone()
+{
+    SplitZone * root = this;
+
+    while ( true )
+    {
+        if ( root->parent )
+        {
+            root = root->parent;
+        }
+        else
+        {
+            return root;
+        }
+    };
+}
+
+void SplitZone::GetRootInfo( SplitZone *& root, std::vector<int> & ref )
+{
+    for ( int i = 0; i < this->dimInfo.dimList.size(); ++ i )
+    {
+        ref[ i ] += this->dimInfo.oriPoint[ i ];
+    }
+
+    if ( this->parent )
+    {
+        this->parent->GetRootInfo( root, ref );
+    }
+    else
+    {
+        root = this;
+    }
+}
+
+void SplitZone::SetParentAndChild( SplitZone * parent )
+{
+    this->parent = parent;
+    if ( parent )
+    {
+        parent->child.push_back( this );
+    }
+}
+
+void SplitZone::GetLeafInterfaceBc( std::vector< InterfaceSplitBc * > & leafInterfaceBcList )
+{
+    int nInterfaceBcs = this->interfaceSplitBcList.size();
+    for ( int i = 0; i < nInterfaceBcs; ++ i )
+    {
+        InterfaceSplitBc * interfaceSplitBc = this->interfaceSplitBcList[ i ];
+        interfaceSplitBc->GetLeafInterfaceBc( leafInterfaceBcList );
+    }
+}
+
+int SplitZone::GetNCell()
+{
+    int numberOfCells = 1;
+    for ( int i = 0; i < this->dimInfo.dim; ++ i )
+    {
+        numberOfCells *= std::max( 1, ( this->dimInfo.dimList[ i ] - 1 ) );
+    }
+
+    return numberOfCells; 
+}
+
+void SplitZone::SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int leftStart = 0;
+    int leftWidth = iSplit - 0;
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, leftStart , leftWidth  );
+}
+
+void SplitZone::SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int rightStart = iSplit - 1;
+    int rightWidth = dimList[ axisNeedSplit ] - ( iSplit - 1 );
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, rightStart, rightWidth );
+}
+
+void SplitZone::Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell )
+{
+    //Find the longest axis
+    int axisNeedSplit = this->FindAxisNeedSplit();
+    int iSplit        = this->FindSplitPosition( axisNeedSplit, nCell );
+
+    zoneL->SetLeftDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+    zoneR->SetRightDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+
+    zoneL->CreateBcFromParent();
+    zoneR->CreateBcFromParent();
+    
+    CreateInterfaceBc( zoneL, zoneR );
+}
+
+void SplitZone::CreateBcFromParent()
+{
+    this->CreatePhysicalBcFromParent();
+    this->CreateInterfaceBcFromParent();
+}
+
+void SplitZone::CreatePhysicalBcFromParent()
+{
+    int nParentPhysicalBcs = this->parent->physicalSplitBcList.size();
+
+    for ( int iParentPhysicalBcs = 0; iParentPhysicalBcs < nParentPhysicalBcs; ++ iParentPhysicalBcs )
+    {
+        PhysicalSplitBc * parentPhysicalSplitBc = this->parent->physicalSplitBcList[ iParentPhysicalBcs ];
+
+        this->CreatePhysicalBcFromParent( parentPhysicalSplitBc );
+    }
+}
+
+void SplitZone::CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentPhysicalSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreatePhysicalBc( overlapRegion, parentPhysicalSplitBc->bcType );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent()
+{
+    int nInterfaceSplitBcs = this->parent->interfaceSplitBcList.size();
+
+    for ( int iInterfaceSplitBcs = 0; iInterfaceSplitBcs < nInterfaceSplitBcs; ++ iInterfaceSplitBcs )
+    {
+        InterfaceSplitBc * parentInterfaceSplitBc = this->parent->interfaceSplitBcList[ iInterfaceSplitBcs ];
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc );
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentInterfaceSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc, overlapRegion );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::FindDonorInterface( InterfaceSplitBc * interfaceSplitBc, InterfaceInfo & interfaceInfo )
+{
+    RangeRegion donor_region = interfaceSplitBc->donor_region;
+    donor_region.Normalize();
+    interfaceInfo.donor_zone = this;
+    for ( int iInterface = 0; iInterface < interfaceSplitBcList.size(); ++ iInterface )
+    {
+        InterfaceSplitBc * candidateDonorBc = interfaceSplitBcList[ iInterface ];
+        bool flag = donor_region.InRegion( candidateDonorBc->region );
+        if ( flag )
+        {
+            if ( donor_region == candidateDonorBc->region )
+            {
+                interfaceInfo.donor_interface = candidateDonorBc;
+                return;
+            }
+            else
+            {
+                InterfaceSplitBc * donorBc = new InterfaceSplitBc();
+                candidateDonorBc->child.push_back( donorBc );
+                donorBc->region = donor_region;
+                donorBc->zone = candidateDonorBc->zone;
+                donorBc->donor_zone = interfaceSplitBc->zone;
+                donorBc->transform = candidateDonorBc->transform;
+                donorBc->CopyMatrix( candidateDonorBc );
+                RangeRegion subDonorRegion( Dim::dim );
+                candidateDonorBc->CalcSubDonorRegion( donorBc->region, subDonorRegion );
+                std::vector<int> & oriPoint = interfaceSplitBc->zone->dimInfo.oriPoint;
+                subDonorRegion.Localize( oriPoint );
+                donorBc->donor_region = subDonorRegion;
+                donorBc->donor_bc = interfaceSplitBc;
+                interfaceInfo.donor_interface = donorBc;
+                return;
+            }
+        }
+    }
+    return;
+}
+
+void SplitZone::GetChildDonorRegion( RangeRegion & subDonorRegion, InterfaceInfo & interfaceInfo )
+{
+    std::cout << "subDonorRegion = \n";
+    //subDonorRegion.Print();
+    RangeRegion normalizedDonorRegion = subDonorRegion;
+    normalizedDonorRegion.Normalize();
+    int nChild = this->child.size();
+    for ( int ichild = 0; ichild < nChild; ++ ichild )
+    {
+        std::cout << " iChild = " << ichild << " nChild = " << nChild << "\n";
+        SplitZone * sub_zone = this->child[ ichild ];
+        std::cout << " zoneIndex = " << sub_zone->zoneIndex << "\n";
+        int nInters = sub_zone->interfaceSplitBcList.size();
+        for ( int iInter = 0; iInter < nInters; ++ iInter )
+        {
+            std::cout << " iInter = " << iInter << "\n";
+            InterfaceSplitBc * interfaceSplitBc = sub_zone->interfaceSplitBcList[ iInter ];
+            std::cout << "interfaceSplitBc local = \n";
+            interfaceSplitBc->region.Print();
+            std::cout << "interfaceSplitBc global = \n";
+            interfaceSplitBc->region.PrintGlobal( sub_zone->dimInfo.oriPoint );
+            RangeRegion g_region = interfaceSplitBc->region;
+            g_region.ToGlobal( sub_zone->dimInfo.oriPoint );
+            if ( g_region == normalizedDonorRegion )
+            {
+                RangeRegion donorRegion = subDonorRegion;
+                donorRegion.ToLocal( sub_zone->dimInfo.oriPoint );
+
+                interfaceInfo.donor_zone = sub_zone;
+                interfaceInfo.donor_interface = interfaceSplitBc;
+                interfaceInfo.donor_region = donorRegion;
+                return;
+            }
+        }
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion )
+{
+    InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+    this->interfaceSplitBcList.push_back( interfaceSplitBc );
+
+    interfaceSplitBc->region = overlapRegion;
+    interfaceSplitBc->zone = this;
+    interfaceSplitBc->transform = parentInterfaceSplitBc->transform;
+    interfaceSplitBc->CopyMatrix( parentInterfaceSplitBc );
+    RangeRegion subDonorRegion( Dim::dim );
+    parentInterfaceSplitBc->CalcSubDonorRegion( overlapRegion, subDonorRegion );
+    interfaceSplitBc->ChangeRegionToLocalCoordinate();
+    interfaceSplitBc->donor_region = subDonorRegion;
+    SplitZone * parent_donor_zone = parentInterfaceSplitBc->donor_zone;
+    std::cout << " parentInterfaceSplitBc->zone->zoneIndex " << parentInterfaceSplitBc->zone->zoneIndex << "\n";
+    std::cout << " parentInterfaceSplitBc->donor_zone->zoneIndex " << parent_donor_zone->zoneIndex << "\n";
+    if ( parent_donor_zone->child.size() > 0 )
+    {
+        InterfaceInfo interfaceInfo;
+        parent_donor_zone->GetChildDonorRegion( subDonorRegion, interfaceInfo );
+        interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+        interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+        interfaceSplitBc->donor_region = interfaceInfo.donor_region;
+        //compatibility
+        InterfaceSplitBc * donor_bc = interfaceSplitBc->donor_bc;
+        SplitZone * donor_zone = interfaceSplitBc->donor_zone;
+        if ( interfaceSplitBc->zone != donor_bc->donor_zone )
+        {
+            if ( interfaceSplitBc->zone->parent == donor_bc->donor_zone )
+            {
+                RangeRegion d_region = donor_bc->donor_region;
+                d_region.ToLocal( interfaceSplitBc->zone->dimInfo.oriPoint );
+                donor_bc->donor_region = d_region;
+            }
+            donor_bc->donor_zone = interfaceSplitBc->zone;
+         
+            int kkk = 1;
+        }
+        int kkk = 1;
+    }
+    else
+    {
+        InterfaceInfo interfaceInfo;
+        parent_donor_zone->FindDonorInterface( interfaceSplitBc, interfaceInfo );
+        interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+        interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+    }
+    
+    int kkk = 1;
+}
+
+void SplitZone::CreatePhysicalBc( RangeRegion & overlapRegion, int bcType )
+{
+    PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+    this->physicalSplitBcList.push_back( physicalSplitBc );
+    physicalSplitBc->SetRegion( overlapRegion );
+    physicalSplitBc->bcType = bcType;
+    physicalSplitBc->splitZone = this;
+    physicalSplitBc->ChangeRegionToLocalCoordinate();
+}
+
+int SplitZone::FindAxisNeedSplit()
+{
+    //Find the longest axis
+    int axisNeedSplit = 0;
+    int maxN = this->dimInfo.dimList[ 0 ];
+
+    for ( int m = 1; m < this->dimInfo.dimList.size(); ++ m )
+    {
+        if ( this->IsPoleBc( m ) )
+        {
+            continue;
+        }
+        int Nm = this->dimInfo.dimList[ m ];
+        if ( maxN < Nm )
+        {
+            maxN = Nm;
+            axisNeedSplit = m;
+        }
+    }
+
+    return axisNeedSplit;
+}
+
+int SplitZone::GetCrossSection( int axis )
+{
+    int nDim = this->dimInfo.dimList.size();
+    int crossSection = 1;
+    int N = nDim - 1;
+    for ( int m = 0; m < N; ++ m )
+    {
+         int mm = ( axis + 1 ) % nDim;
+         int nLineElements = std::max( 1, ( this->dimInfo.dimList[ mm ] - 1 ) );
+         crossSection *= nLineElements;
+    }
+    return crossSection;
+}
+
+int SplitZone::FindSplitPosition( int axisNeedSplit, double nCell )
+{
+    int nDim = this->dimInfo.dimList.size();
+    std::vector<int> crossSections( nDim );
+    for ( int m = 0; m < nDim; ++ m )
+    {
+        crossSections[ m ] = this->GetCrossSection( m );
+    }
+
+    //guess the value
+    double dSplit = nCell / crossSections[ axisNeedSplit ];
+    int  iSplit = 1 + static_cast< int >( std::floor( dSplit + 0.5 ) );
+    return iSplit;
+}
+
+
+bool SplitZone::IsPoleBc( int splitDirection )
+{
+    return false;
+}
+
diff --git a/example/partition/struct/1d/1to8blocks/01/SplitZone.h b/example/partition/struct/1d/1to8blocks/01/SplitZone.h
new file mode 100644
index 00000000..ffe1e306
--- /dev/null
+++ b/example/partition/struct/1d/1to8blocks/01/SplitZone.h
@@ -0,0 +1,196 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class Dim
+{
+public:
+    static int dim;
+};
+
+class SplitZone;
+class RangeRegion;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox );
+
+class DimInfo
+{
+public:
+    DimInfo();
+    ~DimInfo();
+public:
+    int dim;
+    std::vector<int> dimList;
+    std::vector<int> oriPoint;
+    std::vector<int> isize;
+    std::vector<int> rmin;
+    std::vector<int> rmax;
+public:
+    int GetSize() const { return dim; }
+    DimInfo & operator = ( const DimInfo & rhs );
+public:
+    int ComputeNumNodes();
+    void ComputeISize();
+    void ComputeRminmax( std::vector<int> & ref );
+    void Init( int dim );
+    void Init( std::vector<int> & dimList );
+    void SetNewDimension( int axis, int newStart, int newWidth );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+};
+
+class SplitZone;
+class SplitBcPatch;
+
+class RangeRegion
+{
+public:
+    RangeRegion( int nSize = 1 );
+    ~RangeRegion();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    void Init( int nSize );
+    RangeRegion & operator = ( const RangeRegion & rhs );
+    bool operator == ( const RangeRegion & rhs ) const;
+    bool InRegion( const RangeRegion & region );
+    void SetRegion( std::vector<int> &pnts );
+    void Normalize();
+    void Localize( std::vector<int> & oriPoint );
+    void ToGlobal( std::vector<int> & oriPoint );
+    void ToLocal( std::vector<int> & oriPoint );
+    void PrintGlobal( std::vector<int> & oriPoint );
+    void Print();
+};
+
+class PhysicalSplitBc
+{
+public:
+    PhysicalSplitBc();
+    ~PhysicalSplitBc();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class BasicSplitBc
+{
+public:
+    BasicSplitBc();
+    ~BasicSplitBc();
+public:
+    RangeRegion region;
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> & pnts );
+    void SetRegion( RangeRegion & region );
+};
+
+class trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class InterfaceSplitBc;
+class SplitZone;
+
+class InterfaceInfo
+{
+public:
+    InterfaceInfo();
+    ~InterfaceInfo();
+public:
+    InterfaceSplitBc * donor_interface = nullptr;
+    SplitZone * donor_zone = nullptr;
+    RangeRegion donor_region;
+};
+
+class InterfaceSplitBc
+{
+public:
+    InterfaceSplitBc();
+    ~InterfaceSplitBc();
+public:
+    std::vector<int> transform;
+    int Mt[ 3 ][ 3 ];
+    RangeRegion region;
+    SplitZone * zone = nullptr;
+    RangeRegion donor_region;
+    SplitZone * donor_zone = nullptr;
+    InterfaceSplitBc * donor_bc = nullptr;
+public:
+    std::vector<InterfaceSplitBc *> child;
+    void GetLeafInterfaceBc( std::vector< InterfaceSplitBc * > & leafInterfaceBcList );
+public:
+    void CopyMatrix( InterfaceSplitBc * interfaceSplitBc );
+    void CalcTransformMatrix();
+    void CalcSubDonorRegion( RangeRegion & subRegion, RangeRegion & subDonorRegion );
+    void mapindex( std::vector<int> & begin1, std::vector<int> & begin2, std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( int Mt[][ 3 ], std::vector<int> & a, std::vector<int> & b );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class SplitZone
+{
+public:
+    SplitZone();
+    ~SplitZone();
+public:
+    DimInfo dimInfo;
+    int zoneIndex, iProc;
+    int newIndex;
+protected:
+    SplitZone * parent;
+    std::vector<SplitZone *> child;
+public:
+    std::vector< PhysicalSplitBc * > physicalSplitBcList;
+    std::vector< InterfaceSplitBc * > interfaceSplitBcList;
+    void GetLeafInterfaceBc( std::vector< InterfaceSplitBc * > & leafInterfaceBcList );
+public:
+    int GetNCell();
+    void ComputeRminmax();
+    void GetRootInfo( SplitZone *& root, std::vector<int> & ref );
+    void SetZoneIndex( int zoneIndex ) { this->zoneIndex = zoneIndex; }
+    int  GetZoneIndex() { return zoneIndex; }
+    void SetProcId( int iProc ) { this->iProc = iProc; }
+    void SetParent( SplitZone * parent ) { this->parent = parent; };
+    void SetParentAndChild( SplitZone * parent );
+    void FindDonorInterface( InterfaceSplitBc * interfaceSplitBc, InterfaceInfo & interfaceInfo );
+    void GetChildDonorRegion( RangeRegion & subDonorRegion, InterfaceInfo & interfaceInfo );
+public:
+    void CreateBcFromParent();
+    void CreatePhysicalBcFromParent();
+    void CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc );
+    void CreatePhysicalBc( RangeRegion & overlapRegion, int bcType );
+    void CreateInterfaceBcFromParent();
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc );
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion );
+
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+    SplitZone * GetRootZone();
+public:
+    void Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell );
+    void SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+    void SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+private:
+    int FindAxisNeedSplit();
+    int FindSplitPosition( int axisNeedSplit, double nCell );
+    bool IsPoleBc( int splitDirection );
+    int GetCrossSection( int axis );
+};
+
diff --git a/example/partition/struct/1d/1to8blocks/01/heat1d1blocksv1.cgns b/example/partition/struct/1d/1to8blocks/01/heat1d1blocksv1.cgns
new file mode 100644
index 00000000..1d0a3fb2
Binary files /dev/null and b/example/partition/struct/1d/1to8blocks/01/heat1d1blocksv1.cgns differ
diff --git a/example/partition/struct/1d/1to8blocks/01/main.cpp b/example/partition/struct/1d/1to8blocks/01/main.cpp
new file mode 100644
index 00000000..5da1de7c
--- /dev/null
+++ b/example/partition/struct/1d/1to8blocks/01/main.cpp
@@ -0,0 +1,18 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include "Partition.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip>
+
+int main(int argc, char **argv)
+{
+    Partition * partition = new Partition();
+    partition->Solve();
+    delete partition;
+
+    return 0;
+}
diff --git a/example/partition/struct/2d/stage1/01/CMakeLists.txt b/example/partition/struct/2d/stage1/01/CMakeLists.txt
new file mode 100644
index 00000000..9fa577c8
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01/CMakeLists.txt
@@ -0,0 +1,77 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	Partition.h Partition.cpp
+	CgnsGrid.h CgnsGrid.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/partition/struct/2d/stage1/01/CgnsGrid.cpp b/example/partition/struct/2d/stage1/01/CgnsGrid.cpp
new file mode 100644
index 00000000..d287afcb
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01/CgnsGrid.cpp
@@ -0,0 +1,345 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include <map>
+
+Grid::Grid()
+{
+    ;
+}
+
+Grid::~Grid()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if( (i+1)%5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+    delete this->patch;
+}
+
+ZoneBcPatch::ZoneBcPatch()
+{
+    ;
+}
+
+ZoneBcPatch::~ZoneBcPatch()
+{
+}
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+Global::Global()
+{
+    ;
+}
+
+Global::~Global()
+{
+}
+
+void Global::FreeData()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+    zones.resize( 0 );
+}
+
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            //baseZone.baseId = baseId;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin( index_dim );
+            std::vector<cgsize_t> irmax( index_dim );
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                std::vector<char> coord( nNodes * sizeof(double) );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+                coor->DumpCoor();
+            }
+
+            int nbocos = -1;
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc->pnts.push_back( range[ i ] );
+                }
+
+                zonebc->zoneid = gZoneId;
+                zonebc->bcType = BCTypeUserDefined;
+
+                ZoneBcPatch * patch = new ZoneBcPatch();
+                zonebc->patch = patch;
+
+                patch->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    patch->donor_pnts.push_back( donor_range[ i ] );
+                }
+                int kkk = 1;
+            }
+        }
+        int kkk = 1;
+    }
+    int kkk = 1;
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage1/01/CgnsGrid.h b/example/partition/struct/2d/stage1/01/CgnsGrid.h
new file mode 100644
index 00000000..af67a321
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01/CgnsGrid.h
@@ -0,0 +1,123 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <map>
+
+class Grid;
+
+class Zone;
+
+class Grid
+{
+public:
+    Grid();
+    ~Grid();
+public:
+    int nZone;
+    std::vector<double> x;
+    std::vector<Zone *> zones;
+};
+
+class ZoneBc;
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+};
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<Coor *> coors;
+};
+
+class ZoneBcPatch;
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+    ZoneBcPatch * patch = nullptr;
+};
+
+class ZoneBcPatch
+{
+public:
+    ZoneBcPatch();
+    ~ZoneBcPatch();
+public:
+    int donor_zoneid;
+    std::vector<int> donor_pnts;
+};
+
+class BaseZone
+{
+public:
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Global
+{
+public:
+    Global();
+    ~Global();
+public:
+    static int cell_dim;
+    static int phys_dim;
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+public:
+    static void FreeData();
+};
+
+void ReadCgnsGrid( const std::string & filename );
+void ReadCgnsGridBaseZone( const std::string & filename );
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage1/01/Partition.cpp b/example/partition/struct/2d/stage1/01/Partition.cpp
new file mode 100644
index 00000000..022906d4
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01/Partition.cpp
@@ -0,0 +1,1461 @@
+#include "Partition.h"
+#include "CgnsGrid.h"
+#include "cgnslib.h"
+#include <string>
+
+int Dim::dim = -1;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox  )
+{
+    domainBox.start = zoneBox.start;
+    domainBox.end = zoneBox.end;
+
+    int axis = iDomain / 2;
+    int direction = iDomain % 2;
+
+    if ( direction == 0 )
+    {
+        domainBox.end[ axis ] = domainBox.start[ axis ];
+    }
+    else if ( direction == 1 )
+    {
+        domainBox.start[ axis ] = domainBox.end[ axis ];
+    }
+}
+
+DimInfo::DimInfo()
+{
+    this->Init( 1 );
+    //this->dim = 1;
+    //dimList.resize( this->dim, 1 );
+    //oriPoint.resize( this->dim, 0 );
+}
+
+DimInfo::~DimInfo()
+{
+}
+
+void DimInfo::Init( int dim )
+{
+    this->dim = dim;
+    dimList.resize( this->dim, 1 );
+    oriPoint.resize( this->dim, 0 );
+}
+
+DimInfo & DimInfo::operator = ( const DimInfo & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->dim = rhs.dim;
+    this->dimList = rhs.dimList;
+    this->oriPoint = rhs.oriPoint;
+
+    return * this;
+}
+
+int DimInfo::ComputeNumNodes()
+{
+    int nNodes = 1;
+    for ( int m = 0; m < this->dimList.size(); ++ m )
+    {
+        nNodes *= this->dimList[ m ];
+    }
+    return nNodes;
+}
+
+void DimInfo::ComputeISize()
+{
+    int index_dim = this->dimList.size();
+    this->isize.resize( index_dim * 3, 0 );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        isize[ m ] = this->dimList[ m ];
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 1;
+        isize[ start + m ] = this->dimList[ m ] - 1;
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 2;
+        isize[ start + m ] = 0;
+    }
+
+    for ( int i = 0; i < isize.size(); ++ i )
+    {
+        std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+    }
+}
+
+void DimInfo::ComputeRminmax( std::vector<int> & ref )
+{
+    int index_dim = this->dimList.size();
+    this->rmin.resize( index_dim );
+    this->rmax.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        rmin[ m ] = ref[ m ] + 1;
+        rmax[ m ] = ref[ m ] + this->dimList[ m ];
+    }
+
+    std::cout << "rmin, rmax = \n";
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        std::cout << rmin[ m ] << " " << rmax[ m ] << "\n";
+    }
+}
+
+void DimInfo::Init( std::vector<int> & dimList )
+{
+    this->dim = dimList.size();
+    this->dimList = dimList;
+    std::vector<int> zero( dimList.size(), 0 );
+    this->oriPoint = zero;
+}
+
+void DimInfo::SetNewDimension( int axis, int newStart, int newWidth )
+{
+    this->oriPoint[ axis ] = newStart;
+    this->dimList [ axis ] = newWidth;
+}
+
+void DimInfo::GetZoneGlobalBox( RangeRegion &zoneBox )
+{
+    int index_dim = this->dimList.size();
+    zoneBox.start.resize( index_dim );
+    zoneBox.end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        zoneBox.start[ m ] = this->oriPoint[ m ] + 1;
+        zoneBox.end[ m ] = this->oriPoint[ m ] + this->dimList[ m ];
+    }
+}
+
+void DimInfo::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    int index_dim = this->dimList.size();
+    localBox.start.resize( index_dim );
+    localBox.end.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        localBox.start[ m ] = globalBox.start[ m ] - this->oriPoint[ m ];
+        localBox.end[ m ] = globalBox.end[ m ] - this->oriPoint[ m ];
+    }
+}
+
+RangeRegion::RangeRegion( int nSize )
+{
+    this->Init( nSize );
+    //this->start.resize( nSize );
+    //this->end.resize( nSize );
+}
+
+RangeRegion::~RangeRegion()
+{
+}
+
+void RangeRegion::Init( int nSize )
+{
+    this->start.resize( nSize );
+    this->end.resize( nSize );
+}
+
+RangeRegion & RangeRegion::operator = ( const RangeRegion & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+    this->regionAxis = rhs.regionAxis;
+
+    return * this;
+}
+
+bool RangeRegion::operator == ( const RangeRegion & rhs ) const
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] != rhs.start[ m ] || 
+            this->end  [ m ] != rhs.end  [ m ] )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+    this->ComputeRegionAxis();
+}
+
+int RangeRegion::ComputeRegionAxis()
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] == this->end[ m ] )
+        {
+            this->regionAxis = m;
+            return this->regionAxis;
+        }
+    }
+    return this->regionAxis;
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion );
+
+bool ComputeOverlapRegion( RangeRegion & region1, RangeRegion & region2, RangeRegion & overlapRegion )
+{
+    int index_dim = region1.start.size();
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        overlapRegion.start[ m ] = std::max( region1.start[ m ], region2.start[ m ] );
+        overlapRegion.end  [ m ] = std::min( region1.end  [ m ], region2.end  [ m ] );
+    }
+
+    return CheckOverLapping( overlapRegion );
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion )
+{
+    int index_dim = overlapRegion.start.size();
+    int iCount = 0;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        if ( overlapRegion.start[ m ] == overlapRegion.end[ m ] )
+        {
+            ++ iCount;
+        }
+    }
+
+    return ( iCount == 1 );
+}
+
+SplitBc * CreateSplitBc( RangeRegion & bcRegion, RangeRegion & zoneDomainRegion )
+{
+    int sRegionAxis = bcRegion.ComputeRegionAxis();
+    int tRegionAxis = zoneDomainRegion.ComputeRegionAxis();
+
+    //Two regions in different directions
+    if ( sRegionAxis != tRegionAxis )
+    {
+        return 0;
+    }
+
+    //Although the two regions are in the same direction, the coordinates are inconsistent.
+    if ( bcRegion.start[ sRegionAxis ] != zoneDomainRegion.start[ sRegionAxis ] )
+    {
+        return 0;
+    }
+
+    RangeRegion overlapRegion;
+    ComputeOverlapRegion( bcRegion, zoneDomainRegion, overlapRegion );
+
+    if ( CheckOverLapping( overlapRegion ) )
+    {
+        SplitBc * splitBc = new SplitBc();
+        splitBc->SetRegion( overlapRegion );
+        return splitBc;
+    }
+
+    int kkk = 1;
+
+    return 0;
+}
+
+bool GetInterfaceRegion( RangeRegion & zoneBoxL, RangeRegion & zoneBoxR, RangeRegion & interfaceRegion )
+{
+    int index_dim = zoneBoxL.start.size();
+    int nDomains = 2 * index_dim;
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegionL;
+        GetDomainRegion( zoneBoxL, iDomain, domainRegionL );
+
+        for ( int jDomain = 0; jDomain < nDomains; ++ jDomain )
+        {
+            RangeRegion domainRegionR;
+            GetDomainRegion( zoneBoxR, jDomain, domainRegionR );
+
+            if ( domainRegionL == domainRegionR )
+            {
+                interfaceRegion = domainRegionL;
+                return true;
+            }
+        }
+    }
+    return false;
+}
+
+void CreateInterfaceBc( SplitZone * zoneL, SplitZone * zoneR )
+{
+    RangeRegion globalBoxL, globalBoxR, globalInterfaceRegion;
+
+    zoneL->GetZoneGlobalBox( globalBoxL );
+    zoneR->GetZoneGlobalBox( globalBoxR );
+
+    if ( ! GetInterfaceRegion( globalBoxL, globalBoxR, globalInterfaceRegion ) )
+    {
+        int kkk = 1;
+        return;
+    }
+
+    RangeRegion localInterfaceRegionL, localInterfaceRegionR;
+
+    zoneL->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionL );
+    zoneR->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionR );
+
+    int kkk = 1;
+
+    SplitBc * splitBcL = new SplitBc();
+    zoneL->AddSplitBc( splitBcL );
+
+    SplitBc * splitBcR = new SplitBc();
+    zoneR->AddSplitBc( splitBcR );
+
+    splitBcL->splitZone = zoneL;
+    splitBcL->SetRegion( localInterfaceRegionL );
+    splitBcL->bcType = BCTypeUserDefined;
+
+    splitBcR->splitZone = zoneR;
+    splitBcR->SetRegion( localInterfaceRegionR );
+    splitBcR->bcType = BCTypeUserDefined;
+
+    //localInterfaceRegionL.MarkPatchBc();
+    //localInterfaceRegionR.MarkPatchBc();
+
+    SplitBcPatch * splitBcPatchL = new SplitBcPatch();
+    splitBcL->patch = splitBcPatchL;
+    splitBcPatchL->region = localInterfaceRegionR;
+    splitBcPatchL->splitZone = zoneR;
+
+    SplitBcPatch * splitBcPatchR = new SplitBcPatch();
+    splitBcR->patch = splitBcPatchR;
+    splitBcPatchR->region = localInterfaceRegionL;
+    splitBcPatchR->splitZone = zoneL;
+
+    //splitBcL->Normalize();
+    //splitBcR->Normalize();
+}
+
+
+SplitBc::SplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+SplitBc::~SplitBc()
+{
+    delete this->patch;
+}
+
+void SplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void SplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+void SplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = splitZone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void SplitBc::SetZoneBcFromParentBc( SplitBc * parentSplitBc )
+{
+    this->bcType = parentSplitBc->bcType;
+    //this->LocalCoordinate();
+    this->region.regionAxis = parentSplitBc->region.regionAxis;
+    this->CreatePatchBc( parentSplitBc );
+}
+
+void SplitBc::CreatePatchBc( SplitBc * parentSplitBc )
+{
+    if ( parentSplitBc->bcType !=  BCTypeUserDefined ) return;
+
+    this->patch = new SplitBcPatch();
+    this->patch->splitZone = parentSplitBc->patch->splitZone;
+    this->patch->SetRegion( parentSplitBc->patch->region );
+    int kkk = 1;
+
+    //this->patch->faceAxis = parentSplitBc->patch->faceAxis;
+
+    //( * this->patch->vertexMap ) = ( * parentBc->patch->vertexMap );
+
+    ////È»ºó½øÐÐÐÞÕý
+    ////block1->map 1, 33 -> block1 369, 337
+    ////block2->global -> map 1, 33 -> block1 369, 337
+    ////block2->local  -> map 1, 33 -> block1 369, 337
+    ////refOld + M * stold           = block1Startold
+    ////refOld + M * ( stnew + ref ) = block1Startold
+    ////refNew = refOld + M * ( ref )
+
+    //for ( int m = 0; m < 3; ++ m )
+    //{
+    //    for ( int n = 0; n < 3; ++ n )
+    //    {
+    //        this->patch->vertexMap->pt[ m ] += this->patch->vertexMap->vm[ m ][ n ] * ( this->splitZone->sdim->oriPoint )[ n ];
+    //    }
+    //}
+
+    //RangeBox tRangeBox;
+
+    //MappingPatchPoint( this->patch, this->rangeBox, tRangeBox );
+    //tRangeBox.SetOrder();
+
+    ////ÕÒµ½ºÍ±¾¶Ô½Ó±ß½çÏà¶ÔÓ¦µÄ¿é
+    ////´Ópatch->splitZone°´ÕÕoverlapµÄ´óСÕÒµ½¶ÔÓ¦µÄ¶Ô½Ó±ß½ç£¬ÕâÑùÖÁÉÙ¿ÉÒÔÕÒµ½
+    ////¶ÔÃæµÄ¶Ô½Ó±ß½çÌõ¼þÓÉÓÚ±¾¿éµÄsplit±ØȻҪ·¢Éú¸Ä±ä£¬ÕâÀｫÏà¹Ø±ß½ç¼ÓÈë×ӱ߽ç
+    //this->patch->splitZone->CreateChildPatchBc( tRangeBox, this->splitZone );
+}
+
+SplitBcPatch::SplitBcPatch()
+{
+    this->region.Init( Dim::dim );
+}
+
+SplitBcPatch::~SplitBcPatch()
+{
+}
+
+void SplitBcPatch::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void SplitBcPatch::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+SplitZone::SplitZone()
+{
+    this->parent  = 0;
+    this->zoneIndex = 0;
+    this->iProc = 0;
+    dimInfo.Init( Dim::dim );
+    int kk = 1;
+}
+
+SplitZone::~SplitZone()
+{
+    ;
+}
+
+void SplitZone::GetZoneGlobalBox( RangeRegion & zoneBox )
+{
+    this->dimInfo.GetZoneGlobalBox( zoneBox );
+}
+
+void SplitZone::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    this->dimInfo.GetZoneLocalBox( globalBox, localBox );
+}
+
+
+void SplitZone::ComputeRminmax()
+{
+    int index_dim = this->dimInfo.dimList.size();
+    std::vector<int> ref( index_dim, 0 );
+
+    SplitZone * rootSplitZone = 0;
+    this->GetRootInfo( rootSplitZone, ref );
+
+    this->dimInfo.ComputeRminmax( ref );
+}
+
+SplitZone * SplitZone::GetRootZone()
+{
+    SplitZone * root = this;
+
+    while ( true )
+    {
+        if ( root->parent )
+        {
+            root = root->parent;
+        }
+        else
+        {
+            return root;
+        }
+    };
+}
+
+void SplitZone::GetRootInfo( SplitZone *& root, std::vector<int> & ref )
+{
+    for ( int i = 0; i < this->dimInfo.dimList.size(); ++ i )
+    {
+        ref[ i ] += this->dimInfo.oriPoint[ i ];
+    }
+
+    if ( this->parent )
+    {
+        this->parent->GetRootInfo( root, ref );
+    }
+    else
+    {
+        root = this;
+    }
+}
+
+
+int SplitZone::GetNCell()
+{
+    int numberOfCells = 1;
+    for ( int i = 0; i < this->dimInfo.dim; ++ i )
+    {
+        numberOfCells *= std::max( 1, ( this->dimInfo.dimList[ i ] - 1 ) );
+    }
+
+    return numberOfCells; 
+}
+
+void SplitZone::SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int leftStart = 0;
+    int leftWidth = iSplit - 0;
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, leftStart , leftWidth  );
+}
+
+void SplitZone::SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int rightStart = iSplit - 1;
+    int rightWidth = dimList[ axisNeedSplit ] - ( iSplit - 1 );
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, rightStart, rightWidth );
+}
+
+void SplitZone::Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell )
+{
+    //Find the longest axis
+    int axisNeedSplit = this->FindAxisNeedSplit();
+    int iSplit        = this->FindSplitPosition( axisNeedSplit, nCell );
+
+    zoneL = new SplitZone();
+    zoneL->SetParent( this );
+
+    zoneR = new SplitZone();
+    zoneR->SetParent( this );
+
+    zoneL->SetLeftDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+    zoneR->SetRightDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+
+    zoneL->CreateBcFromParent();
+    zoneR->CreateBcFromParent();
+
+    CreateInterfaceBc( zoneL, zoneR );
+}
+
+void SplitZone::CreateBcFromParent()
+{
+    std::vector< SplitBc * > & parentSplitBcList = this->parent->GetSplitBcList();
+
+    int nParentSplitBcs = parentSplitBcList.size();
+
+    for ( int iParentBc = 0; iParentBc < nParentSplitBcs; ++ iParentBc )
+    {
+        SplitBc * parentSplitBc = parentSplitBcList[ iParentBc ];
+
+        this->CreateSplitBc( parentSplitBc );
+    }
+}
+
+void SplitZone::AddSplitBc( SplitBc * splitBc )
+{
+    if ( ! splitBc ) return;
+    this->splitBcList.push_back( splitBc );
+}
+
+void SplitZone::CreateSplitBc( SplitBc * parentSplitBc )
+{
+    if ( ! parentSplitBc->child )
+    {
+        int index_dim = this->dimInfo.dimList.size();
+        int nDomains = 2 * index_dim;
+        RangeRegion zoneBoxRegion( index_dim );
+        this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+        for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+        {
+            RangeRegion domainRegion( index_dim );
+            GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+            RangeRegion overlapRegion;
+            bool overlap_flag = ComputeOverlapRegion( parentSplitBc->region, domainRegion, overlapRegion );
+            if ( ! overlap_flag ) continue;
+
+            SplitBc * splitBc = new SplitBc();
+            this->AddSplitBc( splitBc );
+
+            splitBc->SetRegion( overlapRegion );
+            splitBc->bcType = parentSplitBc->bcType;
+            splitBc->splitZone = this;
+            splitBc->ChangeRegionToLocalCoordinate();
+            splitBc->CreatePatchBc( parentSplitBc );
+            int kkk = 1;
+        }
+    }
+    else
+    {
+        int nChilds = parentSplitBc->child->size();
+        for ( int iChild = 0; iChild < nChilds; ++ iChild )
+        {
+            this->CreateSplitBc( ( * parentSplitBc->child )[ iChild ] );
+        }
+    }
+}
+
+
+int SplitZone::FindAxisNeedSplit()
+{
+    //Find the longest axis
+    int axisNeedSplit = 0;
+    int maxN = this->dimInfo.dimList[ 0 ];
+
+    for ( int m = 1; m < this->dimInfo.dimList.size(); ++ m )
+    {
+        if ( this->IsPoleBc( m ) )
+        {
+            continue;
+        }
+        int Nm = this->dimInfo.dimList[ m ];
+        if ( maxN < Nm )
+        {
+            maxN = Nm;
+            axisNeedSplit = m;
+        }
+    }
+
+    return axisNeedSplit;
+}
+
+int SplitZone::GetCrossSection( int axis )
+{
+    int nDim = this->dimInfo.dimList.size();
+    int crossSection = 1;
+    int N = nDim - 1;
+    for ( int m = 0; m < N; ++ m )
+    {
+         int mm = ( axis + 1 ) % nDim;
+         int nLineElements = std::max( 1, ( this->dimInfo.dimList[ mm ] - 1 ) );
+         crossSection *= nLineElements;
+    }
+    return crossSection;
+}
+
+int SplitZone::FindSplitPosition( int axisNeedSplit, double nCell )
+{
+    int nDim = this->dimInfo.dimList.size();
+    std::vector<int> crossSections( nDim );
+    for ( int m = 0; m < nDim; ++ m )
+    {
+        crossSections[ m ] = this->GetCrossSection( m );
+    }
+
+    //guess the value
+    double dSplit = nCell / crossSections[ axisNeedSplit ];
+    int  iSplit = 1 + static_cast< int >( std::floor( dSplit + 0.5 ) );
+    return iSplit;
+}
+
+
+bool SplitZone::IsPoleBc( int splitDirection )
+{
+    return false;
+}
+
+
+double CalSumOfProcSpeed( std::vector<double> & procSpeed );
+double CalSumOfProcSpeed( std::vector<double> & procSpeed )
+{
+    int nProc = procSpeed.size();
+    double sumOfProcSpeed = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        sumOfProcSpeed += procSpeed[ iProc ];
+    }
+    return sumOfProcSpeed;
+}
+
+Partition::Partition()
+{
+    this->inputName = "../heat2d2blocks.cgns";
+    this->outName =  "../heat2dpart.cgns";
+}
+
+Partition::~Partition()
+{
+    ;
+}
+
+int Partition::GetMinValueIndex( double * data, int numberOfData )
+{
+    double minValue = data[ 0 ];
+    int minimumValueIndex = 0;
+
+    for ( int iData = 1; iData < numberOfData; ++ iData )
+    {
+        if ( minValue > data[ iData ] )
+        {
+            minValue      = data[ iData ];
+            minimumValueIndex = iData;
+        }
+    }
+    return minimumValueIndex;
+}
+
+int Partition::GetMinLoadProc()
+{
+    return this->GetMinValueIndex( this->timeProc.data(), this->nProc );
+}
+
+SplitZone * Partition::GetLargestZone()
+{
+    SplitZone * largestZone = 0;
+
+    double nMaxCell = 0.0;
+
+    for ( std::set< SplitZone * >::iterator iter = unsignedZoneGroup.begin(); iter != unsignedZoneGroup.end(); ++ iter )
+    {
+        double nSize = ( * iter )->GetNCell();
+        if ( nMaxCell < nSize )
+        {
+            nMaxCell    = nSize;
+            largestZone = * iter;
+        }
+    }
+
+    return largestZone;
+}
+
+void Partition::Solve()
+{
+    std::cout << "Partition::Split()\n";
+    this->nProc = 2;
+    //this->nProc = 4;
+    this->ReadGrid();
+    this->Split();
+    this->ModifyZoneIndex();
+    this->DumpPartitionedGridFile();
+    this->FreeAllZones();
+}
+
+void Partition::ReadGrid()
+{
+    ReadCgnsGridBaseZone( this->inputName );
+    ReadCgnsGrid( this->inputName );
+
+    this->nOriZone = ::Global::zones.size();
+    Dim::dim = Global::cell_dim;
+
+    std::cout << "numberOfBlocks = " << nOriZone << "\n";
+
+    this->refZone.resize( nOriZone );
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = new SplitZone();
+        refZone[ iZone ] = splitZone;
+
+        splitZone->SetZoneIndex( iZone );
+        splitZone->SetProcId( 0 );
+        splitZone->SetParent( 0 );
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        Zone * zone = ::Global::zones[ iZone ];
+
+        splitZone->dimInfo.dimList = zone->nijk;
+
+        int nBcRegion = zone->bccos.size();
+        std::cout << "nBcRegion = " << nBcRegion << "\n";
+
+        std::vector< SplitBc * > & splitBcList = splitZone->splitBcList;
+
+        for ( int iBcRegion = 0; iBcRegion < nBcRegion; ++ iBcRegion )
+        {
+            SplitBc * splitBc = new SplitBc();
+            splitBcList.push_back( splitBc );
+
+            ZoneBc * zoneBc = zone->bccos[ iBcRegion ];
+
+            splitBc->splitZone = splitZone;
+            splitBc->bcType = zoneBc->bcType;
+            splitBc->SetRegion( zoneBc->pnts );
+            if ( zoneBc->patch )
+            {
+                SplitBcPatch * patch = new SplitBcPatch();
+                splitBc->patch = patch;
+
+                patch->splitZone = refZone[ zoneBc->patch->donor_zoneid ];
+                patch->SetRegion( zoneBc->patch->donor_pnts );
+            }
+        }
+
+        int kkk = 1;
+    }
+    int kkk = 1;
+}
+
+void Partition::Split()
+{
+    this->InitSplit();
+    this->BinarySplit();
+    //this->SetZoneIndex();
+}
+
+void Partition::InitSplit()
+{
+    //nZone is the number of zones in the original grid
+    //nProc is not the number of blocks in the end, but the number of processes that need to be divided.
+    //This difference occurs because the structure grid can have many blocks per process.
+
+    //this->nProc    = nProc;
+    //this->nPhyBlocks = referenceBlock.size();
+    //this->nZone  = this->nPhyBlocks;
+
+    //tj Computation time on processor j
+    //Nk Number of internal grid-cells for zone j
+    //aveFloatOp:  Number of Real operations per gridcell
+    //Gj The set of blocks allocated to process j
+    //Pj Real operations per second for process j
+
+    //The Greedy Load Balancing Algorithm
+    //1.Compute an "ideal" uniprocessor time, Tuni = sum ( Nk * aveFloatOp )/ sum( Pj ).
+    //2.Set the group of unassigned blocks, Gu, to contain all blocks. The number of blocks in Nu=M, where M is the total number of blocks in the mesh.
+    //3.Start all processors with a very small fictitious zone to get a start tj=delt aveFloatOp/Pj, where delt<<1 is the size of the very small fictious zone.
+    //This is used to find the fastest processor in a heterogeneous system, tj could otherwise be set to 0 in the homogeneous case.
+    this->aveFloatOp = 1.0;
+    this->delta      = 1.0e-5;
+    this->procSpeed.resize( nProc );
+    this->timeProc.resize( nProc );
+
+    this->nTZone = this->nOriZone;
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        procSpeed[ iProc ] = 1.0;
+    }
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        timeProc[ iProc ] = delta * aveFloatOp / procSpeed[ iProc ];
+    }
+
+    double sumProcSpeed = CalSumOfProcSpeed( procSpeed );
+
+    double sumProcOp = 0.0;
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        sumProcOp += refZone[ iZone ]->GetNCell() * aveFloatOp;
+    }
+
+    this->idealUniProcTime = sumProcOp / sumProcSpeed;
+
+    this->eps = 0.05;
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        unsignedZoneGroup.insert( refZone[ iZone ] );
+    }
+
+    //Init zoneStorage
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        zoneStorage.insert( refZone[ iZone ] );
+    }
+
+    //Assign procSplitZone to each process
+    procSplitZone.resize( nProc );
+
+    this->minNode = 1;
+    for ( int m = 0; m < Dim::dim; ++ m )
+    {
+        this->minNode *= 2;
+    }
+
+    int kkk = 1;
+
+}
+
+void Partition::FreeAllZones()
+{
+    int iCount = 0;
+    for ( std::set < SplitZone * >::iterator iter = zoneStorage.begin(); iter != zoneStorage.end(); ++ iter )
+    {
+        //cout << "iCount = " << iCount << "\n";
+        ++ iCount;
+        delete * iter;
+    }
+}
+
+int Partition::GetNZones( int iProc )
+{
+    return this->procSplitZone[ iProc ].size();
+}
+
+SplitZone * Partition::GetSplitZone( int iProc, int zoneId )
+{
+    return this->procSplitZone[ iProc ][ zoneId ];
+}
+
+void Partition::AddZoneToUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.insert( zone );
+}
+
+void Partition::RemoveZoneFromUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.erase( zone );
+}
+
+void Partition::AddZoneToProcess( int iProc, SplitZone * zone )
+{
+    this->procSplitZone[ iProc ].push_back( zone );
+}
+
+void Partition::AddNewZone( SplitZone * zone )
+{
+    zone->SetZoneIndex( nTZone ++ );
+
+    this->AddZoneToUnsignedGroup( zone );
+
+    this->zoneStorage.insert( zone );
+}
+
+SplitZone * Partition::Split( SplitZone * zone, double nCell )
+{
+    SplitZone * zoneL = 0;
+    SplitZone * zoneR = 0;
+
+    zone->Split( zoneL, zoneR, nCell );
+
+    this->AddNewZone( zoneL );
+    this->AddNewZone( zoneR );
+    this->RemoveZoneFromUnsignedGroup( zone );
+
+    return zoneL;
+}
+
+void Partition::BinarySplit()
+{
+    while ( ! unsignedZoneGroup.empty() )
+    {
+        std::cout << "number of unsigned zone = " << unsignedZoneGroup.size() << "\n";
+        int iProc = this->GetMinLoadProc();
+
+        //Get the block with the largest number of grids and its size
+        SplitZone * largestZone = this->GetLargestZone();
+
+        double nMaxCell = largestZone->GetNCell();
+
+        double aveFloatOp = this->aveFloatOp;
+        double tau = timeProc[ iProc ] + nMaxCell * aveFloatOp / procSpeed[ iProc ];
+
+        int kkk = 1;
+
+        //It seems that EPS is still necessary
+        //The idea here is as follows. For the candidate blocks which can be divided into blocks, 
+        //if the difference between the target blocks and the candidate blocks is too wide, 
+        //the binarySplit method is adopted. The binarySplit blocks do not directly join the process,
+        //but enter the next round of screening.
+
+        if ( tau > idealUniProcTime * ( 1.0 + eps ) )
+        {
+            double nRest = ( tau - idealUniProcTime ) * procSpeed[ iProc ] / aveFloatOp;
+
+            double nTarget = nMaxCell - nRest;
+            if ( nRest > this->minNode && nTarget > this->minNode )
+            {
+                //It is necessary to divide blocks only when a certain number of points are satisfied.
+                double nHalf = nMaxCell / 2.0;
+                nMaxCell = nTarget;
+                double ratio = nMaxCell / nRest;
+                double oRatio = 1.0 / ratio;
+
+                if ( std::max( ratio, oRatio ) < 3.0 )
+                {
+                    int kkk = 1;
+                    largestZone = this->Split( largestZone, nMaxCell );
+                    timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                    this->RemoveZoneFromUnsignedGroup( largestZone );
+                    this->AddZoneToProcess( iProc, largestZone );
+                }
+                else
+                {
+                    this->Split( largestZone, nHalf );
+                }
+            }
+            else
+            {
+                //If the block is of the right size, join the process directly, and there is no need to split it.
+                timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                this->RemoveZoneFromUnsignedGroup( largestZone );
+                this->AddZoneToProcess( iProc, largestZone );
+            }
+        }
+        else
+        {
+            //If the block is of the right size, join the process directly, and there is no need to split it.
+            timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+            this->RemoveZoneFromUnsignedGroup( largestZone );
+            this->AddZoneToProcess( iProc, largestZone );
+        }
+    }
+}
+
+void Partition::ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord )
+{
+    SplitZone * rootSplitZone = splitZone->GetRootZone();
+    Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+    int nNodes = splitZone->dimInfo.ComputeNumNodes();
+    std::cout << "nNodes = " << nNodes << "\n";
+
+    coord.resize( nNodes * sizeof(double) );
+
+    int index_dim = splitZone->dimInfo.dimList.size();
+    Coor * coor = zone->coors[ icoord ];
+
+    double * xlocal = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    double * xglobal = reinterpret_cast<double *>( const_cast<char *>( coor->coord.data() ) );
+    if ( index_dim == 1 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        for ( int i = imin; i < imax; ++ i )
+        {
+            xlocal[ icount++ ] = xglobal[ i ];
+        }
+    }
+    else if ( index_dim == 2 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        int jmin = splitZone->dimInfo.rmin[ 1 ] - 1;
+        int jmax = splitZone->dimInfo.rmax[ 1 ];
+        int ni = rootSplitZone->dimInfo.dimList[ 0 ];
+        int nj = rootSplitZone->dimInfo.dimList[ 1 ];
+        for ( int j = jmin; j < jmax; ++ j )
+        {
+            int jstride = j * ni;
+            for ( int i = imin; i < imax; ++ i )
+            {
+                xlocal[ icount++ ] = xglobal[ jstride + i ];
+            }
+        }
+    }
+}
+
+void Partition::DumpBc( SplitZone * splitZone )
+{
+    //std::vector< ZoneBc * > leafZoneBc;
+
+    //std::vector< ZoneBc * > & zoneBcList = splitZone->GetZoneBcList();
+
+    //for ( int i = 0; i < zoneBcList.size(); ++ i )
+    //{
+    //    std::vector< ZoneBc * > cl = zoneBcList[ i ]->GetLeaves();
+    //    for ( int j = 0; j < cl.size(); ++ j )
+    //    {
+    //        leafZoneBc.push_back( cl[ j ] );
+    //    }
+    //}
+
+    //int nZoneBc = leafZoneBc.size();
+
+    //for ( int iZoneBc = 0; iZoneBc < nZoneBc; ++ iZoneBc )
+    //{
+    //    ZoneBc * zoneBc = leafZoneBc[ iZoneBc ];
+    //    zoneBc->DumpBc();
+    //}
+}
+
+void Partition::DumpMultiBasePartitionedGridFile()
+{
+    int fileId = -1;
+    std::string filename = this->outName;
+    cg_open( filename.c_str(), CG_MODE_WRITE, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+
+    std::vector<std::string> coordnames;
+    coordnames.push_back( "CoordinateX" );
+    coordnames.push_back( "CoordinateY" );
+    coordnames.push_back( "CoordinateZ" );
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        int icelldim = Global::cell_dim;
+        int iphysdim = Global::phys_dim;
+        std::string basename = "Base" + std::to_string( iProc );
+
+        int baseId = -1;
+        cg_base_write( fileId, basename.c_str(), icelldim, iphysdim, &baseId );
+
+        std::cout << "baseId = " << baseId << "\n";
+
+        int nZones = this->GetNZones( iProc );
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            ZoneType_t zoneType = Structured;
+
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+
+            int index_dim = splitZone->dimInfo.dimList.size();
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            splitZone->dimInfo.ComputeISize();
+
+            int isize_dim = index_dim * 3;
+
+            std::vector<cgsize_t> isize( index_dim * 3, 0 );
+            for ( int m = 0; m < isize_dim; ++ m )
+            {
+                isize[ m ] = splitZone->dimInfo.isize[ m ];
+            }
+
+            int zoneId = -1;
+
+            std::string zonename = "Zone" + std::to_string( splitZone->zoneIndex );
+
+            cg_zone_write( fileId, baseId, zonename.c_str(), isize.data(), zoneType, &zoneId );
+
+            std::cout << "zoneId = " << zoneId << "\n";
+
+            splitZone->ComputeRminmax();
+
+            SplitZone * rootSplitZone = splitZone->GetRootZone();
+
+            Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+            int ncoords = zone->coors.size();
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = -1;
+                DataType_t dataType = RealDouble;
+                std::string coordname = coordnames[ icoord ];
+                Coor * coor = zone->coors[ icoord ];
+
+                int nNodes = splitZone->dimInfo.ComputeNumNodes();
+                std::cout << "nNodes = " << nNodes << "\n";
+
+                std::vector<char> coord;
+                ComputeCoor( splitZone, icoord, coord );
+
+                cg_coord_write( fileId, baseId, zoneId, dataType, coordname.c_str(), coord.data(), &coorId );
+
+                std::cout << "cg_get_error() = " << cg_get_error() << "\n";
+                std::cout << "fileId = " << fileId  << " baseId = " << baseId << " zoneId = " << zoneId  << " coorId = " << coorId << "\n";
+            }
+
+            int nBcLists = splitZone->splitBcList.size();
+            std::vector<SplitBc * > bccoList;
+            std::vector<SplitBc * > bc1to1List;
+
+            for ( int ibc = 0; ibc < nBcLists; ++ ibc )
+            {
+                SplitBc * splitBc = splitZone->splitBcList[ ibc ];
+                if ( splitBc->bcType == BCTypeUserDefined )
+                {
+                    bc1to1List.push_back( splitBc );
+                }
+                else
+                {
+                    bccoList.push_back( splitBc );
+                }
+            }
+            int nbocos = bccoList.size();
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = -1;
+                GridLocation_t location = Vertex;
+
+                std::string boconame = "BC" + std::to_string( iboco + 1 );
+
+                SplitBc * splitBc = bccoList[ iboco ];
+                BCType_t bocotype = static_cast<BCType_t>( splitBc->bcType );
+                PointSetType_t ptset_type = PointRange;
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> pnts;
+                int nSize = splitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.end[ i ] );
+                }
+
+                cg_boco_write( fileId, baseId, zoneId, boconame.c_str(), bocotype, ptset_type, npnts, pnts.data(), & bccoId );
+            }
+
+            int n1to1 = bc1to1List.size();
+            std::cout << "n1to1 = " << n1to1 << "\n";
+
+            std::vector<int> itranfrm( index_dim );
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                itranfrm[ m ] = m + 1;
+            }
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int index_conn = -1;
+
+                SplitBc * splitBc = bc1to1List[ i1to1 ];
+                BCType_t bocotype = static_cast<BCType_t>( splitBc->bcType );
+
+                std::vector<cgsize_t> pnts;
+                std::vector<cgsize_t> pntsdonor;
+                int nSize = splitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.end[ i ] );
+                }
+
+                int nPatchSize = splitBc->patch->region.start.size();
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( splitBc->patch->region.start[ i ] );
+                }
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( splitBc->patch->region.end[ i ] );
+                }
+                int id = splitBc->patch->splitZone->zoneIndex;
+                std::string donorname = "Zone" + std::to_string( id );
+                std::string connectname = "Interface" + std::to_string( i1to1 );
+
+                cg_1to1_write( fileId, baseId, zoneId, connectname.c_str(), donorname.c_str(), pnts.data(), pntsdonor.data(), itranfrm.data(), &index_conn);
+                std::cout << "index_conn = " << index_conn << "\n";
+            }
+        }
+    }
+    cg_close( fileId );
+}
+
+void Partition::DumpPartitionedGridFile()
+{
+    int fileId = -1;
+    std::string filename = this->outName;
+    cg_open( filename.c_str(), CG_MODE_WRITE, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+
+    std::vector<std::string> coordnames;
+    coordnames.push_back( "CoordinateX" );
+    coordnames.push_back( "CoordinateY" );
+    coordnames.push_back( "CoordinateZ" );
+
+    std::string basename = "Base";
+    int baseId = -1;
+    int icelldim = Global::cell_dim;
+    int iphysdim = Global::phys_dim;
+    cg_base_write( fileId, basename.c_str(), icelldim, iphysdim, &baseId );
+
+    std::cout << "baseId = " << baseId << "\n";
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        int nZones = this->GetNZones( iProc );
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            ZoneType_t zoneType = Structured;
+
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+
+            int index_dim = splitZone->dimInfo.dimList.size();
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            splitZone->dimInfo.ComputeISize();
+
+            int isize_dim = index_dim * 3;
+
+            std::vector<cgsize_t> isize( index_dim * 3, 0 );
+            for ( int m = 0; m < isize_dim; ++ m )
+            {
+                isize[ m ] = splitZone->dimInfo.isize[ m ];
+            }
+
+            int zoneId = -1;
+
+            std::string zonename = "Zone" + std::to_string( splitZone->zoneIndex );
+
+            cg_zone_write( fileId, baseId, zonename.c_str(), isize.data(), zoneType, &zoneId );
+
+            std::cout << "zoneId = " << zoneId << "\n";
+                
+            splitZone->ComputeRminmax();
+
+            SplitZone * rootSplitZone = splitZone->GetRootZone();
+
+            Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+            int ncoords = zone->coors.size();
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = -1;
+                DataType_t dataType = RealDouble;
+                std::string coordname = coordnames[ icoord ];
+                Coor * coor = zone->coors[ icoord ];
+
+                int nNodes = splitZone->dimInfo.ComputeNumNodes();
+                std::cout << "nNodes = " << nNodes << "\n";
+
+                std::vector<char> coord;
+                ComputeCoor( splitZone, icoord, coord );
+
+                cg_coord_write( fileId, baseId, zoneId, dataType, coordname.c_str(), coord.data(), &coorId );
+
+                std::cout << "cg_get_error() = " << cg_get_error() << "\n";
+                std::cout << "fileId = " << fileId  << " baseId = " << baseId << " zoneId = " << zoneId  << " coorId = " << coorId << "\n";
+            }
+
+            int nBcLists = splitZone->splitBcList.size();
+            std::vector<SplitBc * > bccoList;
+            std::vector<SplitBc * > bc1to1List;
+
+            for ( int ibc = 0; ibc < nBcLists; ++ ibc )
+            {
+                SplitBc * splitBc = splitZone->splitBcList[ ibc ];
+                if ( splitBc->bcType == BCTypeUserDefined )
+                {
+                    bc1to1List.push_back( splitBc );
+                }
+                else
+                {
+                    bccoList.push_back( splitBc );
+                }
+            }
+            int nbocos = bccoList.size();
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = -1;
+                GridLocation_t location = Vertex;
+
+                std::string boconame = "BC" + std::to_string( iboco + 1 );
+
+                SplitBc * splitBc = bccoList[ iboco ];
+                BCType_t bocotype = static_cast<BCType_t>( splitBc->bcType );
+                PointSetType_t ptset_type = PointRange;
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> pnts;
+                int nSize = splitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.end[ i ] );
+                }
+
+                cg_boco_write( fileId, baseId, zoneId, boconame.c_str(), bocotype, ptset_type, npnts, pnts.data(), & bccoId );
+            }
+
+            int n1to1 = bc1to1List.size();
+            std::cout << "n1to1 = " << n1to1 << "\n";
+
+            std::vector<int> itranfrm( index_dim );
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                itranfrm[ m ] = m + 1;
+            }
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int index_conn = -1;
+
+                SplitBc * splitBc = bc1to1List[ i1to1 ];
+                BCType_t bocotype = static_cast<BCType_t>( splitBc->bcType );
+
+                std::vector<cgsize_t> pnts;
+                std::vector<cgsize_t> pntsdonor;
+                int nSize = splitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.end[ i ] );
+                }
+
+                int nPatchSize = splitBc->patch->region.start.size();
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( splitBc->patch->region.start[ i ] );
+                }
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( splitBc->patch->region.end[ i ] );
+                }
+                int id = splitBc->patch->splitZone->zoneIndex;
+                std::string donorname = "Zone" + std::to_string( id );
+                std::string connectname = "Interface" + std::to_string( i1to1 );
+
+                cg_1to1_write( fileId, baseId, zoneId, connectname.c_str(), donorname.c_str(), pnts.data(), pntsdonor.data(), itranfrm.data(), &index_conn);
+                std::cout << "index_conn = " << index_conn << "\n";
+            }
+        }
+    }
+    cg_close( fileId );
+}
+
+void Partition::ModifyZoneIndex()
+{
+    int globalZoneId = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        std::cout << "iProc = " << iProc << "\n";
+        int nZones = this->GetNZones( iProc );
+        std::cout << "nZones in Proc " << iProc << "  = " << nZones << "\n";
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+            splitZone->SetZoneIndex( globalZoneId++ );
+        }
+    }
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage1/01/Partition.h b/example/partition/struct/2d/stage1/01/Partition.h
new file mode 100644
index 00000000..cc384b21
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01/Partition.h
@@ -0,0 +1,185 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class Dim
+{
+public:
+    static int dim;
+};
+
+class SplitZone;
+class RangeRegion;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox );
+
+class DimInfo
+{
+public:
+    DimInfo();
+    ~DimInfo();
+public:
+    int dim;
+    std::vector<int> dimList;
+    std::vector<int> oriPoint;
+    std::vector<int> isize;
+    std::vector<int> rmin;
+    std::vector<int> rmax;
+public:
+    int GetSize() const { return dim; }
+    DimInfo & operator = ( const DimInfo & rhs );
+public:
+    int ComputeNumNodes();
+    void ComputeISize();
+    void ComputeRminmax( std::vector<int> & ref );
+    void Init( int dim );
+    void Init( std::vector<int> & dimList );
+    void SetNewDimension( int axis, int newStart, int newWidth );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+};
+
+class SplitZone;
+class SplitBcPatch;
+
+class RangeRegion
+{
+public:
+    RangeRegion( int nSize = 1 );
+    ~RangeRegion();
+public:
+    int regionAxis = -1;
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    void Init( int nSize );
+    RangeRegion & operator = ( const RangeRegion & rhs );
+    bool operator == ( const RangeRegion & rhs ) const;
+    void SetRegion( std::vector<int> &pnts );
+    int ComputeRegionAxis();
+};
+
+class SplitBc
+{
+public:
+    SplitBc();
+    ~SplitBc();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone = nullptr;
+    SplitBcPatch * patch = nullptr;
+    std::vector< SplitBc * > * child = nullptr;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+    void ChangeRegionToLocalCoordinate();
+public:
+    void SetZoneBcFromParentBc( SplitBc * parentSplitBc );
+    void CreatePatchBc( SplitBc * parentSplitBc );
+};
+
+class SplitBcPatch
+{
+public:
+    SplitBcPatch ();
+    ~SplitBcPatch();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+};
+
+
+class SplitZone
+{
+public:
+    SplitZone();
+    ~SplitZone();
+public:
+    DimInfo dimInfo;
+    int zoneIndex, iProc;
+protected:
+    SplitZone * parent;
+public:
+    std::vector< SplitBc * > splitBcList;
+public:
+    int GetNCell();
+    void ComputeRminmax();
+    void GetRootInfo( SplitZone *& root, std::vector<int> & ref );
+    void SetZoneIndex( int zoneIndex ) { this->zoneIndex = zoneIndex; }
+    int  GetZoneIndex() { return zoneIndex; }
+    void SetProcId( int iProc ) { this->iProc = iProc; }
+    void SetParent( SplitZone * parent ) { this->parent = parent; };
+    std::vector< SplitBc * > & GetSplitBcList() { return this->splitBcList; };
+    void CreateBcFromParent();
+    void CreateSplitBc( SplitBc * parentSplitBc );
+    void AddSplitBc( SplitBc * splitBc );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+    SplitZone * GetRootZone();
+public:
+    void Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell );
+    void SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+    void SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+private:
+    int FindAxisNeedSplit();
+    int FindSplitPosition( int axisNeedSplit, double nCell );
+    bool IsPoleBc( int splitDirection );
+    int GetCrossSection( int axis );
+};
+
+class Partition
+{
+public:
+    Partition();
+    ~Partition();
+protected:
+    std::set < SplitZone * > zoneStorage;
+    std::set < SplitZone * > unsignedZoneGroup;
+    std::vector< SplitZone * > refZone;
+    std::vector< std::vector< SplitZone * > > procSplitZone;
+    std::vector<double> procSpeed;
+    std::vector<double> timeProc;
+    double aveFloatOp, delta;
+    double idealUniProcTime, eps;
+    int minNode;
+    int nTZone;
+    int nOriZone;
+    int nProc;
+public:
+    std::string inputName;
+    std::string outName;
+public:
+    void Solve();
+    void ReadGrid();
+    void Split();
+    void InitSplit();
+    void BinarySplit();
+    //void GreedySplit();
+public:
+    void AddNewZone( SplitZone * zone );
+    void AddZoneToUnsignedGroup( SplitZone * zone );
+    void RemoveZoneFromUnsignedGroup( SplitZone * zone );
+    void AddZoneToProcess( int iProc, SplitZone * zone );
+    void DumpMultiBasePartitionedGridFile();
+    void DumpPartitionedGridFile();
+    void ModifyZoneIndex();
+    void FreeAllZones();
+    int GetNZones( int iProc );
+    SplitZone * GetSplitZone( int iProc, int zoneId );
+    void ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord );
+    void DumpBc( SplitZone * splitZone );
+private:
+    int GetMinValueIndex( double * data, int numberOfData );
+    int GetMinLoadProc();
+    SplitZone * GetLargestZone();
+    SplitZone * Split( SplitZone * zone, double nCell );
+};
+
diff --git a/example/partition/struct/2d/stage1/01/README.txt b/example/partition/struct/2d/stage1/01/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/partition/struct/2d/stage1/01/heat2d2blocks.cgns b/example/partition/struct/2d/stage1/01/heat2d2blocks.cgns
new file mode 100644
index 00000000..a9fd7ac5
Binary files /dev/null and b/example/partition/struct/2d/stage1/01/heat2d2blocks.cgns differ
diff --git a/example/partition/struct/2d/stage1/01/main.cpp b/example/partition/struct/2d/stage1/01/main.cpp
new file mode 100644
index 00000000..5da1de7c
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01/main.cpp
@@ -0,0 +1,18 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include "Partition.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip>
+
+int main(int argc, char **argv)
+{
+    Partition * partition = new Partition();
+    partition->Solve();
+    delete partition;
+
+    return 0;
+}
diff --git a/example/partition/struct/2d/stage1/01a/CMakeLists.txt b/example/partition/struct/2d/stage1/01a/CMakeLists.txt
new file mode 100644
index 00000000..9fa577c8
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01a/CMakeLists.txt
@@ -0,0 +1,77 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	Partition.h Partition.cpp
+	CgnsGrid.h CgnsGrid.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/partition/struct/2d/stage1/01a/CgnsGrid.cpp b/example/partition/struct/2d/stage1/01a/CgnsGrid.cpp
new file mode 100644
index 00000000..d287afcb
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01a/CgnsGrid.cpp
@@ -0,0 +1,345 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include <map>
+
+Grid::Grid()
+{
+    ;
+}
+
+Grid::~Grid()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if( (i+1)%5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+    delete this->patch;
+}
+
+ZoneBcPatch::ZoneBcPatch()
+{
+    ;
+}
+
+ZoneBcPatch::~ZoneBcPatch()
+{
+}
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+Global::Global()
+{
+    ;
+}
+
+Global::~Global()
+{
+}
+
+void Global::FreeData()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+    zones.resize( 0 );
+}
+
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            //baseZone.baseId = baseId;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin( index_dim );
+            std::vector<cgsize_t> irmax( index_dim );
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                std::vector<char> coord( nNodes * sizeof(double) );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+                coor->DumpCoor();
+            }
+
+            int nbocos = -1;
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc->pnts.push_back( range[ i ] );
+                }
+
+                zonebc->zoneid = gZoneId;
+                zonebc->bcType = BCTypeUserDefined;
+
+                ZoneBcPatch * patch = new ZoneBcPatch();
+                zonebc->patch = patch;
+
+                patch->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    patch->donor_pnts.push_back( donor_range[ i ] );
+                }
+                int kkk = 1;
+            }
+        }
+        int kkk = 1;
+    }
+    int kkk = 1;
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage1/01a/CgnsGrid.h b/example/partition/struct/2d/stage1/01a/CgnsGrid.h
new file mode 100644
index 00000000..af67a321
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01a/CgnsGrid.h
@@ -0,0 +1,123 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <map>
+
+class Grid;
+
+class Zone;
+
+class Grid
+{
+public:
+    Grid();
+    ~Grid();
+public:
+    int nZone;
+    std::vector<double> x;
+    std::vector<Zone *> zones;
+};
+
+class ZoneBc;
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+};
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<Coor *> coors;
+};
+
+class ZoneBcPatch;
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+    ZoneBcPatch * patch = nullptr;
+};
+
+class ZoneBcPatch
+{
+public:
+    ZoneBcPatch();
+    ~ZoneBcPatch();
+public:
+    int donor_zoneid;
+    std::vector<int> donor_pnts;
+};
+
+class BaseZone
+{
+public:
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Global
+{
+public:
+    Global();
+    ~Global();
+public:
+    static int cell_dim;
+    static int phys_dim;
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+public:
+    static void FreeData();
+};
+
+void ReadCgnsGrid( const std::string & filename );
+void ReadCgnsGridBaseZone( const std::string & filename );
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage1/01a/Partition.cpp b/example/partition/struct/2d/stage1/01a/Partition.cpp
new file mode 100644
index 00000000..6b35b19b
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01a/Partition.cpp
@@ -0,0 +1,1452 @@
+#include "Partition.h"
+#include "CgnsGrid.h"
+#include "cgnslib.h"
+#include <string>
+
+int Dim::dim = -1;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox  )
+{
+    domainBox.start = zoneBox.start;
+    domainBox.end = zoneBox.end;
+
+    int axis = iDomain / 2;
+    int direction = iDomain % 2;
+
+    if ( direction == 0 )
+    {
+        domainBox.end[ axis ] = domainBox.start[ axis ];
+    }
+    else if ( direction == 1 )
+    {
+        domainBox.start[ axis ] = domainBox.end[ axis ];
+    }
+}
+
+DimInfo::DimInfo()
+{
+    this->Init( 1 );
+}
+
+DimInfo::~DimInfo()
+{
+}
+
+void DimInfo::Init( int dim )
+{
+    this->dim = dim;
+    dimList.resize( this->dim, 1 );
+    oriPoint.resize( this->dim, 0 );
+}
+
+DimInfo & DimInfo::operator = ( const DimInfo & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->dim = rhs.dim;
+    this->dimList = rhs.dimList;
+    this->oriPoint = rhs.oriPoint;
+
+    return * this;
+}
+
+int DimInfo::ComputeNumNodes()
+{
+    int nNodes = 1;
+    for ( int m = 0; m < this->dimList.size(); ++ m )
+    {
+        nNodes *= this->dimList[ m ];
+    }
+    return nNodes;
+}
+
+void DimInfo::ComputeISize()
+{
+    int index_dim = this->dimList.size();
+    this->isize.resize( index_dim * 3, 0 );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        isize[ m ] = this->dimList[ m ];
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 1;
+        isize[ start + m ] = this->dimList[ m ] - 1;
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 2;
+        isize[ start + m ] = 0;
+    }
+
+    for ( int i = 0; i < isize.size(); ++ i )
+    {
+        std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+    }
+}
+
+void DimInfo::ComputeRminmax( std::vector<int> & ref )
+{
+    int index_dim = this->dimList.size();
+    this->rmin.resize( index_dim );
+    this->rmax.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        rmin[ m ] = ref[ m ] + 1;
+        rmax[ m ] = ref[ m ] + this->dimList[ m ];
+    }
+
+    std::cout << "rmin, rmax = \n";
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        std::cout << rmin[ m ] << " " << rmax[ m ] << "\n";
+    }
+}
+
+void DimInfo::Init( std::vector<int> & dimList )
+{
+    this->dim = dimList.size();
+    this->dimList = dimList;
+    std::vector<int> zero( dimList.size(), 0 );
+    this->oriPoint = zero;
+}
+
+void DimInfo::SetNewDimension( int axis, int newStart, int newWidth )
+{
+    this->oriPoint[ axis ] = newStart;
+    this->dimList [ axis ] = newWidth;
+}
+
+void DimInfo::GetZoneGlobalBox( RangeRegion &zoneBox )
+{
+    int index_dim = this->dimList.size();
+    zoneBox.start.resize( index_dim );
+    zoneBox.end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        zoneBox.start[ m ] = this->oriPoint[ m ] + 1;
+        zoneBox.end[ m ] = this->oriPoint[ m ] + this->dimList[ m ];
+    }
+}
+
+void DimInfo::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    int index_dim = this->dimList.size();
+    localBox.start.resize( index_dim );
+    localBox.end.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        localBox.start[ m ] = globalBox.start[ m ] - this->oriPoint[ m ];
+        localBox.end[ m ] = globalBox.end[ m ] - this->oriPoint[ m ];
+    }
+}
+
+RangeRegion::RangeRegion( int nSize )
+{
+    this->Init( nSize );
+}
+
+RangeRegion::~RangeRegion()
+{
+}
+
+void RangeRegion::Init( int nSize )
+{
+    this->start.resize( nSize );
+    this->end.resize( nSize );
+}
+
+RangeRegion & RangeRegion::operator = ( const RangeRegion & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+    this->regionAxis = rhs.regionAxis;
+
+    return * this;
+}
+
+bool RangeRegion::operator == ( const RangeRegion & rhs ) const
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] != rhs.start[ m ] || 
+            this->end  [ m ] != rhs.end  [ m ] )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+    this->ComputeRegionAxis();
+}
+
+int RangeRegion::ComputeRegionAxis()
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] == this->end[ m ] )
+        {
+            this->regionAxis = m;
+            return this->regionAxis;
+        }
+    }
+    return this->regionAxis;
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion );
+
+//bool ComputeOverlapRegion( RangeRegion & region1, RangeRegion & region2, RangeRegion & overlapRegion )
+//{
+//    int index_dim = region1.start.size();
+//    overlapRegion.Init( index_dim );
+//    for ( int m = 0; m < index_dim; ++ m )
+//    {
+//        overlapRegion.start[ m ] = std::max( region1.start[ m ], region2.start[ m ] );
+//        overlapRegion.end  [ m ] = std::min( region1.end  [ m ], region2.end  [ m ] );
+//    }
+//
+//    return CheckOverLapping( overlapRegion );
+//}
+
+bool ComputeOverlapRegion( RangeRegion & region1, RangeRegion & region2, RangeRegion & overlapRegion )
+{
+    int index_dim = region1.start.size();
+    overlapRegion.Init( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int ijkmin1 = std::min( region1.start[ m ], region1.end[ m ] );
+        int ijkmax1 = std::max( region1.start[ m ], region1.end[ m ] );
+        int ijkmin2 = std::min( region2.start[ m ], region2.end[ m ] );
+        int ijkmax2 = std::max( region2.start[ m ], region2.end[ m ] );
+        if ( ( ijkmax1 < ijkmin2 ) || ( ijkmin1 > ijkmax2 ) )
+        {
+            return false;
+        }
+
+        int ijkmin = std::max( ijkmin1, ijkmin2 );
+        int ijkmax = std::min( ijkmax1, ijkmax2 );
+
+        overlapRegion.start[ m ] = ijkmin;
+        overlapRegion.end  [ m ] = ijkmax;
+    }
+
+    return CheckOverLapping( overlapRegion );
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion )
+{
+    int index_dim = overlapRegion.start.size();
+    int iCount = 0;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        if ( overlapRegion.start[ m ] == overlapRegion.end[ m ] )
+        {
+            ++ iCount;
+        }
+    }
+
+    return ( iCount == 1 );
+}
+
+bool GetInterfaceRegion( RangeRegion & zoneBoxL, RangeRegion & zoneBoxR, RangeRegion & interfaceRegion )
+{
+    int index_dim = zoneBoxL.start.size();
+    int nDomains = 2 * index_dim;
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegionL;
+        GetDomainRegion( zoneBoxL, iDomain, domainRegionL );
+
+        for ( int jDomain = 0; jDomain < nDomains; ++ jDomain )
+        {
+            RangeRegion domainRegionR;
+            GetDomainRegion( zoneBoxR, jDomain, domainRegionR );
+
+            if ( domainRegionL == domainRegionR )
+            {
+                interfaceRegion = domainRegionL;
+                return true;
+            }
+        }
+    }
+    return false;
+}
+
+void CreateInterfaceBc( SplitZone * zoneL, SplitZone * zoneR )
+{
+    RangeRegion globalBoxL, globalBoxR, globalInterfaceRegion;
+
+    zoneL->GetZoneGlobalBox( globalBoxL );
+    zoneR->GetZoneGlobalBox( globalBoxR );
+
+    if ( ! GetInterfaceRegion( globalBoxL, globalBoxR, globalInterfaceRegion ) )
+    {
+        int kkk = 1;
+        return;
+    }
+
+    RangeRegion localInterfaceRegionL, localInterfaceRegionR;
+
+    zoneL->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionL );
+    zoneR->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionR );
+
+    int kkk = 1;
+
+    SplitBc * splitBcL = new SplitBc();
+    zoneL->AddSplitBc( splitBcL );
+
+    SplitBc * splitBcR = new SplitBc();
+    zoneR->AddSplitBc( splitBcR );
+
+    splitBcL->splitZone = zoneL;
+    splitBcL->SetRegion( localInterfaceRegionL );
+    splitBcL->bcType = BCTypeUserDefined;
+
+    splitBcR->splitZone = zoneR;
+    splitBcR->SetRegion( localInterfaceRegionR );
+    splitBcR->bcType = BCTypeUserDefined;
+
+    //localInterfaceRegionL.MarkPatchBc();
+    //localInterfaceRegionR.MarkPatchBc();
+
+    SplitBcPatch * splitBcPatchL = new SplitBcPatch();
+    splitBcL->patch = splitBcPatchL;
+    splitBcPatchL->region = localInterfaceRegionR;
+    splitBcPatchL->splitZone = zoneR;
+
+    SplitBcPatch * splitBcPatchR = new SplitBcPatch();
+    splitBcR->patch = splitBcPatchR;
+    splitBcPatchR->region = localInterfaceRegionL;
+    splitBcPatchR->splitZone = zoneL;
+
+    //splitBcL->Normalize();
+    //splitBcR->Normalize();
+}
+
+
+SplitBc::SplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+SplitBc::~SplitBc()
+{
+    delete this->patch;
+}
+
+void SplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void SplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+void SplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = splitZone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void SplitBc::SetZoneBcFromParentBc( SplitBc * parentSplitBc )
+{
+    this->bcType = parentSplitBc->bcType;
+    //this->LocalCoordinate();
+    this->region.regionAxis = parentSplitBc->region.regionAxis;
+    this->CreatePatchBc( parentSplitBc );
+}
+
+void SplitBc::CreatePatchBc( SplitBc * parentSplitBc )
+{
+    if ( parentSplitBc->bcType !=  BCTypeUserDefined ) return;
+
+    this->patch = new SplitBcPatch();
+    this->patch->splitZone = parentSplitBc->patch->splitZone;
+    this->patch->SetRegion( parentSplitBc->patch->region );
+    int kkk = 1;
+
+    //this->patch->faceAxis = parentSplitBc->patch->faceAxis;
+
+    //( * this->patch->vertexMap ) = ( * parentBc->patch->vertexMap );
+
+    ////È»ºó½øÐÐÐÞÕý
+    ////block1->map 1, 33 -> block1 369, 337
+    ////block2->global -> map 1, 33 -> block1 369, 337
+    ////block2->local  -> map 1, 33 -> block1 369, 337
+    ////refOld + M * stold           = block1Startold
+    ////refOld + M * ( stnew + ref ) = block1Startold
+    ////refNew = refOld + M * ( ref )
+
+    //for ( int m = 0; m < 3; ++ m )
+    //{
+    //    for ( int n = 0; n < 3; ++ n )
+    //    {
+    //        this->patch->vertexMap->pt[ m ] += this->patch->vertexMap->vm[ m ][ n ] * ( this->splitZone->sdim->oriPoint )[ n ];
+    //    }
+    //}
+
+    //RangeBox tRangeBox;
+
+    //MappingPatchPoint( this->patch, this->rangeBox, tRangeBox );
+    //tRangeBox.SetOrder();
+
+    ////ÕÒµ½ºÍ±¾¶Ô½Ó±ß½çÏà¶ÔÓ¦µÄ¿é
+    ////´Ópatch->splitZone°´ÕÕoverlapµÄ´óСÕÒµ½¶ÔÓ¦µÄ¶Ô½Ó±ß½ç£¬ÕâÑùÖÁÉÙ¿ÉÒÔÕÒµ½
+    ////¶ÔÃæµÄ¶Ô½Ó±ß½çÌõ¼þÓÉÓÚ±¾¿éµÄsplit±ØȻҪ·¢Éú¸Ä±ä£¬ÕâÀｫÏà¹Ø±ß½ç¼ÓÈë×ӱ߽ç
+    //this->patch->splitZone->CreateChildPatchBc( tRangeBox, this->splitZone );
+}
+
+SplitBcPatch::SplitBcPatch()
+{
+    this->region.Init( Dim::dim );
+}
+
+SplitBcPatch::~SplitBcPatch()
+{
+}
+
+void SplitBcPatch::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void SplitBcPatch::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+SplitZone::SplitZone()
+{
+    this->parent  = 0;
+    this->zoneIndex = 0;
+    this->iProc = 0;
+    dimInfo.Init( Dim::dim );
+    int kk = 1;
+}
+
+SplitZone::~SplitZone()
+{
+    ;
+}
+
+void SplitZone::GetZoneGlobalBox( RangeRegion & zoneBox )
+{
+    this->dimInfo.GetZoneGlobalBox( zoneBox );
+}
+
+void SplitZone::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    this->dimInfo.GetZoneLocalBox( globalBox, localBox );
+}
+
+
+void SplitZone::ComputeRminmax()
+{
+    int index_dim = this->dimInfo.dimList.size();
+    std::vector<int> ref( index_dim, 0 );
+
+    SplitZone * rootSplitZone = 0;
+    this->GetRootInfo( rootSplitZone, ref );
+
+    this->dimInfo.ComputeRminmax( ref );
+}
+
+SplitZone * SplitZone::GetRootZone()
+{
+    SplitZone * root = this;
+
+    while ( true )
+    {
+        if ( root->parent )
+        {
+            root = root->parent;
+        }
+        else
+        {
+            return root;
+        }
+    };
+}
+
+void SplitZone::GetRootInfo( SplitZone *& root, std::vector<int> & ref )
+{
+    for ( int i = 0; i < this->dimInfo.dimList.size(); ++ i )
+    {
+        ref[ i ] += this->dimInfo.oriPoint[ i ];
+    }
+
+    if ( this->parent )
+    {
+        this->parent->GetRootInfo( root, ref );
+    }
+    else
+    {
+        root = this;
+    }
+}
+
+
+int SplitZone::GetNCell()
+{
+    int numberOfCells = 1;
+    for ( int i = 0; i < this->dimInfo.dim; ++ i )
+    {
+        numberOfCells *= std::max( 1, ( this->dimInfo.dimList[ i ] - 1 ) );
+    }
+
+    return numberOfCells; 
+}
+
+void SplitZone::SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int leftStart = 0;
+    int leftWidth = iSplit - 0;
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, leftStart , leftWidth  );
+}
+
+void SplitZone::SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int rightStart = iSplit - 1;
+    int rightWidth = dimList[ axisNeedSplit ] - ( iSplit - 1 );
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, rightStart, rightWidth );
+}
+
+void SplitZone::Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell )
+{
+    //Find the longest axis
+    int axisNeedSplit = this->FindAxisNeedSplit();
+    int iSplit        = this->FindSplitPosition( axisNeedSplit, nCell );
+
+    zoneL = new SplitZone();
+    zoneL->SetParent( this );
+
+    zoneR = new SplitZone();
+    zoneR->SetParent( this );
+
+    zoneL->SetLeftDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+    zoneR->SetRightDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+
+    zoneL->CreateBcFromParent();
+    zoneR->CreateBcFromParent();
+
+    CreateInterfaceBc( zoneL, zoneR );
+}
+
+void SplitZone::CreateBcFromParent()
+{
+    std::vector< SplitBc * > & parentSplitBcList = this->parent->GetSplitBcList();
+
+    int nParentSplitBcs = parentSplitBcList.size();
+
+    for ( int iParentBc = 0; iParentBc < nParentSplitBcs; ++ iParentBc )
+    {
+        SplitBc * parentSplitBc = parentSplitBcList[ iParentBc ];
+
+        this->CreateSplitBc( parentSplitBc );
+    }
+}
+
+void SplitZone::AddSplitBc( SplitBc * splitBc )
+{
+    if ( ! splitBc ) return;
+    this->splitBcList.push_back( splitBc );
+}
+
+void SplitZone::CreateSplitBc( SplitBc * parentSplitBc )
+{
+    if ( ! parentSplitBc->child )
+    {
+        int index_dim = this->dimInfo.dimList.size();
+        int nDomains = 2 * index_dim;
+        RangeRegion zoneBoxRegion( index_dim );
+        this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+        for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+        {
+            RangeRegion domainRegion( index_dim );
+            GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+            RangeRegion overlapRegion;
+            bool overlap_flag = ComputeOverlapRegion( parentSplitBc->region, domainRegion, overlapRegion );
+            if ( ! overlap_flag ) continue;
+
+            SplitBc * splitBc = new SplitBc();
+            this->AddSplitBc( splitBc );
+
+            splitBc->SetRegion( overlapRegion );
+            splitBc->bcType = parentSplitBc->bcType;
+            splitBc->splitZone = this;
+            splitBc->ChangeRegionToLocalCoordinate();
+            splitBc->CreatePatchBc( parentSplitBc );
+            int kkk = 1;
+        }
+    }
+    else
+    {
+        int nChilds = parentSplitBc->child->size();
+        for ( int iChild = 0; iChild < nChilds; ++ iChild )
+        {
+            this->CreateSplitBc( ( * parentSplitBc->child )[ iChild ] );
+        }
+    }
+}
+
+
+int SplitZone::FindAxisNeedSplit()
+{
+    //Find the longest axis
+    int axisNeedSplit = 0;
+    int maxN = this->dimInfo.dimList[ 0 ];
+
+    for ( int m = 1; m < this->dimInfo.dimList.size(); ++ m )
+    {
+        if ( this->IsPoleBc( m ) )
+        {
+            continue;
+        }
+        int Nm = this->dimInfo.dimList[ m ];
+        if ( maxN < Nm )
+        {
+            maxN = Nm;
+            axisNeedSplit = m;
+        }
+    }
+
+    return axisNeedSplit;
+}
+
+int SplitZone::GetCrossSection( int axis )
+{
+    int nDim = this->dimInfo.dimList.size();
+    int crossSection = 1;
+    int N = nDim - 1;
+    for ( int m = 0; m < N; ++ m )
+    {
+         int mm = ( axis + 1 ) % nDim;
+         int nLineElements = std::max( 1, ( this->dimInfo.dimList[ mm ] - 1 ) );
+         crossSection *= nLineElements;
+    }
+    return crossSection;
+}
+
+int SplitZone::FindSplitPosition( int axisNeedSplit, double nCell )
+{
+    int nDim = this->dimInfo.dimList.size();
+    std::vector<int> crossSections( nDim );
+    for ( int m = 0; m < nDim; ++ m )
+    {
+        crossSections[ m ] = this->GetCrossSection( m );
+    }
+
+    //guess the value
+    double dSplit = nCell / crossSections[ axisNeedSplit ];
+    int  iSplit = 1 + static_cast< int >( std::floor( dSplit + 0.5 ) );
+    return iSplit;
+}
+
+
+bool SplitZone::IsPoleBc( int splitDirection )
+{
+    return false;
+}
+
+
+double CalSumOfProcSpeed( std::vector<double> & procSpeed );
+double CalSumOfProcSpeed( std::vector<double> & procSpeed )
+{
+    int nProc = procSpeed.size();
+    double sumOfProcSpeed = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        sumOfProcSpeed += procSpeed[ iProc ];
+    }
+    return sumOfProcSpeed;
+}
+
+Partition::Partition()
+{
+    this->inputName = "../heat2d1blocks.cgns";
+    this->outName =  "../heat2dpart.cgns";
+}
+
+Partition::~Partition()
+{
+    ;
+}
+
+int Partition::GetMinValueIndex( double * data, int numberOfData )
+{
+    double minValue = data[ 0 ];
+    int minimumValueIndex = 0;
+
+    for ( int iData = 1; iData < numberOfData; ++ iData )
+    {
+        if ( minValue > data[ iData ] )
+        {
+            minValue      = data[ iData ];
+            minimumValueIndex = iData;
+        }
+    }
+    return minimumValueIndex;
+}
+
+int Partition::GetMinLoadProc()
+{
+    return this->GetMinValueIndex( this->timeProc.data(), this->nProc );
+}
+
+SplitZone * Partition::GetLargestZone()
+{
+    SplitZone * largestZone = 0;
+
+    double nMaxCell = 0.0;
+
+    for ( std::set< SplitZone * >::iterator iter = unsignedZoneGroup.begin(); iter != unsignedZoneGroup.end(); ++ iter )
+    {
+        double nSize = ( * iter )->GetNCell();
+        if ( nMaxCell < nSize )
+        {
+            nMaxCell    = nSize;
+            largestZone = * iter;
+        }
+    }
+
+    return largestZone;
+}
+
+void Partition::Solve()
+{
+    std::cout << "Partition::Split()\n";
+    this->nProc = 2;
+    //this->nProc = 4;
+    this->ReadGrid();
+    this->Split();
+    this->ModifyZoneIndex();
+    this->DumpPartitionedGridFile();
+    this->FreeAllZones();
+}
+
+void Partition::ReadGrid()
+{
+    ReadCgnsGridBaseZone( this->inputName );
+    ReadCgnsGrid( this->inputName );
+
+    this->nOriZone = ::Global::zones.size();
+    Dim::dim = Global::cell_dim;
+
+    std::cout << "numberOfBlocks = " << nOriZone << "\n";
+
+    this->refZone.resize( nOriZone );
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = new SplitZone();
+        refZone[ iZone ] = splitZone;
+
+        splitZone->SetZoneIndex( iZone );
+        splitZone->SetProcId( 0 );
+        splitZone->SetParent( 0 );
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        Zone * zone = ::Global::zones[ iZone ];
+
+        splitZone->dimInfo.dimList = zone->nijk;
+
+        int nBcRegion = zone->bccos.size();
+        std::cout << "nBcRegion = " << nBcRegion << "\n";
+
+        std::vector< SplitBc * > & splitBcList = splitZone->splitBcList;
+
+        for ( int iBcRegion = 0; iBcRegion < nBcRegion; ++ iBcRegion )
+        {
+            SplitBc * splitBc = new SplitBc();
+            splitBcList.push_back( splitBc );
+
+            ZoneBc * zoneBc = zone->bccos[ iBcRegion ];
+
+            splitBc->splitZone = splitZone;
+            splitBc->bcType = zoneBc->bcType;
+            splitBc->SetRegion( zoneBc->pnts );
+            if ( zoneBc->patch )
+            {
+                SplitBcPatch * patch = new SplitBcPatch();
+                splitBc->patch = patch;
+
+                patch->splitZone = refZone[ zoneBc->patch->donor_zoneid ];
+                patch->SetRegion( zoneBc->patch->donor_pnts );
+            }
+        }
+
+        int kkk = 1;
+    }
+    int kkk = 1;
+}
+
+void Partition::Split()
+{
+    this->InitSplit();
+    this->BinarySplit();
+    //this->SetZoneIndex();
+}
+
+void Partition::InitSplit()
+{
+    //nZone is the number of zones in the original grid
+    //nProc is not the number of blocks in the end, but the number of processes that need to be divided.
+    //This difference occurs because the structure grid can have many blocks per process.
+
+    //this->nProc    = nProc;
+    //this->nPhyBlocks = referenceBlock.size();
+    //this->nZone  = this->nPhyBlocks;
+
+    //tj Computation time on processor j
+    //Nk Number of internal grid-cells for zone j
+    //aveFloatOp:  Number of Real operations per gridcell
+    //Gj The set of blocks allocated to process j
+    //Pj Real operations per second for process j
+
+    //The Greedy Load Balancing Algorithm
+    //1.Compute an "ideal" uniprocessor time, Tuni = sum ( Nk * aveFloatOp )/ sum( Pj ).
+    //2.Set the group of unassigned blocks, Gu, to contain all blocks. The number of blocks in Nu=M, where M is the total number of blocks in the mesh.
+    //3.Start all processors with a very small fictitious zone to get a start tj=delt aveFloatOp/Pj, where delt<<1 is the size of the very small fictious zone.
+    //This is used to find the fastest processor in a heterogeneous system, tj could otherwise be set to 0 in the homogeneous case.
+    this->aveFloatOp = 1.0;
+    this->delta      = 1.0e-5;
+    this->procSpeed.resize( nProc );
+    this->timeProc.resize( nProc );
+
+    this->nTZone = this->nOriZone;
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        procSpeed[ iProc ] = 1.0;
+    }
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        timeProc[ iProc ] = delta * aveFloatOp / procSpeed[ iProc ];
+    }
+
+    double sumProcSpeed = CalSumOfProcSpeed( procSpeed );
+
+    double sumProcOp = 0.0;
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        sumProcOp += refZone[ iZone ]->GetNCell() * aveFloatOp;
+    }
+
+    this->idealUniProcTime = sumProcOp / sumProcSpeed;
+
+    this->eps = 0.05;
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        unsignedZoneGroup.insert( refZone[ iZone ] );
+    }
+
+    //Init zoneStorage
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        zoneStorage.insert( refZone[ iZone ] );
+    }
+
+    //Assign procSplitZone to each process
+    procSplitZone.resize( nProc );
+
+    this->minNode = 1;
+    for ( int m = 0; m < Dim::dim; ++ m )
+    {
+        this->minNode *= 2;
+    }
+
+    int kkk = 1;
+
+}
+
+void Partition::FreeAllZones()
+{
+    int iCount = 0;
+    for ( std::set < SplitZone * >::iterator iter = zoneStorage.begin(); iter != zoneStorage.end(); ++ iter )
+    {
+        //cout << "iCount = " << iCount << "\n";
+        ++ iCount;
+        delete * iter;
+    }
+}
+
+int Partition::GetNZones( int iProc )
+{
+    return this->procSplitZone[ iProc ].size();
+}
+
+SplitZone * Partition::GetSplitZone( int iProc, int zoneId )
+{
+    return this->procSplitZone[ iProc ][ zoneId ];
+}
+
+void Partition::AddZoneToUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.insert( zone );
+}
+
+void Partition::RemoveZoneFromUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.erase( zone );
+}
+
+void Partition::AddZoneToProcess( int iProc, SplitZone * zone )
+{
+    this->procSplitZone[ iProc ].push_back( zone );
+}
+
+void Partition::AddNewZone( SplitZone * zone )
+{
+    zone->SetZoneIndex( nTZone ++ );
+
+    this->AddZoneToUnsignedGroup( zone );
+
+    this->zoneStorage.insert( zone );
+}
+
+SplitZone * Partition::Split( SplitZone * zone, double nCell )
+{
+    SplitZone * zoneL = 0;
+    SplitZone * zoneR = 0;
+
+    zone->Split( zoneL, zoneR, nCell );
+
+    this->AddNewZone( zoneL );
+    this->AddNewZone( zoneR );
+    this->RemoveZoneFromUnsignedGroup( zone );
+
+    return zoneL;
+}
+
+void Partition::BinarySplit()
+{
+    while ( ! unsignedZoneGroup.empty() )
+    {
+        std::cout << "number of unsigned zone = " << unsignedZoneGroup.size() << "\n";
+        int iProc = this->GetMinLoadProc();
+
+        //Get the block with the largest number of grids and its size
+        SplitZone * largestZone = this->GetLargestZone();
+
+        double nMaxCell = largestZone->GetNCell();
+
+        double aveFloatOp = this->aveFloatOp;
+        double tau = timeProc[ iProc ] + nMaxCell * aveFloatOp / procSpeed[ iProc ];
+
+        int kkk = 1;
+
+        //It seems that EPS is still necessary
+        //The idea here is as follows. For the candidate blocks which can be divided into blocks, 
+        //if the difference between the target blocks and the candidate blocks is too wide, 
+        //the binarySplit method is adopted. The binarySplit blocks do not directly join the process,
+        //but enter the next round of screening.
+
+        if ( tau > idealUniProcTime * ( 1.0 + eps ) )
+        {
+            double nRest = ( tau - idealUniProcTime ) * procSpeed[ iProc ] / aveFloatOp;
+
+            double nTarget = nMaxCell - nRest;
+            if ( nRest > this->minNode && nTarget > this->minNode )
+            {
+                //It is necessary to divide blocks only when a certain number of points are satisfied.
+                double nHalf = nMaxCell / 2.0;
+                nMaxCell = nTarget;
+                double ratio = nMaxCell / nRest;
+                double oRatio = 1.0 / ratio;
+
+                if ( std::max( ratio, oRatio ) < 3.0 )
+                {
+                    int kkk = 1;
+                    largestZone = this->Split( largestZone, nMaxCell );
+                    timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                    this->RemoveZoneFromUnsignedGroup( largestZone );
+                    this->AddZoneToProcess( iProc, largestZone );
+                }
+                else
+                {
+                    this->Split( largestZone, nHalf );
+                }
+            }
+            else
+            {
+                //If the block is of the right size, join the process directly, and there is no need to split it.
+                timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                this->RemoveZoneFromUnsignedGroup( largestZone );
+                this->AddZoneToProcess( iProc, largestZone );
+            }
+        }
+        else
+        {
+            //If the block is of the right size, join the process directly, and there is no need to split it.
+            timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+            this->RemoveZoneFromUnsignedGroup( largestZone );
+            this->AddZoneToProcess( iProc, largestZone );
+        }
+    }
+}
+
+void Partition::ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord )
+{
+    SplitZone * rootSplitZone = splitZone->GetRootZone();
+    Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+    int nNodes = splitZone->dimInfo.ComputeNumNodes();
+    std::cout << "nNodes = " << nNodes << "\n";
+
+    coord.resize( nNodes * sizeof(double) );
+
+    int index_dim = splitZone->dimInfo.dimList.size();
+    Coor * coor = zone->coors[ icoord ];
+
+    double * xlocal = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    double * xglobal = reinterpret_cast<double *>( const_cast<char *>( coor->coord.data() ) );
+    if ( index_dim == 1 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        for ( int i = imin; i < imax; ++ i )
+        {
+            xlocal[ icount++ ] = xglobal[ i ];
+        }
+    }
+    else if ( index_dim == 2 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        int jmin = splitZone->dimInfo.rmin[ 1 ] - 1;
+        int jmax = splitZone->dimInfo.rmax[ 1 ];
+        int ni = rootSplitZone->dimInfo.dimList[ 0 ];
+        int nj = rootSplitZone->dimInfo.dimList[ 1 ];
+        for ( int j = jmin; j < jmax; ++ j )
+        {
+            int jstride = j * ni;
+            for ( int i = imin; i < imax; ++ i )
+            {
+                xlocal[ icount++ ] = xglobal[ jstride + i ];
+            }
+        }
+    }
+}
+
+void Partition::DumpBc( SplitZone * splitZone )
+{
+    //std::vector< ZoneBc * > leafZoneBc;
+
+    //std::vector< ZoneBc * > & zoneBcList = splitZone->GetZoneBcList();
+
+    //for ( int i = 0; i < zoneBcList.size(); ++ i )
+    //{
+    //    std::vector< ZoneBc * > cl = zoneBcList[ i ]->GetLeaves();
+    //    for ( int j = 0; j < cl.size(); ++ j )
+    //    {
+    //        leafZoneBc.push_back( cl[ j ] );
+    //    }
+    //}
+
+    //int nZoneBc = leafZoneBc.size();
+
+    //for ( int iZoneBc = 0; iZoneBc < nZoneBc; ++ iZoneBc )
+    //{
+    //    ZoneBc * zoneBc = leafZoneBc[ iZoneBc ];
+    //    zoneBc->DumpBc();
+    //}
+}
+
+void Partition::DumpMultiBasePartitionedGridFile()
+{
+    int fileId = -1;
+    std::string filename = this->outName;
+    cg_open( filename.c_str(), CG_MODE_WRITE, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+
+    std::vector<std::string> coordnames;
+    coordnames.push_back( "CoordinateX" );
+    coordnames.push_back( "CoordinateY" );
+    coordnames.push_back( "CoordinateZ" );
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        int icelldim = Global::cell_dim;
+        int iphysdim = Global::phys_dim;
+        std::string basename = "Base" + std::to_string( iProc );
+
+        int baseId = -1;
+        cg_base_write( fileId, basename.c_str(), icelldim, iphysdim, &baseId );
+
+        std::cout << "baseId = " << baseId << "\n";
+
+        int nZones = this->GetNZones( iProc );
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            ZoneType_t zoneType = Structured;
+
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+
+            int index_dim = splitZone->dimInfo.dimList.size();
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            splitZone->dimInfo.ComputeISize();
+
+            int isize_dim = index_dim * 3;
+
+            std::vector<cgsize_t> isize( index_dim * 3, 0 );
+            for ( int m = 0; m < isize_dim; ++ m )
+            {
+                isize[ m ] = splitZone->dimInfo.isize[ m ];
+            }
+
+            int zoneId = -1;
+
+            std::string zonename = "Zone" + std::to_string( splitZone->zoneIndex );
+
+            cg_zone_write( fileId, baseId, zonename.c_str(), isize.data(), zoneType, &zoneId );
+
+            std::cout << "zoneId = " << zoneId << "\n";
+
+            splitZone->ComputeRminmax();
+
+            SplitZone * rootSplitZone = splitZone->GetRootZone();
+
+            Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+            int ncoords = zone->coors.size();
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = -1;
+                DataType_t dataType = RealDouble;
+                std::string coordname = coordnames[ icoord ];
+                Coor * coor = zone->coors[ icoord ];
+
+                int nNodes = splitZone->dimInfo.ComputeNumNodes();
+                std::cout << "nNodes = " << nNodes << "\n";
+
+                std::vector<char> coord;
+                ComputeCoor( splitZone, icoord, coord );
+
+                cg_coord_write( fileId, baseId, zoneId, dataType, coordname.c_str(), coord.data(), &coorId );
+
+                std::cout << "cg_get_error() = " << cg_get_error() << "\n";
+                std::cout << "fileId = " << fileId  << " baseId = " << baseId << " zoneId = " << zoneId  << " coorId = " << coorId << "\n";
+            }
+
+            int nBcLists = splitZone->splitBcList.size();
+            std::vector<SplitBc * > bccoList;
+            std::vector<SplitBc * > bc1to1List;
+
+            for ( int ibc = 0; ibc < nBcLists; ++ ibc )
+            {
+                SplitBc * splitBc = splitZone->splitBcList[ ibc ];
+                if ( splitBc->bcType == BCTypeUserDefined )
+                {
+                    bc1to1List.push_back( splitBc );
+                }
+                else
+                {
+                    bccoList.push_back( splitBc );
+                }
+            }
+            int nbocos = bccoList.size();
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = -1;
+                GridLocation_t location = Vertex;
+
+                std::string boconame = "BC" + std::to_string( iboco + 1 );
+
+                SplitBc * splitBc = bccoList[ iboco ];
+                BCType_t bocotype = static_cast<BCType_t>( splitBc->bcType );
+                PointSetType_t ptset_type = PointRange;
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> pnts;
+                int nSize = splitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.end[ i ] );
+                }
+
+                cg_boco_write( fileId, baseId, zoneId, boconame.c_str(), bocotype, ptset_type, npnts, pnts.data(), & bccoId );
+            }
+
+            int n1to1 = bc1to1List.size();
+            std::cout << "n1to1 = " << n1to1 << "\n";
+
+            std::vector<int> itranfrm( index_dim );
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                itranfrm[ m ] = m + 1;
+            }
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int index_conn = -1;
+
+                SplitBc * splitBc = bc1to1List[ i1to1 ];
+                BCType_t bocotype = static_cast<BCType_t>( splitBc->bcType );
+
+                std::vector<cgsize_t> pnts;
+                std::vector<cgsize_t> pntsdonor;
+                int nSize = splitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.end[ i ] );
+                }
+
+                int nPatchSize = splitBc->patch->region.start.size();
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( splitBc->patch->region.start[ i ] );
+                }
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( splitBc->patch->region.end[ i ] );
+                }
+                int id = splitBc->patch->splitZone->zoneIndex;
+                std::string donorname = "Zone" + std::to_string( id );
+                std::string connectname = "Interface" + std::to_string( i1to1 );
+
+                cg_1to1_write( fileId, baseId, zoneId, connectname.c_str(), donorname.c_str(), pnts.data(), pntsdonor.data(), itranfrm.data(), &index_conn);
+                std::cout << "index_conn = " << index_conn << "\n";
+            }
+        }
+    }
+    cg_close( fileId );
+}
+
+void Partition::DumpPartitionedGridFile()
+{
+    int fileId = -1;
+    std::string filename = this->outName;
+    int ierr = cg_open( filename.c_str(), CG_MODE_WRITE, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+
+    std::vector<std::string> coordnames;
+    coordnames.push_back( "CoordinateX" );
+    coordnames.push_back( "CoordinateY" );
+    coordnames.push_back( "CoordinateZ" );
+
+    std::string basename = "Base";
+    int baseId = -1;
+    int icelldim = Global::cell_dim;
+    int iphysdim = Global::phys_dim;
+    cg_base_write( fileId, basename.c_str(), icelldim, iphysdim, &baseId );
+
+    std::cout << "baseId = " << baseId << "\n";
+
+    std::cout << "cg_get_error() 111 = " << cg_get_error() << "\n";
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        int nZones = this->GetNZones( iProc );
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            ZoneType_t zoneType = Structured;
+
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+
+            int index_dim = splitZone->dimInfo.dimList.size();
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            splitZone->dimInfo.ComputeISize();
+
+            int isize_dim = index_dim * 3;
+
+            std::vector<cgsize_t> isize( index_dim * 3, 0 );
+            for ( int m = 0; m < isize_dim; ++ m )
+            {
+                isize[ m ] = splitZone->dimInfo.isize[ m ];
+            }
+
+            int zoneId = -1;
+
+            std::string zonename = "Zone" + std::to_string( splitZone->zoneIndex );
+
+            cg_zone_write( fileId, baseId, zonename.c_str(), isize.data(), zoneType, &zoneId );
+
+            std::cout << "zoneId = " << zoneId << "\n";
+                
+            splitZone->ComputeRminmax();
+
+            SplitZone * rootSplitZone = splitZone->GetRootZone();
+
+            Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+            int ncoords = zone->coors.size();
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = -1;
+                DataType_t dataType = RealDouble;
+                std::string coordname = coordnames[ icoord ];
+                Coor * coor = zone->coors[ icoord ];
+
+                int nNodes = splitZone->dimInfo.ComputeNumNodes();
+                std::cout << "nNodes = " << nNodes << "\n";
+
+                std::vector<char> coord;
+                ComputeCoor( splitZone, icoord, coord );
+
+                cg_coord_write( fileId, baseId, zoneId, dataType, coordname.c_str(), coord.data(), &coorId );
+
+                std::cout << "cg_get_error() = " << cg_get_error() << "\n";
+                std::cout << "fileId = " << fileId  << " baseId = " << baseId << " zoneId = " << zoneId  << " coorId = " << coorId << "\n";
+            }
+
+            int nBcLists = splitZone->splitBcList.size();
+            std::vector<SplitBc * > bccoList;
+            std::vector<SplitBc * > bc1to1List;
+
+            for ( int ibc = 0; ibc < nBcLists; ++ ibc )
+            {
+                SplitBc * splitBc = splitZone->splitBcList[ ibc ];
+                if ( splitBc->bcType == BCTypeUserDefined )
+                {
+                    bc1to1List.push_back( splitBc );
+                }
+                else
+                {
+                    bccoList.push_back( splitBc );
+                }
+            }
+            int nbocos = bccoList.size();
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = -1;
+                GridLocation_t location = Vertex;
+
+                std::string boconame = "BC" + std::to_string( iboco + 1 );
+
+                SplitBc * splitBc = bccoList[ iboco ];
+                BCType_t bocotype = static_cast<BCType_t>( splitBc->bcType );
+                PointSetType_t ptset_type = PointRange;
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> pnts;
+                int nSize = splitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.end[ i ] );
+                }
+
+                cg_boco_write( fileId, baseId, zoneId, boconame.c_str(), bocotype, ptset_type, npnts, pnts.data(), & bccoId );
+            }
+
+            int n1to1 = bc1to1List.size();
+            std::cout << "n1to1 = " << n1to1 << "\n";
+
+            std::vector<int> itranfrm( index_dim );
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                itranfrm[ m ] = m + 1;
+            }
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int index_conn = -1;
+
+                SplitBc * splitBc = bc1to1List[ i1to1 ];
+                BCType_t bocotype = static_cast<BCType_t>( splitBc->bcType );
+
+                std::vector<cgsize_t> pnts;
+                std::vector<cgsize_t> pntsdonor;
+                int nSize = splitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.end[ i ] );
+                }
+
+                int nPatchSize = splitBc->patch->region.start.size();
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( splitBc->patch->region.start[ i ] );
+                }
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( splitBc->patch->region.end[ i ] );
+                }
+                int id = splitBc->patch->splitZone->zoneIndex;
+                std::string donorname = "Zone" + std::to_string( id );
+                std::string connectname = "Interface" + std::to_string( i1to1 );
+
+                cg_1to1_write( fileId, baseId, zoneId, connectname.c_str(), donorname.c_str(), pnts.data(), pntsdonor.data(), itranfrm.data(), &index_conn);
+                std::cout << "index_conn = " << index_conn << "\n";
+            }
+        }
+    }
+    cg_close( fileId );
+}
+
+void Partition::ModifyZoneIndex()
+{
+    int globalZoneId = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        std::cout << "iProc = " << iProc << "\n";
+        int nZones = this->GetNZones( iProc );
+        std::cout << "nZones in Proc " << iProc << "  = " << nZones << "\n";
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+            splitZone->SetZoneIndex( globalZoneId++ );
+        }
+    }
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage1/01a/Partition.h b/example/partition/struct/2d/stage1/01a/Partition.h
new file mode 100644
index 00000000..cc384b21
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01a/Partition.h
@@ -0,0 +1,185 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class Dim
+{
+public:
+    static int dim;
+};
+
+class SplitZone;
+class RangeRegion;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox );
+
+class DimInfo
+{
+public:
+    DimInfo();
+    ~DimInfo();
+public:
+    int dim;
+    std::vector<int> dimList;
+    std::vector<int> oriPoint;
+    std::vector<int> isize;
+    std::vector<int> rmin;
+    std::vector<int> rmax;
+public:
+    int GetSize() const { return dim; }
+    DimInfo & operator = ( const DimInfo & rhs );
+public:
+    int ComputeNumNodes();
+    void ComputeISize();
+    void ComputeRminmax( std::vector<int> & ref );
+    void Init( int dim );
+    void Init( std::vector<int> & dimList );
+    void SetNewDimension( int axis, int newStart, int newWidth );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+};
+
+class SplitZone;
+class SplitBcPatch;
+
+class RangeRegion
+{
+public:
+    RangeRegion( int nSize = 1 );
+    ~RangeRegion();
+public:
+    int regionAxis = -1;
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    void Init( int nSize );
+    RangeRegion & operator = ( const RangeRegion & rhs );
+    bool operator == ( const RangeRegion & rhs ) const;
+    void SetRegion( std::vector<int> &pnts );
+    int ComputeRegionAxis();
+};
+
+class SplitBc
+{
+public:
+    SplitBc();
+    ~SplitBc();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone = nullptr;
+    SplitBcPatch * patch = nullptr;
+    std::vector< SplitBc * > * child = nullptr;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+    void ChangeRegionToLocalCoordinate();
+public:
+    void SetZoneBcFromParentBc( SplitBc * parentSplitBc );
+    void CreatePatchBc( SplitBc * parentSplitBc );
+};
+
+class SplitBcPatch
+{
+public:
+    SplitBcPatch ();
+    ~SplitBcPatch();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+};
+
+
+class SplitZone
+{
+public:
+    SplitZone();
+    ~SplitZone();
+public:
+    DimInfo dimInfo;
+    int zoneIndex, iProc;
+protected:
+    SplitZone * parent;
+public:
+    std::vector< SplitBc * > splitBcList;
+public:
+    int GetNCell();
+    void ComputeRminmax();
+    void GetRootInfo( SplitZone *& root, std::vector<int> & ref );
+    void SetZoneIndex( int zoneIndex ) { this->zoneIndex = zoneIndex; }
+    int  GetZoneIndex() { return zoneIndex; }
+    void SetProcId( int iProc ) { this->iProc = iProc; }
+    void SetParent( SplitZone * parent ) { this->parent = parent; };
+    std::vector< SplitBc * > & GetSplitBcList() { return this->splitBcList; };
+    void CreateBcFromParent();
+    void CreateSplitBc( SplitBc * parentSplitBc );
+    void AddSplitBc( SplitBc * splitBc );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+    SplitZone * GetRootZone();
+public:
+    void Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell );
+    void SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+    void SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+private:
+    int FindAxisNeedSplit();
+    int FindSplitPosition( int axisNeedSplit, double nCell );
+    bool IsPoleBc( int splitDirection );
+    int GetCrossSection( int axis );
+};
+
+class Partition
+{
+public:
+    Partition();
+    ~Partition();
+protected:
+    std::set < SplitZone * > zoneStorage;
+    std::set < SplitZone * > unsignedZoneGroup;
+    std::vector< SplitZone * > refZone;
+    std::vector< std::vector< SplitZone * > > procSplitZone;
+    std::vector<double> procSpeed;
+    std::vector<double> timeProc;
+    double aveFloatOp, delta;
+    double idealUniProcTime, eps;
+    int minNode;
+    int nTZone;
+    int nOriZone;
+    int nProc;
+public:
+    std::string inputName;
+    std::string outName;
+public:
+    void Solve();
+    void ReadGrid();
+    void Split();
+    void InitSplit();
+    void BinarySplit();
+    //void GreedySplit();
+public:
+    void AddNewZone( SplitZone * zone );
+    void AddZoneToUnsignedGroup( SplitZone * zone );
+    void RemoveZoneFromUnsignedGroup( SplitZone * zone );
+    void AddZoneToProcess( int iProc, SplitZone * zone );
+    void DumpMultiBasePartitionedGridFile();
+    void DumpPartitionedGridFile();
+    void ModifyZoneIndex();
+    void FreeAllZones();
+    int GetNZones( int iProc );
+    SplitZone * GetSplitZone( int iProc, int zoneId );
+    void ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord );
+    void DumpBc( SplitZone * splitZone );
+private:
+    int GetMinValueIndex( double * data, int numberOfData );
+    int GetMinLoadProc();
+    SplitZone * GetLargestZone();
+    SplitZone * Split( SplitZone * zone, double nCell );
+};
+
diff --git a/example/partition/struct/2d/stage1/01a/README.txt b/example/partition/struct/2d/stage1/01a/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01a/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/partition/struct/2d/stage1/01a/heat2d1blocks.cgns b/example/partition/struct/2d/stage1/01a/heat2d1blocks.cgns
new file mode 100644
index 00000000..ba7fd0a4
Binary files /dev/null and b/example/partition/struct/2d/stage1/01a/heat2d1blocks.cgns differ
diff --git a/example/partition/struct/2d/stage1/01a/main.cpp b/example/partition/struct/2d/stage1/01a/main.cpp
new file mode 100644
index 00000000..5da1de7c
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01a/main.cpp
@@ -0,0 +1,18 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include "Partition.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip>
+
+int main(int argc, char **argv)
+{
+    Partition * partition = new Partition();
+    partition->Solve();
+    delete partition;
+
+    return 0;
+}
diff --git a/example/partition/struct/2d/stage1/01b/CMakeLists.txt b/example/partition/struct/2d/stage1/01b/CMakeLists.txt
new file mode 100644
index 00000000..9fa577c8
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01b/CMakeLists.txt
@@ -0,0 +1,77 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	Partition.h Partition.cpp
+	CgnsGrid.h CgnsGrid.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/partition/struct/2d/stage1/01b/CgnsGrid.cpp b/example/partition/struct/2d/stage1/01b/CgnsGrid.cpp
new file mode 100644
index 00000000..d287afcb
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01b/CgnsGrid.cpp
@@ -0,0 +1,345 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include <map>
+
+Grid::Grid()
+{
+    ;
+}
+
+Grid::~Grid()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if( (i+1)%5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+    delete this->patch;
+}
+
+ZoneBcPatch::ZoneBcPatch()
+{
+    ;
+}
+
+ZoneBcPatch::~ZoneBcPatch()
+{
+}
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+Global::Global()
+{
+    ;
+}
+
+Global::~Global()
+{
+}
+
+void Global::FreeData()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+    zones.resize( 0 );
+}
+
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            //baseZone.baseId = baseId;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin( index_dim );
+            std::vector<cgsize_t> irmax( index_dim );
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                std::vector<char> coord( nNodes * sizeof(double) );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+                coor->DumpCoor();
+            }
+
+            int nbocos = -1;
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc->pnts.push_back( range[ i ] );
+                }
+
+                zonebc->zoneid = gZoneId;
+                zonebc->bcType = BCTypeUserDefined;
+
+                ZoneBcPatch * patch = new ZoneBcPatch();
+                zonebc->patch = patch;
+
+                patch->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    patch->donor_pnts.push_back( donor_range[ i ] );
+                }
+                int kkk = 1;
+            }
+        }
+        int kkk = 1;
+    }
+    int kkk = 1;
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage1/01b/CgnsGrid.h b/example/partition/struct/2d/stage1/01b/CgnsGrid.h
new file mode 100644
index 00000000..af67a321
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01b/CgnsGrid.h
@@ -0,0 +1,123 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <map>
+
+class Grid;
+
+class Zone;
+
+class Grid
+{
+public:
+    Grid();
+    ~Grid();
+public:
+    int nZone;
+    std::vector<double> x;
+    std::vector<Zone *> zones;
+};
+
+class ZoneBc;
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+};
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<Coor *> coors;
+};
+
+class ZoneBcPatch;
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+    ZoneBcPatch * patch = nullptr;
+};
+
+class ZoneBcPatch
+{
+public:
+    ZoneBcPatch();
+    ~ZoneBcPatch();
+public:
+    int donor_zoneid;
+    std::vector<int> donor_pnts;
+};
+
+class BaseZone
+{
+public:
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Global
+{
+public:
+    Global();
+    ~Global();
+public:
+    static int cell_dim;
+    static int phys_dim;
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+public:
+    static void FreeData();
+};
+
+void ReadCgnsGrid( const std::string & filename );
+void ReadCgnsGridBaseZone( const std::string & filename );
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage1/01b/Partition.cpp b/example/partition/struct/2d/stage1/01b/Partition.cpp
new file mode 100644
index 00000000..0ef2b155
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01b/Partition.cpp
@@ -0,0 +1,1547 @@
+#include "Partition.h"
+#include "CgnsGrid.h"
+#include "cgnslib.h"
+#include <string>
+
+int Dim::dim = -1;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox  )
+{
+    domainBox.start = zoneBox.start;
+    domainBox.end = zoneBox.end;
+
+    int axis = iDomain / 2;
+    int direction = iDomain % 2;
+
+    if ( direction == 0 )
+    {
+        domainBox.end[ axis ] = domainBox.start[ axis ];
+    }
+    else if ( direction == 1 )
+    {
+        domainBox.start[ axis ] = domainBox.end[ axis ];
+    }
+}
+
+DimInfo::DimInfo()
+{
+    this->Init( 1 );
+}
+
+DimInfo::~DimInfo()
+{
+}
+
+void DimInfo::Init( int dim )
+{
+    this->dim = dim;
+    dimList.resize( this->dim, 1 );
+    oriPoint.resize( this->dim, 0 );
+}
+
+DimInfo & DimInfo::operator = ( const DimInfo & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->dim = rhs.dim;
+    this->dimList = rhs.dimList;
+    this->oriPoint = rhs.oriPoint;
+
+    return * this;
+}
+
+int DimInfo::ComputeNumNodes()
+{
+    int nNodes = 1;
+    for ( int m = 0; m < this->dimList.size(); ++ m )
+    {
+        nNodes *= this->dimList[ m ];
+    }
+    return nNodes;
+}
+
+void DimInfo::ComputeISize()
+{
+    int index_dim = this->dimList.size();
+    this->isize.resize( index_dim * 3, 0 );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        isize[ m ] = this->dimList[ m ];
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 1;
+        isize[ start + m ] = this->dimList[ m ] - 1;
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 2;
+        isize[ start + m ] = 0;
+    }
+
+    for ( int i = 0; i < isize.size(); ++ i )
+    {
+        std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+    }
+}
+
+void DimInfo::ComputeRminmax( std::vector<int> & ref )
+{
+    int index_dim = this->dimList.size();
+    this->rmin.resize( index_dim );
+    this->rmax.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        rmin[ m ] = ref[ m ] + 1;
+        rmax[ m ] = ref[ m ] + this->dimList[ m ];
+    }
+
+    std::cout << "rmin, rmax = \n";
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        std::cout << rmin[ m ] << " " << rmax[ m ] << "\n";
+    }
+}
+
+void DimInfo::Init( std::vector<int> & dimList )
+{
+    this->dim = dimList.size();
+    this->dimList = dimList;
+    std::vector<int> zero( dimList.size(), 0 );
+    this->oriPoint = zero;
+}
+
+void DimInfo::SetNewDimension( int axis, int newStart, int newWidth )
+{
+    this->oriPoint[ axis ] = newStart;
+    this->dimList [ axis ] = newWidth;
+}
+
+void DimInfo::GetZoneGlobalBox( RangeRegion &zoneBox )
+{
+    int index_dim = this->dimList.size();
+    zoneBox.start.resize( index_dim );
+    zoneBox.end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        zoneBox.start[ m ] = this->oriPoint[ m ] + 1;
+        zoneBox.end[ m ] = this->oriPoint[ m ] + this->dimList[ m ];
+    }
+}
+
+void DimInfo::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    int index_dim = this->dimList.size();
+    localBox.start.resize( index_dim );
+    localBox.end.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        localBox.start[ m ] = globalBox.start[ m ] - this->oriPoint[ m ];
+        localBox.end[ m ] = globalBox.end[ m ] - this->oriPoint[ m ];
+    }
+}
+
+RangeRegion::RangeRegion( int nSize )
+{
+    this->Init( nSize );
+}
+
+RangeRegion::~RangeRegion()
+{
+}
+
+void RangeRegion::Init( int nSize )
+{
+    this->start.resize( nSize );
+    this->end.resize( nSize );
+}
+
+RangeRegion & RangeRegion::operator = ( const RangeRegion & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+    this->regionAxis = rhs.regionAxis;
+
+    return * this;
+}
+
+bool RangeRegion::operator == ( const RangeRegion & rhs ) const
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] != rhs.start[ m ] || 
+            this->end  [ m ] != rhs.end  [ m ] )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+    this->ComputeRegionAxis();
+}
+
+int RangeRegion::ComputeRegionAxis()
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] == this->end[ m ] )
+        {
+            this->regionAxis = m;
+            return this->regionAxis;
+        }
+    }
+    return this->regionAxis;
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion );
+
+bool ComputeOverlapRegion( RangeRegion & region1, RangeRegion & region2, RangeRegion & overlapRegion )
+{
+    int index_dim = region1.start.size();
+    overlapRegion.Init( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int ijkmin1 = std::min( region1.start[ m ], region1.end[ m ] );
+        int ijkmax1 = std::max( region1.start[ m ], region1.end[ m ] );
+        int ijkmin2 = std::min( region2.start[ m ], region2.end[ m ] );
+        int ijkmax2 = std::max( region2.start[ m ], region2.end[ m ] );
+        if ( ( ijkmax1 < ijkmin2 ) || ( ijkmin1 > ijkmax2 ) )
+        {
+            return false;
+        }
+
+        int ijkmin = std::max( ijkmin1, ijkmin2 );
+        int ijkmax = std::min( ijkmax1, ijkmax2 );
+
+        overlapRegion.start[ m ] = ijkmin;
+        overlapRegion.end  [ m ] = ijkmax;
+    }
+
+    return CheckOverLapping( overlapRegion );
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion )
+{
+    int index_dim = overlapRegion.start.size();
+    int iCount = 0;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        if ( overlapRegion.start[ m ] == overlapRegion.end[ m ] )
+        {
+            ++ iCount;
+        }
+    }
+
+    return ( iCount == 1 );
+}
+
+bool GetInterfaceRegion( RangeRegion & zoneBoxL, RangeRegion & zoneBoxR, RangeRegion & interfaceRegion )
+{
+    int index_dim = zoneBoxL.start.size();
+    int nDomains = 2 * index_dim;
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegionL;
+        GetDomainRegion( zoneBoxL, iDomain, domainRegionL );
+
+        for ( int jDomain = 0; jDomain < nDomains; ++ jDomain )
+        {
+            RangeRegion domainRegionR;
+            GetDomainRegion( zoneBoxR, jDomain, domainRegionR );
+
+            if ( domainRegionL == domainRegionR )
+            {
+                interfaceRegion = domainRegionL;
+                return true;
+            }
+        }
+    }
+    return false;
+}
+
+void CreateInterfaceBc( SplitZone * zoneL, SplitZone * zoneR )
+{
+    RangeRegion globalBoxL, globalBoxR, globalInterfaceRegion;
+
+    zoneL->GetZoneGlobalBox( globalBoxL );
+    zoneR->GetZoneGlobalBox( globalBoxR );
+
+    if ( ! GetInterfaceRegion( globalBoxL, globalBoxR, globalInterfaceRegion ) )
+    {
+        int kkk = 1;
+        return;
+    }
+
+    RangeRegion localInterfaceRegionL, localInterfaceRegionR;
+
+    zoneL->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionL );
+    zoneR->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionR );
+
+    int kkk = 1;
+
+    SplitBc * splitBcL = new SplitBc();
+    zoneL->AddSplitBc( splitBcL );
+
+    SplitBc * splitBcR = new SplitBc();
+    zoneR->AddSplitBc( splitBcR );
+
+    splitBcL->splitZone = zoneL;
+    splitBcL->SetRegion( localInterfaceRegionL );
+    splitBcL->bcType = BCTypeUserDefined;
+
+    splitBcR->splitZone = zoneR;
+    splitBcR->SetRegion( localInterfaceRegionR );
+    splitBcR->bcType = BCTypeUserDefined;
+
+    //localInterfaceRegionL.MarkPatchBc();
+    //localInterfaceRegionR.MarkPatchBc();
+
+    SplitBcPatch * splitBcPatchL = new SplitBcPatch();
+    splitBcL->patch = splitBcPatchL;
+    splitBcPatchL->region = localInterfaceRegionR;
+    splitBcPatchL->splitZone = zoneR;
+
+    SplitBcPatch * splitBcPatchR = new SplitBcPatch();
+    splitBcR->patch = splitBcPatchR;
+    splitBcPatchR->region = localInterfaceRegionL;
+    splitBcPatchR->splitZone = zoneL;
+
+    //splitBcL->Normalize();
+    //splitBcR->Normalize();
+}
+
+
+SplitBc::SplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+SplitBc::~SplitBc()
+{
+    delete this->patch;
+}
+
+void SplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void SplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+void SplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = splitZone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void SplitBc::CreateInterfaceBcFromParentBc( SplitBc * parentSplitBc )
+{
+    if ( parentSplitBc->bcType !=  BCTypeUserDefined ) return;
+
+    this->patch = new SplitBcPatch();
+    this->patch->splitZone = parentSplitBc->patch->splitZone;
+    this->patch->SetRegion( parentSplitBc->patch->region );
+    int kkk = 1;
+
+    //Find the block corresponding to this docking boundary
+    //From patch->splitZone, find the corresponding docking boundary according to the size of overlapt
+    //The boundary conditions on the opposite side must change due to the split of this block.
+    //Here, the relevant boundaries are added to the sub-boundaries.
+
+    RangeRegion targetRegionBox;
+    targetRegionBox = parentSplitBc->patch->region;
+
+    SplitZone * targetZone = this->patch->splitZone;
+
+    targetZone->CreateChildInterfaceBc( targetRegionBox, this->splitZone );
+
+    //this->patch->faceAxis = parentSplitBc->patch->faceAxis;
+
+    //( * this->patch->vertexMap ) = ( * parentBc->patch->vertexMap );
+
+    ////È»ºó½øÐÐÐÞÕý
+    ////block1->map 1, 33 -> block1 369, 337
+    ////block2->global -> map 1, 33 -> block1 369, 337
+    ////block2->local  -> map 1, 33 -> block1 369, 337
+    ////refOld + M * stold           = block1Startold
+    ////refOld + M * ( stnew + ref ) = block1Startold
+    ////refNew = refOld + M * ( ref )
+
+    //for ( int m = 0; m < 3; ++ m )
+    //{
+    //    for ( int n = 0; n < 3; ++ n )
+    //    {
+    //        this->patch->vertexMap->pt[ m ] += this->patch->vertexMap->vm[ m ][ n ] * ( this->splitZone->sdim->oriPoint )[ n ];
+    //    }
+    //}
+
+    //RangeBox tRangeBox;
+
+    //MappingPatchPoint( this->patch, this->rangeBox, tRangeBox );
+    //tRangeBox.SetOrder();
+
+    ////ÕÒµ½ºÍ±¾¶Ô½Ó±ß½çÏà¶ÔÓ¦µÄ¿é
+    ////´Ópatch->splitZone°´ÕÕoverlapµÄ´óСÕÒµ½¶ÔÓ¦µÄ¶Ô½Ó±ß½ç£¬ÕâÑùÖÁÉÙ¿ÉÒÔÕÒµ½
+    ////¶ÔÃæµÄ¶Ô½Ó±ß½çÌõ¼þÓÉÓÚ±¾¿éµÄsplit±ØȻҪ·¢Éú¸Ä±ä£¬ÕâÀｫÏà¹Ø±ß½ç¼ÓÈë×ӱ߽ç
+    //this->patch->splitZone->CreateChildInterfaceBc( tRangeBox, this->splitZone );
+}
+
+
+SplitBcPatch::SplitBcPatch()
+{
+    this->region.Init( Dim::dim );
+}
+
+SplitBcPatch::~SplitBcPatch()
+{
+}
+
+void SplitBcPatch::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void SplitBcPatch::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+SplitZone::SplitZone()
+{
+    this->parent  = 0;
+    this->zoneIndex = 0;
+    this->iProc = 0;
+    dimInfo.Init( Dim::dim );
+    int kk = 1;
+}
+
+SplitZone::~SplitZone()
+{
+    ;
+}
+
+void SplitZone::GetZoneGlobalBox( RangeRegion & zoneBox )
+{
+    this->dimInfo.GetZoneGlobalBox( zoneBox );
+}
+
+void SplitZone::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    this->dimInfo.GetZoneLocalBox( globalBox, localBox );
+}
+
+
+void SplitZone::ComputeRminmax()
+{
+    int index_dim = this->dimInfo.dimList.size();
+    std::vector<int> ref( index_dim, 0 );
+
+    SplitZone * rootSplitZone = 0;
+    this->GetRootInfo( rootSplitZone, ref );
+
+    this->dimInfo.ComputeRminmax( ref );
+}
+
+SplitZone * SplitZone::GetRootZone()
+{
+    SplitZone * root = this;
+
+    while ( true )
+    {
+        if ( root->parent )
+        {
+            root = root->parent;
+        }
+        else
+        {
+            return root;
+        }
+    };
+}
+
+void SplitZone::GetRootInfo( SplitZone *& root, std::vector<int> & ref )
+{
+    for ( int i = 0; i < this->dimInfo.dimList.size(); ++ i )
+    {
+        ref[ i ] += this->dimInfo.oriPoint[ i ];
+    }
+
+    if ( this->parent )
+    {
+        this->parent->GetRootInfo( root, ref );
+    }
+    else
+    {
+        root = this;
+    }
+}
+
+
+int SplitZone::GetNCell()
+{
+    int numberOfCells = 1;
+    for ( int i = 0; i < this->dimInfo.dim; ++ i )
+    {
+        numberOfCells *= std::max( 1, ( this->dimInfo.dimList[ i ] - 1 ) );
+    }
+
+    return numberOfCells; 
+}
+
+void SplitZone::SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int leftStart = 0;
+    int leftWidth = iSplit - 0;
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, leftStart , leftWidth  );
+}
+
+void SplitZone::SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int rightStart = iSplit - 1;
+    int rightWidth = dimList[ axisNeedSplit ] - ( iSplit - 1 );
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, rightStart, rightWidth );
+}
+
+void SplitZone::Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell )
+{
+    //Find the longest axis
+    int axisNeedSplit = this->FindAxisNeedSplit();
+    int iSplit        = this->FindSplitPosition( axisNeedSplit, nCell );
+
+    zoneL->SetLeftDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+    zoneR->SetRightDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+
+    zoneL->CreateBcFromParent();
+    zoneR->CreateBcFromParent();
+
+    CreateInterfaceBc( zoneL, zoneR );
+}
+
+void SplitZone::CreateBcFromParent()
+{
+    std::vector< SplitBc * > & parentSplitBcList = this->parent->GetSplitBcList();
+
+    int nParentSplitBcs = parentSplitBcList.size();
+
+    for ( int iParentBc = 0; iParentBc < nParentSplitBcs; ++ iParentBc )
+    {
+        SplitBc * parentSplitBc = parentSplitBcList[ iParentBc ];
+
+        this->CreateSplitBc( parentSplitBc );
+    }
+}
+
+void SplitZone::CreateChildInterfaceBc( RangeRegion &targeRegionBox, SplitZone * sourceZone )
+{
+    std::vector< SplitBc * > & splitBcList = this->GetSplitBcList();
+
+    int nSplitBcs = splitBcList.size();
+
+    for ( int iSplitBc = 0; iSplitBc < nSplitBcs; ++ iSplitBc )
+    {
+        SplitBc * splitBc = splitBcList[ iSplitBc ];
+
+        //Only consider the interface boundaries
+        if ( splitBc->bcType !=  BCTypeUserDefined ) continue;
+
+        if ( this->CreateChildInterfaceBc( splitBc, targeRegionBox, sourceZone ) ) return;
+    }
+}
+
+bool SplitZone::CreateChildInterfaceBc( SplitBc * interfaceBc, RangeRegion & targeRegionBox, SplitZone * sourceZone )
+{
+    RangeRegion overlapRegion;
+    bool overlap_flag = ComputeOverlapRegion( interfaceBc->region, targeRegionBox, overlapRegion );
+    if ( ! overlap_flag ) return false;
+
+    //1. Èç¹ûsplitBcºÍinterfaceBcÓн»¼¯£¬µ«ÊÇinterfaceBcûÓÐchild£¬Ôò´ËsplitBc×÷ΪinterfaceBcµÄÒ»¸öchild
+    //2. Èç¹ûsplitBcºÍinterfaceBcÓн»¼¯£¬ÇÒinterfaceBcÓÐchild£¬Èç¹ûsplitBcºÍËùÓÐchildûÓн»¼¯£¬
+    //   ÔòsplitBc¼ÓÈëinterfaceBcµÄÒ»¸öchild
+    //3. Èç¹ûsplitBcºÍinterfaceBcÓн»¼¯£¬ÇÒinterfaceBcÓÐchild£¬Èç¹ûsplitBcºÍchildÓн»¼¯£¬Ôò´Ëchild×÷ΪеÄinterfaceBc
+
+    std::vector< SplitBc * > * child = interfaceBc->child;
+
+    if ( interfaceBc->child )
+    {
+        for ( int iChild = 0; iChild < interfaceBc->child->size(); ++ iChild )
+        {
+            SplitBc * childSplitBc = ( * interfaceBc->child )[ iChild ];
+            if ( this->CreateChildInterfaceBc( childSplitBc, targeRegionBox, sourceZone ) ) return true;
+        }
+    }
+    else
+    {
+        interfaceBc->child = new std::vector< SplitBc * >();
+    }
+
+    SplitBc * childInterfaceBc = new SplitBc();
+    //this->AddSplitBc( splitBc );
+
+    childInterfaceBc->SetRegion( overlapRegion );
+    childInterfaceBc->bcType = interfaceBc->bcType;
+    childInterfaceBc->splitZone = interfaceBc->splitZone;
+
+
+    interfaceBc->child->push_back( childInterfaceBc );
+
+    //vector< int > & parentFaceDirectionContainer = interfaceBc->GetFaceDirectionContainer();
+    //vector< int > & faceDirectionContainer  = childInterfaceBc->GetFaceDirectionContainer();
+
+    //for ( int m = 0; m < 3; ++ m )
+    //{
+    //    faceDirectionContainer[ m ] = parentFaceDirectionContainer[ m ];
+    //}
+
+    //½«´ËÐÂÉú³ÉµÄ¶Ô½Ó±ß½ç¼ÓÈë±¾¿éÀïÃæ
+    SplitBcPatch * patch = new SplitBcPatch();
+    childInterfaceBc->patch = patch;
+    patch->splitZone = sourceZone;
+
+    //patch->CopyVertexMappingContent( interfaceBc->GetZoneBoundaryConditionPatch()->GetVertexMapping() );
+
+    //vector< int > & pNextFaceDirectionContainer = interfaceBc->GetZoneBoundaryConditionPatch()->GetFaceDirectionContainer();
+    //vector< int > & patchFaceDirectionContainer = patch->GetFaceDirectionContainer();
+
+    //for ( int m = 0; m < 3; ++ m )
+    //{
+    //    patchFaceDirectionContainer[ m ] = pNextFaceDirectionContainer[ m ];
+    //}
+
+    //Ô­¶Ô½Ó±ß½çÂú×ã
+    //t0 = tref + M * s0
+    //еĶԽӱ߽çÂú×ã
+    //t0newblock + refNewblock = tref + M * s0
+    //t0newblock = ( tref - refNewblock ) + M * s0
+
+    //È»ºó½øÐÐÐÞÕý
+    //for ( int m = 0; m < 3; ++ m )
+    //{
+    //    ( patch->GetVertexMapping() )[ m ][ 3 ] -= ( sourceZone->GetOriginalPointIndexContainer() )[ m ];
+    //}
+
+    return true;
+}
+
+void SplitZone::AddSplitBc( SplitBc * splitBc )
+{
+    if ( ! splitBc ) return;
+    this->splitBcList.push_back( splitBc );
+}
+
+void SplitZone::CreateSplitBc( SplitBc * parentSplitBc )
+{
+    if ( ! parentSplitBc->child )
+    {
+        int index_dim = this->dimInfo.dimList.size();
+        int nDomains = 2 * index_dim;
+        RangeRegion zoneBoxRegion( index_dim );
+        this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+        for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+        {
+            RangeRegion domainRegion( index_dim );
+            GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+            RangeRegion overlapRegion;
+            bool overlap_flag = ComputeOverlapRegion( parentSplitBc->region, domainRegion, overlapRegion );
+            if ( ! overlap_flag ) continue;
+
+            this->CreateSplitBcFromOverlapRegion( parentSplitBc, overlapRegion );
+
+            //SplitBc * splitBc = new SplitBc();
+            //this->AddSplitBc( splitBc );
+
+            //splitBc->SetRegion( overlapRegion );
+            //splitBc->bcType = parentSplitBc->bcType;
+            //splitBc->splitZone = this;
+            //splitBc->ChangeRegionToLocalCoordinate();
+            //splitBc->CreateInterfaceBcFromParentBc( parentSplitBc );
+            int kkk = 1;
+        }
+    }
+    else
+    {
+        int nChilds = parentSplitBc->child->size();
+        for ( int iChild = 0; iChild < nChilds; ++ iChild )
+        {
+            this->CreateSplitBc( ( * parentSplitBc->child )[ iChild ] );
+        }
+    }
+}
+
+void SplitZone::CreateSplitBcFromOverlapRegion( SplitBc * parentSplitBc, RangeRegion & overlapRegion )
+{
+    SplitBc * splitBc = new SplitBc();
+    this->AddSplitBc( splitBc );
+
+    splitBc->SetRegion( overlapRegion );
+    splitBc->bcType = parentSplitBc->bcType;
+    splitBc->splitZone = this;
+    splitBc->ChangeRegionToLocalCoordinate();
+    splitBc->CreateInterfaceBcFromParentBc( parentSplitBc );
+}
+
+int SplitZone::FindAxisNeedSplit()
+{
+    //Find the longest axis
+    int axisNeedSplit = 0;
+    int maxN = this->dimInfo.dimList[ 0 ];
+
+    for ( int m = 1; m < this->dimInfo.dimList.size(); ++ m )
+    {
+        if ( this->IsPoleBc( m ) )
+        {
+            continue;
+        }
+        int Nm = this->dimInfo.dimList[ m ];
+        if ( maxN < Nm )
+        {
+            maxN = Nm;
+            axisNeedSplit = m;
+        }
+    }
+
+    return axisNeedSplit;
+}
+
+int SplitZone::GetCrossSection( int axis )
+{
+    int nDim = this->dimInfo.dimList.size();
+    int crossSection = 1;
+    int N = nDim - 1;
+    for ( int m = 0; m < N; ++ m )
+    {
+         int mm = ( axis + 1 ) % nDim;
+         int nLineElements = std::max( 1, ( this->dimInfo.dimList[ mm ] - 1 ) );
+         crossSection *= nLineElements;
+    }
+    return crossSection;
+}
+
+int SplitZone::FindSplitPosition( int axisNeedSplit, double nCell )
+{
+    int nDim = this->dimInfo.dimList.size();
+    std::vector<int> crossSections( nDim );
+    for ( int m = 0; m < nDim; ++ m )
+    {
+        crossSections[ m ] = this->GetCrossSection( m );
+    }
+
+    //guess the value
+    double dSplit = nCell / crossSections[ axisNeedSplit ];
+    int  iSplit = 1 + static_cast< int >( std::floor( dSplit + 0.5 ) );
+    return iSplit;
+}
+
+
+bool SplitZone::IsPoleBc( int splitDirection )
+{
+    return false;
+}
+
+
+double CalSumOfProcSpeed( std::vector<double> & procSpeed );
+double CalSumOfProcSpeed( std::vector<double> & procSpeed )
+{
+    int nProc = procSpeed.size();
+    double sumOfProcSpeed = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        sumOfProcSpeed += procSpeed[ iProc ];
+    }
+    return sumOfProcSpeed;
+}
+
+Partition::Partition()
+{
+    this->inputName = "../heat2d2blocks.cgns";
+    this->outName =  "../heat2dpart.cgns";
+}
+
+Partition::~Partition()
+{
+    ;
+}
+
+int Partition::GetMinValueIndex( double * data, int numberOfData )
+{
+    double minValue = data[ 0 ];
+    int minimumValueIndex = 0;
+
+    for ( int iData = 1; iData < numberOfData; ++ iData )
+    {
+        if ( minValue > data[ iData ] )
+        {
+            minValue      = data[ iData ];
+            minimumValueIndex = iData;
+        }
+    }
+    return minimumValueIndex;
+}
+
+int Partition::GetMinLoadProc()
+{
+    return this->GetMinValueIndex( this->timeProc.data(), this->nProc );
+}
+
+SplitZone * Partition::GetLargestZone()
+{
+    SplitZone * largestZone = 0;
+
+    double nMaxCell = 0.0;
+
+    for ( std::set< SplitZone * >::iterator iter = unsignedZoneGroup.begin(); iter != unsignedZoneGroup.end(); ++ iter )
+    {
+        double nSize = ( * iter )->GetNCell();
+        if ( nMaxCell < nSize )
+        {
+            nMaxCell    = nSize;
+            largestZone = * iter;
+        }
+    }
+
+    return largestZone;
+}
+
+void Partition::Solve()
+{
+    std::cout << "Partition::Split()\n";
+    //this->nProc = 2;
+    this->nProc = 3;
+    this->ReadGrid();
+    this->Split();
+    this->ModifyZoneIndex();
+    this->DumpPartitionedGridFile();
+    this->FreeAllZones();
+}
+
+void Partition::ReadGrid()
+{
+    ReadCgnsGridBaseZone( this->inputName );
+    ReadCgnsGrid( this->inputName );
+
+    this->nOriZone = ::Global::zones.size();
+    Dim::dim = Global::cell_dim;
+
+    std::cout << "numberOfBlocks = " << nOriZone << "\n";
+
+    this->refZone.resize( nOriZone );
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = new SplitZone();
+        refZone[ iZone ] = splitZone;
+
+        splitZone->SetZoneIndex( iZone );
+        splitZone->SetProcId( 0 );
+        splitZone->SetParent( 0 );
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        Zone * zone = ::Global::zones[ iZone ];
+
+        splitZone->dimInfo.dimList = zone->nijk;
+
+        int nBcRegion = zone->bccos.size();
+        std::cout << "nBcRegion = " << nBcRegion << "\n";
+
+        std::vector< SplitBc * > & splitBcList = splitZone->splitBcList;
+
+        for ( int iBcRegion = 0; iBcRegion < nBcRegion; ++ iBcRegion )
+        {
+            SplitBc * splitBc = new SplitBc();
+            splitBcList.push_back( splitBc );
+
+            ZoneBc * zoneBc = zone->bccos[ iBcRegion ];
+
+            splitBc->splitZone = splitZone;
+            splitBc->bcType = zoneBc->bcType;
+            splitBc->SetRegion( zoneBc->pnts );
+            if ( zoneBc->patch )
+            {
+                SplitBcPatch * patch = new SplitBcPatch();
+                splitBc->patch = patch;
+
+                patch->splitZone = refZone[ zoneBc->patch->donor_zoneid ];
+                patch->SetRegion( zoneBc->patch->donor_pnts );
+            }
+        }
+
+        int kkk = 1;
+    }
+    int kkk = 1;
+}
+
+void Partition::Split()
+{
+    this->InitSplit();
+    this->BinarySplit();
+    //this->SetZoneIndex();
+}
+
+void Partition::InitSplit()
+{
+    //nZone is the number of zones in the original grid
+    //nProc is not the number of blocks in the end, but the number of processes that need to be divided.
+    //This difference occurs because the structure grid can have many blocks per process.
+
+    //this->nProc    = nProc;
+    //this->nPhyBlocks = referenceBlock.size();
+    //this->nZone  = this->nPhyBlocks;
+
+    //tj Computation time on processor j
+    //Nk Number of internal grid-cells for zone j
+    //aveFloatOp:  Number of Real operations per gridcell
+    //Gj The set of blocks allocated to process j
+    //Pj Real operations per second for process j
+
+    //The Greedy Load Balancing Algorithm
+    //1.Compute an "ideal" uniprocessor time, Tuni = sum ( Nk * aveFloatOp )/ sum( Pj ).
+    //2.Set the group of unassigned blocks, Gu, to contain all blocks. The number of blocks in Nu=M, where M is the total number of blocks in the mesh.
+    //3.Start all processors with a very small fictitious zone to get a start tj=delt aveFloatOp/Pj, where delt<<1 is the size of the very small fictious zone.
+    //This is used to find the fastest processor in a heterogeneous system, tj could otherwise be set to 0 in the homogeneous case.
+    this->aveFloatOp = 1.0;
+    this->delta      = 1.0e-5;
+    this->procSpeed.resize( nProc );
+    this->timeProc.resize( nProc );
+
+    this->nTZone = this->nOriZone;
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        procSpeed[ iProc ] = 1.0;
+    }
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        timeProc[ iProc ] = delta * aveFloatOp / procSpeed[ iProc ];
+    }
+
+    double sumProcSpeed = CalSumOfProcSpeed( procSpeed );
+
+    double sumProcOp = 0.0;
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        sumProcOp += refZone[ iZone ]->GetNCell() * aveFloatOp;
+    }
+
+    this->idealUniProcTime = sumProcOp / sumProcSpeed;
+
+    this->eps = 0.05;
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        unsignedZoneGroup.insert( refZone[ iZone ] );
+    }
+
+    //Init zoneStorage
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        zoneStorage.insert( refZone[ iZone ] );
+    }
+
+    //Assign procSplitZone to each process
+    procSplitZone.resize( nProc );
+
+    this->minNumberCell = 1;
+    for ( int m = 0; m < Dim::dim; ++ m )
+    {
+        this->minNumberCell *= 1;
+    }
+
+    int kkk = 1;
+
+}
+
+void Partition::FreeAllZones()
+{
+    int iCount = 0;
+    for ( std::set < SplitZone * >::iterator iter = zoneStorage.begin(); iter != zoneStorage.end(); ++ iter )
+    {
+        //cout << "iCount = " << iCount << "\n";
+        ++ iCount;
+        delete * iter;
+    }
+}
+
+int Partition::GetNZones( int iProc )
+{
+    return this->procSplitZone[ iProc ].size();
+}
+
+SplitZone * Partition::GetSplitZone( int iProc, int zoneId )
+{
+    return this->procSplitZone[ iProc ][ zoneId ];
+}
+
+void Partition::AddZoneToUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.insert( zone );
+}
+
+void Partition::RemoveZoneFromUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.erase( zone );
+}
+
+void Partition::AddZoneToProcess( int iProc, SplitZone * zone )
+{
+    this->procSplitZone[ iProc ].push_back( zone );
+}
+
+void Partition::AddNewZone( SplitZone * zone )
+{
+    zone->SetZoneIndex( nTZone ++ );
+
+    this->AddZoneToUnsignedGroup( zone );
+
+    this->zoneStorage.insert( zone );
+}
+
+SplitZone * Partition::Split( SplitZone * zone, double nCell )
+{
+    SplitZone * zoneL = new SplitZone();
+    zoneL->SetParent( zone );
+
+    SplitZone * zoneR = new SplitZone();
+    zoneR->SetParent( zone );
+
+    //Remove the original block from the UnsignedGroup
+    this->RemoveZoneFromUnsignedGroup( zone );
+
+    this->AddNewZone( zoneL );
+    this->AddNewZone( zoneR );
+
+    zone->Split( zoneL, zoneR, nCell );
+
+    return zoneL;
+}
+
+void Partition::BinarySplit()
+{
+    while ( ! unsignedZoneGroup.empty() )
+    {
+        std::cout << "number of unsigned zone = " << unsignedZoneGroup.size() << "\n";
+        int iProc = this->GetMinLoadProc();
+
+        //Get the block with the largest number of grids and its size
+        SplitZone * largestZone = this->GetLargestZone();
+
+        double nMaxCell = largestZone->GetNCell();
+
+        double aveFloatOp = this->aveFloatOp;
+        double tau = timeProc[ iProc ] + nMaxCell * aveFloatOp / procSpeed[ iProc ];
+
+        int kkk = 1;
+
+        //It seems that EPS is still necessary
+        //The idea here is as follows. For the candidate blocks which can be divided into blocks, 
+        //if the difference between the target blocks and the candidate blocks is too wide, 
+        //the binarySplit method is adopted. The binarySplit blocks do not directly join the process,
+        //but enter the next round of screening.
+
+        if ( tau > idealUniProcTime * ( 1.0 + eps ) )
+        {
+            double nRest = ( tau - idealUniProcTime ) * procSpeed[ iProc ] / aveFloatOp;
+
+            double nTarget = nMaxCell - nRest;
+            if ( nRest > this->minNumberCell && nTarget > this->minNumberCell )
+            {
+                //It is necessary to divide blocks only when a certain number of points are satisfied.
+                double nHalf = nMaxCell / 2.0;
+                nMaxCell = nTarget;
+                double ratio = nMaxCell / nRest;
+                double oRatio = 1.0 / ratio;
+
+                if ( std::max( ratio, oRatio ) < 3.0 )
+                {
+                    int kkk = 1;
+                    largestZone = this->Split( largestZone, nMaxCell );
+                    timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                    this->RemoveZoneFromUnsignedGroup( largestZone );
+                    this->AddZoneToProcess( iProc, largestZone );
+                }
+                else
+                {
+                    this->Split( largestZone, nHalf );
+                }
+            }
+            else
+            {
+                //If the block is of the right size, join the process directly, and there is no need to split it.
+                timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                this->RemoveZoneFromUnsignedGroup( largestZone );
+                this->AddZoneToProcess( iProc, largestZone );
+            }
+        }
+        else
+        {
+            //If the block is of the right size, join the process directly, and there is no need to split it.
+            timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+            this->RemoveZoneFromUnsignedGroup( largestZone );
+            this->AddZoneToProcess( iProc, largestZone );
+        }
+    }
+}
+
+void Partition::ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord )
+{
+    SplitZone * rootSplitZone = splitZone->GetRootZone();
+    Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+    int nNodes = splitZone->dimInfo.ComputeNumNodes();
+    std::cout << "nNodes = " << nNodes << "\n";
+
+    coord.resize( nNodes * sizeof(double) );
+
+    int index_dim = splitZone->dimInfo.dimList.size();
+    Coor * coor = zone->coors[ icoord ];
+
+    double * xlocal = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    double * xglobal = reinterpret_cast<double *>( const_cast<char *>( coor->coord.data() ) );
+    if ( index_dim == 1 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        for ( int i = imin; i < imax; ++ i )
+        {
+            xlocal[ icount++ ] = xglobal[ i ];
+        }
+    }
+    else if ( index_dim == 2 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        int jmin = splitZone->dimInfo.rmin[ 1 ] - 1;
+        int jmax = splitZone->dimInfo.rmax[ 1 ];
+        int ni = rootSplitZone->dimInfo.dimList[ 0 ];
+        int nj = rootSplitZone->dimInfo.dimList[ 1 ];
+        for ( int j = jmin; j < jmax; ++ j )
+        {
+            int jstride = j * ni;
+            for ( int i = imin; i < imax; ++ i )
+            {
+                xlocal[ icount++ ] = xglobal[ jstride + i ];
+            }
+        }
+    }
+}
+
+void Partition::DumpBc( SplitZone * splitZone )
+{
+    //std::vector< ZoneBc * > leafZoneBc;
+
+    //std::vector< ZoneBc * > & zoneBcList = splitZone->GetZoneBcList();
+
+    //for ( int i = 0; i < zoneBcList.size(); ++ i )
+    //{
+    //    std::vector< ZoneBc * > cl = zoneBcList[ i ]->GetLeaves();
+    //    for ( int j = 0; j < cl.size(); ++ j )
+    //    {
+    //        leafZoneBc.push_back( cl[ j ] );
+    //    }
+    //}
+
+    //int nZoneBc = leafZoneBc.size();
+
+    //for ( int iZoneBc = 0; iZoneBc < nZoneBc; ++ iZoneBc )
+    //{
+    //    ZoneBc * zoneBc = leafZoneBc[ iZoneBc ];
+    //    zoneBc->DumpBc();
+    //}
+}
+
+void Partition::DumpMultiBasePartitionedGridFile()
+{
+    int fileId = -1;
+    std::string filename = this->outName;
+    cg_open( filename.c_str(), CG_MODE_WRITE, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+
+    std::vector<std::string> coordnames;
+    coordnames.push_back( "CoordinateX" );
+    coordnames.push_back( "CoordinateY" );
+    coordnames.push_back( "CoordinateZ" );
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        int icelldim = Global::cell_dim;
+        int iphysdim = Global::phys_dim;
+        std::string basename = "Base" + std::to_string( iProc );
+
+        int baseId = -1;
+        cg_base_write( fileId, basename.c_str(), icelldim, iphysdim, &baseId );
+
+        std::cout << "baseId = " << baseId << "\n";
+
+        int nZones = this->GetNZones( iProc );
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            ZoneType_t zoneType = Structured;
+
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+
+            int index_dim = splitZone->dimInfo.dimList.size();
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            splitZone->dimInfo.ComputeISize();
+
+            int isize_dim = index_dim * 3;
+
+            std::vector<cgsize_t> isize( index_dim * 3, 0 );
+            for ( int m = 0; m < isize_dim; ++ m )
+            {
+                isize[ m ] = splitZone->dimInfo.isize[ m ];
+            }
+
+            int zoneId = -1;
+
+            std::string zonename = "Zone" + std::to_string( splitZone->zoneIndex );
+
+            cg_zone_write( fileId, baseId, zonename.c_str(), isize.data(), zoneType, &zoneId );
+
+            std::cout << "zoneId = " << zoneId << "\n";
+
+            splitZone->ComputeRminmax();
+
+            SplitZone * rootSplitZone = splitZone->GetRootZone();
+
+            Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+            int ncoords = zone->coors.size();
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = -1;
+                DataType_t dataType = RealDouble;
+                std::string coordname = coordnames[ icoord ];
+                Coor * coor = zone->coors[ icoord ];
+
+                int nNodes = splitZone->dimInfo.ComputeNumNodes();
+                std::cout << "nNodes = " << nNodes << "\n";
+
+                std::vector<char> coord;
+                ComputeCoor( splitZone, icoord, coord );
+
+                cg_coord_write( fileId, baseId, zoneId, dataType, coordname.c_str(), coord.data(), &coorId );
+
+                std::cout << "fileId = " << fileId  << " baseId = " << baseId << " zoneId = " << zoneId  << " coorId = " << coorId << "\n";
+            }
+
+            int nBcLists = splitZone->splitBcList.size();
+            std::vector<SplitBc * > bccoList;
+            std::vector<SplitBc * > bc1to1List;
+
+            for ( int ibc = 0; ibc < nBcLists; ++ ibc )
+            {
+                SplitBc * splitBc = splitZone->splitBcList[ ibc ];
+                if ( splitBc->bcType == BCTypeUserDefined )
+                {
+                    bc1to1List.push_back( splitBc );
+                }
+                else
+                {
+                    bccoList.push_back( splitBc );
+                }
+            }
+            int nbocos = bccoList.size();
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = -1;
+                GridLocation_t location = Vertex;
+
+                std::string boconame = "BC" + std::to_string( iboco + 1 );
+
+                SplitBc * splitBc = bccoList[ iboco ];
+                BCType_t bocotype = static_cast<BCType_t>( splitBc->bcType );
+                PointSetType_t ptset_type = PointRange;
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> pnts;
+                int nSize = splitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.end[ i ] );
+                }
+
+                cg_boco_write( fileId, baseId, zoneId, boconame.c_str(), bocotype, ptset_type, npnts, pnts.data(), & bccoId );
+            }
+
+            int n1to1 = bc1to1List.size();
+            std::cout << "n1to1 = " << n1to1 << "\n";
+
+            std::vector<int> itranfrm( index_dim );
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                itranfrm[ m ] = m + 1;
+            }
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int index_conn = -1;
+
+                SplitBc * splitBc = bc1to1List[ i1to1 ];
+                BCType_t bocotype = static_cast<BCType_t>( splitBc->bcType );
+
+                std::vector<cgsize_t> pnts;
+                std::vector<cgsize_t> pntsdonor;
+                int nSize = splitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.end[ i ] );
+                }
+
+                int nPatchSize = splitBc->patch->region.start.size();
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( splitBc->patch->region.start[ i ] );
+                }
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( splitBc->patch->region.end[ i ] );
+                }
+                int id = splitBc->patch->splitZone->zoneIndex;
+                std::string donorname = "Zone" + std::to_string( id );
+                std::string connectname = "Interface" + std::to_string( i1to1 );
+
+                cg_1to1_write( fileId, baseId, zoneId, connectname.c_str(), donorname.c_str(), pnts.data(), pntsdonor.data(), itranfrm.data(), &index_conn);
+                std::cout << "index_conn = " << index_conn << "\n";
+            }
+        }
+    }
+    cg_close( fileId );
+}
+
+void Partition::DumpPartitionedGridFile()
+{
+    int fileId = -1;
+    std::string filename = this->outName;
+    int ierr = cg_open( filename.c_str(), CG_MODE_WRITE, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+
+    std::vector<std::string> coordnames;
+    coordnames.push_back( "CoordinateX" );
+    coordnames.push_back( "CoordinateY" );
+    coordnames.push_back( "CoordinateZ" );
+
+    std::string basename = "Base";
+    int baseId = -1;
+    int icelldim = Global::cell_dim;
+    int iphysdim = Global::phys_dim;
+    cg_base_write( fileId, basename.c_str(), icelldim, iphysdim, &baseId );
+
+    std::cout << "baseId = " << baseId << "\n";
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        int nZones = this->GetNZones( iProc );
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            ZoneType_t zoneType = Structured;
+
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+
+            int index_dim = splitZone->dimInfo.dimList.size();
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            splitZone->dimInfo.ComputeISize();
+
+            int isize_dim = index_dim * 3;
+
+            std::vector<cgsize_t> isize( index_dim * 3, 0 );
+            for ( int m = 0; m < isize_dim; ++ m )
+            {
+                isize[ m ] = splitZone->dimInfo.isize[ m ];
+            }
+
+            int zoneId = -1;
+
+            std::string zonename = "Zone" + std::to_string( splitZone->newIndex );
+
+            cg_zone_write( fileId, baseId, zonename.c_str(), isize.data(), zoneType, &zoneId );
+
+            std::cout << "zoneId = " << zoneId << "\n";
+                
+            splitZone->ComputeRminmax();
+
+            SplitZone * rootSplitZone = splitZone->GetRootZone();
+
+            Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+            int ncoords = zone->coors.size();
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = -1;
+                DataType_t dataType = RealDouble;
+                std::string coordname = coordnames[ icoord ];
+                Coor * coor = zone->coors[ icoord ];
+
+                int nNodes = splitZone->dimInfo.ComputeNumNodes();
+                std::cout << "nNodes = " << nNodes << "\n";
+
+                std::vector<char> coord;
+                ComputeCoor( splitZone, icoord, coord );
+
+                cg_coord_write( fileId, baseId, zoneId, dataType, coordname.c_str(), coord.data(), &coorId );
+
+                std::cout << "fileId = " << fileId  << " baseId = " << baseId << " zoneId = " << zoneId  << " coorId = " << coorId << "\n";
+            }
+
+            int nBcLists = splitZone->splitBcList.size();
+            std::vector<SplitBc * > bccoList;
+            std::vector<SplitBc * > bc1to1List;
+
+            for ( int ibc = 0; ibc < nBcLists; ++ ibc )
+            {
+                SplitBc * splitBc = splitZone->splitBcList[ ibc ];
+                if ( splitBc->bcType == BCTypeUserDefined )
+                {
+                    bc1to1List.push_back( splitBc );
+                }
+                else
+                {
+                    bccoList.push_back( splitBc );
+                }
+            }
+            int nbocos = bccoList.size();
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = -1;
+                GridLocation_t location = Vertex;
+
+                std::string boconame = "BC" + std::to_string( iboco + 1 );
+
+                SplitBc * splitBc = bccoList[ iboco ];
+                BCType_t bocotype = static_cast<BCType_t>( splitBc->bcType );
+                PointSetType_t ptset_type = PointRange;
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> pnts;
+                int nSize = splitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.end[ i ] );
+                }
+
+                cg_boco_write( fileId, baseId, zoneId, boconame.c_str(), bocotype, ptset_type, npnts, pnts.data(), & bccoId );
+            }
+
+            int n1to1 = bc1to1List.size();
+            std::cout << "n1to1 = " << n1to1 << "\n";
+
+            std::vector<int> itranfrm( index_dim );
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                itranfrm[ m ] = m + 1;
+            }
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int index_conn = -1;
+
+                SplitBc * splitBc = bc1to1List[ i1to1 ];
+                BCType_t bocotype = static_cast<BCType_t>( splitBc->bcType );
+
+                std::vector<cgsize_t> pnts;
+                std::vector<cgsize_t> pntsdonor;
+                int nSize = splitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.end[ i ] );
+                }
+
+                int nPatchSize = splitBc->patch->region.start.size();
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( splitBc->patch->region.start[ i ] );
+                }
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( splitBc->patch->region.end[ i ] );
+                }
+                int id = splitBc->patch->splitZone->newIndex;
+                int oldZoneIndex = splitBc->patch->splitZone->zoneIndex;
+                std::cout << "id = " << id << "\n";
+                std::cout << "oldZoneIndex = " << oldZoneIndex << "\n";
+                std::string donorname = "Zone" + std::to_string( id );
+                std::string connectname = "Interface" + std::to_string( i1to1 );
+
+                cg_1to1_write( fileId, baseId, zoneId, connectname.c_str(), donorname.c_str(), pnts.data(), pntsdonor.data(), itranfrm.data(), &index_conn);
+                std::cout << "index_conn = " << index_conn << "\n";
+            }
+        }
+    }
+    cg_close( fileId );
+}
+
+void Partition::ModifyZoneIndex()
+{
+    int globalZoneId = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        std::cout << "iProc = " << iProc << "\n";
+        int nZones = this->GetNZones( iProc );
+        std::cout << "nZones in Proc " << iProc << "  = " << nZones << "\n";
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+            //splitZone->SetZoneIndex( globalZoneId++ );
+            splitZone->newIndex = ( globalZoneId++ );
+        }
+    }
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage1/01b/Partition.h b/example/partition/struct/2d/stage1/01b/Partition.h
new file mode 100644
index 00000000..ff83de0e
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01b/Partition.h
@@ -0,0 +1,188 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class Dim
+{
+public:
+    static int dim;
+};
+
+class SplitZone;
+class RangeRegion;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox );
+
+class DimInfo
+{
+public:
+    DimInfo();
+    ~DimInfo();
+public:
+    int dim;
+    std::vector<int> dimList;
+    std::vector<int> oriPoint;
+    std::vector<int> isize;
+    std::vector<int> rmin;
+    std::vector<int> rmax;
+public:
+    int GetSize() const { return dim; }
+    DimInfo & operator = ( const DimInfo & rhs );
+public:
+    int ComputeNumNodes();
+    void ComputeISize();
+    void ComputeRminmax( std::vector<int> & ref );
+    void Init( int dim );
+    void Init( std::vector<int> & dimList );
+    void SetNewDimension( int axis, int newStart, int newWidth );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+};
+
+class SplitZone;
+class SplitBcPatch;
+
+class RangeRegion
+{
+public:
+    RangeRegion( int nSize = 1 );
+    ~RangeRegion();
+public:
+    int regionAxis = -1;
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    void Init( int nSize );
+    RangeRegion & operator = ( const RangeRegion & rhs );
+    bool operator == ( const RangeRegion & rhs ) const;
+    void SetRegion( std::vector<int> &pnts );
+    int ComputeRegionAxis();
+};
+
+class SplitBc
+{
+public:
+    SplitBc();
+    ~SplitBc();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone = nullptr;
+    SplitBcPatch * patch = nullptr;
+    std::vector< SplitBc * > * child = nullptr;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+    void ChangeRegionToLocalCoordinate();
+public:
+    void CreateInterfaceBcFromParentBc( SplitBc * parentSplitBc );
+};
+
+class SplitBcPatch
+{
+public:
+    SplitBcPatch ();
+    ~SplitBcPatch();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+};
+
+
+class SplitZone
+{
+public:
+    SplitZone();
+    ~SplitZone();
+public:
+    DimInfo dimInfo;
+    int zoneIndex, iProc;
+    int newIndex;
+protected:
+    SplitZone * parent;
+public:
+    std::vector< SplitBc * > splitBcList;
+public:
+    int GetNCell();
+    void ComputeRminmax();
+    void GetRootInfo( SplitZone *& root, std::vector<int> & ref );
+    void SetZoneIndex( int zoneIndex ) { this->zoneIndex = zoneIndex; }
+    int  GetZoneIndex() { return zoneIndex; }
+    void SetProcId( int iProc ) { this->iProc = iProc; }
+    void SetParent( SplitZone * parent ) { this->parent = parent; };
+    std::vector< SplitBc * > & GetSplitBcList() { return this->splitBcList; };
+    void CreateBcFromParent();
+    void CreateSplitBcFromOverlapRegion( SplitBc * parentSplitBc, RangeRegion & overlapRegion );
+    void CreateChildInterfaceBc( RangeRegion & targeRegionBox, SplitZone * sourceZone );
+    bool CreateChildInterfaceBc( SplitBc * parentSplitBc, RangeRegion & targeRegionBox, SplitZone * sourceZone );
+    void CreateSplitBc( SplitBc * parentSplitBc );
+    void AddSplitBc( SplitBc * splitBc );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+    SplitZone * GetRootZone();
+public:
+    void Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell );
+    void SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+    void SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+private:
+    int FindAxisNeedSplit();
+    int FindSplitPosition( int axisNeedSplit, double nCell );
+    bool IsPoleBc( int splitDirection );
+    int GetCrossSection( int axis );
+};
+
+class Partition
+{
+public:
+    Partition();
+    ~Partition();
+protected:
+    std::set < SplitZone * > zoneStorage;
+    std::set < SplitZone * > unsignedZoneGroup;
+    std::vector< SplitZone * > refZone;
+    std::vector< std::vector< SplitZone * > > procSplitZone;
+    std::vector<double> procSpeed;
+    std::vector<double> timeProc;
+    double aveFloatOp, delta;
+    double idealUniProcTime, eps;
+    int minNumberCell;
+    int nTZone;
+    int nOriZone;
+    int nProc;
+public:
+    std::string inputName;
+    std::string outName;
+public:
+    void Solve();
+    void ReadGrid();
+    void Split();
+    void InitSplit();
+    void BinarySplit();
+    //void GreedySplit();
+public:
+    void AddNewZone( SplitZone * zone );
+    void AddZoneToUnsignedGroup( SplitZone * zone );
+    void RemoveZoneFromUnsignedGroup( SplitZone * zone );
+    void AddZoneToProcess( int iProc, SplitZone * zone );
+    void DumpMultiBasePartitionedGridFile();
+    void DumpPartitionedGridFile();
+    void ModifyZoneIndex();
+    void FreeAllZones();
+    int GetNZones( int iProc );
+    SplitZone * GetSplitZone( int iProc, int zoneId );
+    void ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord );
+    void DumpBc( SplitZone * splitZone );
+private:
+    int GetMinValueIndex( double * data, int numberOfData );
+    int GetMinLoadProc();
+    SplitZone * GetLargestZone();
+    SplitZone * Split( SplitZone * zone, double nCell );
+};
+
diff --git a/example/partition/struct/2d/stage1/01b/README.txt b/example/partition/struct/2d/stage1/01b/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01b/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/partition/struct/2d/stage1/01b/heat2d2blocks.cgns b/example/partition/struct/2d/stage1/01b/heat2d2blocks.cgns
new file mode 100644
index 00000000..2ce29d4c
Binary files /dev/null and b/example/partition/struct/2d/stage1/01b/heat2d2blocks.cgns differ
diff --git a/example/partition/struct/2d/stage1/01b/main.cpp b/example/partition/struct/2d/stage1/01b/main.cpp
new file mode 100644
index 00000000..5da1de7c
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01b/main.cpp
@@ -0,0 +1,18 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include "Partition.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip>
+
+int main(int argc, char **argv)
+{
+    Partition * partition = new Partition();
+    partition->Solve();
+    delete partition;
+
+    return 0;
+}
diff --git a/example/partition/struct/2d/stage1/01c/CMakeLists.txt b/example/partition/struct/2d/stage1/01c/CMakeLists.txt
new file mode 100644
index 00000000..9fa577c8
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01c/CMakeLists.txt
@@ -0,0 +1,77 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	Partition.h Partition.cpp
+	CgnsGrid.h CgnsGrid.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/partition/struct/2d/stage1/01c/CgnsGrid.cpp b/example/partition/struct/2d/stage1/01c/CgnsGrid.cpp
new file mode 100644
index 00000000..d287afcb
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01c/CgnsGrid.cpp
@@ -0,0 +1,345 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include <map>
+
+Grid::Grid()
+{
+    ;
+}
+
+Grid::~Grid()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if( (i+1)%5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+    delete this->patch;
+}
+
+ZoneBcPatch::ZoneBcPatch()
+{
+    ;
+}
+
+ZoneBcPatch::~ZoneBcPatch()
+{
+}
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+Global::Global()
+{
+    ;
+}
+
+Global::~Global()
+{
+}
+
+void Global::FreeData()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+    zones.resize( 0 );
+}
+
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            //baseZone.baseId = baseId;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin( index_dim );
+            std::vector<cgsize_t> irmax( index_dim );
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                std::vector<char> coord( nNodes * sizeof(double) );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+                coor->DumpCoor();
+            }
+
+            int nbocos = -1;
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc->pnts.push_back( range[ i ] );
+                }
+
+                zonebc->zoneid = gZoneId;
+                zonebc->bcType = BCTypeUserDefined;
+
+                ZoneBcPatch * patch = new ZoneBcPatch();
+                zonebc->patch = patch;
+
+                patch->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    patch->donor_pnts.push_back( donor_range[ i ] );
+                }
+                int kkk = 1;
+            }
+        }
+        int kkk = 1;
+    }
+    int kkk = 1;
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage1/01c/CgnsGrid.h b/example/partition/struct/2d/stage1/01c/CgnsGrid.h
new file mode 100644
index 00000000..af67a321
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01c/CgnsGrid.h
@@ -0,0 +1,123 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <map>
+
+class Grid;
+
+class Zone;
+
+class Grid
+{
+public:
+    Grid();
+    ~Grid();
+public:
+    int nZone;
+    std::vector<double> x;
+    std::vector<Zone *> zones;
+};
+
+class ZoneBc;
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+};
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<Coor *> coors;
+};
+
+class ZoneBcPatch;
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+    ZoneBcPatch * patch = nullptr;
+};
+
+class ZoneBcPatch
+{
+public:
+    ZoneBcPatch();
+    ~ZoneBcPatch();
+public:
+    int donor_zoneid;
+    std::vector<int> donor_pnts;
+};
+
+class BaseZone
+{
+public:
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Global
+{
+public:
+    Global();
+    ~Global();
+public:
+    static int cell_dim;
+    static int phys_dim;
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+public:
+    static void FreeData();
+};
+
+void ReadCgnsGrid( const std::string & filename );
+void ReadCgnsGridBaseZone( const std::string & filename );
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage1/01c/Partition.cpp b/example/partition/struct/2d/stage1/01c/Partition.cpp
new file mode 100644
index 00000000..31b9ac1e
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01c/Partition.cpp
@@ -0,0 +1,1722 @@
+#include "Partition.h"
+#include "CgnsGrid.h"
+#include "cgnslib.h"
+#include <string>
+
+int Dim::dim = -1;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox  )
+{
+    domainBox.start = zoneBox.start;
+    domainBox.end = zoneBox.end;
+
+    int axis = iDomain / 2;
+    int direction = iDomain % 2;
+
+    if ( direction == 0 )
+    {
+        domainBox.end[ axis ] = domainBox.start[ axis ];
+    }
+    else if ( direction == 1 )
+    {
+        domainBox.start[ axis ] = domainBox.end[ axis ];
+    }
+}
+
+DimInfo::DimInfo()
+{
+    this->Init( 1 );
+}
+
+DimInfo::~DimInfo()
+{
+}
+
+void DimInfo::Init( int dim )
+{
+    this->dim = dim;
+    dimList.resize( this->dim, 1 );
+    oriPoint.resize( this->dim, 0 );
+}
+
+DimInfo & DimInfo::operator = ( const DimInfo & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->dim = rhs.dim;
+    this->dimList = rhs.dimList;
+    this->oriPoint = rhs.oriPoint;
+
+    return * this;
+}
+
+int DimInfo::ComputeNumNodes()
+{
+    int nNodes = 1;
+    for ( int m = 0; m < this->dimList.size(); ++ m )
+    {
+        nNodes *= this->dimList[ m ];
+    }
+    return nNodes;
+}
+
+void DimInfo::ComputeISize()
+{
+    int index_dim = this->dimList.size();
+    this->isize.resize( index_dim * 3, 0 );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        isize[ m ] = this->dimList[ m ];
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 1;
+        isize[ start + m ] = this->dimList[ m ] - 1;
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 2;
+        isize[ start + m ] = 0;
+    }
+
+    for ( int i = 0; i < isize.size(); ++ i )
+    {
+        std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+    }
+}
+
+void DimInfo::ComputeRminmax( std::vector<int> & ref )
+{
+    int index_dim = this->dimList.size();
+    this->rmin.resize( index_dim );
+    this->rmax.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        rmin[ m ] = ref[ m ] + 1;
+        rmax[ m ] = ref[ m ] + this->dimList[ m ];
+    }
+
+    std::cout << "rmin, rmax = \n";
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        std::cout << rmin[ m ] << " " << rmax[ m ] << "\n";
+    }
+}
+
+void DimInfo::Init( std::vector<int> & dimList )
+{
+    this->dim = dimList.size();
+    this->dimList = dimList;
+    std::vector<int> zero( dimList.size(), 0 );
+    this->oriPoint = zero;
+}
+
+void DimInfo::SetNewDimension( int axis, int newStart, int newWidth )
+{
+    this->oriPoint[ axis ] = newStart;
+    this->dimList [ axis ] = newWidth;
+}
+
+void DimInfo::GetZoneGlobalBox( RangeRegion &zoneBox )
+{
+    int index_dim = this->dimList.size();
+    zoneBox.start.resize( index_dim );
+    zoneBox.end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        zoneBox.start[ m ] = this->oriPoint[ m ] + 1;
+        zoneBox.end[ m ] = this->oriPoint[ m ] + this->dimList[ m ];
+    }
+}
+
+void DimInfo::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    int index_dim = this->dimList.size();
+    localBox.start.resize( index_dim );
+    localBox.end.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        localBox.start[ m ] = globalBox.start[ m ] - this->oriPoint[ m ];
+        localBox.end[ m ] = globalBox.end[ m ] - this->oriPoint[ m ];
+    }
+}
+
+RangeRegion::RangeRegion( int nSize )
+{
+    this->Init( nSize );
+}
+
+RangeRegion::~RangeRegion()
+{
+}
+
+void RangeRegion::Init( int nSize )
+{
+    this->start.resize( nSize );
+    this->end.resize( nSize );
+}
+
+RangeRegion & RangeRegion::operator = ( const RangeRegion & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+    this->regionAxis = rhs.regionAxis;
+
+    return * this;
+}
+
+bool RangeRegion::operator == ( const RangeRegion & rhs ) const
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] != rhs.start[ m ] || 
+            this->end  [ m ] != rhs.end  [ m ] )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+    this->ComputeRegionAxis();
+}
+
+int RangeRegion::ComputeRegionAxis()
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] == this->end[ m ] )
+        {
+            this->regionAxis = m;
+            return this->regionAxis;
+        }
+    }
+    return this->regionAxis;
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion );
+
+bool ComputeOverlapRegion( RangeRegion & region1, RangeRegion & region2, RangeRegion & overlapRegion )
+{
+    int index_dim = region1.start.size();
+    overlapRegion.Init( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int ijkmin1 = std::min( region1.start[ m ], region1.end[ m ] );
+        int ijkmax1 = std::max( region1.start[ m ], region1.end[ m ] );
+        int ijkmin2 = std::min( region2.start[ m ], region2.end[ m ] );
+        int ijkmax2 = std::max( region2.start[ m ], region2.end[ m ] );
+        if ( ( ijkmax1 < ijkmin2 ) || ( ijkmin1 > ijkmax2 ) )
+        {
+            return false;
+        }
+
+        int ijkmin = std::max( ijkmin1, ijkmin2 );
+        int ijkmax = std::min( ijkmax1, ijkmax2 );
+
+        overlapRegion.start[ m ] = ijkmin;
+        overlapRegion.end  [ m ] = ijkmax;
+    }
+
+    return CheckOverLapping( overlapRegion );
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion )
+{
+    int index_dim = overlapRegion.start.size();
+    int iCount = 0;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        if ( overlapRegion.start[ m ] == overlapRegion.end[ m ] )
+        {
+            ++ iCount;
+        }
+    }
+
+    return ( iCount == 1 );
+}
+
+bool GetInterfaceRegion( RangeRegion & zoneBoxL, RangeRegion & zoneBoxR, RangeRegion & interfaceRegion )
+{
+    int index_dim = zoneBoxL.start.size();
+    int nDomains = 2 * index_dim;
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegionL;
+        GetDomainRegion( zoneBoxL, iDomain, domainRegionL );
+
+        for ( int jDomain = 0; jDomain < nDomains; ++ jDomain )
+        {
+            RangeRegion domainRegionR;
+            GetDomainRegion( zoneBoxR, jDomain, domainRegionR );
+
+            if ( domainRegionL == domainRegionR )
+            {
+                interfaceRegion = domainRegionL;
+                return true;
+            }
+        }
+    }
+    return false;
+}
+
+void CreateInterfaceBc( SplitZone * zoneL, SplitZone * zoneR )
+{
+    RangeRegion globalBoxL, globalBoxR, globalInterfaceRegion;
+
+    zoneL->GetZoneGlobalBox( globalBoxL );
+    zoneR->GetZoneGlobalBox( globalBoxR );
+
+    if ( ! GetInterfaceRegion( globalBoxL, globalBoxR, globalInterfaceRegion ) )
+    {
+        int kkk = 1;
+        return;
+    }
+
+    RangeRegion localInterfaceRegionL, localInterfaceRegionR;
+
+    zoneL->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionL );
+    zoneR->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionR );
+
+    int kkk = 1;
+
+    SplitBc * splitBcL = new SplitBc();
+    zoneL->AddSplitBc( splitBcL );
+
+    SplitBc * splitBcR = new SplitBc();
+    zoneR->AddSplitBc( splitBcR );
+
+    splitBcL->splitZone = zoneL;
+    splitBcL->SetRegion( localInterfaceRegionL );
+    splitBcL->bcType = BCTypeUserDefined;
+
+    splitBcR->splitZone = zoneR;
+    splitBcR->SetRegion( localInterfaceRegionR );
+    splitBcR->bcType = BCTypeUserDefined;
+
+    //localInterfaceRegionL.MarkPatchBc();
+    //localInterfaceRegionR.MarkPatchBc();
+
+    SplitBcPatch * splitBcPatchL = new SplitBcPatch();
+    splitBcL->patch = splitBcPatchL;
+    splitBcPatchL->region = localInterfaceRegionR;
+    splitBcPatchL->splitZone = zoneR;
+
+    SplitBcPatch * splitBcPatchR = new SplitBcPatch();
+    splitBcR->patch = splitBcPatchR;
+    splitBcPatchR->region = localInterfaceRegionL;
+    splitBcPatchR->splitZone = zoneL;
+
+    //splitBcL->Normalize();
+    //splitBcR->Normalize();
+}
+
+
+SplitBc::SplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+SplitBc::~SplitBc()
+{
+    delete this->patch;
+}
+
+void SplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void SplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+void SplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = splitZone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void SplitBc::GetLeafBcs( std::vector< SplitBc * > & leafBcs )
+{
+    if ( ! this->child )
+    {
+        leafBcs.push_back( this );
+        return;
+    }
+
+    for ( int i = 0; i < this->child->size(); ++ i )
+    {
+        std::vector< SplitBc * > child_leafBcs;
+        ( * child )[ i ]->GetLeafBcs( child_leafBcs );
+        for ( int j = 0; j < child_leafBcs.size(); ++ j )
+        {
+            leafBcs.push_back( child_leafBcs[ j ] );
+        }
+    }
+
+    return;
+}
+
+void SplitBc::CreateInterfaceBcFromParentBcNewVersion( SplitBc * parentSplitBc )
+{
+    if ( parentSplitBc->bcType !=  BCTypeUserDefined ) return;
+
+    this->patch = new SplitBcPatch();
+    this->patch->splitZone = parentSplitBc->patch->splitZone;
+    this->patch->SetRegion( parentSplitBc->patch->region );
+    int kkk = 1;
+
+    //Find the block corresponding to this docking boundary
+    //From patch->splitZone, find the corresponding docking boundary according to the size of overlapt
+    //The boundary conditions on the opposite side must change due to the split of this block.
+    //Here, the relevant boundaries are added to the sub-boundaries.
+
+    RangeRegion targetRegionBox;
+    targetRegionBox = parentSplitBc->patch->region;
+
+    SplitZone * targetZone = this->patch->splitZone;
+
+    //targetZone->CreateChildInterfaceBc( targetRegionBox, this->splitZone );
+    targetZone->CreateChildInterfaceBc( this );
+
+    //this->patch->faceAxis = parentSplitBc->patch->faceAxis;
+
+    //( * this->patch->vertexMap ) = ( * parentBc->patch->vertexMap );
+
+    ////È»ºó½øÐÐÐÞÕý
+    ////block1->map 1, 33 -> block1 369, 337
+    ////block2->global -> map 1, 33 -> block1 369, 337
+    ////block2->local  -> map 1, 33 -> block1 369, 337
+    ////refOld + M * stold           = block1Startold
+    ////refOld + M * ( stnew + ref ) = block1Startold
+    ////refNew = refOld + M * ( ref )
+
+    //for ( int m = 0; m < 3; ++ m )
+    //{
+    //    for ( int n = 0; n < 3; ++ n )
+    //    {
+    //        this->patch->vertexMap->pt[ m ] += this->patch->vertexMap->vm[ m ][ n ] * ( this->splitZone->sdim->oriPoint )[ n ];
+    //    }
+    //}
+
+    //RangeBox tRangeBox;
+
+    //MappingPatchPoint( this->patch, this->rangeBox, tRangeBox );
+    //tRangeBox.SetOrder();
+
+    ////ÕÒµ½ºÍ±¾¶Ô½Ó±ß½çÏà¶ÔÓ¦µÄ¿é
+    ////´Ópatch->splitZone°´ÕÕoverlapµÄ´óСÕÒµ½¶ÔÓ¦µÄ¶Ô½Ó±ß½ç£¬ÕâÑùÖÁÉÙ¿ÉÒÔÕÒµ½
+    ////¶ÔÃæµÄ¶Ô½Ó±ß½çÌõ¼þÓÉÓÚ±¾¿éµÄsplit±ØȻҪ·¢Éú¸Ä±ä£¬ÕâÀｫÏà¹Ø±ß½ç¼ÓÈë×ӱ߽ç
+    //this->patch->splitZone->CreateChildInterfaceBc( tRangeBox, this->splitZone );
+}
+
+void SplitBc::CreateInterfaceBcFromParentBc( SplitBc * parentSplitBc )
+{
+    if ( parentSplitBc->bcType !=  BCTypeUserDefined ) return;
+
+    this->patch = new SplitBcPatch();
+    this->patch->splitZone = parentSplitBc->patch->splitZone;
+    this->patch->SetRegion( parentSplitBc->patch->region );
+    int kkk = 1;
+
+    //Find the block corresponding to this docking boundary
+    //From patch->splitZone, find the corresponding docking boundary according to the size of overlapt
+    //The boundary conditions on the opposite side must change due to the split of this block.
+    //Here, the relevant boundaries are added to the sub-boundaries.
+
+    RangeRegion targetRegionBox;
+    targetRegionBox = parentSplitBc->patch->region;
+
+    SplitZone * targetZone = this->patch->splitZone;
+
+    targetZone->CreateChildInterfaceBc( targetRegionBox, this->splitZone );
+
+    //this->patch->faceAxis = parentSplitBc->patch->faceAxis;
+
+    //( * this->patch->vertexMap ) = ( * parentBc->patch->vertexMap );
+
+    ////È»ºó½øÐÐÐÞÕý
+    ////block1->map 1, 33 -> block1 369, 337
+    ////block2->global -> map 1, 33 -> block1 369, 337
+    ////block2->local  -> map 1, 33 -> block1 369, 337
+    ////refOld + M * stold           = block1Startold
+    ////refOld + M * ( stnew + ref ) = block1Startold
+    ////refNew = refOld + M * ( ref )
+
+    //for ( int m = 0; m < 3; ++ m )
+    //{
+    //    for ( int n = 0; n < 3; ++ n )
+    //    {
+    //        this->patch->vertexMap->pt[ m ] += this->patch->vertexMap->vm[ m ][ n ] * ( this->splitZone->sdim->oriPoint )[ n ];
+    //    }
+    //}
+
+    //RangeBox tRangeBox;
+
+    //MappingPatchPoint( this->patch, this->rangeBox, tRangeBox );
+    //tRangeBox.SetOrder();
+
+    ////ÕÒµ½ºÍ±¾¶Ô½Ó±ß½çÏà¶ÔÓ¦µÄ¿é
+    ////´Ópatch->splitZone°´ÕÕoverlapµÄ´óСÕÒµ½¶ÔÓ¦µÄ¶Ô½Ó±ß½ç£¬ÕâÑùÖÁÉÙ¿ÉÒÔÕÒµ½
+    ////¶ÔÃæµÄ¶Ô½Ó±ß½çÌõ¼þÓÉÓÚ±¾¿éµÄsplit±ØȻҪ·¢Éú¸Ä±ä£¬ÕâÀｫÏà¹Ø±ß½ç¼ÓÈë×ӱ߽ç
+    //this->patch->splitZone->CreateChildInterfaceBc( tRangeBox, this->splitZone );
+}
+
+
+SplitBcPatch::SplitBcPatch()
+{
+    this->region.Init( Dim::dim );
+}
+
+SplitBcPatch::~SplitBcPatch()
+{
+}
+
+void SplitBcPatch::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void SplitBcPatch::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+SplitZone::SplitZone()
+{
+    this->parent  = 0;
+    this->zoneIndex = 0;
+    this->iProc = 0;
+    dimInfo.Init( Dim::dim );
+    int kk = 1;
+}
+
+SplitZone::~SplitZone()
+{
+    ;
+}
+
+void SplitZone::GetZoneGlobalBox( RangeRegion & zoneBox )
+{
+    this->dimInfo.GetZoneGlobalBox( zoneBox );
+}
+
+void SplitZone::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    this->dimInfo.GetZoneLocalBox( globalBox, localBox );
+}
+
+
+void SplitZone::ComputeRminmax()
+{
+    int index_dim = this->dimInfo.dimList.size();
+    std::vector<int> ref( index_dim, 0 );
+
+    SplitZone * rootSplitZone = 0;
+    this->GetRootInfo( rootSplitZone, ref );
+
+    this->dimInfo.ComputeRminmax( ref );
+}
+
+SplitZone * SplitZone::GetRootZone()
+{
+    SplitZone * root = this;
+
+    while ( true )
+    {
+        if ( root->parent )
+        {
+            root = root->parent;
+        }
+        else
+        {
+            return root;
+        }
+    };
+}
+
+void SplitZone::GetRootInfo( SplitZone *& root, std::vector<int> & ref )
+{
+    for ( int i = 0; i < this->dimInfo.dimList.size(); ++ i )
+    {
+        ref[ i ] += this->dimInfo.oriPoint[ i ];
+    }
+
+    if ( this->parent )
+    {
+        this->parent->GetRootInfo( root, ref );
+    }
+    else
+    {
+        root = this;
+    }
+}
+
+
+int SplitZone::GetNCell()
+{
+    int numberOfCells = 1;
+    for ( int i = 0; i < this->dimInfo.dim; ++ i )
+    {
+        numberOfCells *= std::max( 1, ( this->dimInfo.dimList[ i ] - 1 ) );
+    }
+
+    return numberOfCells; 
+}
+
+void SplitZone::GetLeafBcList( std::vector< SplitBc * > & leafBcList )
+{
+    int nSplitBcs = this->splitBcList.size();
+
+    for ( int iSplitBcs = 0; iSplitBcs < nSplitBcs; ++ iSplitBcs )
+    {
+        SplitBc * splitBc = splitBcList[ iSplitBcs ];
+
+        std::vector< SplitBc * > leafBcs;
+        splitBc->GetLeafBcs( leafBcs );
+        for ( int j = 0; j < leafBcs.size(); ++ j )
+        {
+            leafBcList.push_back( leafBcs[ j ] );
+        }
+    }
+}
+
+void SplitZone::SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int leftStart = 0;
+    int leftWidth = iSplit - 0;
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, leftStart , leftWidth  );
+}
+
+void SplitZone::SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int rightStart = iSplit - 1;
+    int rightWidth = dimList[ axisNeedSplit ] - ( iSplit - 1 );
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, rightStart, rightWidth );
+}
+
+void SplitZone::Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell )
+{
+    //Find the longest axis
+    int axisNeedSplit = this->FindAxisNeedSplit();
+    int iSplit        = this->FindSplitPosition( axisNeedSplit, nCell );
+
+    zoneL->SetLeftDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+    zoneR->SetRightDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+
+    zoneL->CreateBcFromParent();
+    zoneR->CreateBcFromParent();
+
+    CreateInterfaceBc( zoneL, zoneR );
+}
+
+void SplitZone::CreateBcFromParent()
+{
+    std::vector< SplitBc * > & parentSplitBcList = this->parent->GetSplitBcList();
+
+    int nParentSplitBcs = parentSplitBcList.size();
+
+    for ( int iParentBc = 0; iParentBc < nParentSplitBcs; ++ iParentBc )
+    {
+        SplitBc * parentSplitBc = parentSplitBcList[ iParentBc ];
+
+        this->CreateSplitBc( parentSplitBc );
+    }
+}
+
+void SplitZone::CreateChildInterfaceBc( SplitBc * targetInterfaceBc )
+{
+    std::vector< SplitBc * > & splitBcList = this->GetSplitBcList();
+
+    int nSplitBcs = splitBcList.size();
+
+    for ( int iSplitBc = 0; iSplitBc < nSplitBcs; ++ iSplitBc )
+    {
+        SplitBc * splitBc = splitBcList[ iSplitBc ];
+
+        //Only consider the interface boundaries
+        if ( splitBc->bcType !=  BCTypeUserDefined ) continue;
+        SplitBc * candidateInterfaceBc = splitBc;
+
+        if ( this->CreateChildInterfaceBc( candidateInterfaceBc, targetInterfaceBc ) )
+        {
+            return;
+        }
+    }
+}
+
+bool SplitZone::CreateChildInterfaceBc( SplitBc * candidateInterfaceBc, SplitBc * targetInterfaceBc )
+{
+    RangeRegion overlapRegion;
+    bool overlap_flag = ComputeOverlapRegion( candidateInterfaceBc->region, targetInterfaceBc->patch->region, overlapRegion );
+    if ( ! overlap_flag ) return false;
+
+    //1. Èç¹ûsplitBcºÍinterfaceBcÓн»¼¯£¬µ«ÊÇinterfaceBcûÓÐchild£¬Ôò´ËsplitBc×÷ΪinterfaceBcµÄÒ»¸öchild
+    //2. Èç¹ûsplitBcºÍinterfaceBcÓн»¼¯£¬ÇÒinterfaceBcÓÐchild£¬Èç¹ûsplitBcºÍËùÓÐchildûÓн»¼¯£¬
+    //   ÔòsplitBc¼ÓÈëinterfaceBcµÄÒ»¸öchild
+    //3. Èç¹ûsplitBcºÍinterfaceBcÓн»¼¯£¬ÇÒinterfaceBcÓÐchild£¬Èç¹ûsplitBcºÍchildÓн»¼¯£¬Ôò´Ëchild×÷ΪеÄinterfaceBc
+
+    std::vector< SplitBc * > * child = candidateInterfaceBc->child;
+
+    if ( candidateInterfaceBc->child )
+    {
+        for ( int iChild = 0; iChild < candidateInterfaceBc->child->size(); ++ iChild )
+        {
+            SplitBc * childSplitBc = ( * candidateInterfaceBc->child )[ iChild ];
+            if ( this->CreateChildInterfaceBc( childSplitBc, targetInterfaceBc ) ) return true;
+        }
+    }
+    else
+    {
+        candidateInterfaceBc->child = new std::vector< SplitBc * >();
+    }
+
+    SplitBc * childInterfaceBc = new SplitBc();
+
+    childInterfaceBc->SetRegion( overlapRegion );
+    childInterfaceBc->bcType = candidateInterfaceBc->bcType;
+    childInterfaceBc->splitZone = candidateInterfaceBc->splitZone;
+
+    candidateInterfaceBc->child->push_back( childInterfaceBc );
+
+    //vector< int > & parentFaceDirectionContainer = interfaceBc->GetFaceDirectionContainer();
+    //vector< int > & faceDirectionContainer  = childInterfaceBc->GetFaceDirectionContainer();
+
+    //for ( int m = 0; m < 3; ++ m )
+    //{
+    //    faceDirectionContainer[ m ] = parentFaceDirectionContainer[ m ];
+    //}
+
+    //½«´ËÐÂÉú³ÉµÄ¶Ô½Ó±ß½ç¼ÓÈë±¾¿éÀïÃæ
+    SplitBcPatch * patch = new SplitBcPatch();
+    childInterfaceBc->patch = patch;
+    patch->splitZone = targetInterfaceBc->splitZone;
+    patch->region = targetInterfaceBc->region;
+
+    //patch->CopyVertexMappingContent( interfaceBc->GetZoneBoundaryConditionPatch()->GetVertexMapping() );
+
+    //vector< int > & pNextFaceDirectionContainer = interfaceBc->GetZoneBoundaryConditionPatch()->GetFaceDirectionContainer();
+    //vector< int > & patchFaceDirectionContainer = patch->GetFaceDirectionContainer();
+
+    //for ( int m = 0; m < 3; ++ m )
+    //{
+    //    patchFaceDirectionContainer[ m ] = pNextFaceDirectionContainer[ m ];
+    //}
+
+    //Ô­¶Ô½Ó±ß½çÂú×ã
+    //t0 = tref + M * s0
+    //еĶԽӱ߽çÂú×ã
+    //t0newblock + refNewblock = tref + M * s0
+    //t0newblock = ( tref - refNewblock ) + M * s0
+
+    //È»ºó½øÐÐÐÞÕý
+    //for ( int m = 0; m < 3; ++ m )
+    //{
+    //    ( patch->GetVertexMapping() )[ m ][ 3 ] -= ( sourceZone->GetOriginalPointIndexContainer() )[ m ];
+    //}
+
+    return true;
+}
+
+void SplitZone::CreateChildInterfaceBc( RangeRegion &targeRegionBox, SplitZone * sourceZone )
+{
+    std::vector< SplitBc * > & splitBcList = this->GetSplitBcList();
+
+    int nSplitBcs = splitBcList.size();
+
+    for ( int iSplitBc = 0; iSplitBc < nSplitBcs; ++ iSplitBc )
+    {
+        SplitBc * splitBc = splitBcList[ iSplitBc ];
+
+        //Only consider the interface boundaries
+        if ( splitBc->bcType !=  BCTypeUserDefined ) continue;
+
+        if ( this->CreateChildInterfaceBc( splitBc, targeRegionBox, sourceZone ) ) return;
+    }
+}
+
+bool SplitZone::CreateChildInterfaceBc( SplitBc * interfaceBc, RangeRegion & targeRegionBox, SplitZone * sourceZone )
+{
+    RangeRegion overlapRegion;
+    bool overlap_flag = ComputeOverlapRegion( interfaceBc->region, targeRegionBox, overlapRegion );
+    if ( ! overlap_flag ) return false;
+
+    //1. Èç¹ûsplitBcºÍinterfaceBcÓн»¼¯£¬µ«ÊÇinterfaceBcûÓÐchild£¬Ôò´ËsplitBc×÷ΪinterfaceBcµÄÒ»¸öchild
+    //2. Èç¹ûsplitBcºÍinterfaceBcÓн»¼¯£¬ÇÒinterfaceBcÓÐchild£¬Èç¹ûsplitBcºÍËùÓÐchildûÓн»¼¯£¬
+    //   ÔòsplitBc¼ÓÈëinterfaceBcµÄÒ»¸öchild
+    //3. Èç¹ûsplitBcºÍinterfaceBcÓн»¼¯£¬ÇÒinterfaceBcÓÐchild£¬Èç¹ûsplitBcºÍchildÓн»¼¯£¬Ôò´Ëchild×÷ΪеÄinterfaceBc
+
+    std::vector< SplitBc * > * child = interfaceBc->child;
+
+    if ( interfaceBc->child )
+    {
+        for ( int iChild = 0; iChild < interfaceBc->child->size(); ++ iChild )
+        {
+            SplitBc * childSplitBc = ( * interfaceBc->child )[ iChild ];
+            if ( this->CreateChildInterfaceBc( childSplitBc, targeRegionBox, sourceZone ) ) return true;
+        }
+    }
+    else
+    {
+        interfaceBc->child = new std::vector< SplitBc * >();
+    }
+
+    SplitBc * childInterfaceBc = new SplitBc();
+    //this->AddSplitBc( splitBc );
+
+    childInterfaceBc->SetRegion( overlapRegion );
+    childInterfaceBc->bcType = interfaceBc->bcType;
+    childInterfaceBc->splitZone = interfaceBc->splitZone;
+
+
+    interfaceBc->child->push_back( childInterfaceBc );
+
+    //vector< int > & parentFaceDirectionContainer = interfaceBc->GetFaceDirectionContainer();
+    //vector< int > & faceDirectionContainer  = childInterfaceBc->GetFaceDirectionContainer();
+
+    //for ( int m = 0; m < 3; ++ m )
+    //{
+    //    faceDirectionContainer[ m ] = parentFaceDirectionContainer[ m ];
+    //}
+
+    //½«´ËÐÂÉú³ÉµÄ¶Ô½Ó±ß½ç¼ÓÈë±¾¿éÀïÃæ
+    SplitBcPatch * patch = new SplitBcPatch();
+    childInterfaceBc->patch = patch;
+    patch->splitZone = sourceZone;
+
+    //patch->CopyVertexMappingContent( interfaceBc->GetZoneBoundaryConditionPatch()->GetVertexMapping() );
+
+    //vector< int > & pNextFaceDirectionContainer = interfaceBc->GetZoneBoundaryConditionPatch()->GetFaceDirectionContainer();
+    //vector< int > & patchFaceDirectionContainer = patch->GetFaceDirectionContainer();
+
+    //for ( int m = 0; m < 3; ++ m )
+    //{
+    //    patchFaceDirectionContainer[ m ] = pNextFaceDirectionContainer[ m ];
+    //}
+
+    //Ô­¶Ô½Ó±ß½çÂú×ã
+    //t0 = tref + M * s0
+    //еĶԽӱ߽çÂú×ã
+    //t0newblock + refNewblock = tref + M * s0
+    //t0newblock = ( tref - refNewblock ) + M * s0
+
+    //È»ºó½øÐÐÐÞÕý
+    //for ( int m = 0; m < 3; ++ m )
+    //{
+    //    ( patch->GetVertexMapping() )[ m ][ 3 ] -= ( sourceZone->GetOriginalPointIndexContainer() )[ m ];
+    //}
+
+    return true;
+}
+
+void SplitZone::AddSplitBc( SplitBc * splitBc )
+{
+    if ( ! splitBc ) return;
+    this->splitBcList.push_back( splitBc );
+}
+
+void SplitZone::CreateSplitBc( SplitBc * parentSplitBc )
+{
+    if ( ! parentSplitBc->child )
+    {
+        int index_dim = this->dimInfo.dimList.size();
+        int nDomains = 2 * index_dim;
+        RangeRegion zoneBoxRegion( index_dim );
+        this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+        for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+        {
+            RangeRegion domainRegion( index_dim );
+            GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+            RangeRegion overlapRegion;
+            bool overlap_flag = ComputeOverlapRegion( parentSplitBc->region, domainRegion, overlapRegion );
+            if ( ! overlap_flag ) continue;
+
+            this->CreateSplitBcFromOverlapRegion( parentSplitBc, overlapRegion );
+
+            int kkk = 1;
+        }
+    }
+    else
+    {
+        int nChilds = parentSplitBc->child->size();
+        for ( int iChild = 0; iChild < nChilds; ++ iChild )
+        {
+            this->CreateSplitBc( ( * parentSplitBc->child )[ iChild ] );
+        }
+    }
+}
+
+void SplitZone::CreateSplitBcFromOverlapRegion( SplitBc * parentSplitBc, RangeRegion & overlapRegion )
+{
+    SplitBc * splitBc = new SplitBc();
+    this->AddSplitBc( splitBc );
+
+    splitBc->SetRegion( overlapRegion );
+    splitBc->bcType = parentSplitBc->bcType;
+    splitBc->splitZone = this;
+    splitBc->ChangeRegionToLocalCoordinate();
+    //splitBc->CreateInterfaceBcFromParentBc( parentSplitBc );
+    splitBc->CreateInterfaceBcFromParentBcNewVersion( parentSplitBc );
+}
+
+int SplitZone::FindAxisNeedSplit()
+{
+    //Find the longest axis
+    int axisNeedSplit = 0;
+    int maxN = this->dimInfo.dimList[ 0 ];
+
+    for ( int m = 1; m < this->dimInfo.dimList.size(); ++ m )
+    {
+        if ( this->IsPoleBc( m ) )
+        {
+            continue;
+        }
+        int Nm = this->dimInfo.dimList[ m ];
+        if ( maxN < Nm )
+        {
+            maxN = Nm;
+            axisNeedSplit = m;
+        }
+    }
+
+    return axisNeedSplit;
+}
+
+int SplitZone::GetCrossSection( int axis )
+{
+    int nDim = this->dimInfo.dimList.size();
+    int crossSection = 1;
+    int N = nDim - 1;
+    for ( int m = 0; m < N; ++ m )
+    {
+         int mm = ( axis + 1 ) % nDim;
+         int nLineElements = std::max( 1, ( this->dimInfo.dimList[ mm ] - 1 ) );
+         crossSection *= nLineElements;
+    }
+    return crossSection;
+}
+
+int SplitZone::FindSplitPosition( int axisNeedSplit, double nCell )
+{
+    int nDim = this->dimInfo.dimList.size();
+    std::vector<int> crossSections( nDim );
+    for ( int m = 0; m < nDim; ++ m )
+    {
+        crossSections[ m ] = this->GetCrossSection( m );
+    }
+
+    //guess the value
+    double dSplit = nCell / crossSections[ axisNeedSplit ];
+    int  iSplit = 1 + static_cast< int >( std::floor( dSplit + 0.5 ) );
+    return iSplit;
+}
+
+
+bool SplitZone::IsPoleBc( int splitDirection )
+{
+    return false;
+}
+
+
+double CalSumOfProcSpeed( std::vector<double> & procSpeed );
+double CalSumOfProcSpeed( std::vector<double> & procSpeed )
+{
+    int nProc = procSpeed.size();
+    double sumOfProcSpeed = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        sumOfProcSpeed += procSpeed[ iProc ];
+    }
+    return sumOfProcSpeed;
+}
+
+Partition::Partition()
+{
+    this->inputName = "../heat2d2blocks.cgns";
+    this->outName =  "../heat2dpart.cgns";
+}
+
+Partition::~Partition()
+{
+    ;
+}
+
+int Partition::GetMinValueIndex( double * data, int numberOfData )
+{
+    double minValue = data[ 0 ];
+    int minimumValueIndex = 0;
+
+    for ( int iData = 1; iData < numberOfData; ++ iData )
+    {
+        if ( minValue > data[ iData ] )
+        {
+            minValue      = data[ iData ];
+            minimumValueIndex = iData;
+        }
+    }
+    return minimumValueIndex;
+}
+
+int Partition::GetMinLoadProc()
+{
+    return this->GetMinValueIndex( this->timeProc.data(), this->nProc );
+}
+
+SplitZone * Partition::GetLargestZone()
+{
+    SplitZone * largestZone = 0;
+
+    double nMaxCell = 0.0;
+
+    for ( std::set< SplitZone * >::iterator iter = unsignedZoneGroup.begin(); iter != unsignedZoneGroup.end(); ++ iter )
+    {
+        double nSize = ( * iter )->GetNCell();
+        if ( nMaxCell < nSize )
+        {
+            nMaxCell    = nSize;
+            largestZone = * iter;
+        }
+    }
+
+    return largestZone;
+}
+
+void Partition::Solve()
+{
+    std::cout << "Partition::Split()\n";
+    //this->nProc = 2;
+    this->nProc = 3;
+    this->ReadGrid();
+    this->Split();
+    this->DumpPartitionedGridFile();
+    this->FreeAllZones();
+}
+
+void Partition::ReadGrid()
+{
+    ReadCgnsGridBaseZone( this->inputName );
+    ReadCgnsGrid( this->inputName );
+
+    this->nOriZone = ::Global::zones.size();
+    Dim::dim = Global::cell_dim;
+
+    std::cout << "numberOfBlocks = " << nOriZone << "\n";
+
+    this->refZone.resize( nOriZone );
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = new SplitZone();
+        refZone[ iZone ] = splitZone;
+
+        splitZone->SetZoneIndex( iZone );
+        splitZone->SetProcId( 0 );
+        splitZone->SetParent( 0 );
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        Zone * zone = ::Global::zones[ iZone ];
+
+        splitZone->dimInfo.dimList = zone->nijk;
+
+        int nBcRegion = zone->bccos.size();
+        std::cout << "nBcRegion = " << nBcRegion << "\n";
+
+        std::vector< SplitBc * > & splitBcList = splitZone->splitBcList;
+
+        for ( int iBcRegion = 0; iBcRegion < nBcRegion; ++ iBcRegion )
+        {
+            SplitBc * splitBc = new SplitBc();
+            splitBcList.push_back( splitBc );
+
+            ZoneBc * zoneBc = zone->bccos[ iBcRegion ];
+
+            splitBc->splitZone = splitZone;
+            splitBc->bcType = zoneBc->bcType;
+            splitBc->SetRegion( zoneBc->pnts );
+            if ( zoneBc->patch )
+            {
+                SplitBcPatch * patch = new SplitBcPatch();
+                splitBc->patch = patch;
+
+                patch->splitZone = refZone[ zoneBc->patch->donor_zoneid ];
+                patch->SetRegion( zoneBc->patch->donor_pnts );
+            }
+        }
+
+        int kkk = 1;
+    }
+    int kkk = 1;
+}
+
+void Partition::Split()
+{
+    this->InitSplit();
+    this->BinarySplit();
+    this->ModifyZoneIndex();
+    int kkk = 1;
+}
+
+void Partition::InitSplit()
+{
+    //nZone is the number of zones in the original grid
+    //nProc is not the number of blocks in the end, but the number of processes that need to be divided.
+    //This difference occurs because the structure grid can have many blocks per process.
+
+    //this->nProc    = nProc;
+    //this->nPhyBlocks = referenceBlock.size();
+    //this->nZone  = this->nPhyBlocks;
+
+    //tj Computation time on processor j
+    //Nk Number of internal grid-cells for zone j
+    //aveFloatOp:  Number of Real operations per gridcell
+    //Gj The set of blocks allocated to process j
+    //Pj Real operations per second for process j
+
+    //The Greedy Load Balancing Algorithm
+    //1.Compute an "ideal" uniprocessor time, Tuni = sum ( Nk * aveFloatOp )/ sum( Pj ).
+    //2.Set the group of unassigned blocks, Gu, to contain all blocks. The number of blocks in Nu=M, where M is the total number of blocks in the mesh.
+    //3.Start all processors with a very small fictitious zone to get a start tj=delt aveFloatOp/Pj, where delt<<1 is the size of the very small fictious zone.
+    //This is used to find the fastest processor in a heterogeneous system, tj could otherwise be set to 0 in the homogeneous case.
+    this->aveFloatOp = 1.0;
+    this->delta      = 1.0e-5;
+    this->procSpeed.resize( nProc );
+    this->timeProc.resize( nProc );
+
+    this->nTZone = this->nOriZone;
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        procSpeed[ iProc ] = 1.0;
+    }
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        timeProc[ iProc ] = delta * aveFloatOp / procSpeed[ iProc ];
+    }
+
+    double sumProcSpeed = CalSumOfProcSpeed( procSpeed );
+
+    double sumProcOp = 0.0;
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        sumProcOp += refZone[ iZone ]->GetNCell() * aveFloatOp;
+    }
+
+    this->idealUniProcTime = sumProcOp / sumProcSpeed;
+
+    this->eps = 0.05;
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        unsignedZoneGroup.insert( refZone[ iZone ] );
+    }
+
+    //Init zoneStorage
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        zoneStorage.insert( refZone[ iZone ] );
+    }
+
+    //Assign procSplitZone to each process
+    procSplitZone.resize( nProc );
+
+    this->minNumberCell = 1;
+    for ( int m = 0; m < Dim::dim; ++ m )
+    {
+        this->minNumberCell *= 1;
+    }
+
+    int kkk = 1;
+
+}
+
+void Partition::FreeAllZones()
+{
+    int iCount = 0;
+    for ( std::set < SplitZone * >::iterator iter = zoneStorage.begin(); iter != zoneStorage.end(); ++ iter )
+    {
+        //cout << "iCount = " << iCount << "\n";
+        ++ iCount;
+        delete * iter;
+    }
+}
+
+int Partition::GetNZones( int iProc )
+{
+    return this->procSplitZone[ iProc ].size();
+}
+
+SplitZone * Partition::GetSplitZone( int iProc, int zoneId )
+{
+    return this->procSplitZone[ iProc ][ zoneId ];
+}
+
+void Partition::AddZoneToUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.insert( zone );
+}
+
+void Partition::RemoveZoneFromUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.erase( zone );
+}
+
+void Partition::AddZoneToProcess( int iProc, SplitZone * zone )
+{
+    this->procSplitZone[ iProc ].push_back( zone );
+}
+
+void Partition::AddNewZone( SplitZone * zone )
+{
+    zone->SetZoneIndex( nTZone ++ );
+
+    this->AddZoneToUnsignedGroup( zone );
+
+    this->zoneStorage.insert( zone );
+}
+
+SplitZone * Partition::Split( SplitZone * zone, double nCell )
+{
+    SplitZone * zoneL = new SplitZone();
+    zoneL->SetParent( zone );
+
+    SplitZone * zoneR = new SplitZone();
+    zoneR->SetParent( zone );
+
+    //Remove the original block from the UnsignedGroup
+    this->RemoveZoneFromUnsignedGroup( zone );
+
+    this->AddNewZone( zoneL );
+    this->AddNewZone( zoneR );
+
+    zone->Split( zoneL, zoneR, nCell );
+
+    return zoneL;
+}
+
+void Partition::BinarySplit()
+{
+    while ( ! unsignedZoneGroup.empty() )
+    {
+        std::cout << "number of unsigned zone = " << unsignedZoneGroup.size() << "\n";
+        int iProc = this->GetMinLoadProc();
+
+        //Get the block with the largest number of grids and its size
+        SplitZone * largestZone = this->GetLargestZone();
+
+        double nMaxCell = largestZone->GetNCell();
+
+        double aveFloatOp = this->aveFloatOp;
+        double tau = timeProc[ iProc ] + nMaxCell * aveFloatOp / procSpeed[ iProc ];
+
+        int kkk = 1;
+
+        //It seems that EPS is still necessary
+        //The idea here is as follows. For the candidate blocks which can be divided into blocks, 
+        //if the difference between the target blocks and the candidate blocks is too wide, 
+        //the binarySplit method is adopted. The binarySplit blocks do not directly join the process,
+        //but enter the next round of screening.
+
+        if ( tau > idealUniProcTime * ( 1.0 + eps ) )
+        {
+            double nRest = ( tau - idealUniProcTime ) * procSpeed[ iProc ] / aveFloatOp;
+
+            double nTarget = nMaxCell - nRest;
+            if ( nRest > this->minNumberCell && nTarget > this->minNumberCell )
+            {
+                //It is necessary to divide blocks only when a certain number of points are satisfied.
+                double nHalf = nMaxCell / 2.0;
+                nMaxCell = nTarget;
+                double ratio = nMaxCell / nRest;
+                double oRatio = 1.0 / ratio;
+
+                if ( std::max( ratio, oRatio ) < 3.0 )
+                {
+                    int kkk = 1;
+                    largestZone = this->Split( largestZone, nMaxCell );
+                    timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                    this->RemoveZoneFromUnsignedGroup( largestZone );
+                    this->AddZoneToProcess( iProc, largestZone );
+                }
+                else
+                {
+                    this->Split( largestZone, nHalf );
+                }
+            }
+            else
+            {
+                //If the block is of the right size, join the process directly, and there is no need to split it.
+                timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                this->RemoveZoneFromUnsignedGroup( largestZone );
+                this->AddZoneToProcess( iProc, largestZone );
+            }
+        }
+        else
+        {
+            //If the block is of the right size, join the process directly, and there is no need to split it.
+            timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+            this->RemoveZoneFromUnsignedGroup( largestZone );
+            this->AddZoneToProcess( iProc, largestZone );
+        }
+    }
+}
+
+void Partition::ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord )
+{
+    SplitZone * rootSplitZone = splitZone->GetRootZone();
+    Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+    int nNodes = splitZone->dimInfo.ComputeNumNodes();
+    std::cout << "nNodes = " << nNodes << "\n";
+
+    coord.resize( nNodes * sizeof(double) );
+
+    int index_dim = splitZone->dimInfo.dimList.size();
+    Coor * coor = zone->coors[ icoord ];
+
+    double * xlocal = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    double * xglobal = reinterpret_cast<double *>( const_cast<char *>( coor->coord.data() ) );
+    if ( index_dim == 1 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        for ( int i = imin; i < imax; ++ i )
+        {
+            xlocal[ icount++ ] = xglobal[ i ];
+        }
+    }
+    else if ( index_dim == 2 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        int jmin = splitZone->dimInfo.rmin[ 1 ] - 1;
+        int jmax = splitZone->dimInfo.rmax[ 1 ];
+        int ni = rootSplitZone->dimInfo.dimList[ 0 ];
+        int nj = rootSplitZone->dimInfo.dimList[ 1 ];
+        for ( int j = jmin; j < jmax; ++ j )
+        {
+            int jstride = j * ni;
+            for ( int i = imin; i < imax; ++ i )
+            {
+                xlocal[ icount++ ] = xglobal[ jstride + i ];
+            }
+        }
+    }
+}
+
+void Partition::DumpBc( SplitZone * splitZone )
+{
+}
+
+void Partition::DumpMultiBasePartitionedGridFile()
+{
+    int fileId = -1;
+    std::string filename = this->outName;
+    cg_open( filename.c_str(), CG_MODE_WRITE, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+
+    std::vector<std::string> coordnames;
+    coordnames.push_back( "CoordinateX" );
+    coordnames.push_back( "CoordinateY" );
+    coordnames.push_back( "CoordinateZ" );
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        int icelldim = Global::cell_dim;
+        int iphysdim = Global::phys_dim;
+        std::string basename = "Base" + std::to_string( iProc );
+
+        int baseId = -1;
+        cg_base_write( fileId, basename.c_str(), icelldim, iphysdim, &baseId );
+
+        std::cout << "baseId = " << baseId << "\n";
+
+        int nZones = this->GetNZones( iProc );
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            ZoneType_t zoneType = Structured;
+
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+
+            int index_dim = splitZone->dimInfo.dimList.size();
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            splitZone->dimInfo.ComputeISize();
+
+            int isize_dim = index_dim * 3;
+
+            std::vector<cgsize_t> isize( index_dim * 3, 0 );
+            for ( int m = 0; m < isize_dim; ++ m )
+            {
+                isize[ m ] = splitZone->dimInfo.isize[ m ];
+            }
+
+            int zoneId = -1;
+
+            std::string zonename = "Zone" + std::to_string( splitZone->zoneIndex );
+
+            cg_zone_write( fileId, baseId, zonename.c_str(), isize.data(), zoneType, &zoneId );
+
+            std::cout << "zoneId = " << zoneId << "\n";
+
+            splitZone->ComputeRminmax();
+
+            SplitZone * rootSplitZone = splitZone->GetRootZone();
+
+            Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+            int ncoords = zone->coors.size();
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = -1;
+                DataType_t dataType = RealDouble;
+                std::string coordname = coordnames[ icoord ];
+                Coor * coor = zone->coors[ icoord ];
+
+                int nNodes = splitZone->dimInfo.ComputeNumNodes();
+                std::cout << "nNodes = " << nNodes << "\n";
+
+                std::vector<char> coord;
+                ComputeCoor( splitZone, icoord, coord );
+
+                cg_coord_write( fileId, baseId, zoneId, dataType, coordname.c_str(), coord.data(), &coorId );
+
+                std::cout << "fileId = " << fileId  << " baseId = " << baseId << " zoneId = " << zoneId  << " coorId = " << coorId << "\n";
+            }
+
+            int nBcLists = splitZone->splitBcList.size();
+            std::vector<SplitBc * > bccoList;
+            std::vector<SplitBc * > bc1to1List;
+
+            for ( int ibc = 0; ibc < nBcLists; ++ ibc )
+            {
+                SplitBc * splitBc = splitZone->splitBcList[ ibc ];
+                if ( splitBc->bcType == BCTypeUserDefined )
+                {
+                    bc1to1List.push_back( splitBc );
+                }
+                else
+                {
+                    bccoList.push_back( splitBc );
+                }
+            }
+            int nbocos = bccoList.size();
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = -1;
+                GridLocation_t location = Vertex;
+
+                std::string boconame = "BC" + std::to_string( iboco + 1 );
+
+                SplitBc * splitBc = bccoList[ iboco ];
+                BCType_t bocotype = static_cast<BCType_t>( splitBc->bcType );
+                PointSetType_t ptset_type = PointRange;
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> pnts;
+                int nSize = splitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.end[ i ] );
+                }
+
+                cg_boco_write( fileId, baseId, zoneId, boconame.c_str(), bocotype, ptset_type, npnts, pnts.data(), & bccoId );
+            }
+
+            int n1to1 = bc1to1List.size();
+            std::cout << "n1to1 = " << n1to1 << "\n";
+
+            std::vector<int> itranfrm( index_dim );
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                itranfrm[ m ] = m + 1;
+            }
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int index_conn = -1;
+
+                SplitBc * splitBc = bc1to1List[ i1to1 ];
+                BCType_t bocotype = static_cast<BCType_t>( splitBc->bcType );
+
+                std::vector<cgsize_t> pnts;
+                std::vector<cgsize_t> pntsdonor;
+                int nSize = splitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.end[ i ] );
+                }
+
+                int nPatchSize = splitBc->patch->region.start.size();
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( splitBc->patch->region.start[ i ] );
+                }
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( splitBc->patch->region.end[ i ] );
+                }
+                int id = splitBc->patch->splitZone->zoneIndex;
+                std::string donorname = "Zone" + std::to_string( id );
+                std::string connectname = "Interface" + std::to_string( i1to1 );
+
+                cg_1to1_write( fileId, baseId, zoneId, connectname.c_str(), donorname.c_str(), pnts.data(), pntsdonor.data(), itranfrm.data(), &index_conn);
+                std::cout << "index_conn = " << index_conn << "\n";
+            }
+        }
+    }
+    cg_close( fileId );
+}
+
+void Partition::DumpPartitionedGridFile()
+{
+    std::cout << "\n";
+    std::cout << "DumpPartitionedGridFile -------------------------------" << "\n";
+    std::cout << "\n";
+    int fileId = -1;
+    std::string filename = this->outName;
+    int ierr = cg_open( filename.c_str(), CG_MODE_WRITE, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+
+    std::vector<std::string> coordnames;
+    coordnames.push_back( "CoordinateX" );
+    coordnames.push_back( "CoordinateY" );
+    coordnames.push_back( "CoordinateZ" );
+
+    std::string basename = "Base";
+    int baseId = -1;
+    int icelldim = Global::cell_dim;
+    int iphysdim = Global::phys_dim;
+    cg_base_write( fileId, basename.c_str(), icelldim, iphysdim, &baseId );
+
+    std::cout << "baseId = " << baseId << "\n";
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        int nZones = this->GetNZones( iProc );
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            ZoneType_t zoneType = Structured;
+
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+
+            int index_dim = splitZone->dimInfo.dimList.size();
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            splitZone->dimInfo.ComputeISize();
+
+            int isize_dim = index_dim * 3;
+
+            std::vector<cgsize_t> isize( index_dim * 3, 0 );
+            for ( int m = 0; m < isize_dim; ++ m )
+            {
+                isize[ m ] = splitZone->dimInfo.isize[ m ];
+            }
+
+            int zoneId = -1;
+
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+
+            std::string zonename = "Zone" + std::to_string( splitZone->newIndex );
+
+            cg_zone_write( fileId, baseId, zonename.c_str(), isize.data(), zoneType, &zoneId );
+
+            std::cout << "zoneId = " << zoneId << "\n";
+            std::cout << "zonename = " << zonename << "\n";
+                
+            splitZone->ComputeRminmax();
+
+            SplitZone * rootSplitZone = splitZone->GetRootZone();
+
+            Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+            int ncoords = zone->coors.size();
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = -1;
+                DataType_t dataType = RealDouble;
+                std::string coordname = coordnames[ icoord ];
+                Coor * coor = zone->coors[ icoord ];
+
+                int nNodes = splitZone->dimInfo.ComputeNumNodes();
+                std::cout << "nNodes = " << nNodes << "\n";
+
+                std::vector<char> coord;
+                ComputeCoor( splitZone, icoord, coord );
+
+                cg_coord_write( fileId, baseId, zoneId, dataType, coordname.c_str(), coord.data(), &coorId );
+
+                std::cout << "fileId = " << fileId  << " baseId = " << baseId << " zoneId = " << zoneId  << " coorId = " << coorId << "\n";
+            }
+
+            //int nBcLists = splitZone->splitBcList.size();
+            std::vector< SplitBc * > leafBcList;
+            splitZone->GetLeafBcList( leafBcList );
+            int nLeafBcList = leafBcList.size();
+
+            std::vector<SplitBc * > bccoList;
+            std::vector<SplitBc * > bc1to1List;
+
+            for ( int ibc = 0; ibc < nLeafBcList; ++ ibc )
+            {
+                SplitBc * splitBc = leafBcList[ ibc ];
+                if ( splitBc->bcType == BCTypeUserDefined )
+                {
+                    bc1to1List.push_back( splitBc );
+                }
+                else
+                {
+                    bccoList.push_back( splitBc );
+                }
+            }
+            int nbocos = bccoList.size();
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = -1;
+                GridLocation_t location = Vertex;
+
+                std::string boconame = "BC" + std::to_string( iboco + 1 );
+
+                SplitBc * splitBc = bccoList[ iboco ];
+                BCType_t bocotype = static_cast<BCType_t>( splitBc->bcType );
+                PointSetType_t ptset_type = PointRange;
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> pnts;
+                int nSize = splitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.end[ i ] );
+                }
+
+                cg_boco_write( fileId, baseId, zoneId, boconame.c_str(), bocotype, ptset_type, npnts, pnts.data(), & bccoId );
+            }
+
+            int n1to1 = bc1to1List.size();
+            std::cout << "n1to1 = " << n1to1 << "\n";
+
+            std::vector<int> itranfrm( index_dim );
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                itranfrm[ m ] = m + 1;
+            }
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int index_conn = -1;
+
+                SplitBc * splitBc = bc1to1List[ i1to1 ];
+                BCType_t bocotype = static_cast<BCType_t>( splitBc->bcType );
+
+                std::vector<cgsize_t> pnts;
+                std::vector<cgsize_t> pntsdonor;
+                int nSize = splitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.end[ i ] );
+                }
+
+                int nPatchSize = splitBc->patch->region.start.size();
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( splitBc->patch->region.start[ i ] );
+                }
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( splitBc->patch->region.end[ i ] );
+                }
+                int id = splitBc->patch->splitZone->newIndex;
+                int oldZoneIndex = splitBc->patch->splitZone->zoneIndex;
+                std::cout << "id = " << id << "\n";
+                std::cout << "oldZoneIndex = " << oldZoneIndex << "\n";
+                std::string donorname = "Zone" + std::to_string( id );
+                std::string connectname = "Interface" + std::to_string( i1to1 );
+
+                std::cout << "donorname = " << donorname << "\n";
+                std::cout << "connectname = " << connectname << "\n";
+
+                cg_1to1_write( fileId, baseId, zoneId, connectname.c_str(), donorname.c_str(), pnts.data(), pntsdonor.data(), itranfrm.data(), &index_conn);
+                std::cout << "index_conn = " << index_conn << "\n";
+            }
+        }
+    }
+    cg_close( fileId );
+}
+
+void Partition::ModifyZoneIndex()
+{
+    std::cout << "ModifyZoneIndex +++++++++++++++++++++++++ " << "\n";
+    int globalZoneId = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        std::cout << "iProc = " << iProc << "\n";
+        int nZones = this->GetNZones( iProc );
+        std::cout << "nZones in Proc " << iProc << "  = " << nZones << "\n";
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+            //splitZone->SetZoneIndex( globalZoneId++ );
+            splitZone->newIndex = ( globalZoneId++ );
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+        }
+    }
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage1/01c/Partition.h b/example/partition/struct/2d/stage1/01c/Partition.h
new file mode 100644
index 00000000..2d976fd2
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01c/Partition.h
@@ -0,0 +1,194 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class Dim
+{
+public:
+    static int dim;
+};
+
+class SplitZone;
+class RangeRegion;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox );
+
+class DimInfo
+{
+public:
+    DimInfo();
+    ~DimInfo();
+public:
+    int dim;
+    std::vector<int> dimList;
+    std::vector<int> oriPoint;
+    std::vector<int> isize;
+    std::vector<int> rmin;
+    std::vector<int> rmax;
+public:
+    int GetSize() const { return dim; }
+    DimInfo & operator = ( const DimInfo & rhs );
+public:
+    int ComputeNumNodes();
+    void ComputeISize();
+    void ComputeRminmax( std::vector<int> & ref );
+    void Init( int dim );
+    void Init( std::vector<int> & dimList );
+    void SetNewDimension( int axis, int newStart, int newWidth );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+};
+
+class SplitZone;
+class SplitBcPatch;
+
+class RangeRegion
+{
+public:
+    RangeRegion( int nSize = 1 );
+    ~RangeRegion();
+public:
+    int regionAxis = -1;
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    void Init( int nSize );
+    RangeRegion & operator = ( const RangeRegion & rhs );
+    bool operator == ( const RangeRegion & rhs ) const;
+    void SetRegion( std::vector<int> &pnts );
+    int ComputeRegionAxis();
+};
+
+class SplitBc
+{
+public:
+    SplitBc();
+    ~SplitBc();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone = nullptr;
+    SplitBcPatch * patch = nullptr;
+    std::vector< SplitBc * > * child = nullptr;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+    void ChangeRegionToLocalCoordinate();
+public:
+    void CreateInterfaceBcFromParentBc( SplitBc * parentSplitBc );
+    void CreateInterfaceBcFromParentBcNewVersion( SplitBc * parentSplitBc );
+    void GetLeafBcs( std::vector< SplitBc * > & leafBcs );
+};
+
+class SplitBcPatch
+{
+public:
+    SplitBcPatch ();
+    ~SplitBcPatch();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+};
+
+
+class SplitZone
+{
+public:
+    SplitZone();
+    ~SplitZone();
+public:
+    DimInfo dimInfo;
+    int zoneIndex, iProc;
+    int newIndex;
+protected:
+    SplitZone * parent;
+public:
+    std::vector< SplitBc * > splitBcList;
+public:
+    int GetNCell();
+    void ComputeRminmax();
+    void GetRootInfo( SplitZone *& root, std::vector<int> & ref );
+    void SetZoneIndex( int zoneIndex ) { this->zoneIndex = zoneIndex; }
+    int  GetZoneIndex() { return zoneIndex; }
+    void SetProcId( int iProc ) { this->iProc = iProc; }
+    void SetParent( SplitZone * parent ) { this->parent = parent; };
+    std::vector< SplitBc * > & GetSplitBcList() { return this->splitBcList; };
+    void CreateBcFromParent();
+    void CreateSplitBcFromOverlapRegion( SplitBc * parentSplitBc, RangeRegion & overlapRegion );
+    void CreateChildInterfaceBc( SplitBc * targetInterfaceBc );
+    bool CreateChildInterfaceBc( SplitBc * candidateInterfaceBc, SplitBc * targetInterfaceBc );
+
+    void CreateChildInterfaceBc( RangeRegion & targeRegionBox, SplitZone * sourceZone );
+    bool CreateChildInterfaceBc( SplitBc * parentSplitBc, RangeRegion & targeRegionBox, SplitZone * sourceZone );
+    void CreateSplitBc( SplitBc * parentSplitBc );
+    void AddSplitBc( SplitBc * splitBc );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+    SplitZone * GetRootZone();
+    void GetLeafBcList( std::vector< SplitBc * > & leafBcList );
+public:
+    void Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell );
+    void SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+    void SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+private:
+    int FindAxisNeedSplit();
+    int FindSplitPosition( int axisNeedSplit, double nCell );
+    bool IsPoleBc( int splitDirection );
+    int GetCrossSection( int axis );
+};
+
+class Partition
+{
+public:
+    Partition();
+    ~Partition();
+protected:
+    std::set < SplitZone * > zoneStorage;
+    std::set < SplitZone * > unsignedZoneGroup;
+    std::vector< SplitZone * > refZone;
+    std::vector< std::vector< SplitZone * > > procSplitZone;
+    std::vector<double> procSpeed;
+    std::vector<double> timeProc;
+    double aveFloatOp, delta;
+    double idealUniProcTime, eps;
+    int minNumberCell;
+    int nTZone;
+    int nOriZone;
+    int nProc;
+public:
+    std::string inputName;
+    std::string outName;
+public:
+    void Solve();
+    void ReadGrid();
+    void Split();
+    void InitSplit();
+    void BinarySplit();
+    //void GreedySplit();
+public:
+    void AddNewZone( SplitZone * zone );
+    void AddZoneToUnsignedGroup( SplitZone * zone );
+    void RemoveZoneFromUnsignedGroup( SplitZone * zone );
+    void AddZoneToProcess( int iProc, SplitZone * zone );
+    void DumpMultiBasePartitionedGridFile();
+    void DumpPartitionedGridFile();
+    void ModifyZoneIndex();
+    void FreeAllZones();
+    int GetNZones( int iProc );
+    SplitZone * GetSplitZone( int iProc, int zoneId );
+    void ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord );
+    void DumpBc( SplitZone * splitZone );
+private:
+    int GetMinValueIndex( double * data, int numberOfData );
+    int GetMinLoadProc();
+    SplitZone * GetLargestZone();
+    SplitZone * Split( SplitZone * zone, double nCell );
+};
+
diff --git a/example/partition/struct/2d/stage1/01c/README.txt b/example/partition/struct/2d/stage1/01c/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01c/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/partition/struct/2d/stage1/01c/heat2d2blocks.cgns b/example/partition/struct/2d/stage1/01c/heat2d2blocks.cgns
new file mode 100644
index 00000000..2ce29d4c
Binary files /dev/null and b/example/partition/struct/2d/stage1/01c/heat2d2blocks.cgns differ
diff --git a/example/partition/struct/2d/stage1/01c/heat2dpart.cgns b/example/partition/struct/2d/stage1/01c/heat2dpart.cgns
new file mode 100644
index 00000000..6351f809
Binary files /dev/null and b/example/partition/struct/2d/stage1/01c/heat2dpart.cgns differ
diff --git a/example/partition/struct/2d/stage1/01c/main.cpp b/example/partition/struct/2d/stage1/01c/main.cpp
new file mode 100644
index 00000000..5da1de7c
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01c/main.cpp
@@ -0,0 +1,18 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include "Partition.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip>
+
+int main(int argc, char **argv)
+{
+    Partition * partition = new Partition();
+    partition->Solve();
+    delete partition;
+
+    return 0;
+}
diff --git a/example/partition/struct/2d/stage1/01d/CMakeLists.txt b/example/partition/struct/2d/stage1/01d/CMakeLists.txt
new file mode 100644
index 00000000..74ceea7d
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01d/CMakeLists.txt
@@ -0,0 +1,78 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	Partition.h Partition.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	SplitZone.h SplitZone.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/partition/struct/2d/stage1/01d/CgnsGrid.cpp b/example/partition/struct/2d/stage1/01d/CgnsGrid.cpp
new file mode 100644
index 00000000..d287afcb
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01d/CgnsGrid.cpp
@@ -0,0 +1,345 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include <map>
+
+Grid::Grid()
+{
+    ;
+}
+
+Grid::~Grid()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if( (i+1)%5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+    delete this->patch;
+}
+
+ZoneBcPatch::ZoneBcPatch()
+{
+    ;
+}
+
+ZoneBcPatch::~ZoneBcPatch()
+{
+}
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+Global::Global()
+{
+    ;
+}
+
+Global::~Global()
+{
+}
+
+void Global::FreeData()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+    zones.resize( 0 );
+}
+
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            //baseZone.baseId = baseId;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin( index_dim );
+            std::vector<cgsize_t> irmax( index_dim );
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                std::vector<char> coord( nNodes * sizeof(double) );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+                coor->DumpCoor();
+            }
+
+            int nbocos = -1;
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc->pnts.push_back( range[ i ] );
+                }
+
+                zonebc->zoneid = gZoneId;
+                zonebc->bcType = BCTypeUserDefined;
+
+                ZoneBcPatch * patch = new ZoneBcPatch();
+                zonebc->patch = patch;
+
+                patch->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    patch->donor_pnts.push_back( donor_range[ i ] );
+                }
+                int kkk = 1;
+            }
+        }
+        int kkk = 1;
+    }
+    int kkk = 1;
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage1/01d/CgnsGrid.h b/example/partition/struct/2d/stage1/01d/CgnsGrid.h
new file mode 100644
index 00000000..af67a321
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01d/CgnsGrid.h
@@ -0,0 +1,123 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <map>
+
+class Grid;
+
+class Zone;
+
+class Grid
+{
+public:
+    Grid();
+    ~Grid();
+public:
+    int nZone;
+    std::vector<double> x;
+    std::vector<Zone *> zones;
+};
+
+class ZoneBc;
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+};
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<Coor *> coors;
+};
+
+class ZoneBcPatch;
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+    ZoneBcPatch * patch = nullptr;
+};
+
+class ZoneBcPatch
+{
+public:
+    ZoneBcPatch();
+    ~ZoneBcPatch();
+public:
+    int donor_zoneid;
+    std::vector<int> donor_pnts;
+};
+
+class BaseZone
+{
+public:
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Global
+{
+public:
+    Global();
+    ~Global();
+public:
+    static int cell_dim;
+    static int phys_dim;
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+public:
+    static void FreeData();
+};
+
+void ReadCgnsGrid( const std::string & filename );
+void ReadCgnsGridBaseZone( const std::string & filename );
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage1/01d/Partition.cpp b/example/partition/struct/2d/stage1/01d/Partition.cpp
new file mode 100644
index 00000000..4d2bcf39
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01d/Partition.cpp
@@ -0,0 +1,610 @@
+#include "Partition.h"
+#include "CgnsGrid.h"
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+double CalSumOfProcSpeed( std::vector<double> & procSpeed );
+double CalSumOfProcSpeed( std::vector<double> & procSpeed )
+{
+    int nProc = procSpeed.size();
+    double sumOfProcSpeed = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        sumOfProcSpeed += procSpeed[ iProc ];
+    }
+    return sumOfProcSpeed;
+}
+
+Partition::Partition()
+{
+    this->inputName = "../heat2d2blocks.cgns";
+    this->outName =  "../heat2dpart.cgns";
+}
+
+Partition::~Partition()
+{
+    ;
+}
+
+int Partition::GetMinValueIndex( double * data, int numberOfData )
+{
+    double minValue = data[ 0 ];
+    int minimumValueIndex = 0;
+
+    for ( int iData = 1; iData < numberOfData; ++ iData )
+    {
+        if ( minValue > data[ iData ] )
+        {
+            minValue      = data[ iData ];
+            minimumValueIndex = iData;
+        }
+    }
+    return minimumValueIndex;
+}
+
+int Partition::GetMinLoadProc()
+{
+    return this->GetMinValueIndex( this->timeProc.data(), this->nProc );
+}
+
+SplitZone * Partition::GetLargestZone()
+{
+    SplitZone * largestZone = 0;
+
+    double nMaxCell = 0.0;
+
+    for ( std::set< SplitZone * >::iterator iter = unsignedZoneGroup.begin(); iter != unsignedZoneGroup.end(); ++ iter )
+    {
+        double nSize = ( * iter )->GetNCell();
+        if ( nMaxCell < nSize )
+        {
+            nMaxCell    = nSize;
+            largestZone = * iter;
+        }
+    }
+
+    return largestZone;
+}
+
+void Partition::Solve()
+{
+    std::cout << "Partition::Split()\n";
+    //this->nProc = 2;
+    this->nProc = 4;
+    this->ReadGrid();
+    this->Split();
+    this->DumpPartitionedGridFile();
+    this->FreeAllZones();
+}
+
+void Partition::ReadGrid()
+{
+    ReadCgnsGridBaseZone( this->inputName );
+    ReadCgnsGrid( this->inputName );
+
+    this->nOriZone = ::Global::zones.size();
+    Dim::dim = Global::cell_dim;
+
+    std::cout << "numberOfBlocks = " << nOriZone << "\n";
+
+    this->refZone.resize( nOriZone );
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = new SplitZone();
+        refZone[ iZone ] = splitZone;
+
+        splitZone->SetZoneIndex( iZone );
+        splitZone->SetProcId( 0 );
+        splitZone->SetParent( 0 );
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        Zone * zone = ::Global::zones[ iZone ];
+
+        splitZone->dimInfo.dimList = zone->nijk;
+
+        int nBcRegion = zone->bccos.size();
+        std::cout << "nBcRegion = " << nBcRegion << "\n";
+
+        std::vector< SplitBc * > & splitBcList = splitZone->splitBcList;
+
+        for ( int iBcRegion = 0; iBcRegion < nBcRegion; ++ iBcRegion )
+        {
+            SplitBc * splitBc = new SplitBc();
+            splitBcList.push_back( splitBc );
+
+            ZoneBc * zoneBc = zone->bccos[ iBcRegion ];
+
+            splitBc->splitZone = splitZone;
+            splitBc->bcType = zoneBc->bcType;
+            splitBc->SetRegion( zoneBc->pnts );
+            if ( zoneBc->patch )
+            {
+                SplitBcPatch * patch = new SplitBcPatch();
+                splitBc->patch = patch;
+
+                patch->splitZone = refZone[ zoneBc->patch->donor_zoneid ];
+                patch->SetRegion( zoneBc->patch->donor_pnts );
+            }
+        }
+
+        int kkk = 1;
+    }
+    int kkk = 1;
+}
+
+void Partition::Split()
+{
+    this->InitSplit();
+    this->BinarySplit();
+    this->ModifyZoneIndex();
+    int kkk = 1;
+}
+
+void Partition::InitSplit()
+{
+    //nZone is the number of zones in the original grid
+    //nProc is not the number of blocks in the end, but the number of processes that need to be divided.
+    //This difference occurs because the structure grid can have many blocks per process.
+
+    //this->nProc    = nProc;
+    //this->nPhyBlocks = referenceBlock.size();
+    //this->nZone  = this->nPhyBlocks;
+
+    //tj Computation time on processor j
+    //Nk Number of internal grid-cells for zone j
+    //aveFloatOp:  Number of Real operations per gridcell
+    //Gj The set of blocks allocated to process j
+    //Pj Real operations per second for process j
+
+    //The Greedy Load Balancing Algorithm
+    //1.Compute an "ideal" uniprocessor time, Tuni = sum ( Nk * aveFloatOp )/ sum( Pj ).
+    //2.Set the group of unassigned blocks, Gu, to contain all blocks. The number of blocks in Nu=M, where M is the total number of blocks in the mesh.
+    //3.Start all processors with a very small fictitious zone to get a start tj=delt aveFloatOp/Pj, where delt<<1 is the size of the very small fictious zone.
+    //This is used to find the fastest processor in a heterogeneous system, tj could otherwise be set to 0 in the homogeneous case.
+    this->aveFloatOp = 1.0;
+    this->delta      = 1.0e-5;
+    this->procSpeed.resize( nProc );
+    this->timeProc.resize( nProc );
+
+    this->nTZone = this->nOriZone;
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        procSpeed[ iProc ] = 1.0;
+    }
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        timeProc[ iProc ] = delta * aveFloatOp / procSpeed[ iProc ];
+    }
+
+    double sumProcSpeed = CalSumOfProcSpeed( procSpeed );
+
+    double sumProcOp = 0.0;
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        sumProcOp += refZone[ iZone ]->GetNCell() * aveFloatOp;
+    }
+
+    this->idealUniProcTime = sumProcOp / sumProcSpeed;
+
+    this->eps = 0.05;
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        unsignedZoneGroup.insert( refZone[ iZone ] );
+    }
+
+    //Init zoneStorage
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        zoneStorage.insert( refZone[ iZone ] );
+    }
+
+    //Assign procSplitZone to each process
+    procSplitZone.resize( nProc );
+
+    this->minNumberCell = 1;
+    for ( int m = 0; m < Dim::dim; ++ m )
+    {
+        this->minNumberCell *= 1;
+    }
+
+    int kkk = 1;
+
+}
+
+void Partition::FreeAllZones()
+{
+    int iCount = 0;
+    for ( std::set < SplitZone * >::iterator iter = zoneStorage.begin(); iter != zoneStorage.end(); ++ iter )
+    {
+        //cout << "iCount = " << iCount << "\n";
+        ++ iCount;
+        delete * iter;
+    }
+}
+
+int Partition::GetNZones( int iProc )
+{
+    return this->procSplitZone[ iProc ].size();
+}
+
+SplitZone * Partition::GetSplitZone( int iProc, int zoneId )
+{
+    return this->procSplitZone[ iProc ][ zoneId ];
+}
+
+void Partition::AddZoneToUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.insert( zone );
+}
+
+void Partition::RemoveZoneFromUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.erase( zone );
+}
+
+void Partition::AddZoneToProcess( int iProc, SplitZone * zone )
+{
+    this->procSplitZone[ iProc ].push_back( zone );
+}
+
+void Partition::AddNewZone( SplitZone * zone )
+{
+    zone->SetZoneIndex( nTZone ++ );
+
+    this->AddZoneToUnsignedGroup( zone );
+
+    this->zoneStorage.insert( zone );
+}
+
+SplitZone * Partition::Split( SplitZone * zone, double nCell )
+{
+    SplitZone * zoneL = new SplitZone();
+    zoneL->SetParent( zone );
+
+    SplitZone * zoneR = new SplitZone();
+    zoneR->SetParent( zone );
+
+    //Remove the original block from the UnsignedGroup
+    this->RemoveZoneFromUnsignedGroup( zone );
+
+    this->AddNewZone( zoneL );
+    this->AddNewZone( zoneR );
+
+    zone->Split( zoneL, zoneR, nCell );
+
+    return zoneL;
+}
+
+void Partition::BinarySplit()
+{
+    while ( ! unsignedZoneGroup.empty() )
+    {
+        std::cout << "number of unsigned zone = " << unsignedZoneGroup.size() << "\n";
+        int iProc = this->GetMinLoadProc();
+
+        //Get the block with the largest number of grids and its size
+        SplitZone * largestZone = this->GetLargestZone();
+
+        double nMaxCell = largestZone->GetNCell();
+
+        double aveFloatOp = this->aveFloatOp;
+        double tau = timeProc[ iProc ] + nMaxCell * aveFloatOp / procSpeed[ iProc ];
+
+        int kkk = 1;
+
+        //It seems that EPS is still necessary
+        //The idea here is as follows. For the candidate blocks which can be divided into blocks, 
+        //if the difference between the target blocks and the candidate blocks is too wide, 
+        //the binarySplit method is adopted. The binarySplit blocks do not directly join the process,
+        //but enter the next round of screening.
+
+        if ( tau > idealUniProcTime * ( 1.0 + eps ) )
+        {
+            double nRest = ( tau - idealUniProcTime ) * procSpeed[ iProc ] / aveFloatOp;
+
+            double nTarget = nMaxCell - nRest;
+            if ( nRest > this->minNumberCell && nTarget > this->minNumberCell )
+            {
+                //It is necessary to divide blocks only when a certain number of points are satisfied.
+                double nHalf = nMaxCell / 2.0;
+                nMaxCell = nTarget;
+                double ratio = nMaxCell / nRest;
+                double oRatio = 1.0 / ratio;
+
+                if ( std::max( ratio, oRatio ) < 3.0 )
+                {
+                    int kkk = 1;
+                    largestZone = this->Split( largestZone, nMaxCell );
+                    timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                    this->RemoveZoneFromUnsignedGroup( largestZone );
+                    this->AddZoneToProcess( iProc, largestZone );
+                }
+                else
+                {
+                    this->Split( largestZone, nHalf );
+                }
+            }
+            else
+            {
+                //If the block is of the right size, join the process directly, and there is no need to split it.
+                timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                this->RemoveZoneFromUnsignedGroup( largestZone );
+                this->AddZoneToProcess( iProc, largestZone );
+            }
+        }
+        else
+        {
+            //If the block is of the right size, join the process directly, and there is no need to split it.
+            timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+            this->RemoveZoneFromUnsignedGroup( largestZone );
+            this->AddZoneToProcess( iProc, largestZone );
+        }
+    }
+}
+
+void Partition::ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord )
+{
+    SplitZone * rootSplitZone = splitZone->GetRootZone();
+    Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+    int nNodes = splitZone->dimInfo.ComputeNumNodes();
+    std::cout << "nNodes = " << nNodes << "\n";
+
+    coord.resize( nNodes * sizeof(double) );
+
+    int index_dim = splitZone->dimInfo.dimList.size();
+    Coor * coor = zone->coors[ icoord ];
+
+    double * xlocal = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    double * xglobal = reinterpret_cast<double *>( const_cast<char *>( coor->coord.data() ) );
+    if ( index_dim == 1 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        for ( int i = imin; i < imax; ++ i )
+        {
+            xlocal[ icount++ ] = xglobal[ i ];
+        }
+    }
+    else if ( index_dim == 2 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        int jmin = splitZone->dimInfo.rmin[ 1 ] - 1;
+        int jmax = splitZone->dimInfo.rmax[ 1 ];
+        int ni = rootSplitZone->dimInfo.dimList[ 0 ];
+        int nj = rootSplitZone->dimInfo.dimList[ 1 ];
+        for ( int j = jmin; j < jmax; ++ j )
+        {
+            int jstride = j * ni;
+            for ( int i = imin; i < imax; ++ i )
+            {
+                xlocal[ icount++ ] = xglobal[ jstride + i ];
+            }
+        }
+    }
+}
+
+void Partition::DumpBc( SplitZone * splitZone )
+{
+}
+
+void Partition::DumpPartitionedGridFile()
+{
+    std::cout << "\n";
+    std::cout << "DumpPartitionedGridFile -------------------------------" << "\n";
+    std::cout << "\n";
+    int fileId = -1;
+    std::string filename = this->outName;
+    int ierr = cg_open( filename.c_str(), CG_MODE_WRITE, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+
+    std::vector<std::string> coordnames;
+    coordnames.push_back( "CoordinateX" );
+    coordnames.push_back( "CoordinateY" );
+    coordnames.push_back( "CoordinateZ" );
+
+    std::string basename = "Base";
+    int baseId = -1;
+    int icelldim = Global::cell_dim;
+    int iphysdim = Global::phys_dim;
+    cg_base_write( fileId, basename.c_str(), icelldim, iphysdim, &baseId );
+
+    std::cout << "baseId = " << baseId << "\n";
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        int nZones = this->GetNZones( iProc );
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            ZoneType_t zoneType = Structured;
+
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+
+            int index_dim = splitZone->dimInfo.dimList.size();
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            splitZone->dimInfo.ComputeISize();
+
+            int isize_dim = index_dim * 3;
+
+            std::vector<cgsize_t> isize( index_dim * 3, 0 );
+            for ( int m = 0; m < isize_dim; ++ m )
+            {
+                isize[ m ] = splitZone->dimInfo.isize[ m ];
+            }
+
+            int zoneId = -1;
+
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+
+            std::string zonename = "Zone" + std::to_string( splitZone->newIndex );
+
+            cg_zone_write( fileId, baseId, zonename.c_str(), isize.data(), zoneType, &zoneId );
+
+            std::cout << "zoneId = " << zoneId << "\n";
+            std::cout << "zonename = " << zonename << "\n";
+                
+            splitZone->ComputeRminmax();
+
+            SplitZone * rootSplitZone = splitZone->GetRootZone();
+
+            Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+            int ncoords = zone->coors.size();
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = -1;
+                DataType_t dataType = RealDouble;
+                std::string coordname = coordnames[ icoord ];
+                Coor * coor = zone->coors[ icoord ];
+
+                int nNodes = splitZone->dimInfo.ComputeNumNodes();
+                std::cout << "nNodes = " << nNodes << "\n";
+
+                std::vector<char> coord;
+                ComputeCoor( splitZone, icoord, coord );
+
+                cg_coord_write( fileId, baseId, zoneId, dataType, coordname.c_str(), coord.data(), &coorId );
+
+                std::cout << "fileId = " << fileId  << " baseId = " << baseId << " zoneId = " << zoneId  << " coorId = " << coorId << "\n";
+            }
+
+            //int nBcLists = splitZone->splitBcList.size();
+            std::vector< SplitBc * > leafBcList;
+            splitZone->GetLeafBcList( leafBcList );
+            int nLeafBcList = leafBcList.size();
+
+            std::vector<SplitBc * > bccoList;
+            std::vector<SplitBc * > bc1to1List;
+
+            for ( int ibc = 0; ibc < nLeafBcList; ++ ibc )
+            {
+                SplitBc * splitBc = leafBcList[ ibc ];
+                if ( splitBc->bcType == BCTypeUserDefined )
+                {
+                    bc1to1List.push_back( splitBc );
+                }
+                else
+                {
+                    bccoList.push_back( splitBc );
+                }
+            }
+            int nbocos = bccoList.size();
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = -1;
+                GridLocation_t location = Vertex;
+
+                std::string boconame = "BC" + std::to_string( iboco + 1 );
+
+                SplitBc * splitBc = bccoList[ iboco ];
+                BCType_t bocotype = static_cast<BCType_t>( splitBc->bcType );
+                PointSetType_t ptset_type = PointRange;
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> pnts;
+                int nSize = splitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.end[ i ] );
+                }
+
+                cg_boco_write( fileId, baseId, zoneId, boconame.c_str(), bocotype, ptset_type, npnts, pnts.data(), & bccoId );
+            }
+
+            int n1to1 = bc1to1List.size();
+            std::cout << "n1to1 = " << n1to1 << "\n";
+
+            std::vector<int> itranfrm( index_dim );
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                itranfrm[ m ] = m + 1;
+            }
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int index_conn = -1;
+
+                SplitBc * splitBc = bc1to1List[ i1to1 ];
+                BCType_t bocotype = static_cast<BCType_t>( splitBc->bcType );
+
+                std::vector<cgsize_t> pnts;
+                std::vector<cgsize_t> pntsdonor;
+                int nSize = splitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.end[ i ] );
+                }
+
+                int nPatchSize = splitBc->patch->region.start.size();
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( splitBc->patch->region.start[ i ] );
+                }
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( splitBc->patch->region.end[ i ] );
+                }
+                int id = splitBc->patch->splitZone->newIndex;
+                int oldZoneIndex = splitBc->patch->splitZone->zoneIndex;
+                std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+                std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+                std::cout << "donor zone id = " << id << "\n";
+                std::cout << "donor zone oldZoneIndex = " << oldZoneIndex << "\n";
+                std::string donorname = "Zone" + std::to_string( id );
+                std::string connectname = "Interface" + std::to_string( i1to1 );
+
+                std::cout << "donorname = " << donorname << "\n";
+                std::cout << "connectname = " << connectname << "\n";
+
+                cg_1to1_write( fileId, baseId, zoneId, connectname.c_str(), donorname.c_str(), pnts.data(), pntsdonor.data(), itranfrm.data(), &index_conn);
+                std::cout << "index_conn = " << index_conn << "\n";
+            }
+        }
+    }
+    cg_close( fileId );
+}
+
+void Partition::ModifyZoneIndex()
+{
+    std::cout << "ModifyZoneIndex +++++++++++++++++++++++++ " << "\n";
+    int globalZoneId = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        std::cout << "iProc = " << iProc << "\n";
+        int nZones = this->GetNZones( iProc );
+        std::cout << "nZones in Proc " << iProc << "  = " << nZones << "\n";
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+            //splitZone->SetZoneIndex( globalZoneId++ );
+            splitZone->newIndex = ( globalZoneId++ );
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+        }
+    }
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage1/01d/Partition.h b/example/partition/struct/2d/stage1/01d/Partition.h
new file mode 100644
index 00000000..257548f7
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01d/Partition.h
@@ -0,0 +1,54 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class SplitZone;
+
+class Partition
+{
+public:
+    Partition();
+    ~Partition();
+protected:
+    std::set < SplitZone * > zoneStorage;
+    std::set < SplitZone * > unsignedZoneGroup;
+    std::vector< SplitZone * > refZone;
+    std::vector< std::vector< SplitZone * > > procSplitZone;
+    std::vector<double> procSpeed;
+    std::vector<double> timeProc;
+    double aveFloatOp, delta;
+    double idealUniProcTime, eps;
+    int minNumberCell;
+    int nTZone;
+    int nOriZone;
+    int nProc;
+public:
+    std::string inputName;
+    std::string outName;
+public:
+    void Solve();
+    void ReadGrid();
+    void Split();
+    void InitSplit();
+    void BinarySplit();
+    //void GreedySplit();
+public:
+    void AddNewZone( SplitZone * zone );
+    void AddZoneToUnsignedGroup( SplitZone * zone );
+    void RemoveZoneFromUnsignedGroup( SplitZone * zone );
+    void AddZoneToProcess( int iProc, SplitZone * zone );
+    void DumpPartitionedGridFile();
+    void ModifyZoneIndex();
+    void FreeAllZones();
+    int GetNZones( int iProc );
+    SplitZone * GetSplitZone( int iProc, int zoneId );
+    void ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord );
+    void DumpBc( SplitZone * splitZone );
+private:
+    int GetMinValueIndex( double * data, int numberOfData );
+    int GetMinLoadProc();
+    SplitZone * GetLargestZone();
+    SplitZone * Split( SplitZone * zone, double nCell );
+};
+
diff --git a/example/partition/struct/2d/stage1/01d/README.txt b/example/partition/struct/2d/stage1/01d/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01d/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/partition/struct/2d/stage1/01d/SplitZone.cpp b/example/partition/struct/2d/stage1/01d/SplitZone.cpp
new file mode 100644
index 00000000..707c66b2
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01d/SplitZone.cpp
@@ -0,0 +1,804 @@
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+int Dim::dim = -1;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox  )
+{
+    domainBox.start = zoneBox.start;
+    domainBox.end = zoneBox.end;
+
+    int axis = iDomain / 2;
+    int direction = iDomain % 2;
+
+    if ( direction == 0 )
+    {
+        domainBox.end[ axis ] = domainBox.start[ axis ];
+    }
+    else if ( direction == 1 )
+    {
+        domainBox.start[ axis ] = domainBox.end[ axis ];
+    }
+}
+
+DimInfo::DimInfo()
+{
+    this->Init( 1 );
+}
+
+DimInfo::~DimInfo()
+{
+}
+
+void DimInfo::Init( int dim )
+{
+    this->dim = dim;
+    dimList.resize( this->dim, 1 );
+    oriPoint.resize( this->dim, 0 );
+}
+
+DimInfo & DimInfo::operator = ( const DimInfo & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->dim = rhs.dim;
+    this->dimList = rhs.dimList;
+    this->oriPoint = rhs.oriPoint;
+
+    return * this;
+}
+
+int DimInfo::ComputeNumNodes()
+{
+    int nNodes = 1;
+    for ( int m = 0; m < this->dimList.size(); ++ m )
+    {
+        nNodes *= this->dimList[ m ];
+    }
+    return nNodes;
+}
+
+void DimInfo::ComputeISize()
+{
+    int index_dim = this->dimList.size();
+    this->isize.resize( index_dim * 3, 0 );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        isize[ m ] = this->dimList[ m ];
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 1;
+        isize[ start + m ] = this->dimList[ m ] - 1;
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 2;
+        isize[ start + m ] = 0;
+    }
+
+    for ( int i = 0; i < isize.size(); ++ i )
+    {
+        std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+    }
+}
+
+void DimInfo::ComputeRminmax( std::vector<int> & ref )
+{
+    int index_dim = this->dimList.size();
+    this->rmin.resize( index_dim );
+    this->rmax.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        rmin[ m ] = ref[ m ] + 1;
+        rmax[ m ] = ref[ m ] + this->dimList[ m ];
+    }
+
+    std::cout << "rmin, rmax = \n";
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        std::cout << rmin[ m ] << " " << rmax[ m ] << "\n";
+    }
+}
+
+void DimInfo::Init( std::vector<int> & dimList )
+{
+    this->dim = dimList.size();
+    this->dimList = dimList;
+    std::vector<int> zero( dimList.size(), 0 );
+    this->oriPoint = zero;
+}
+
+void DimInfo::SetNewDimension( int axis, int newStart, int newWidth )
+{
+    this->oriPoint[ axis ] = newStart;
+    this->dimList [ axis ] = newWidth;
+}
+
+void DimInfo::GetZoneGlobalBox( RangeRegion &zoneBox )
+{
+    int index_dim = this->dimList.size();
+    zoneBox.start.resize( index_dim );
+    zoneBox.end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        zoneBox.start[ m ] = this->oriPoint[ m ] + 1;
+        zoneBox.end[ m ] = this->oriPoint[ m ] + this->dimList[ m ];
+    }
+}
+
+void DimInfo::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    int index_dim = this->dimList.size();
+    localBox.start.resize( index_dim );
+    localBox.end.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        localBox.start[ m ] = globalBox.start[ m ] - this->oriPoint[ m ];
+        localBox.end[ m ] = globalBox.end[ m ] - this->oriPoint[ m ];
+    }
+}
+
+RangeRegion::RangeRegion( int nSize )
+{
+    this->Init( nSize );
+}
+
+RangeRegion::~RangeRegion()
+{
+}
+
+void RangeRegion::Init( int nSize )
+{
+    this->start.resize( nSize );
+    this->end.resize( nSize );
+}
+
+RangeRegion & RangeRegion::operator = ( const RangeRegion & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+    this->regionAxis = rhs.regionAxis;
+
+    return * this;
+}
+
+bool RangeRegion::operator == ( const RangeRegion & rhs ) const
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] != rhs.start[ m ] || 
+            this->end  [ m ] != rhs.end  [ m ] )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+    this->ComputeRegionAxis();
+}
+
+int RangeRegion::ComputeRegionAxis()
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] == this->end[ m ] )
+        {
+            this->regionAxis = m;
+            return this->regionAxis;
+        }
+    }
+    return this->regionAxis;
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion );
+
+bool ComputeOverlapRegion( RangeRegion & region1, RangeRegion & region2, RangeRegion & overlapRegion )
+{
+    int index_dim = region1.start.size();
+    overlapRegion.Init( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int ijkmin1 = std::min( region1.start[ m ], region1.end[ m ] );
+        int ijkmax1 = std::max( region1.start[ m ], region1.end[ m ] );
+        int ijkmin2 = std::min( region2.start[ m ], region2.end[ m ] );
+        int ijkmax2 = std::max( region2.start[ m ], region2.end[ m ] );
+        if ( ( ijkmax1 < ijkmin2 ) || ( ijkmin1 > ijkmax2 ) )
+        {
+            return false;
+        }
+
+        int ijkmin = std::max( ijkmin1, ijkmin2 );
+        int ijkmax = std::min( ijkmax1, ijkmax2 );
+
+        overlapRegion.start[ m ] = ijkmin;
+        overlapRegion.end  [ m ] = ijkmax;
+    }
+
+    return CheckOverLapping( overlapRegion );
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion )
+{
+    int index_dim = overlapRegion.start.size();
+    int iCount = 0;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        if ( overlapRegion.start[ m ] == overlapRegion.end[ m ] )
+        {
+            ++ iCount;
+        }
+    }
+
+    return ( iCount == 1 );
+}
+
+bool GetInterfaceRegion( RangeRegion & zoneBoxL, RangeRegion & zoneBoxR, RangeRegion & interfaceRegion )
+{
+    int index_dim = zoneBoxL.start.size();
+    int nDomains = 2 * index_dim;
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegionL;
+        GetDomainRegion( zoneBoxL, iDomain, domainRegionL );
+
+        for ( int jDomain = 0; jDomain < nDomains; ++ jDomain )
+        {
+            RangeRegion domainRegionR;
+            GetDomainRegion( zoneBoxR, jDomain, domainRegionR );
+
+            if ( domainRegionL == domainRegionR )
+            {
+                interfaceRegion = domainRegionL;
+                return true;
+            }
+        }
+    }
+    return false;
+}
+
+void CreateInterfaceBc( SplitZone * zoneL, SplitZone * zoneR )
+{
+    RangeRegion globalBoxL, globalBoxR, globalInterfaceRegion;
+
+    zoneL->GetZoneGlobalBox( globalBoxL );
+    zoneR->GetZoneGlobalBox( globalBoxR );
+
+    if ( ! GetInterfaceRegion( globalBoxL, globalBoxR, globalInterfaceRegion ) )
+    {
+        int kkk = 1;
+        return;
+    }
+
+    RangeRegion localInterfaceRegionL, localInterfaceRegionR;
+
+    zoneL->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionL );
+    zoneR->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionR );
+
+    int kkk = 1;
+
+    SplitBc * splitBcL = new SplitBc();
+    zoneL->AddSplitBc( splitBcL );
+
+    SplitBc * splitBcR = new SplitBc();
+    zoneR->AddSplitBc( splitBcR );
+
+    splitBcL->splitZone = zoneL;
+    splitBcL->SetRegion( localInterfaceRegionL );
+    splitBcL->bcType = BCTypeUserDefined;
+
+    splitBcR->splitZone = zoneR;
+    splitBcR->SetRegion( localInterfaceRegionR );
+    splitBcR->bcType = BCTypeUserDefined;
+
+    //localInterfaceRegionL.MarkPatchBc();
+    //localInterfaceRegionR.MarkPatchBc();
+
+    SplitBcPatch * splitBcPatchL = new SplitBcPatch();
+    splitBcL->patch = splitBcPatchL;
+    splitBcPatchL->region = localInterfaceRegionR;
+    splitBcPatchL->splitZone = zoneR;
+
+    SplitBcPatch * splitBcPatchR = new SplitBcPatch();
+    splitBcR->patch = splitBcPatchR;
+    splitBcPatchR->region = localInterfaceRegionL;
+    splitBcPatchR->splitZone = zoneL;
+
+    //splitBcL->Normalize();
+    //splitBcR->Normalize();
+}
+
+
+SplitBc::SplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+SplitBc::~SplitBc()
+{
+    delete this->patch;
+}
+
+void SplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void SplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+void SplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = splitZone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void SplitBc::GetLeafBcs( std::vector< SplitBc * > & leafBcs )
+{
+    if ( ! this->child )
+    {
+        leafBcs.push_back( this );
+        return;
+    }
+
+    for ( int i = 0; i < this->child->size(); ++ i )
+    {
+        std::vector< SplitBc * > child_leafBcs;
+        ( * child )[ i ]->GetLeafBcs( child_leafBcs );
+        for ( int j = 0; j < child_leafBcs.size(); ++ j )
+        {
+            leafBcs.push_back( child_leafBcs[ j ] );
+        }
+    }
+
+    return;
+}
+
+void SplitBc::CreateInterfaceBcFromParentBcNewVersion( SplitBc * parentSplitBc )
+{
+    if ( parentSplitBc->bcType !=  BCTypeUserDefined ) return;
+
+    this->patch = new SplitBcPatch();
+    this->patch->splitZone = parentSplitBc->patch->splitZone;
+    this->patch->SetRegion( parentSplitBc->patch->region );
+    int kkk = 1;
+
+    //Find the block corresponding to this docking boundary
+    //From patch->splitZone, find the corresponding docking boundary according to the size of overlapt
+    //The boundary conditions on the opposite side must change due to the split of this block.
+    //Here, the relevant boundaries are added to the sub-boundaries.
+
+    RangeRegion targetRegionBox;
+    targetRegionBox = parentSplitBc->patch->region;
+
+    SplitZone * targetZone = this->patch->splitZone;
+
+    targetZone->CreateChildInterfaceBc( this );
+
+    //this->patch->faceAxis = parentSplitBc->patch->faceAxis;
+
+    //( * this->patch->vertexMap ) = ( * parentBc->patch->vertexMap );
+
+    ////È»ºó½øÐÐÐÞÕý
+    ////block1->map 1, 33 -> block1 369, 337
+    ////block2->global -> map 1, 33 -> block1 369, 337
+    ////block2->local  -> map 1, 33 -> block1 369, 337
+    ////refOld + M * stold           = block1Startold
+    ////refOld + M * ( stnew + ref ) = block1Startold
+    ////refNew = refOld + M * ( ref )
+
+    //for ( int m = 0; m < 3; ++ m )
+    //{
+    //    for ( int n = 0; n < 3; ++ n )
+    //    {
+    //        this->patch->vertexMap->pt[ m ] += this->patch->vertexMap->vm[ m ][ n ] * ( this->splitZone->sdim->oriPoint )[ n ];
+    //    }
+    //}
+
+    //RangeBox tRangeBox;
+
+    //MappingPatchPoint( this->patch, this->rangeBox, tRangeBox );
+    //tRangeBox.SetOrder();
+
+    ////ÕÒµ½ºÍ±¾¶Ô½Ó±ß½çÏà¶ÔÓ¦µÄ¿é
+    ////´Ópatch->splitZone°´ÕÕoverlapµÄ´óСÕÒµ½¶ÔÓ¦µÄ¶Ô½Ó±ß½ç£¬ÕâÑùÖÁÉÙ¿ÉÒÔÕÒµ½
+    ////¶ÔÃæµÄ¶Ô½Ó±ß½çÌõ¼þÓÉÓÚ±¾¿éµÄsplit±ØȻҪ·¢Éú¸Ä±ä£¬ÕâÀｫÏà¹Ø±ß½ç¼ÓÈë×ӱ߽ç
+    //this->patch->splitZone->CreateChildInterfaceBc( tRangeBox, this->splitZone );
+}
+
+SplitBcPatch::SplitBcPatch()
+{
+    this->region.Init( Dim::dim );
+}
+
+SplitBcPatch::~SplitBcPatch()
+{
+}
+
+void SplitBcPatch::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void SplitBcPatch::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+SplitZone::SplitZone()
+{
+    this->parent  = 0;
+    this->zoneIndex = 0;
+    this->iProc = 0;
+    dimInfo.Init( Dim::dim );
+    int kk = 1;
+}
+
+SplitZone::~SplitZone()
+{
+    ;
+}
+
+void SplitZone::GetZoneGlobalBox( RangeRegion & zoneBox )
+{
+    this->dimInfo.GetZoneGlobalBox( zoneBox );
+}
+
+void SplitZone::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    this->dimInfo.GetZoneLocalBox( globalBox, localBox );
+}
+
+
+void SplitZone::ComputeRminmax()
+{
+    int index_dim = this->dimInfo.dimList.size();
+    std::vector<int> ref( index_dim, 0 );
+
+    SplitZone * rootSplitZone = 0;
+    this->GetRootInfo( rootSplitZone, ref );
+
+    this->dimInfo.ComputeRminmax( ref );
+}
+
+SplitZone * SplitZone::GetRootZone()
+{
+    SplitZone * root = this;
+
+    while ( true )
+    {
+        if ( root->parent )
+        {
+            root = root->parent;
+        }
+        else
+        {
+            return root;
+        }
+    };
+}
+
+void SplitZone::GetRootInfo( SplitZone *& root, std::vector<int> & ref )
+{
+    for ( int i = 0; i < this->dimInfo.dimList.size(); ++ i )
+    {
+        ref[ i ] += this->dimInfo.oriPoint[ i ];
+    }
+
+    if ( this->parent )
+    {
+        this->parent->GetRootInfo( root, ref );
+    }
+    else
+    {
+        root = this;
+    }
+}
+
+
+int SplitZone::GetNCell()
+{
+    int numberOfCells = 1;
+    for ( int i = 0; i < this->dimInfo.dim; ++ i )
+    {
+        numberOfCells *= std::max( 1, ( this->dimInfo.dimList[ i ] - 1 ) );
+    }
+
+    return numberOfCells; 
+}
+
+void SplitZone::GetLeafBcList( std::vector< SplitBc * > & leafBcList )
+{
+    int nSplitBcs = this->splitBcList.size();
+
+    for ( int iSplitBcs = 0; iSplitBcs < nSplitBcs; ++ iSplitBcs )
+    {
+        SplitBc * splitBc = splitBcList[ iSplitBcs ];
+
+        std::vector< SplitBc * > leafBcs;
+        splitBc->GetLeafBcs( leafBcs );
+        for ( int j = 0; j < leafBcs.size(); ++ j )
+        {
+            leafBcList.push_back( leafBcs[ j ] );
+        }
+    }
+}
+
+void SplitZone::SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int leftStart = 0;
+    int leftWidth = iSplit - 0;
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, leftStart , leftWidth  );
+}
+
+void SplitZone::SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int rightStart = iSplit - 1;
+    int rightWidth = dimList[ axisNeedSplit ] - ( iSplit - 1 );
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, rightStart, rightWidth );
+}
+
+void SplitZone::Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell )
+{
+    //Find the longest axis
+    int axisNeedSplit = this->FindAxisNeedSplit();
+    int iSplit        = this->FindSplitPosition( axisNeedSplit, nCell );
+
+    zoneL->SetLeftDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+    zoneR->SetRightDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+
+    zoneL->CreateBcFromParent();
+    zoneR->CreateBcFromParent();
+
+    CreateInterfaceBc( zoneL, zoneR );
+}
+
+void SplitZone::CreateBcFromParent()
+{
+    std::vector< SplitBc * > & parentSplitBcList = this->parent->GetSplitBcList();
+
+    int nParentSplitBcs = parentSplitBcList.size();
+
+    for ( int iParentBc = 0; iParentBc < nParentSplitBcs; ++ iParentBc )
+    {
+        SplitBc * parentSplitBc = parentSplitBcList[ iParentBc ];
+
+        this->CreateSplitBc( parentSplitBc );
+    }
+    int kkk = 1;
+}
+
+void SplitZone::CreateChildInterfaceBc( SplitBc * targetInterfaceBc )
+{
+    std::vector< SplitBc * > & splitBcList = this->GetSplitBcList();
+
+    int nSplitBcs = splitBcList.size();
+
+    for ( int iSplitBc = 0; iSplitBc < nSplitBcs; ++ iSplitBc )
+    {
+        SplitBc * splitBc = splitBcList[ iSplitBc ];
+
+        //Only consider the interface boundaries
+        if ( splitBc->bcType !=  BCTypeUserDefined ) continue;
+        SplitBc * candidateInterfaceBc = splitBc;
+
+        if ( this->CreateChildInterfaceBc( candidateInterfaceBc, targetInterfaceBc ) )
+        {
+            return;
+        }
+    }
+}
+
+bool SplitZone::CreateChildInterfaceBc( SplitBc * candidateInterfaceBc, SplitBc * targetInterfaceBc )
+{
+    RangeRegion overlapRegion;
+    bool overlap_flag = ComputeOverlapRegion( candidateInterfaceBc->region, targetInterfaceBc->patch->region, overlapRegion );
+    if ( ! overlap_flag ) return false;
+
+    //1. Èç¹ûsplitBcºÍinterfaceBcÓн»¼¯£¬µ«ÊÇinterfaceBcûÓÐchild£¬Ôò´ËsplitBc×÷ΪinterfaceBcµÄÒ»¸öchild
+    //2. Èç¹ûsplitBcºÍinterfaceBcÓн»¼¯£¬ÇÒinterfaceBcÓÐchild£¬Èç¹ûsplitBcºÍËùÓÐchildûÓн»¼¯£¬
+    //   ÔòsplitBc¼ÓÈëinterfaceBcµÄÒ»¸öchild
+    //3. Èç¹ûsplitBcºÍinterfaceBcÓн»¼¯£¬ÇÒinterfaceBcÓÐchild£¬Èç¹ûsplitBcºÍchildÓн»¼¯£¬Ôò´Ëchild×÷ΪеÄinterfaceBc
+
+    std::vector< SplitBc * > * child = candidateInterfaceBc->child;
+
+    if ( candidateInterfaceBc->child )
+    {
+        for ( int iChild = 0; iChild < candidateInterfaceBc->child->size(); ++ iChild )
+        {
+            SplitBc * childSplitBc = ( * candidateInterfaceBc->child )[ iChild ];
+            if ( this->CreateChildInterfaceBc( childSplitBc, targetInterfaceBc ) ) return true;
+        }
+    }
+    else
+    {
+        candidateInterfaceBc->child = new std::vector< SplitBc * >();
+    }
+
+    SplitBc * childInterfaceBc = new SplitBc();
+
+    childInterfaceBc->SetRegion( overlapRegion );
+    childInterfaceBc->bcType = candidateInterfaceBc->bcType;
+    childInterfaceBc->splitZone = candidateInterfaceBc->splitZone;
+
+    candidateInterfaceBc->child->push_back( childInterfaceBc );
+
+    //vector< int > & parentFaceDirectionContainer = interfaceBc->GetFaceDirectionContainer();
+    //vector< int > & faceDirectionContainer  = childInterfaceBc->GetFaceDirectionContainer();
+
+    //for ( int m = 0; m < 3; ++ m )
+    //{
+    //    faceDirectionContainer[ m ] = parentFaceDirectionContainer[ m ];
+    //}
+
+    //½«´ËÐÂÉú³ÉµÄ¶Ô½Ó±ß½ç¼ÓÈë±¾¿éÀïÃæ
+    SplitBcPatch * patch = new SplitBcPatch();
+    childInterfaceBc->patch = patch;
+    patch->splitZone = targetInterfaceBc->splitZone;
+    patch->region = targetInterfaceBc->region;
+
+    //patch->CopyVertexMappingContent( interfaceBc->GetZoneBoundaryConditionPatch()->GetVertexMapping() );
+
+    //vector< int > & pNextFaceDirectionContainer = interfaceBc->GetZoneBoundaryConditionPatch()->GetFaceDirectionContainer();
+    //vector< int > & patchFaceDirectionContainer = patch->GetFaceDirectionContainer();
+
+    //for ( int m = 0; m < 3; ++ m )
+    //{
+    //    patchFaceDirectionContainer[ m ] = pNextFaceDirectionContainer[ m ];
+    //}
+
+    //Ô­¶Ô½Ó±ß½çÂú×ã
+    //t0 = tref + M * s0
+    //еĶԽӱ߽çÂú×ã
+    //t0newblock + refNewblock = tref + M * s0
+    //t0newblock = ( tref - refNewblock ) + M * s0
+
+    //È»ºó½øÐÐÐÞÕý
+    //for ( int m = 0; m < 3; ++ m )
+    //{
+    //    ( patch->GetVertexMapping() )[ m ][ 3 ] -= ( sourceZone->GetOriginalPointIndexContainer() )[ m ];
+    //}
+
+    return true;
+}
+
+void SplitZone::AddSplitBc( SplitBc * splitBc )
+{
+    if ( ! splitBc ) return;
+    this->splitBcList.push_back( splitBc );
+}
+
+void SplitZone::CreateSplitBc( SplitBc * parentSplitBc )
+{
+    if ( ! parentSplitBc->child )
+    {
+        int index_dim = this->dimInfo.dimList.size();
+        int nDomains = 2 * index_dim;
+        RangeRegion zoneBoxRegion( index_dim );
+        this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+        for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+        {
+            RangeRegion domainRegion( index_dim );
+            GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+            RangeRegion overlapRegion;
+            bool overlap_flag = ComputeOverlapRegion( parentSplitBc->region, domainRegion, overlapRegion );
+            if ( ! overlap_flag ) continue;
+
+            this->CreateSplitBcFromOverlapRegion( parentSplitBc, overlapRegion );
+
+            int kkk = 1;
+        }
+    }
+    else
+    {
+        int nChilds = parentSplitBc->child->size();
+        for ( int iChild = 0; iChild < nChilds; ++ iChild )
+        {
+            this->CreateSplitBc( ( * parentSplitBc->child )[ iChild ] );
+        }
+    }
+}
+
+void SplitZone::CreateSplitBcFromOverlapRegion( SplitBc * parentSplitBc, RangeRegion & overlapRegion )
+{
+    SplitBc * splitBc = new SplitBc();
+    this->AddSplitBc( splitBc );
+
+    splitBc->SetRegion( overlapRegion );
+    splitBc->bcType = parentSplitBc->bcType;
+    splitBc->splitZone = this;
+    splitBc->ChangeRegionToLocalCoordinate();
+    //splitBc->CreateInterfaceBcFromParentBc( parentSplitBc );
+    splitBc->CreateInterfaceBcFromParentBcNewVersion( parentSplitBc );
+}
+
+int SplitZone::FindAxisNeedSplit()
+{
+    //Find the longest axis
+    int axisNeedSplit = 0;
+    int maxN = this->dimInfo.dimList[ 0 ];
+
+    for ( int m = 1; m < this->dimInfo.dimList.size(); ++ m )
+    {
+        if ( this->IsPoleBc( m ) )
+        {
+            continue;
+        }
+        int Nm = this->dimInfo.dimList[ m ];
+        if ( maxN < Nm )
+        {
+            maxN = Nm;
+            axisNeedSplit = m;
+        }
+    }
+
+    return axisNeedSplit;
+}
+
+int SplitZone::GetCrossSection( int axis )
+{
+    int nDim = this->dimInfo.dimList.size();
+    int crossSection = 1;
+    int N = nDim - 1;
+    for ( int m = 0; m < N; ++ m )
+    {
+         int mm = ( axis + 1 ) % nDim;
+         int nLineElements = std::max( 1, ( this->dimInfo.dimList[ mm ] - 1 ) );
+         crossSection *= nLineElements;
+    }
+    return crossSection;
+}
+
+int SplitZone::FindSplitPosition( int axisNeedSplit, double nCell )
+{
+    int nDim = this->dimInfo.dimList.size();
+    std::vector<int> crossSections( nDim );
+    for ( int m = 0; m < nDim; ++ m )
+    {
+        crossSections[ m ] = this->GetCrossSection( m );
+    }
+
+    //guess the value
+    double dSplit = nCell / crossSections[ axisNeedSplit ];
+    int  iSplit = 1 + static_cast< int >( std::floor( dSplit + 0.5 ) );
+    return iSplit;
+}
+
+
+bool SplitZone::IsPoleBc( int splitDirection )
+{
+    return false;
+}
+
diff --git a/example/partition/struct/2d/stage1/01d/SplitZone.h b/example/partition/struct/2d/stage1/01d/SplitZone.h
new file mode 100644
index 00000000..7a2ed24b
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01d/SplitZone.h
@@ -0,0 +1,143 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class Dim
+{
+public:
+    static int dim;
+};
+
+class SplitZone;
+class RangeRegion;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox );
+
+class DimInfo
+{
+public:
+    DimInfo();
+    ~DimInfo();
+public:
+    int dim;
+    std::vector<int> dimList;
+    std::vector<int> oriPoint;
+    std::vector<int> isize;
+    std::vector<int> rmin;
+    std::vector<int> rmax;
+public:
+    int GetSize() const { return dim; }
+    DimInfo & operator = ( const DimInfo & rhs );
+public:
+    int ComputeNumNodes();
+    void ComputeISize();
+    void ComputeRminmax( std::vector<int> & ref );
+    void Init( int dim );
+    void Init( std::vector<int> & dimList );
+    void SetNewDimension( int axis, int newStart, int newWidth );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+};
+
+class SplitZone;
+class SplitBcPatch;
+
+class RangeRegion
+{
+public:
+    RangeRegion( int nSize = 1 );
+    ~RangeRegion();
+public:
+    int regionAxis = -1;
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    void Init( int nSize );
+    RangeRegion & operator = ( const RangeRegion & rhs );
+    bool operator == ( const RangeRegion & rhs ) const;
+    void SetRegion( std::vector<int> &pnts );
+    int ComputeRegionAxis();
+};
+
+class SplitBc
+{
+public:
+    SplitBc();
+    ~SplitBc();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone = nullptr;
+    SplitBcPatch * patch = nullptr;
+    std::vector< SplitBc * > * child = nullptr;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+    void ChangeRegionToLocalCoordinate();
+public:
+    void CreateInterfaceBcFromParentBcNewVersion( SplitBc * parentSplitBc );
+    void GetLeafBcs( std::vector< SplitBc * > & leafBcs );
+};
+
+class SplitBcPatch
+{
+public:
+    SplitBcPatch ();
+    ~SplitBcPatch();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+};
+
+
+class SplitZone
+{
+public:
+    SplitZone();
+    ~SplitZone();
+public:
+    DimInfo dimInfo;
+    int zoneIndex, iProc;
+    int newIndex;
+protected:
+    SplitZone * parent;
+public:
+    std::vector< SplitBc * > splitBcList;
+public:
+    int GetNCell();
+    void ComputeRminmax();
+    void GetRootInfo( SplitZone *& root, std::vector<int> & ref );
+    void SetZoneIndex( int zoneIndex ) { this->zoneIndex = zoneIndex; }
+    int  GetZoneIndex() { return zoneIndex; }
+    void SetProcId( int iProc ) { this->iProc = iProc; }
+    void SetParent( SplitZone * parent ) { this->parent = parent; };
+    std::vector< SplitBc * > & GetSplitBcList() { return this->splitBcList; };
+    void CreateBcFromParent();
+    void CreateSplitBcFromOverlapRegion( SplitBc * parentSplitBc, RangeRegion & overlapRegion );
+    void CreateChildInterfaceBc( SplitBc * targetInterfaceBc );
+    bool CreateChildInterfaceBc( SplitBc * candidateInterfaceBc, SplitBc * targetInterfaceBc );
+
+    void CreateSplitBc( SplitBc * parentSplitBc );
+    void AddSplitBc( SplitBc * splitBc );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+    SplitZone * GetRootZone();
+    void GetLeafBcList( std::vector< SplitBc * > & leafBcList );
+public:
+    void Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell );
+    void SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+    void SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+private:
+    int FindAxisNeedSplit();
+    int FindSplitPosition( int axisNeedSplit, double nCell );
+    bool IsPoleBc( int splitDirection );
+    int GetCrossSection( int axis );
+};
+
diff --git a/example/partition/struct/2d/stage1/01d/heat2d2blocks.cgns b/example/partition/struct/2d/stage1/01d/heat2d2blocks.cgns
new file mode 100644
index 00000000..ab4dcea5
Binary files /dev/null and b/example/partition/struct/2d/stage1/01d/heat2d2blocks.cgns differ
diff --git a/example/partition/struct/2d/stage1/01d/heat2dpart.cgns b/example/partition/struct/2d/stage1/01d/heat2dpart.cgns
new file mode 100644
index 00000000..7d2865a0
Binary files /dev/null and b/example/partition/struct/2d/stage1/01d/heat2dpart.cgns differ
diff --git a/example/partition/struct/2d/stage1/01d/main.cpp b/example/partition/struct/2d/stage1/01d/main.cpp
new file mode 100644
index 00000000..5da1de7c
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01d/main.cpp
@@ -0,0 +1,18 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include "Partition.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip>
+
+int main(int argc, char **argv)
+{
+    Partition * partition = new Partition();
+    partition->Solve();
+    delete partition;
+
+    return 0;
+}
diff --git a/example/partition/struct/2d/stage1/01e/CMakeLists.txt b/example/partition/struct/2d/stage1/01e/CMakeLists.txt
new file mode 100644
index 00000000..74ceea7d
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01e/CMakeLists.txt
@@ -0,0 +1,78 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	Partition.h Partition.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	SplitZone.h SplitZone.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/partition/struct/2d/stage1/01e/CgnsGrid.cpp b/example/partition/struct/2d/stage1/01e/CgnsGrid.cpp
new file mode 100644
index 00000000..51872e02
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01e/CgnsGrid.cpp
@@ -0,0 +1,365 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include <map>
+
+Grid::Grid()
+{
+    ;
+}
+
+Grid::~Grid()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if( (i+1)%5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+    delete this->patch;
+}
+
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+ZoneBcPatch::ZoneBcPatch()
+{
+    ;
+}
+
+ZoneBcPatch::~ZoneBcPatch()
+{
+}
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+Global::Global()
+{
+    ;
+}
+
+Global::~Global()
+{
+}
+
+void Global::FreeData()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+    zones.resize( 0 );
+}
+
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            //baseZone.baseId = baseId;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin( index_dim );
+            std::vector<cgsize_t> irmax( index_dim );
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                std::vector<char> coord( nNodes * sizeof(double) );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+                coor->DumpCoor();
+            }
+
+            int nbocos = -1;
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+                //ZoneBc * zonebc = new ZoneBc();
+                //zone->bccos.push_back( zonebc );
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    //zonebc->pnts.push_back( range[ i ] );
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                }
+
+                zonebc_1to1->zoneid = gZoneId;
+
+                //zonebc->zoneid = gZoneId;
+                //zonebc->bcType = BCTypeUserDefined;
+
+                //ZoneBcPatch * patch = new ZoneBcPatch();
+                //zonebc->patch = patch;
+                //patch->transform = transform;
+                //patch->donor_zoneid = gDonorZoneId;
+
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    //patch->donor_pnts.push_back( donor_range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+                int kkk = 1;
+            }
+        }
+        int kkk = 1;
+    }
+    int kkk = 1;
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage1/01e/CgnsGrid.h b/example/partition/struct/2d/stage1/01e/CgnsGrid.h
new file mode 100644
index 00000000..053c467b
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01e/CgnsGrid.h
@@ -0,0 +1,140 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <map>
+
+class Grid;
+
+class Zone;
+
+class Grid
+{
+public:
+    Grid();
+    ~Grid();
+public:
+    int nZone;
+    std::vector<double> x;
+    std::vector<Zone *> zones;
+};
+
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+};
+
+class ZoneBc;
+class ZoneBc1To1;
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class ZoneBcPatch;
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+    ZoneBcPatch * patch = nullptr;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+class ZoneBcPatch
+{
+public:
+    ZoneBcPatch();
+    ~ZoneBcPatch();
+public:
+    int donor_zoneid;
+    std::vector<int> transform;
+    std::vector<int> donor_pnts;
+};
+
+class BaseZone
+{
+public:
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Global
+{
+public:
+    Global();
+    ~Global();
+public:
+    static int cell_dim;
+    static int phys_dim;
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+public:
+    static void FreeData();
+};
+
+void ReadCgnsGrid( const std::string & filename );
+void ReadCgnsGridBaseZone( const std::string & filename );
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage1/01e/Partition.cpp b/example/partition/struct/2d/stage1/01e/Partition.cpp
new file mode 100644
index 00000000..c8dc64c4
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01e/Partition.cpp
@@ -0,0 +1,618 @@
+#include "Partition.h"
+#include "CgnsGrid.h"
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+double CalSumOfProcSpeed( std::vector<double> & procSpeed );
+double CalSumOfProcSpeed( std::vector<double> & procSpeed )
+{
+    int nProc = procSpeed.size();
+    double sumOfProcSpeed = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        sumOfProcSpeed += procSpeed[ iProc ];
+    }
+    return sumOfProcSpeed;
+}
+
+Partition::Partition()
+{
+    this->inputName = "../heat2d2blocks.cgns";
+    this->outName =  "../heat2dpart.cgns";
+}
+
+Partition::~Partition()
+{
+    ;
+}
+
+int Partition::GetMinValueIndex( double * data, int numberOfData )
+{
+    double minValue = data[ 0 ];
+    int minimumValueIndex = 0;
+
+    for ( int iData = 1; iData < numberOfData; ++ iData )
+    {
+        if ( minValue > data[ iData ] )
+        {
+            minValue      = data[ iData ];
+            minimumValueIndex = iData;
+        }
+    }
+    return minimumValueIndex;
+}
+
+int Partition::GetMinLoadProc()
+{
+    return this->GetMinValueIndex( this->timeProc.data(), this->nProc );
+}
+
+SplitZone * Partition::GetLargestZone()
+{
+    SplitZone * largestZone = 0;
+
+    double nMaxCell = 0.0;
+
+    for ( std::set< SplitZone * >::iterator iter = unsignedZoneGroup.begin(); iter != unsignedZoneGroup.end(); ++ iter )
+    {
+        double nSize = ( * iter )->GetNCell();
+        if ( nMaxCell < nSize )
+        {
+            nMaxCell    = nSize;
+            largestZone = * iter;
+        }
+    }
+
+    return largestZone;
+}
+
+void Partition::Solve()
+{
+    std::cout << "Partition::Split()\n";
+    //this->nProc = 2;
+    this->nProc = 4;
+    this->ReadGrid();
+    this->Split();
+    this->DumpPartitionedGridFile();
+    this->FreeAllZones();
+}
+
+void Partition::ReadGrid()
+{
+    ReadCgnsGridBaseZone( this->inputName );
+    ReadCgnsGrid( this->inputName );
+
+    this->nOriZone = ::Global::zones.size();
+    Dim::dim = Global::cell_dim;
+
+    std::cout << "numberOfBlocks = " << nOriZone << "\n";
+
+    this->refZone.resize( nOriZone );
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = new SplitZone();
+        refZone[ iZone ] = splitZone;
+
+        splitZone->SetZoneIndex( iZone );
+        splitZone->SetProcId( 0 );
+        splitZone->SetParent( 0 );
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        Zone * zone = ::Global::zones[ iZone ];
+
+        splitZone->dimInfo.dimList = zone->nijk;
+
+        int nbccos = zone->bccos.size();
+        std::cout << "nbccos = " << nbccos << "\n";
+
+        std::vector< SplitBc * > & splitBcList = splitZone->splitBcList;
+
+        for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+        {
+            ZoneBc * zoneBc = zone->bccos[ ibcco ];
+
+            PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+            splitZone->physicalSplitBcList.push_back( physicalSplitBc );
+            physicalSplitBc->bcType = zoneBc->bcType;
+            physicalSplitBc->SetRegion( zoneBc->pnts );
+            physicalSplitBc->splitZone = splitZone;
+        }
+
+        int nbc1to1s = zone->bc1to1s.size();
+
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * zoneBc1To1 = zone->bc1to1s[ ibc1to1 ];
+
+            InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+            splitZone->interfaceSplitBcList.push_back( interfaceSplitBc );
+            interfaceSplitBc->zone = splitZone;
+            interfaceSplitBc->region.SetRegion( zoneBc1To1->pnts );
+
+            interfaceSplitBc->transform = zoneBc1To1->transform;
+            interfaceSplitBc->CalcTransformMatrix();
+
+            interfaceSplitBc->donor_zone = refZone[ zoneBc1To1->donor_zoneid ];
+            interfaceSplitBc->donor_region.SetRegion( zoneBc1To1->donor_pnts );
+            //interfaceSplitBc->donor_bc 
+        }
+    }
+    int kkk = 1;
+}
+
+void Partition::Split()
+{
+    this->InitSplit();
+    this->BinarySplit();
+    this->ModifyZoneIndex();
+    int kkk = 1;
+}
+
+void Partition::InitSplit()
+{
+    //nZone is the number of zones in the original grid
+    //nProc is not the number of blocks in the end, but the number of processes that need to be divided.
+    //This difference occurs because the structure grid can have many blocks per process.
+
+    //this->nProc    = nProc;
+    //this->nPhyBlocks = referenceBlock.size();
+    //this->nZone  = this->nPhyBlocks;
+
+    //tj Computation time on processor j
+    //Nk Number of internal grid-cells for zone j
+    //aveFloatOp:  Number of Real operations per gridcell
+    //Gj The set of blocks allocated to process j
+    //Pj Real operations per second for process j
+
+    //The Greedy Load Balancing Algorithm
+    //1.Compute an "ideal" uniprocessor time, Tuni = sum ( Nk * aveFloatOp )/ sum( Pj ).
+    //2.Set the group of unassigned blocks, Gu, to contain all blocks. The number of blocks in Nu=M, where M is the total number of blocks in the mesh.
+    //3.Start all processors with a very small fictitious zone to get a start tj=delt aveFloatOp/Pj, where delt<<1 is the size of the very small fictious zone.
+    //This is used to find the fastest processor in a heterogeneous system, tj could otherwise be set to 0 in the homogeneous case.
+    this->aveFloatOp = 1.0;
+    this->delta      = 1.0e-5;
+    this->procSpeed.resize( nProc );
+    this->timeProc.resize( nProc );
+
+    this->nTZone = this->nOriZone;
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        procSpeed[ iProc ] = 1.0;
+    }
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        timeProc[ iProc ] = delta * aveFloatOp / procSpeed[ iProc ];
+    }
+
+    double sumProcSpeed = CalSumOfProcSpeed( procSpeed );
+
+    double sumProcOp = 0.0;
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        sumProcOp += refZone[ iZone ]->GetNCell() * aveFloatOp;
+    }
+
+    this->idealUniProcTime = sumProcOp / sumProcSpeed;
+
+    this->eps = 0.05;
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        unsignedZoneGroup.insert( refZone[ iZone ] );
+    }
+
+    //Init zoneStorage
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        zoneStorage.insert( refZone[ iZone ] );
+    }
+
+    //Assign procSplitZone to each process
+    procSplitZone.resize( nProc );
+
+    this->minNumberCell = 1;
+    for ( int m = 0; m < Dim::dim; ++ m )
+    {
+        this->minNumberCell *= 1;
+    }
+
+    int kkk = 1;
+
+}
+
+void Partition::FreeAllZones()
+{
+    int iCount = 0;
+    for ( std::set < SplitZone * >::iterator iter = zoneStorage.begin(); iter != zoneStorage.end(); ++ iter )
+    {
+        //cout << "iCount = " << iCount << "\n";
+        ++ iCount;
+        delete * iter;
+    }
+}
+
+int Partition::GetNZones( int iProc )
+{
+    return this->procSplitZone[ iProc ].size();
+}
+
+SplitZone * Partition::GetSplitZone( int iProc, int zoneId )
+{
+    return this->procSplitZone[ iProc ][ zoneId ];
+}
+
+void Partition::AddZoneToUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.insert( zone );
+}
+
+void Partition::RemoveZoneFromUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.erase( zone );
+}
+
+void Partition::AddZoneToProcess( int iProc, SplitZone * zone )
+{
+    this->procSplitZone[ iProc ].push_back( zone );
+}
+
+void Partition::AddNewZone( SplitZone * zone )
+{
+    zone->SetZoneIndex( nTZone ++ );
+
+    this->AddZoneToUnsignedGroup( zone );
+
+    this->zoneStorage.insert( zone );
+}
+
+SplitZone * Partition::Split( SplitZone * zone, double nCell )
+{
+    SplitZone * zoneL = new SplitZone();
+    zoneL->SetParent( zone );
+
+    SplitZone * zoneR = new SplitZone();
+    zoneR->SetParent( zone );
+
+    //Remove the original block from the UnsignedGroup
+    this->RemoveZoneFromUnsignedGroup( zone );
+
+    this->AddNewZone( zoneL );
+    this->AddNewZone( zoneR );
+
+    zone->Split( zoneL, zoneR, nCell );
+
+    return zoneL;
+}
+
+void Partition::BinarySplit()
+{
+    while ( ! unsignedZoneGroup.empty() )
+    {
+        std::cout << "number of unsigned zone = " << unsignedZoneGroup.size() << "\n";
+        int iProc = this->GetMinLoadProc();
+
+        //Get the block with the largest number of grids and its size
+        SplitZone * largestZone = this->GetLargestZone();
+
+        double nMaxCell = largestZone->GetNCell();
+
+        double aveFloatOp = this->aveFloatOp;
+        double tau = timeProc[ iProc ] + nMaxCell * aveFloatOp / procSpeed[ iProc ];
+
+        int kkk = 1;
+
+        //It seems that EPS is still necessary
+        //The idea here is as follows. For the candidate blocks which can be divided into blocks, 
+        //if the difference between the target blocks and the candidate blocks is too wide, 
+        //the binarySplit method is adopted. The binarySplit blocks do not directly join the process,
+        //but enter the next round of screening.
+
+        if ( tau > idealUniProcTime * ( 1.0 + eps ) )
+        {
+            double nRest = ( tau - idealUniProcTime ) * procSpeed[ iProc ] / aveFloatOp;
+
+            double nTarget = nMaxCell - nRest;
+            if ( nRest > this->minNumberCell && nTarget > this->minNumberCell )
+            {
+                //It is necessary to divide blocks only when a certain number of points are satisfied.
+                double nHalf = nMaxCell / 2.0;
+                nMaxCell = nTarget;
+                double ratio = nMaxCell / nRest;
+                double oRatio = 1.0 / ratio;
+
+                if ( std::max( ratio, oRatio ) < 3.0 )
+                {
+                    int kkk = 1;
+                    largestZone = this->Split( largestZone, nMaxCell );
+                    timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                    this->RemoveZoneFromUnsignedGroup( largestZone );
+                    this->AddZoneToProcess( iProc, largestZone );
+                }
+                else
+                {
+                    this->Split( largestZone, nHalf );
+                }
+            }
+            else
+            {
+                //If the block is of the right size, join the process directly, and there is no need to split it.
+                timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                this->RemoveZoneFromUnsignedGroup( largestZone );
+                this->AddZoneToProcess( iProc, largestZone );
+            }
+        }
+        else
+        {
+            //If the block is of the right size, join the process directly, and there is no need to split it.
+            timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+            this->RemoveZoneFromUnsignedGroup( largestZone );
+            this->AddZoneToProcess( iProc, largestZone );
+        }
+    }
+}
+
+void Partition::ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord )
+{
+    SplitZone * rootSplitZone = splitZone->GetRootZone();
+    Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+    int nNodes = splitZone->dimInfo.ComputeNumNodes();
+    std::cout << "nNodes = " << nNodes << "\n";
+
+    coord.resize( nNodes * sizeof(double) );
+
+    int index_dim = splitZone->dimInfo.dimList.size();
+    Coor * coor = zone->coors[ icoord ];
+
+    double * xlocal = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    double * xglobal = reinterpret_cast<double *>( const_cast<char *>( coor->coord.data() ) );
+    if ( index_dim == 1 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        for ( int i = imin; i < imax; ++ i )
+        {
+            xlocal[ icount++ ] = xglobal[ i ];
+        }
+    }
+    else if ( index_dim == 2 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        int jmin = splitZone->dimInfo.rmin[ 1 ] - 1;
+        int jmax = splitZone->dimInfo.rmax[ 1 ];
+        int ni = rootSplitZone->dimInfo.dimList[ 0 ];
+        int nj = rootSplitZone->dimInfo.dimList[ 1 ];
+        for ( int j = jmin; j < jmax; ++ j )
+        {
+            int jstride = j * ni;
+            for ( int i = imin; i < imax; ++ i )
+            {
+                xlocal[ icount++ ] = xglobal[ jstride + i ];
+            }
+        }
+    }
+}
+
+void Partition::DumpBc( SplitZone * splitZone )
+{
+}
+
+void Partition::DumpPartitionedGridFile()
+{
+    std::cout << "\n";
+    std::cout << "DumpPartitionedGridFile -------------------------------" << "\n";
+    std::cout << "\n";
+    int fileId = -1;
+    std::string filename = this->outName;
+    int ierr = cg_open( filename.c_str(), CG_MODE_WRITE, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+
+    std::vector<std::string> coordnames;
+    coordnames.push_back( "CoordinateX" );
+    coordnames.push_back( "CoordinateY" );
+    coordnames.push_back( "CoordinateZ" );
+
+    std::string basename = "Base";
+    int baseId = -1;
+    int icelldim = Global::cell_dim;
+    int iphysdim = Global::phys_dim;
+    cg_base_write( fileId, basename.c_str(), icelldim, iphysdim, &baseId );
+
+    std::cout << "baseId = " << baseId << "\n";
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        int nZones = this->GetNZones( iProc );
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            ZoneType_t zoneType = Structured;
+
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+
+            int index_dim = splitZone->dimInfo.dimList.size();
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            splitZone->dimInfo.ComputeISize();
+
+            int isize_dim = index_dim * 3;
+
+            std::vector<cgsize_t> isize( index_dim * 3, 0 );
+            for ( int m = 0; m < isize_dim; ++ m )
+            {
+                isize[ m ] = splitZone->dimInfo.isize[ m ];
+            }
+
+            int zoneId = -1;
+
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+
+            std::string zonename = "Zone" + std::to_string( splitZone->newIndex );
+
+            cg_zone_write( fileId, baseId, zonename.c_str(), isize.data(), zoneType, &zoneId );
+
+            std::cout << "zoneId = " << zoneId << "\n";
+            std::cout << "zonename = " << zonename << "\n";
+                
+            splitZone->ComputeRminmax();
+
+            SplitZone * rootSplitZone = splitZone->GetRootZone();
+
+            Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+            int ncoords = zone->coors.size();
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = -1;
+                DataType_t dataType = RealDouble;
+                std::string coordname = coordnames[ icoord ];
+                Coor * coor = zone->coors[ icoord ];
+
+                int nNodes = splitZone->dimInfo.ComputeNumNodes();
+                std::cout << "nNodes = " << nNodes << "\n";
+
+                std::vector<char> coord;
+                ComputeCoor( splitZone, icoord, coord );
+
+                cg_coord_write( fileId, baseId, zoneId, dataType, coordname.c_str(), coord.data(), &coorId );
+
+                std::cout << "fileId = " << fileId  << " baseId = " << baseId << " zoneId = " << zoneId  << " coorId = " << coorId << "\n";
+            }
+
+            //int nBcLists = splitZone->splitBcList.size();
+            std::vector< SplitBc * > leafBcList;
+            splitZone->GetLeafBcList( leafBcList );
+            int nLeafBcList = leafBcList.size();
+
+            std::vector<SplitBc * > bccoList;
+            std::vector<SplitBc * > bc1to1List;
+
+            for ( int ibc = 0; ibc < nLeafBcList; ++ ibc )
+            {
+                SplitBc * splitBc = leafBcList[ ibc ];
+                if ( splitBc->bcType == BCTypeUserDefined )
+                {
+                    bc1to1List.push_back( splitBc );
+                }
+                else
+                {
+                    bccoList.push_back( splitBc );
+                }
+            }
+            int nbocos = bccoList.size();
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = -1;
+                GridLocation_t location = Vertex;
+
+                std::string boconame = "BC" + std::to_string( iboco + 1 );
+
+                SplitBc * splitBc = bccoList[ iboco ];
+                BCType_t bocotype = static_cast<BCType_t>( splitBc->bcType );
+                PointSetType_t ptset_type = PointRange;
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> pnts;
+                int nSize = splitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.end[ i ] );
+                }
+
+                cg_boco_write( fileId, baseId, zoneId, boconame.c_str(), bocotype, ptset_type, npnts, pnts.data(), & bccoId );
+            }
+
+            int n1to1 = bc1to1List.size();
+            std::cout << "n1to1 = " << n1to1 << "\n";
+
+            std::vector<int> itranfrm( index_dim );
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                itranfrm[ m ] = m + 1;
+            }
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int index_conn = -1;
+
+                SplitBc * splitBc = bc1to1List[ i1to1 ];
+                BCType_t bocotype = static_cast<BCType_t>( splitBc->bcType );
+
+                std::vector<cgsize_t> pnts;
+                std::vector<cgsize_t> pntsdonor;
+                int nSize = splitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( splitBc->region.end[ i ] );
+                }
+
+                int nPatchSize = splitBc->patch->region.start.size();
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( splitBc->patch->region.start[ i ] );
+                }
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( splitBc->patch->region.end[ i ] );
+                }
+                int id = splitBc->patch->splitZone->newIndex;
+                int oldZoneIndex = splitBc->patch->splitZone->zoneIndex;
+                std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+                std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+                std::cout << "donor zone id = " << id << "\n";
+                std::cout << "donor zone oldZoneIndex = " << oldZoneIndex << "\n";
+                std::string donorname = "Zone" + std::to_string( id );
+                std::string connectname = "Interface" + std::to_string( i1to1 );
+
+                std::cout << "donorname = " << donorname << "\n";
+                std::cout << "connectname = " << connectname << "\n";
+
+                cg_1to1_write( fileId, baseId, zoneId, connectname.c_str(), donorname.c_str(), pnts.data(), pntsdonor.data(), itranfrm.data(), &index_conn );
+                std::cout << "index_conn = " << index_conn << "\n";
+            }
+        }
+    }
+    cg_close( fileId );
+}
+
+void Partition::ModifyZoneIndex()
+{
+    std::cout << "ModifyZoneIndex +++++++++++++++++++++++++ " << "\n";
+    int globalZoneId = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        std::cout << "iProc = " << iProc << "\n";
+        int nZones = this->GetNZones( iProc );
+        std::cout << "nZones in Proc " << iProc << "  = " << nZones << "\n";
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+            //splitZone->SetZoneIndex( globalZoneId++ );
+            splitZone->newIndex = ( globalZoneId++ );
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+        }
+    }
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage1/01e/Partition.h b/example/partition/struct/2d/stage1/01e/Partition.h
new file mode 100644
index 00000000..257548f7
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01e/Partition.h
@@ -0,0 +1,54 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class SplitZone;
+
+class Partition
+{
+public:
+    Partition();
+    ~Partition();
+protected:
+    std::set < SplitZone * > zoneStorage;
+    std::set < SplitZone * > unsignedZoneGroup;
+    std::vector< SplitZone * > refZone;
+    std::vector< std::vector< SplitZone * > > procSplitZone;
+    std::vector<double> procSpeed;
+    std::vector<double> timeProc;
+    double aveFloatOp, delta;
+    double idealUniProcTime, eps;
+    int minNumberCell;
+    int nTZone;
+    int nOriZone;
+    int nProc;
+public:
+    std::string inputName;
+    std::string outName;
+public:
+    void Solve();
+    void ReadGrid();
+    void Split();
+    void InitSplit();
+    void BinarySplit();
+    //void GreedySplit();
+public:
+    void AddNewZone( SplitZone * zone );
+    void AddZoneToUnsignedGroup( SplitZone * zone );
+    void RemoveZoneFromUnsignedGroup( SplitZone * zone );
+    void AddZoneToProcess( int iProc, SplitZone * zone );
+    void DumpPartitionedGridFile();
+    void ModifyZoneIndex();
+    void FreeAllZones();
+    int GetNZones( int iProc );
+    SplitZone * GetSplitZone( int iProc, int zoneId );
+    void ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord );
+    void DumpBc( SplitZone * splitZone );
+private:
+    int GetMinValueIndex( double * data, int numberOfData );
+    int GetMinLoadProc();
+    SplitZone * GetLargestZone();
+    SplitZone * Split( SplitZone * zone, double nCell );
+};
+
diff --git a/example/partition/struct/2d/stage1/01e/README.txt b/example/partition/struct/2d/stage1/01e/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01e/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/partition/struct/2d/stage1/01e/SplitZone.cpp b/example/partition/struct/2d/stage1/01e/SplitZone.cpp
new file mode 100644
index 00000000..5af6d830
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01e/SplitZone.cpp
@@ -0,0 +1,1110 @@
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+int Dim::dim = -1;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox  )
+{
+    domainBox.start = zoneBox.start;
+    domainBox.end = zoneBox.end;
+
+    int axis = iDomain / 2;
+    int direction = iDomain % 2;
+
+    if ( direction == 0 )
+    {
+        domainBox.end[ axis ] = domainBox.start[ axis ];
+    }
+    else if ( direction == 1 )
+    {
+        domainBox.start[ axis ] = domainBox.end[ axis ];
+    }
+}
+
+DimInfo::DimInfo()
+{
+    this->Init( 1 );
+}
+
+DimInfo::~DimInfo()
+{
+}
+
+void DimInfo::Init( int dim )
+{
+    this->dim = dim;
+    dimList.resize( this->dim, 1 );
+    oriPoint.resize( this->dim, 0 );
+}
+
+DimInfo & DimInfo::operator = ( const DimInfo & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->dim = rhs.dim;
+    this->dimList = rhs.dimList;
+    this->oriPoint = rhs.oriPoint;
+
+    return * this;
+}
+
+int DimInfo::ComputeNumNodes()
+{
+    int nNodes = 1;
+    for ( int m = 0; m < this->dimList.size(); ++ m )
+    {
+        nNodes *= this->dimList[ m ];
+    }
+    return nNodes;
+}
+
+void DimInfo::ComputeISize()
+{
+    int index_dim = this->dimList.size();
+    this->isize.resize( index_dim * 3, 0 );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        isize[ m ] = this->dimList[ m ];
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 1;
+        isize[ start + m ] = this->dimList[ m ] - 1;
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 2;
+        isize[ start + m ] = 0;
+    }
+
+    for ( int i = 0; i < isize.size(); ++ i )
+    {
+        std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+    }
+}
+
+void DimInfo::ComputeRminmax( std::vector<int> & ref )
+{
+    int index_dim = this->dimList.size();
+    this->rmin.resize( index_dim );
+    this->rmax.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        rmin[ m ] = ref[ m ] + 1;
+        rmax[ m ] = ref[ m ] + this->dimList[ m ];
+    }
+
+    std::cout << "rmin, rmax = \n";
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        std::cout << rmin[ m ] << " " << rmax[ m ] << "\n";
+    }
+}
+
+void DimInfo::Init( std::vector<int> & dimList )
+{
+    this->dim = dimList.size();
+    this->dimList = dimList;
+    std::vector<int> zero( dimList.size(), 0 );
+    this->oriPoint = zero;
+}
+
+void DimInfo::SetNewDimension( int axis, int newStart, int newWidth )
+{
+    this->oriPoint[ axis ] = newStart;
+    this->dimList [ axis ] = newWidth;
+}
+
+void DimInfo::GetZoneGlobalBox( RangeRegion &zoneBox )
+{
+    int index_dim = this->dimList.size();
+    zoneBox.start.resize( index_dim );
+    zoneBox.end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        zoneBox.start[ m ] = this->oriPoint[ m ] + 1;
+        zoneBox.end[ m ] = this->oriPoint[ m ] + this->dimList[ m ];
+    }
+}
+
+void DimInfo::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    int index_dim = this->dimList.size();
+    localBox.start.resize( index_dim );
+    localBox.end.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        localBox.start[ m ] = globalBox.start[ m ] - this->oriPoint[ m ];
+        localBox.end[ m ] = globalBox.end[ m ] - this->oriPoint[ m ];
+    }
+}
+
+RangeRegion::RangeRegion( int nSize )
+{
+    this->Init( nSize );
+}
+
+RangeRegion::~RangeRegion()
+{
+}
+
+void RangeRegion::Init( int nSize )
+{
+    this->start.resize( nSize );
+    this->end.resize( nSize );
+}
+
+RangeRegion & RangeRegion::operator = ( const RangeRegion & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+bool RangeRegion::operator == ( const RangeRegion & rhs ) const
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] != rhs.start[ m ] || 
+            this->end  [ m ] != rhs.end  [ m ] )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion );
+
+bool ComputeOverlapRegion( RangeRegion & region1, RangeRegion & region2, RangeRegion & overlapRegion )
+{
+    int index_dim = region1.start.size();
+    overlapRegion.Init( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int ijkmin1 = std::min( region1.start[ m ], region1.end[ m ] );
+        int ijkmax1 = std::max( region1.start[ m ], region1.end[ m ] );
+        int ijkmin2 = std::min( region2.start[ m ], region2.end[ m ] );
+        int ijkmax2 = std::max( region2.start[ m ], region2.end[ m ] );
+        if ( ( ijkmax1 < ijkmin2 ) || ( ijkmin1 > ijkmax2 ) )
+        {
+            return false;
+        }
+
+        int ijkmin = std::max( ijkmin1, ijkmin2 );
+        int ijkmax = std::min( ijkmax1, ijkmax2 );
+
+        overlapRegion.start[ m ] = ijkmin;
+        overlapRegion.end  [ m ] = ijkmax;
+    }
+
+    return CheckOverLapping( overlapRegion );
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion )
+{
+    int index_dim = overlapRegion.start.size();
+    int iCount = 0;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        if ( overlapRegion.start[ m ] == overlapRegion.end[ m ] )
+        {
+            ++ iCount;
+        }
+    }
+
+    return ( iCount == 1 );
+}
+
+bool GetInterfaceRegion( RangeRegion & zoneBoxL, RangeRegion & zoneBoxR, RangeRegion & interfaceRegion )
+{
+    int index_dim = zoneBoxL.start.size();
+    int nDomains = 2 * index_dim;
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegionL;
+        GetDomainRegion( zoneBoxL, iDomain, domainRegionL );
+
+        for ( int jDomain = 0; jDomain < nDomains; ++ jDomain )
+        {
+            RangeRegion domainRegionR;
+            GetDomainRegion( zoneBoxR, jDomain, domainRegionR );
+
+            if ( domainRegionL == domainRegionR )
+            {
+                interfaceRegion = domainRegionL;
+                return true;
+            }
+        }
+    }
+    return false;
+}
+
+void CreateInterfaceBc( SplitZone * zoneL, SplitZone * zoneR )
+{
+    RangeRegion globalBoxL, globalBoxR, globalInterfaceRegion;
+
+    zoneL->GetZoneGlobalBox( globalBoxL );
+    zoneR->GetZoneGlobalBox( globalBoxR );
+
+    if ( ! GetInterfaceRegion( globalBoxL, globalBoxR, globalInterfaceRegion ) )
+    {
+        int kkk = 1;
+        return;
+    }
+
+    RangeRegion localInterfaceRegionL, localInterfaceRegionR;
+
+    zoneL->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionL );
+    zoneR->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionR );
+
+    int kkk = 1;
+
+    SplitBc * splitBcL = new SplitBc();
+    zoneL->AddSplitBc( splitBcL );
+
+    SplitBc * splitBcR = new SplitBc();
+    zoneR->AddSplitBc( splitBcR );
+
+    splitBcL->splitZone = zoneL;
+    splitBcL->SetRegion( localInterfaceRegionL );
+    splitBcL->bcType = BCTypeUserDefined;
+
+    splitBcR->splitZone = zoneR;
+    splitBcR->SetRegion( localInterfaceRegionR );
+    splitBcR->bcType = BCTypeUserDefined;
+
+    //localInterfaceRegionL.MarkPatchBc();
+    //localInterfaceRegionR.MarkPatchBc();
+
+    SplitBcPatch * splitBcPatchL = new SplitBcPatch();
+    splitBcL->patch = splitBcPatchL;
+    splitBcPatchL->region = localInterfaceRegionR;
+    splitBcPatchL->splitZone = zoneR;
+
+    SplitBcPatch * splitBcPatchR = new SplitBcPatch();
+    splitBcR->patch = splitBcPatchR;
+    splitBcPatchR->region = localInterfaceRegionL;
+    splitBcPatchR->splitZone = zoneL;
+
+    //splitBcL->Normalize();
+    //splitBcR->Normalize();
+}
+
+
+PhysicalSplitBc::PhysicalSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+PhysicalSplitBc::~PhysicalSplitBc()
+{
+}
+
+void PhysicalSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void PhysicalSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+void PhysicalSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = splitZone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+SplitBc::SplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+SplitBc::~SplitBc()
+{
+    delete this->patch;
+}
+
+void SplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void SplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+void SplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = splitZone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void SplitBc::GetLeafBcs( std::vector< SplitBc * > & leafBcs )
+{
+    if ( ! this->child )
+    {
+        leafBcs.push_back( this );
+        return;
+    }
+
+    for ( int i = 0; i < this->child->size(); ++ i )
+    {
+        std::vector< SplitBc * > child_leafBcs;
+        ( * child )[ i ]->GetLeafBcs( child_leafBcs );
+        for ( int j = 0; j < child_leafBcs.size(); ++ j )
+        {
+            leafBcs.push_back( child_leafBcs[ j ] );
+        }
+    }
+
+    return;
+}
+
+void SplitBc::CreateInterfaceBcFromParentBc( SplitBc * parentSplitBc )
+{
+    if ( parentSplitBc->bcType !=  BCTypeUserDefined ) return;
+
+    this->patch = new SplitBcPatch();
+    this->patch->splitZone = parentSplitBc->patch->splitZone;
+    this->patch->SetRegion( parentSplitBc->patch->region );
+    int kkk = 1;
+
+    //Find the block corresponding to this docking boundary
+    //From patch->splitZone, find the corresponding docking boundary according to the size of overlapt
+    //The boundary conditions on the opposite side must change due to the split of this block.
+    //Here, the relevant boundaries are added to the sub-boundaries.
+
+    RangeRegion targetRegionBox;
+    targetRegionBox = parentSplitBc->patch->region;
+
+    SplitZone * targetZone = this->patch->splitZone;
+
+    targetZone->CreateChildInterfaceBc( this );
+
+    //this->patch->faceAxis = parentSplitBc->patch->faceAxis;
+
+    //( * this->patch->vertexMap ) = ( * parentBc->patch->vertexMap );
+
+    ////È»ºó½øÐÐÐÞÕý
+    ////block1->map 1, 33 -> block1 369, 337
+    ////block2->global -> map 1, 33 -> block1 369, 337
+    ////block2->local  -> map 1, 33 -> block1 369, 337
+    ////refOld + M * stold           = block1Startold
+    ////refOld + M * ( stnew + ref ) = block1Startold
+    ////refNew = refOld + M * ( ref )
+
+    //for ( int m = 0; m < 3; ++ m )
+    //{
+    //    for ( int n = 0; n < 3; ++ n )
+    //    {
+    //        this->patch->vertexMap->pt[ m ] += this->patch->vertexMap->vm[ m ][ n ] * ( this->splitZone->sdim->oriPoint )[ n ];
+    //    }
+    //}
+
+    //RangeBox tRangeBox;
+
+    //MappingPatchPoint( this->patch, this->rangeBox, tRangeBox );
+    //tRangeBox.SetOrder();
+
+    ////ÕÒµ½ºÍ±¾¶Ô½Ó±ß½çÏà¶ÔÓ¦µÄ¿é
+    ////´Ópatch->splitZone°´ÕÕoverlapµÄ´óСÕÒµ½¶ÔÓ¦µÄ¶Ô½Ó±ß½ç£¬ÕâÑùÖÁÉÙ¿ÉÒÔÕÒµ½
+    ////¶ÔÃæµÄ¶Ô½Ó±ß½çÌõ¼þÓÉÓÚ±¾¿éµÄsplit±ØȻҪ·¢Éú¸Ä±ä£¬ÕâÀｫÏà¹Ø±ß½ç¼ÓÈë×ӱ߽ç
+    //this->patch->splitZone->CreateChildInterfaceBc( tRangeBox, this->splitZone );
+}
+
+SplitBcPatch::SplitBcPatch()
+{
+    this->region.Init( Dim::dim );
+}
+
+SplitBcPatch::~SplitBcPatch()
+{
+}
+
+void SplitBcPatch::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void SplitBcPatch::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+BasicSplitBc::BasicSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+BasicSplitBc::~BasicSplitBc()
+{
+    ;
+}
+
+void BasicSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void BasicSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+int trans::M[ 3 ][ 3 ];
+std::vector<int> trans::transform;
+
+int trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void trans::CalcTransformMatrix()
+{
+    int dim = trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = trans::transform[ 0 ];
+        int sgna = trans::sgn( a );
+        int a1 = trans::del( a, 1 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int c = trans::transform[ 2 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int sgnc = trans::sgn( c );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int a3 = trans::del( a, 3 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        int b3 = trans::del( b, 3 );
+        int c1 = trans::del( c, 1 );
+        int c2 = trans::del( c, 2 );
+        int c3 = trans::del( c, 3 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 2 ][ 0 ] = sgna * a3;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+        trans::M[ 2 ][ 1 ] = sgnb * b3;
+        trans::M[ 0 ][ 2 ] = sgnc * c1;
+        trans::M[ 1 ][ 2 ] = sgnc * c2;
+        trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+InterfaceSplitBc::InterfaceSplitBc()
+{
+    //this->left = new BasicSplitBc();
+    //this->right = new BasicSplitBc();
+    this->region.Init( Dim::dim );
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceSplitBc::~InterfaceSplitBc()
+{
+    //delete this->left;
+    //delete this->right;
+}
+
+void InterfaceSplitBc::CopyMatrix( InterfaceSplitBc * interfaceSplitBc )
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = interfaceSplitBc->Mt[ i ][ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::CalcTransformMatrix()
+{
+    trans::ZeroMatrix();
+    trans::transform = this->transform;
+    trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = trans::M[ i ][ j ];
+        }
+    }
+
+}
+
+void InterfaceSplitBc::RecalcDonorRegion()
+{
+}
+
+void InterfaceSplitBc::mapindex( std::vector<int> & begin1, std::vector<int> & begin2,  std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = Dim::dim;
+    std::vector<int> diff( dim );
+    for ( int m = 0; m < dim; ++ m )
+    {
+        diff[ m ] = index1[ m ] - begin1[ m ];
+    }
+
+    std::vector<int> mul( dim );
+
+    Multiply( Mt, diff, mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = mul[ m ] + begin2[ m ];
+    }
+}
+
+void InterfaceSplitBc::Multiply( int Mt[][3], std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = Dim::dim;
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::CalcSubDonorRegion( RangeRegion &subRegion, RangeRegion &subDonorRegion )
+{
+    std::vector<int> begin1 = this->region.start;
+    std::vector<int> end1 = this->region.end;
+    std::vector<int> begin2 = this->donor_region.start;
+    std::vector<int> end2 = this->donor_region.end;
+
+    std::vector<int> new_begin1 = subRegion.start;
+    std::vector<int> new_end1 = subRegion.end;
+
+    int dim = Dim::dim;
+    std::vector<int> new_begin2( dim );
+    std::vector<int> new_end2( dim );
+
+    mapindex( begin1, begin2, new_begin1, new_begin2 );
+    mapindex( begin1, begin2, new_end1, new_end2 );
+
+    subDonorRegion.start = new_begin2;
+    subDonorRegion.end = new_end2;
+}
+
+SplitZone::SplitZone()
+{
+    this->parent  = 0;
+    this->zoneIndex = 0;
+    this->iProc = 0;
+    dimInfo.Init( Dim::dim );
+    int kk = 1;
+}
+
+SplitZone::~SplitZone()
+{
+    ;
+}
+
+void SplitZone::GetZoneGlobalBox( RangeRegion & zoneBox )
+{
+    this->dimInfo.GetZoneGlobalBox( zoneBox );
+}
+
+void SplitZone::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    this->dimInfo.GetZoneLocalBox( globalBox, localBox );
+}
+
+
+void SplitZone::ComputeRminmax()
+{
+    int index_dim = this->dimInfo.dimList.size();
+    std::vector<int> ref( index_dim, 0 );
+
+    SplitZone * rootSplitZone = 0;
+    this->GetRootInfo( rootSplitZone, ref );
+
+    this->dimInfo.ComputeRminmax( ref );
+}
+
+SplitZone * SplitZone::GetRootZone()
+{
+    SplitZone * root = this;
+
+    while ( true )
+    {
+        if ( root->parent )
+        {
+            root = root->parent;
+        }
+        else
+        {
+            return root;
+        }
+    };
+}
+
+void SplitZone::GetRootInfo( SplitZone *& root, std::vector<int> & ref )
+{
+    for ( int i = 0; i < this->dimInfo.dimList.size(); ++ i )
+    {
+        ref[ i ] += this->dimInfo.oriPoint[ i ];
+    }
+
+    if ( this->parent )
+    {
+        this->parent->GetRootInfo( root, ref );
+    }
+    else
+    {
+        root = this;
+    }
+}
+
+
+int SplitZone::GetNCell()
+{
+    int numberOfCells = 1;
+    for ( int i = 0; i < this->dimInfo.dim; ++ i )
+    {
+        numberOfCells *= std::max( 1, ( this->dimInfo.dimList[ i ] - 1 ) );
+    }
+
+    return numberOfCells; 
+}
+
+void SplitZone::GetLeafBcList( std::vector< SplitBc * > & leafBcList )
+{
+    int nSplitBcs = this->splitBcList.size();
+
+    for ( int iSplitBcs = 0; iSplitBcs < nSplitBcs; ++ iSplitBcs )
+    {
+        SplitBc * splitBc = splitBcList[ iSplitBcs ];
+
+        std::vector< SplitBc * > leafBcs;
+        splitBc->GetLeafBcs( leafBcs );
+        for ( int j = 0; j < leafBcs.size(); ++ j )
+        {
+            leafBcList.push_back( leafBcs[ j ] );
+        }
+    }
+}
+
+void SplitZone::SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int leftStart = 0;
+    int leftWidth = iSplit - 0;
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, leftStart , leftWidth  );
+}
+
+void SplitZone::SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int rightStart = iSplit - 1;
+    int rightWidth = dimList[ axisNeedSplit ] - ( iSplit - 1 );
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, rightStart, rightWidth );
+}
+
+void SplitZone::Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell )
+{
+    //Find the longest axis
+    int axisNeedSplit = this->FindAxisNeedSplit();
+    int iSplit        = this->FindSplitPosition( axisNeedSplit, nCell );
+
+    zoneL->SetLeftDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+    zoneR->SetRightDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+
+    zoneL->CreateBcFromParent();
+    zoneR->CreateBcFromParent();
+    
+    CreateInterfaceBc( zoneL, zoneR );
+}
+
+void SplitZone::CreateBcFromParent()
+{
+    this->CreatePhysicalBcFromParent();
+    this->CreateInterfaceBcFromParent();
+}
+
+void SplitZone::CreatePhysicalBcFromParent()
+{
+    int nParentPhysicalBcs = this->parent->physicalSplitBcList.size();
+
+    for ( int iParentPhysicalBcs = 0; iParentPhysicalBcs < nParentPhysicalBcs; ++ iParentPhysicalBcs )
+    {
+        PhysicalSplitBc * parentPhysicalSplitBc = this->parent->physicalSplitBcList[ iParentPhysicalBcs ];
+
+        this->CreatePhysicalBcFromParent( parentPhysicalSplitBc );
+    }
+}
+
+void SplitZone::CreatePhysicalBcFromParent(  PhysicalSplitBc * parentPhysicalSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentPhysicalSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreatePhysicalBc( overlapRegion, parentPhysicalSplitBc->bcType );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent()
+{
+    int nInterfaceSplitBcs = this->parent->interfaceSplitBcList.size();
+
+    for ( int iInterfaceSplitBcs = 0; iInterfaceSplitBcs < nInterfaceSplitBcs; ++ iInterfaceSplitBcs )
+    {
+        InterfaceSplitBc * parentInterfaceSplitBc = this->parent->interfaceSplitBcList[ iInterfaceSplitBcs ];
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc );
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent(  InterfaceSplitBc * parentInterfaceSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentInterfaceSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc, overlapRegion );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion )
+{
+    InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+    interfaceSplitBc->region = overlapRegion;
+    interfaceSplitBc->zone = this;
+    interfaceSplitBc->donor_zone = parentInterfaceSplitBc->donor_zone;
+    interfaceSplitBc->CopyMatrix( parentInterfaceSplitBc );
+    RangeRegion subDonorRegion( Dim::dim );
+    parentInterfaceSplitBc->CalcSubDonorRegion( overlapRegion, subDonorRegion );
+    interfaceSplitBc->donor_region = subDonorRegion;
+    SplitZone * splitZone = interfaceSplitBc->donor_zone;
+    //splitZone->
+}
+
+void SplitZone::CreateChildInterfaceBc( SplitBc * targetInterfaceBc )
+{
+    std::vector< SplitBc * > & splitBcList = this->GetSplitBcList();
+
+    int nSplitBcs = splitBcList.size();
+
+    for ( int iSplitBc = 0; iSplitBc < nSplitBcs; ++ iSplitBc )
+    {
+        SplitBc * splitBc = splitBcList[ iSplitBc ];
+
+        //Only consider the interface boundaries
+        if ( splitBc->bcType !=  BCTypeUserDefined ) continue;
+        SplitBc * candidateInterfaceBc = splitBc;
+
+        if ( this->CreateChildInterfaceBc( candidateInterfaceBc, targetInterfaceBc ) )
+        {
+            return;
+        }
+    }
+}
+
+bool SplitZone::CreateChildInterfaceBc( SplitBc * candidateInterfaceBc, SplitBc * targetInterfaceBc )
+{
+    RangeRegion overlapRegion;
+    bool overlap_flag = ComputeOverlapRegion( candidateInterfaceBc->region, targetInterfaceBc->patch->region, overlapRegion );
+    if ( ! overlap_flag ) return false;
+
+    //1. Èç¹ûsplitBcºÍinterfaceBcÓн»¼¯£¬µ«ÊÇinterfaceBcûÓÐchild£¬Ôò´ËsplitBc×÷ΪinterfaceBcµÄÒ»¸öchild
+    //2. Èç¹ûsplitBcºÍinterfaceBcÓн»¼¯£¬ÇÒinterfaceBcÓÐchild£¬Èç¹ûsplitBcºÍËùÓÐchildûÓн»¼¯£¬
+    //   ÔòsplitBc¼ÓÈëinterfaceBcµÄÒ»¸öchild
+    //3. Èç¹ûsplitBcºÍinterfaceBcÓн»¼¯£¬ÇÒinterfaceBcÓÐchild£¬Èç¹ûsplitBcºÍchildÓн»¼¯£¬Ôò´Ëchild×÷ΪеÄinterfaceBc
+
+    std::vector< SplitBc * > * child = candidateInterfaceBc->child;
+
+    if ( candidateInterfaceBc->child )
+    {
+        for ( int iChild = 0; iChild < candidateInterfaceBc->child->size(); ++ iChild )
+        {
+            SplitBc * childSplitBc = ( * candidateInterfaceBc->child )[ iChild ];
+            if ( this->CreateChildInterfaceBc( childSplitBc, targetInterfaceBc ) ) return true;
+        }
+    }
+    else
+    {
+        candidateInterfaceBc->child = new std::vector< SplitBc * >();
+    }
+
+    SplitBc * childInterfaceBc = new SplitBc();
+
+    childInterfaceBc->SetRegion( overlapRegion );
+    childInterfaceBc->bcType = candidateInterfaceBc->bcType;
+    childInterfaceBc->splitZone = candidateInterfaceBc->splitZone;
+
+    candidateInterfaceBc->child->push_back( childInterfaceBc );
+
+    //vector< int > & parentFaceDirectionContainer = interfaceBc->GetFaceDirectionContainer();
+    //vector< int > & faceDirectionContainer  = childInterfaceBc->GetFaceDirectionContainer();
+
+    //for ( int m = 0; m < 3; ++ m )
+    //{
+    //    faceDirectionContainer[ m ] = parentFaceDirectionContainer[ m ];
+    //}
+
+    //½«´ËÐÂÉú³ÉµÄ¶Ô½Ó±ß½ç¼ÓÈë±¾¿éÀïÃæ
+    SplitBcPatch * patch = new SplitBcPatch();
+    childInterfaceBc->patch = patch;
+    patch->splitZone = targetInterfaceBc->splitZone;
+    patch->region = targetInterfaceBc->region;
+
+    //patch->CopyVertexMappingContent( interfaceBc->GetZoneBoundaryConditionPatch()->GetVertexMapping() );
+
+    //vector< int > & pNextFaceDirectionContainer = interfaceBc->GetZoneBoundaryConditionPatch()->GetFaceDirectionContainer();
+    //vector< int > & patchFaceDirectionContainer = patch->GetFaceDirectionContainer();
+
+    //for ( int m = 0; m < 3; ++ m )
+    //{
+    //    patchFaceDirectionContainer[ m ] = pNextFaceDirectionContainer[ m ];
+    //}
+
+    //Ô­¶Ô½Ó±ß½çÂú×ã
+    //t0 = tref + M * s0
+    //еĶԽӱ߽çÂú×ã
+    //t0newblock + refNewblock = tref + M * s0
+    //t0newblock = ( tref - refNewblock ) + M * s0
+
+    //È»ºó½øÐÐÐÞÕý
+    //for ( int m = 0; m < 3; ++ m )
+    //{
+    //    ( patch->GetVertexMapping() )[ m ][ 3 ] -= ( sourceZone->GetOriginalPointIndexContainer() )[ m ];
+    //}
+
+    return true;
+}
+
+void SplitZone::AddSplitBc( SplitBc * splitBc )
+{
+    if ( ! splitBc ) return;
+    this->splitBcList.push_back( splitBc );
+}
+
+void SplitZone::CreateSplitBc( SplitBc * parentSplitBc )
+{
+    if ( ! parentSplitBc->child )
+    {
+        int index_dim = this->dimInfo.dimList.size();
+        int nDomains = 2 * index_dim;
+        RangeRegion zoneBoxRegion( index_dim );
+        this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+        for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+        {
+            RangeRegion domainRegion( index_dim );
+            GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+            RangeRegion overlapRegion;
+            bool overlap_flag = ComputeOverlapRegion( parentSplitBc->region, domainRegion, overlapRegion );
+            if ( ! overlap_flag ) continue;
+
+            this->CreateSplitBcFromOverlapRegion( parentSplitBc, overlapRegion );
+
+            int kkk = 1;
+        }
+    }
+    else
+    {
+        int nChilds = parentSplitBc->child->size();
+        for ( int iChild = 0; iChild < nChilds; ++ iChild )
+        {
+            this->CreateSplitBc( ( * parentSplitBc->child )[ iChild ] );
+        }
+    }
+}
+
+void SplitZone::CreatePhysicalBc( RangeRegion & overlapRegion, int bcType )
+{
+    PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+    this->physicalSplitBcList.push_back( physicalSplitBc );
+    physicalSplitBc->SetRegion( overlapRegion );
+    physicalSplitBc->bcType = bcType;
+    physicalSplitBc->splitZone = this;
+    physicalSplitBc->ChangeRegionToLocalCoordinate();
+}
+
+void SplitZone::CreateSplitBcFromOverlapRegion( SplitBc * parentSplitBc, RangeRegion & overlapRegion )
+{
+    SplitBc * splitBc = new SplitBc();
+    this->AddSplitBc( splitBc );
+
+    splitBc->SetRegion( overlapRegion );
+    splitBc->bcType = parentSplitBc->bcType;
+    splitBc->splitZone = this;
+    splitBc->ChangeRegionToLocalCoordinate();
+    splitBc->CreateInterfaceBcFromParentBc( parentSplitBc );
+}
+
+int SplitZone::FindAxisNeedSplit()
+{
+    //Find the longest axis
+    int axisNeedSplit = 0;
+    int maxN = this->dimInfo.dimList[ 0 ];
+
+    for ( int m = 1; m < this->dimInfo.dimList.size(); ++ m )
+    {
+        if ( this->IsPoleBc( m ) )
+        {
+            continue;
+        }
+        int Nm = this->dimInfo.dimList[ m ];
+        if ( maxN < Nm )
+        {
+            maxN = Nm;
+            axisNeedSplit = m;
+        }
+    }
+
+    return axisNeedSplit;
+}
+
+int SplitZone::GetCrossSection( int axis )
+{
+    int nDim = this->dimInfo.dimList.size();
+    int crossSection = 1;
+    int N = nDim - 1;
+    for ( int m = 0; m < N; ++ m )
+    {
+         int mm = ( axis + 1 ) % nDim;
+         int nLineElements = std::max( 1, ( this->dimInfo.dimList[ mm ] - 1 ) );
+         crossSection *= nLineElements;
+    }
+    return crossSection;
+}
+
+int SplitZone::FindSplitPosition( int axisNeedSplit, double nCell )
+{
+    int nDim = this->dimInfo.dimList.size();
+    std::vector<int> crossSections( nDim );
+    for ( int m = 0; m < nDim; ++ m )
+    {
+        crossSections[ m ] = this->GetCrossSection( m );
+    }
+
+    //guess the value
+    double dSplit = nCell / crossSections[ axisNeedSplit ];
+    int  iSplit = 1 + static_cast< int >( std::floor( dSplit + 0.5 ) );
+    return iSplit;
+}
+
+
+bool SplitZone::IsPoleBc( int splitDirection )
+{
+    return false;
+}
+
diff --git a/example/partition/struct/2d/stage1/01e/SplitZone.h b/example/partition/struct/2d/stage1/01e/SplitZone.h
new file mode 100644
index 00000000..c71bf579
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01e/SplitZone.h
@@ -0,0 +1,213 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class Dim
+{
+public:
+    static int dim;
+};
+
+class SplitZone;
+class RangeRegion;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox );
+
+class DimInfo
+{
+public:
+    DimInfo();
+    ~DimInfo();
+public:
+    int dim;
+    std::vector<int> dimList;
+    std::vector<int> oriPoint;
+    std::vector<int> isize;
+    std::vector<int> rmin;
+    std::vector<int> rmax;
+public:
+    int GetSize() const { return dim; }
+    DimInfo & operator = ( const DimInfo & rhs );
+public:
+    int ComputeNumNodes();
+    void ComputeISize();
+    void ComputeRminmax( std::vector<int> & ref );
+    void Init( int dim );
+    void Init( std::vector<int> & dimList );
+    void SetNewDimension( int axis, int newStart, int newWidth );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+};
+
+class SplitZone;
+class SplitBcPatch;
+
+class RangeRegion
+{
+public:
+    RangeRegion( int nSize = 1 );
+    ~RangeRegion();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    void Init( int nSize );
+    RangeRegion & operator = ( const RangeRegion & rhs );
+    bool operator == ( const RangeRegion & rhs ) const;
+    void SetRegion( std::vector<int> &pnts );
+};
+
+class PhysicalSplitBc
+{
+public:
+    PhysicalSplitBc();
+    ~PhysicalSplitBc();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class SplitBc
+{
+public:
+    SplitBc();
+    ~SplitBc();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone = nullptr;
+    SplitBcPatch * patch = nullptr;
+    std::vector< SplitBc * > * child = nullptr;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+    void ChangeRegionToLocalCoordinate();
+public:
+    void CreateInterfaceBcFromParentBc( SplitBc * parentSplitBc );
+    void GetLeafBcs( std::vector< SplitBc * > & leafBcs );
+};
+
+class SplitBcPatch
+{
+public:
+    SplitBcPatch ();
+    ~SplitBcPatch();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+};
+
+class BasicSplitBc
+{
+public:
+    BasicSplitBc();
+    ~BasicSplitBc();
+public:
+    RangeRegion region;
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> & pnts );
+    void SetRegion( RangeRegion & region );
+};
+
+class trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class InterfaceSplitBc
+{
+public:
+    InterfaceSplitBc();
+    ~InterfaceSplitBc();
+public:
+    std::vector<int> transform;
+    int Mt[ 3 ][ 3 ];
+    //BasicSplitBc * left;
+    //BasicSplitBc * right;
+    RangeRegion region;
+    SplitZone * zone = nullptr;
+    RangeRegion donor_region;
+    SplitZone * donor_zone = nullptr;
+    InterfaceSplitBc * donor_bc = nullptr;
+public:
+    void CopyMatrix( InterfaceSplitBc * interfaceSplitBc );
+    void CalcTransformMatrix();
+    void RecalcDonorRegion();
+    void CalcSubDonorRegion( RangeRegion & subRegion, RangeRegion & subDonorRegion );
+    void mapindex( std::vector<int> & begin1, std::vector<int> & begin2, std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( int Mt[][ 3 ], std::vector<int> & a, std::vector<int> & b );
+};
+
+class SplitZone
+{
+public:
+    SplitZone();
+    ~SplitZone();
+public:
+    DimInfo dimInfo;
+    int zoneIndex, iProc;
+    int newIndex;
+protected:
+    SplitZone * parent;
+public:
+    std::vector< SplitBc * > splitBcList;
+    std::vector< PhysicalSplitBc * > physicalSplitBcList;
+    std::vector< InterfaceSplitBc * > interfaceSplitBcList;
+public:
+    int GetNCell();
+    void ComputeRminmax();
+    void GetRootInfo( SplitZone *& root, std::vector<int> & ref );
+    void SetZoneIndex( int zoneIndex ) { this->zoneIndex = zoneIndex; }
+    int  GetZoneIndex() { return zoneIndex; }
+    void SetProcId( int iProc ) { this->iProc = iProc; }
+    void SetParent( SplitZone * parent ) { this->parent = parent; };
+    std::vector< SplitBc * > & GetSplitBcList() { return this->splitBcList; };
+public:
+    void CreateBcFromParent();
+    void CreatePhysicalBcFromParent();
+    void CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc );
+    void CreatePhysicalBc( RangeRegion & overlapRegion, int bcType );
+    void CreateInterfaceBcFromParent();
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc );
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion );
+    void CreateSplitBcFromOverlapRegion( SplitBc * parentSplitBc, RangeRegion & overlapRegion );
+    void CreateChildInterfaceBc( SplitBc * targetInterfaceBc );
+    bool CreateChildInterfaceBc( SplitBc * candidateInterfaceBc, SplitBc * targetInterfaceBc );
+
+    void CreateSplitBc( SplitBc * parentSplitBc );
+    void AddSplitBc( SplitBc * splitBc );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+    SplitZone * GetRootZone();
+    void GetLeafBcList( std::vector< SplitBc * > & leafBcList );
+public:
+    void Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell );
+    void SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+    void SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+private:
+    int FindAxisNeedSplit();
+    int FindSplitPosition( int axisNeedSplit, double nCell );
+    bool IsPoleBc( int splitDirection );
+    int GetCrossSection( int axis );
+};
+
diff --git a/example/partition/struct/2d/stage1/01e/heat2d2blocks.cgns b/example/partition/struct/2d/stage1/01e/heat2d2blocks.cgns
new file mode 100644
index 00000000..ab4dcea5
Binary files /dev/null and b/example/partition/struct/2d/stage1/01e/heat2d2blocks.cgns differ
diff --git a/example/partition/struct/2d/stage1/01e/main.cpp b/example/partition/struct/2d/stage1/01e/main.cpp
new file mode 100644
index 00000000..5da1de7c
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01e/main.cpp
@@ -0,0 +1,18 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include "Partition.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip>
+
+int main(int argc, char **argv)
+{
+    Partition * partition = new Partition();
+    partition->Solve();
+    delete partition;
+
+    return 0;
+}
diff --git a/example/partition/struct/2d/stage1/01f/CMakeLists.txt b/example/partition/struct/2d/stage1/01f/CMakeLists.txt
new file mode 100644
index 00000000..74ceea7d
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01f/CMakeLists.txt
@@ -0,0 +1,78 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	Partition.h Partition.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	SplitZone.h SplitZone.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/partition/struct/2d/stage1/01f/CgnsGrid.cpp b/example/partition/struct/2d/stage1/01f/CgnsGrid.cpp
new file mode 100644
index 00000000..dfe750bd
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01f/CgnsGrid.cpp
@@ -0,0 +1,349 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include <map>
+
+Grid::Grid()
+{
+    ;
+}
+
+Grid::~Grid()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if( (i+1)%5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+    delete this->patch;
+}
+
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+ZoneBcPatch::ZoneBcPatch()
+{
+    ;
+}
+
+ZoneBcPatch::~ZoneBcPatch()
+{
+}
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+Global::Global()
+{
+    ;
+}
+
+Global::~Global()
+{
+}
+
+void Global::FreeData()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+    zones.resize( 0 );
+}
+
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            //baseZone.baseId = baseId;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin( index_dim );
+            std::vector<cgsize_t> irmax( index_dim );
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                std::vector<char> coord( nNodes * sizeof(double) );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+                coor->DumpCoor();
+            }
+
+            int nbocos = -1;
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+                int kkk = 1;
+            }
+        }
+        int kkk = 1;
+    }
+    int kkk = 1;
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage1/01f/CgnsGrid.h b/example/partition/struct/2d/stage1/01f/CgnsGrid.h
new file mode 100644
index 00000000..053c467b
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01f/CgnsGrid.h
@@ -0,0 +1,140 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <map>
+
+class Grid;
+
+class Zone;
+
+class Grid
+{
+public:
+    Grid();
+    ~Grid();
+public:
+    int nZone;
+    std::vector<double> x;
+    std::vector<Zone *> zones;
+};
+
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+};
+
+class ZoneBc;
+class ZoneBc1To1;
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class ZoneBcPatch;
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+    ZoneBcPatch * patch = nullptr;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+class ZoneBcPatch
+{
+public:
+    ZoneBcPatch();
+    ~ZoneBcPatch();
+public:
+    int donor_zoneid;
+    std::vector<int> transform;
+    std::vector<int> donor_pnts;
+};
+
+class BaseZone
+{
+public:
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Global
+{
+public:
+    Global();
+    ~Global();
+public:
+    static int cell_dim;
+    static int phys_dim;
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+public:
+    static void FreeData();
+};
+
+void ReadCgnsGrid( const std::string & filename );
+void ReadCgnsGridBaseZone( const std::string & filename );
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage1/01f/Partition.cpp b/example/partition/struct/2d/stage1/01f/Partition.cpp
new file mode 100644
index 00000000..0d400c1c
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01f/Partition.cpp
@@ -0,0 +1,618 @@
+#include "Partition.h"
+#include "CgnsGrid.h"
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+double CalSumOfProcSpeed( std::vector<double> & procSpeed );
+double CalSumOfProcSpeed( std::vector<double> & procSpeed )
+{
+    int nProc = procSpeed.size();
+    double sumOfProcSpeed = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        sumOfProcSpeed += procSpeed[ iProc ];
+    }
+    return sumOfProcSpeed;
+}
+
+Partition::Partition()
+{
+    this->inputName = "../heat2d2blocks.cgns";
+    this->outName =  "../heat2dpart.cgns";
+}
+
+Partition::~Partition()
+{
+    ;
+}
+
+int Partition::GetMinValueIndex( double * data, int numberOfData )
+{
+    double minValue = data[ 0 ];
+    int minimumValueIndex = 0;
+
+    for ( int iData = 1; iData < numberOfData; ++ iData )
+    {
+        if ( minValue > data[ iData ] )
+        {
+            minValue      = data[ iData ];
+            minimumValueIndex = iData;
+        }
+    }
+    return minimumValueIndex;
+}
+
+int Partition::GetMinLoadProc()
+{
+    return this->GetMinValueIndex( this->timeProc.data(), this->nProc );
+}
+
+SplitZone * Partition::GetLargestZone()
+{
+    SplitZone * largestZone = 0;
+
+    double nMaxCell = 0.0;
+
+    for ( std::set< SplitZone * >::iterator iter = unsignedZoneGroup.begin(); iter != unsignedZoneGroup.end(); ++ iter )
+    {
+        double nSize = ( * iter )->GetNCell();
+        if ( nMaxCell < nSize )
+        {
+            nMaxCell    = nSize;
+            largestZone = * iter;
+        }
+    }
+
+    return largestZone;
+}
+
+void Partition::Solve()
+{
+    std::cout << "Partition::Split()\n";
+    //this->nProc = 2;
+    this->nProc = 4;
+    this->ReadGrid();
+    this->Split();
+    this->DumpPartitionedGridFile();
+    this->FreeAllZones();
+}
+
+void Partition::ReadGrid()
+{
+    ReadCgnsGridBaseZone( this->inputName );
+    ReadCgnsGrid( this->inputName );
+
+    this->nOriZone = ::Global::zones.size();
+    Dim::dim = Global::cell_dim;
+
+    std::cout << "numberOfBlocks = " << nOriZone << "\n";
+
+    this->refZone.resize( nOriZone );
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = new SplitZone();
+        refZone[ iZone ] = splitZone;
+
+        splitZone->SetZoneIndex( iZone );
+        splitZone->SetProcId( 0 );
+        splitZone->SetParent( 0 );
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        Zone * zone = ::Global::zones[ iZone ];
+
+        splitZone->dimInfo.dimList = zone->nijk;
+
+        int nbccos = zone->bccos.size();
+        std::cout << "nbccos = " << nbccos << "\n";
+
+        std::vector< SplitBc * > & splitBcList = splitZone->splitBcList;
+
+        for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+        {
+            ZoneBc * zoneBc = zone->bccos[ ibcco ];
+
+            PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+            splitZone->physicalSplitBcList.push_back( physicalSplitBc );
+            physicalSplitBc->bcType = zoneBc->bcType;
+            physicalSplitBc->SetRegion( zoneBc->pnts );
+            physicalSplitBc->splitZone = splitZone;
+        }
+
+        int nbc1to1s = zone->bc1to1s.size();
+
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * zoneBc1To1 = zone->bc1to1s[ ibc1to1 ];
+
+            InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+            splitZone->interfaceSplitBcList.push_back( interfaceSplitBc );
+            interfaceSplitBc->zone = splitZone;
+            interfaceSplitBc->region.SetRegion( zoneBc1To1->pnts );
+
+            interfaceSplitBc->transform = zoneBc1To1->transform;
+            interfaceSplitBc->CalcTransformMatrix();
+
+            interfaceSplitBc->donor_zone = refZone[ zoneBc1To1->donor_zoneid ];
+            interfaceSplitBc->donor_region.SetRegion( zoneBc1To1->donor_pnts );
+        }
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        int nbc1to1s = splitZone->interfaceSplitBcList.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            InterfaceSplitBc * interfaceSplitBc = splitZone->interfaceSplitBcList[ ibc1to1 ];
+            InterfaceSplitBc * donorInterface = interfaceSplitBc->donor_zone->FindDonorInterface( interfaceSplitBc );
+            interfaceSplitBc->donor_bc = donorInterface;
+        }
+    }
+}
+
+void Partition::Split()
+{
+    this->InitSplit();
+    this->BinarySplit();
+    this->ModifyZoneIndex();
+    int kkk = 1;
+}
+
+void Partition::InitSplit()
+{
+    //nZone is the number of zones in the original grid
+    //nProc is not the number of blocks in the end, but the number of processes that need to be divided.
+    //This difference occurs because the structure grid can have many blocks per process.
+
+    //this->nProc    = nProc;
+    //this->nPhyBlocks = referenceBlock.size();
+    //this->nZone  = this->nPhyBlocks;
+
+    //tj Computation time on processor j
+    //Nk Number of internal grid-cells for zone j
+    //aveFloatOp:  Number of Real operations per gridcell
+    //Gj The set of blocks allocated to process j
+    //Pj Real operations per second for process j
+
+    //The Greedy Load Balancing Algorithm
+    //1.Compute an "ideal" uniprocessor time, Tuni = sum ( Nk * aveFloatOp )/ sum( Pj ).
+    //2.Set the group of unassigned blocks, Gu, to contain all blocks. The number of blocks in Nu=M, where M is the total number of blocks in the mesh.
+    //3.Start all processors with a very small fictitious zone to get a start tj=delt aveFloatOp/Pj, where delt<<1 is the size of the very small fictious zone.
+    //This is used to find the fastest processor in a heterogeneous system, tj could otherwise be set to 0 in the homogeneous case.
+    this->aveFloatOp = 1.0;
+    this->delta      = 1.0e-5;
+    this->procSpeed.resize( nProc );
+    this->timeProc.resize( nProc );
+
+    this->nTZone = this->nOriZone;
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        procSpeed[ iProc ] = 1.0;
+    }
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        timeProc[ iProc ] = delta * aveFloatOp / procSpeed[ iProc ];
+    }
+
+    double sumProcSpeed = CalSumOfProcSpeed( procSpeed );
+
+    double sumProcOp = 0.0;
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        sumProcOp += refZone[ iZone ]->GetNCell() * aveFloatOp;
+    }
+
+    this->idealUniProcTime = sumProcOp / sumProcSpeed;
+
+    this->eps = 0.05;
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        unsignedZoneGroup.insert( refZone[ iZone ] );
+    }
+
+    //Init zoneStorage
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        zoneStorage.insert( refZone[ iZone ] );
+    }
+
+    //Assign procSplitZone to each process
+    procSplitZone.resize( nProc );
+
+    this->minNumberCell = 1;
+    for ( int m = 0; m < Dim::dim; ++ m )
+    {
+        this->minNumberCell *= 1;
+    }
+
+    int kkk = 1;
+
+}
+
+void Partition::FreeAllZones()
+{
+    int iCount = 0;
+    for ( std::set < SplitZone * >::iterator iter = zoneStorage.begin(); iter != zoneStorage.end(); ++ iter )
+    {
+        //cout << "iCount = " << iCount << "\n";
+        ++ iCount;
+        delete * iter;
+    }
+}
+
+int Partition::GetNZones( int iProc )
+{
+    return this->procSplitZone[ iProc ].size();
+}
+
+SplitZone * Partition::GetSplitZone( int iProc, int zoneId )
+{
+    return this->procSplitZone[ iProc ][ zoneId ];
+}
+
+void Partition::AddZoneToUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.insert( zone );
+}
+
+void Partition::RemoveZoneFromUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.erase( zone );
+}
+
+void Partition::AddZoneToProcess( int iProc, SplitZone * zone )
+{
+    this->procSplitZone[ iProc ].push_back( zone );
+}
+
+void Partition::AddNewZone( SplitZone * zone )
+{
+    zone->SetZoneIndex( nTZone ++ );
+
+    this->AddZoneToUnsignedGroup( zone );
+
+    this->zoneStorage.insert( zone );
+}
+
+SplitZone * Partition::Split( SplitZone * zone, double nCell )
+{
+    SplitZone * zoneL = new SplitZone();
+    zoneL->SetParent( zone );
+
+    SplitZone * zoneR = new SplitZone();
+    zoneR->SetParent( zone );
+
+    //Remove the original block from the UnsignedGroup
+    this->RemoveZoneFromUnsignedGroup( zone );
+
+    this->AddNewZone( zoneL );
+    this->AddNewZone( zoneR );
+
+    zone->Split( zoneL, zoneR, nCell );
+
+    return zoneL;
+}
+
+void Partition::BinarySplit()
+{
+    while ( ! unsignedZoneGroup.empty() )
+    {
+        std::cout << "number of unsigned zone = " << unsignedZoneGroup.size() << "\n";
+        int iProc = this->GetMinLoadProc();
+
+        //Get the block with the largest number of grids and its size
+        SplitZone * largestZone = this->GetLargestZone();
+
+        double nMaxCell = largestZone->GetNCell();
+
+        double aveFloatOp = this->aveFloatOp;
+        double tau = timeProc[ iProc ] + nMaxCell * aveFloatOp / procSpeed[ iProc ];
+
+        int kkk = 1;
+
+        //It seems that EPS is still necessary
+        //The idea here is as follows. For the candidate blocks which can be divided into blocks, 
+        //if the difference between the target blocks and the candidate blocks is too wide, 
+        //the binarySplit method is adopted. The binarySplit blocks do not directly join the process,
+        //but enter the next round of screening.
+
+        if ( tau > idealUniProcTime * ( 1.0 + eps ) )
+        {
+            double nRest = ( tau - idealUniProcTime ) * procSpeed[ iProc ] / aveFloatOp;
+
+            double nTarget = nMaxCell - nRest;
+            if ( nRest > this->minNumberCell && nTarget > this->minNumberCell )
+            {
+                //It is necessary to divide blocks only when a certain number of points are satisfied.
+                double nHalf = nMaxCell / 2.0;
+                nMaxCell = nTarget;
+                double ratio = nMaxCell / nRest;
+                double oRatio = 1.0 / ratio;
+
+                if ( std::max( ratio, oRatio ) < 3.0 )
+                {
+                    int kkk = 1;
+                    largestZone = this->Split( largestZone, nMaxCell );
+                    timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                    this->RemoveZoneFromUnsignedGroup( largestZone );
+                    this->AddZoneToProcess( iProc, largestZone );
+                }
+                else
+                {
+                    this->Split( largestZone, nHalf );
+                }
+            }
+            else
+            {
+                //If the block is of the right size, join the process directly, and there is no need to split it.
+                timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                this->RemoveZoneFromUnsignedGroup( largestZone );
+                this->AddZoneToProcess( iProc, largestZone );
+            }
+        }
+        else
+        {
+            //If the block is of the right size, join the process directly, and there is no need to split it.
+            timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+            this->RemoveZoneFromUnsignedGroup( largestZone );
+            this->AddZoneToProcess( iProc, largestZone );
+        }
+    }
+}
+
+void Partition::ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord )
+{
+    SplitZone * rootSplitZone = splitZone->GetRootZone();
+    Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+    int nNodes = splitZone->dimInfo.ComputeNumNodes();
+    std::cout << "nNodes = " << nNodes << "\n";
+
+    coord.resize( nNodes * sizeof(double) );
+
+    int index_dim = splitZone->dimInfo.dimList.size();
+    Coor * coor = zone->coors[ icoord ];
+
+    double * xlocal = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    double * xglobal = reinterpret_cast<double *>( const_cast<char *>( coor->coord.data() ) );
+    if ( index_dim == 1 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        for ( int i = imin; i < imax; ++ i )
+        {
+            xlocal[ icount++ ] = xglobal[ i ];
+        }
+    }
+    else if ( index_dim == 2 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        int jmin = splitZone->dimInfo.rmin[ 1 ] - 1;
+        int jmax = splitZone->dimInfo.rmax[ 1 ];
+        int ni = rootSplitZone->dimInfo.dimList[ 0 ];
+        int nj = rootSplitZone->dimInfo.dimList[ 1 ];
+        for ( int j = jmin; j < jmax; ++ j )
+        {
+            int jstride = j * ni;
+            for ( int i = imin; i < imax; ++ i )
+            {
+                xlocal[ icount++ ] = xglobal[ jstride + i ];
+            }
+        }
+    }
+}
+
+void Partition::DumpBc( SplitZone * splitZone )
+{
+}
+
+void Partition::DumpPartitionedGridFile()
+{
+    std::cout << "\n";
+    std::cout << "DumpPartitionedGridFile -------------------------------" << "\n";
+    std::cout << "\n";
+    int fileId = -1;
+    std::string filename = this->outName;
+    int ierr = cg_open( filename.c_str(), CG_MODE_WRITE, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+
+    std::vector<std::string> coordnames;
+    coordnames.push_back( "CoordinateX" );
+    coordnames.push_back( "CoordinateY" );
+    coordnames.push_back( "CoordinateZ" );
+
+    std::string basename = "Base";
+    int baseId = -1;
+    int icelldim = Global::cell_dim;
+    int iphysdim = Global::phys_dim;
+    cg_base_write( fileId, basename.c_str(), icelldim, iphysdim, &baseId );
+
+    std::cout << "baseId = " << baseId << "\n";
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        int nZones = this->GetNZones( iProc );
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            ZoneType_t zoneType = Structured;
+
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+
+            int index_dim = splitZone->dimInfo.dimList.size();
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            splitZone->dimInfo.ComputeISize();
+
+            int isize_dim = index_dim * 3;
+
+            std::vector<cgsize_t> isize( index_dim * 3, 0 );
+            for ( int m = 0; m < isize_dim; ++ m )
+            {
+                isize[ m ] = splitZone->dimInfo.isize[ m ];
+            }
+
+            int zoneId = -1;
+
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+
+            std::string zonename = "Zone" + std::to_string( splitZone->newIndex );
+
+            cg_zone_write( fileId, baseId, zonename.c_str(), isize.data(), zoneType, &zoneId );
+
+            std::cout << "zoneId = " << zoneId << "\n";
+            std::cout << "zonename = " << zonename << "\n";
+                
+            splitZone->ComputeRminmax();
+
+            SplitZone * rootSplitZone = splitZone->GetRootZone();
+
+            Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+            int ncoords = zone->coors.size();
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = -1;
+                DataType_t dataType = RealDouble;
+                std::string coordname = coordnames[ icoord ];
+                Coor * coor = zone->coors[ icoord ];
+
+                int nNodes = splitZone->dimInfo.ComputeNumNodes();
+                std::cout << "nNodes = " << nNodes << "\n";
+
+                std::vector<char> coord;
+                ComputeCoor( splitZone, icoord, coord );
+
+                cg_coord_write( fileId, baseId, zoneId, dataType, coordname.c_str(), coord.data(), &coorId );
+
+                std::cout << "fileId = " << fileId  << " baseId = " << baseId << " zoneId = " << zoneId  << " coorId = " << coorId << "\n";
+            }
+
+            std::vector< SplitBc * > leafBcList;
+            splitZone->GetLeafBcList( leafBcList );
+            int nLeafBcList = leafBcList.size();
+
+            std::vector< PhysicalSplitBc * > &bccoList = splitZone->physicalSplitBcList;
+
+            int nbocos = bccoList.size();
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = -1;
+                GridLocation_t location = Vertex;
+
+                std::string boconame = "BC" + std::to_string( iboco + 1 );
+
+                PhysicalSplitBc * physicalSplitBc = bccoList[ iboco ];
+                BCType_t bocotype = static_cast<BCType_t>( physicalSplitBc->bcType );
+                PointSetType_t ptset_type = PointRange;
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> pnts;
+                int nSize = physicalSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.end[ i ] );
+                }
+
+                cg_boco_write( fileId, baseId, zoneId, boconame.c_str(), bocotype, ptset_type, npnts, pnts.data(), & bccoId );
+            }
+
+            std::vector< InterfaceSplitBc * > & bc1to1List = splitZone->interfaceSplitBcList;
+
+            int n1to1 = bc1to1List.size();
+            std::cout << "n1to1 = " << n1to1 << "\n";
+
+            std::vector<int> itranfrm( index_dim );
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                itranfrm[ m ] = m + 1;
+            }
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int index_conn = -1;
+
+                InterfaceSplitBc * interfaceSplitBc = bc1to1List[ i1to1 ];
+
+                std::vector<cgsize_t> pnts;
+                std::vector<cgsize_t> pntsdonor;
+                int nSize = interfaceSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.end[ i ] );
+                }
+
+                int nPatchSize = interfaceSplitBc->donor_region.start.size();
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.start[ i ] );
+                }
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.end[ i ] );
+                }
+                int id = interfaceSplitBc->donor_zone->newIndex;
+                int oldZoneIndex = interfaceSplitBc->donor_zone->zoneIndex;
+                std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+                std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+                std::cout << "donor zone id = " << id << "\n";
+                std::cout << "donor zone oldZoneIndex = " << oldZoneIndex << "\n";
+                std::string donorname = "Zone" + std::to_string( id );
+                std::string connectname = "Interface" + std::to_string( i1to1 );
+
+                std::cout << "donorname = " << donorname << "\n";
+                std::cout << "connectname = " << connectname << "\n";
+
+                std::vector<int> & itranfrm = interfaceSplitBc->transform;
+
+                cg_1to1_write( fileId, baseId, zoneId, connectname.c_str(), donorname.c_str(), pnts.data(), pntsdonor.data(), itranfrm.data(), &index_conn );
+                std::cout << "index_conn = " << index_conn << "\n";
+            }
+        }
+    }
+    cg_close( fileId );
+}
+
+void Partition::ModifyZoneIndex()
+{
+    std::cout << "ModifyZoneIndex +++++++++++++++++++++++++ " << "\n";
+    int globalZoneId = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        std::cout << "iProc = " << iProc << "\n";
+        int nZones = this->GetNZones( iProc );
+        std::cout << "nZones in Proc " << iProc << "  = " << nZones << "\n";
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+            //splitZone->SetZoneIndex( globalZoneId++ );
+            splitZone->newIndex = ( globalZoneId++ );
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+        }
+    }
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage1/01f/Partition.h b/example/partition/struct/2d/stage1/01f/Partition.h
new file mode 100644
index 00000000..257548f7
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01f/Partition.h
@@ -0,0 +1,54 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class SplitZone;
+
+class Partition
+{
+public:
+    Partition();
+    ~Partition();
+protected:
+    std::set < SplitZone * > zoneStorage;
+    std::set < SplitZone * > unsignedZoneGroup;
+    std::vector< SplitZone * > refZone;
+    std::vector< std::vector< SplitZone * > > procSplitZone;
+    std::vector<double> procSpeed;
+    std::vector<double> timeProc;
+    double aveFloatOp, delta;
+    double idealUniProcTime, eps;
+    int minNumberCell;
+    int nTZone;
+    int nOriZone;
+    int nProc;
+public:
+    std::string inputName;
+    std::string outName;
+public:
+    void Solve();
+    void ReadGrid();
+    void Split();
+    void InitSplit();
+    void BinarySplit();
+    //void GreedySplit();
+public:
+    void AddNewZone( SplitZone * zone );
+    void AddZoneToUnsignedGroup( SplitZone * zone );
+    void RemoveZoneFromUnsignedGroup( SplitZone * zone );
+    void AddZoneToProcess( int iProc, SplitZone * zone );
+    void DumpPartitionedGridFile();
+    void ModifyZoneIndex();
+    void FreeAllZones();
+    int GetNZones( int iProc );
+    SplitZone * GetSplitZone( int iProc, int zoneId );
+    void ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord );
+    void DumpBc( SplitZone * splitZone );
+private:
+    int GetMinValueIndex( double * data, int numberOfData );
+    int GetMinLoadProc();
+    SplitZone * GetLargestZone();
+    SplitZone * Split( SplitZone * zone, double nCell );
+};
+
diff --git a/example/partition/struct/2d/stage1/01f/README.txt b/example/partition/struct/2d/stage1/01f/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01f/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/partition/struct/2d/stage1/01f/SplitZone.cpp b/example/partition/struct/2d/stage1/01f/SplitZone.cpp
new file mode 100644
index 00000000..09356f6f
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01f/SplitZone.cpp
@@ -0,0 +1,998 @@
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+int Dim::dim = -1;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox  )
+{
+    domainBox.start = zoneBox.start;
+    domainBox.end = zoneBox.end;
+
+    int axis = iDomain / 2;
+    int direction = iDomain % 2;
+
+    if ( direction == 0 )
+    {
+        domainBox.end[ axis ] = domainBox.start[ axis ];
+    }
+    else if ( direction == 1 )
+    {
+        domainBox.start[ axis ] = domainBox.end[ axis ];
+    }
+}
+
+DimInfo::DimInfo()
+{
+    this->Init( 1 );
+}
+
+DimInfo::~DimInfo()
+{
+}
+
+void DimInfo::Init( int dim )
+{
+    this->dim = dim;
+    dimList.resize( this->dim, 1 );
+    oriPoint.resize( this->dim, 0 );
+}
+
+DimInfo & DimInfo::operator = ( const DimInfo & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->dim = rhs.dim;
+    this->dimList = rhs.dimList;
+    this->oriPoint = rhs.oriPoint;
+
+    return * this;
+}
+
+int DimInfo::ComputeNumNodes()
+{
+    int nNodes = 1;
+    for ( int m = 0; m < this->dimList.size(); ++ m )
+    {
+        nNodes *= this->dimList[ m ];
+    }
+    return nNodes;
+}
+
+void DimInfo::ComputeISize()
+{
+    int index_dim = this->dimList.size();
+    this->isize.resize( index_dim * 3, 0 );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        isize[ m ] = this->dimList[ m ];
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 1;
+        isize[ start + m ] = this->dimList[ m ] - 1;
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 2;
+        isize[ start + m ] = 0;
+    }
+
+    for ( int i = 0; i < isize.size(); ++ i )
+    {
+        std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+    }
+}
+
+void DimInfo::ComputeRminmax( std::vector<int> & ref )
+{
+    int index_dim = this->dimList.size();
+    this->rmin.resize( index_dim );
+    this->rmax.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        rmin[ m ] = ref[ m ] + 1;
+        rmax[ m ] = ref[ m ] + this->dimList[ m ];
+    }
+
+    std::cout << "rmin, rmax = \n";
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        std::cout << rmin[ m ] << " " << rmax[ m ] << "\n";
+    }
+}
+
+void DimInfo::Init( std::vector<int> & dimList )
+{
+    this->dim = dimList.size();
+    this->dimList = dimList;
+    std::vector<int> zero( dimList.size(), 0 );
+    this->oriPoint = zero;
+}
+
+void DimInfo::SetNewDimension( int axis, int newStart, int newWidth )
+{
+    this->oriPoint[ axis ] = newStart;
+    this->dimList [ axis ] = newWidth;
+}
+
+void DimInfo::GetZoneGlobalBox( RangeRegion &zoneBox )
+{
+    int index_dim = this->dimList.size();
+    zoneBox.start.resize( index_dim );
+    zoneBox.end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        zoneBox.start[ m ] = this->oriPoint[ m ] + 1;
+        zoneBox.end[ m ] = this->oriPoint[ m ] + this->dimList[ m ];
+    }
+}
+
+void DimInfo::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    int index_dim = this->dimList.size();
+    localBox.start.resize( index_dim );
+    localBox.end.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        localBox.start[ m ] = globalBox.start[ m ] - this->oriPoint[ m ];
+        localBox.end[ m ] = globalBox.end[ m ] - this->oriPoint[ m ];
+    }
+}
+
+RangeRegion::RangeRegion( int nSize )
+{
+    this->Init( nSize );
+}
+
+RangeRegion::~RangeRegion()
+{
+}
+
+void RangeRegion::Init( int nSize )
+{
+    this->start.resize( nSize );
+    this->end.resize( nSize );
+}
+
+RangeRegion & RangeRegion::operator = ( const RangeRegion & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+bool RangeRegion::operator == ( const RangeRegion & rhs ) const
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] != rhs.start[ m ] || 
+            this->end  [ m ] != rhs.end  [ m ] )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+bool RangeRegion::InRegion( const RangeRegion & region )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( ( this->start[ m ] < region.start[ m ] ) || ( this->end[ m ] > region.end[ m ] ) )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::Normalize()
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        int minv = std::min( this->start[ m ], this->end[ m ] );
+        int maxv = std::max( this->start[ m ], this->end[ m ] );
+        this->start[ m ] = minv;
+        this->end[ m ] = maxv;
+    }
+}
+
+void RangeRegion::Localize( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] -= oriPoint[ m ];
+        this->end[ m ] -= oriPoint[ m ];
+    }
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion );
+
+bool ComputeOverlapRegion( RangeRegion & region1, RangeRegion & region2, RangeRegion & overlapRegion )
+{
+    int index_dim = region1.start.size();
+    overlapRegion.Init( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int ijkmin1 = std::min( region1.start[ m ], region1.end[ m ] );
+        int ijkmax1 = std::max( region1.start[ m ], region1.end[ m ] );
+        int ijkmin2 = std::min( region2.start[ m ], region2.end[ m ] );
+        int ijkmax2 = std::max( region2.start[ m ], region2.end[ m ] );
+        if ( ( ijkmax1 < ijkmin2 ) || ( ijkmin1 > ijkmax2 ) )
+        {
+            return false;
+        }
+
+        int ijkmin = std::max( ijkmin1, ijkmin2 );
+        int ijkmax = std::min( ijkmax1, ijkmax2 );
+
+        overlapRegion.start[ m ] = ijkmin;
+        overlapRegion.end  [ m ] = ijkmax;
+    }
+
+    return CheckOverLapping( overlapRegion );
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion )
+{
+    int index_dim = overlapRegion.start.size();
+    int iCount = 0;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        if ( overlapRegion.start[ m ] == overlapRegion.end[ m ] )
+        {
+            ++ iCount;
+        }
+    }
+
+    return ( iCount == 1 );
+}
+
+bool GetInterfaceRegion( RangeRegion & zoneBoxL, RangeRegion & zoneBoxR, RangeRegion & interfaceRegion )
+{
+    int index_dim = zoneBoxL.start.size();
+    int nDomains = 2 * index_dim;
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegionL;
+        GetDomainRegion( zoneBoxL, iDomain, domainRegionL );
+
+        for ( int jDomain = 0; jDomain < nDomains; ++ jDomain )
+        {
+            RangeRegion domainRegionR;
+            GetDomainRegion( zoneBoxR, jDomain, domainRegionR );
+
+            if ( domainRegionL == domainRegionR )
+            {
+                interfaceRegion = domainRegionL;
+                return true;
+            }
+        }
+    }
+    return false;
+}
+
+void CreateInterfaceBc( SplitZone * zoneL, SplitZone * zoneR )
+{
+    RangeRegion globalBoxL, globalBoxR, globalInterfaceRegion;
+
+    zoneL->GetZoneGlobalBox( globalBoxL );
+    zoneR->GetZoneGlobalBox( globalBoxR );
+
+    if ( ! GetInterfaceRegion( globalBoxL, globalBoxR, globalInterfaceRegion ) )
+    {
+        return;
+    }
+
+    RangeRegion localInterfaceRegionL, localInterfaceRegionR;
+
+    zoneL->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionL );
+    zoneR->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionR );
+
+    int kkk = 1;
+
+    InterfaceSplitBc * interfaceSplitBcL = new InterfaceSplitBc();
+    zoneL->interfaceSplitBcList.push_back( interfaceSplitBcL );
+    interfaceSplitBcL->zone = zoneL;
+    interfaceSplitBcL->region = localInterfaceRegionL;
+
+    int nSize = localInterfaceRegionL.start.size();
+
+    std::vector<int> transform;
+
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        transform.push_back( m + 1 );
+    }
+
+    interfaceSplitBcL->transform = transform;
+    interfaceSplitBcL->CalcTransformMatrix();
+
+    interfaceSplitBcL->donor_zone = zoneR;
+    interfaceSplitBcL->donor_region = localInterfaceRegionR;
+
+    InterfaceSplitBc * interfaceSplitBcR = new InterfaceSplitBc();
+    zoneR->interfaceSplitBcList.push_back( interfaceSplitBcR );
+
+    interfaceSplitBcR->zone = zoneR;
+    interfaceSplitBcR->region = localInterfaceRegionR;
+
+    interfaceSplitBcR->transform = transform;
+    interfaceSplitBcR->CalcTransformMatrix();
+
+    interfaceSplitBcR->donor_zone = zoneL;
+    interfaceSplitBcR->donor_region = localInterfaceRegionL;
+}
+
+
+PhysicalSplitBc::PhysicalSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+PhysicalSplitBc::~PhysicalSplitBc()
+{
+}
+
+void PhysicalSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void PhysicalSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+void PhysicalSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = splitZone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+SplitBc::SplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+SplitBc::~SplitBc()
+{
+    delete this->patch;
+}
+
+void SplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void SplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+void SplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = splitZone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void SplitBc::GetLeafBcs( std::vector< SplitBc * > & leafBcs )
+{
+    if ( ! this->child )
+    {
+        leafBcs.push_back( this );
+        return;
+    }
+
+    for ( int i = 0; i < this->child->size(); ++ i )
+    {
+        std::vector< SplitBc * > child_leafBcs;
+        ( * child )[ i ]->GetLeafBcs( child_leafBcs );
+        for ( int j = 0; j < child_leafBcs.size(); ++ j )
+        {
+            leafBcs.push_back( child_leafBcs[ j ] );
+        }
+    }
+
+    return;
+}
+
+SplitBcPatch::SplitBcPatch()
+{
+    this->region.Init( Dim::dim );
+}
+
+SplitBcPatch::~SplitBcPatch()
+{
+}
+
+void SplitBcPatch::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void SplitBcPatch::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+BasicSplitBc::BasicSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+BasicSplitBc::~BasicSplitBc()
+{
+    ;
+}
+
+void BasicSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void BasicSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+int trans::M[ 3 ][ 3 ];
+std::vector<int> trans::transform;
+
+int trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void trans::CalcTransformMatrix()
+{
+    int dim = trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = trans::transform[ 0 ];
+        int sgna = trans::sgn( a );
+        int a1 = trans::del( a, 1 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int c = trans::transform[ 2 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int sgnc = trans::sgn( c );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int a3 = trans::del( a, 3 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        int b3 = trans::del( b, 3 );
+        int c1 = trans::del( c, 1 );
+        int c2 = trans::del( c, 2 );
+        int c3 = trans::del( c, 3 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 2 ][ 0 ] = sgna * a3;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+        trans::M[ 2 ][ 1 ] = sgnb * b3;
+        trans::M[ 0 ][ 2 ] = sgnc * c1;
+        trans::M[ 1 ][ 2 ] = sgnc * c2;
+        trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+InterfaceSplitBc::InterfaceSplitBc()
+{
+    this->region.Init( Dim::dim );
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceSplitBc::~InterfaceSplitBc()
+{
+}
+
+void InterfaceSplitBc::CopyMatrix( InterfaceSplitBc * interfaceSplitBc )
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = interfaceSplitBc->Mt[ i ][ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::CalcTransformMatrix()
+{
+    trans::ZeroMatrix();
+    trans::transform = this->transform;
+    trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = trans::M[ i ][ j ];
+        }
+    }
+
+}
+
+void InterfaceSplitBc::mapindex( std::vector<int> & begin1, std::vector<int> & begin2,  std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = Dim::dim;
+    std::vector<int> diff( dim );
+    for ( int m = 0; m < dim; ++ m )
+    {
+        diff[ m ] = index1[ m ] - begin1[ m ];
+    }
+
+    std::vector<int> mul( dim );
+
+    Multiply( Mt, diff, mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = mul[ m ] + begin2[ m ];
+    }
+}
+
+void InterfaceSplitBc::Multiply( int Mt[][3], std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = Dim::dim;
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = this->zone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void InterfaceSplitBc::CalcSubDonorRegion( RangeRegion &subRegion, RangeRegion &subDonorRegion )
+{
+    std::vector<int> begin1 = this->region.start;
+    std::vector<int> end1 = this->region.end;
+    std::vector<int> begin2 = this->donor_region.start;
+    std::vector<int> end2 = this->donor_region.end;
+
+    std::vector<int> new_begin1 = subRegion.start;
+    std::vector<int> new_end1 = subRegion.end;
+
+    int dim = Dim::dim;
+    std::vector<int> new_begin2( dim );
+    std::vector<int> new_end2( dim );
+
+    mapindex( begin1, begin2, new_begin1, new_begin2 );
+    mapindex( begin1, begin2, new_end1, new_end2 );
+
+    subDonorRegion.start = new_begin2;
+    subDonorRegion.end = new_end2;
+}
+
+SplitZone::SplitZone()
+{
+    this->parent  = 0;
+    this->zoneIndex = 0;
+    this->iProc = 0;
+    dimInfo.Init( Dim::dim );
+    int kk = 1;
+}
+
+SplitZone::~SplitZone()
+{
+    ;
+}
+
+void SplitZone::GetZoneGlobalBox( RangeRegion & zoneBox )
+{
+    this->dimInfo.GetZoneGlobalBox( zoneBox );
+}
+
+void SplitZone::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    this->dimInfo.GetZoneLocalBox( globalBox, localBox );
+}
+
+
+void SplitZone::ComputeRminmax()
+{
+    int index_dim = this->dimInfo.dimList.size();
+    std::vector<int> ref( index_dim, 0 );
+
+    SplitZone * rootSplitZone = 0;
+    this->GetRootInfo( rootSplitZone, ref );
+
+    this->dimInfo.ComputeRminmax( ref );
+}
+
+InterfaceSplitBc * SplitZone::FindDonorInterface( InterfaceSplitBc * interfaceSplitBc )
+{
+    RangeRegion donor_region = interfaceSplitBc->donor_region;
+    donor_region.Normalize();
+    for ( int iInterface = 0; iInterface < interfaceSplitBcList.size(); ++ iInterface )
+    {
+        InterfaceSplitBc * candidateDonorBc = interfaceSplitBcList[ iInterface ];
+        bool flag = donor_region.InRegion( candidateDonorBc->region );
+        if ( flag )
+        {
+            if ( donor_region == candidateDonorBc->region )
+            {
+                return candidateDonorBc;
+            }
+            else
+            {
+                InterfaceSplitBc * donorBc = new InterfaceSplitBc();
+                candidateDonorBc->child.push_back( donorBc );
+                donorBc->region = donor_region;
+                donorBc->zone = candidateDonorBc->zone;
+                donorBc->donor_zone = interfaceSplitBc->zone;
+                donorBc->transform = candidateDonorBc->transform;
+                donorBc->CopyMatrix( candidateDonorBc );
+                RangeRegion subDonorRegion( Dim::dim );
+                candidateDonorBc->CalcSubDonorRegion( donorBc->region, subDonorRegion );
+                std::vector<int> & oriPoint = interfaceSplitBc->zone->dimInfo.oriPoint;
+                subDonorRegion.Localize( oriPoint );
+                donorBc->donor_region = subDonorRegion;
+                donorBc->donor_bc = interfaceSplitBc;
+                return donorBc;
+            }
+        }
+    }
+    return nullptr;
+}
+
+SplitZone * SplitZone::GetRootZone()
+{
+    SplitZone * root = this;
+
+    while ( true )
+    {
+        if ( root->parent )
+        {
+            root = root->parent;
+        }
+        else
+        {
+            return root;
+        }
+    };
+}
+
+void SplitZone::GetRootInfo( SplitZone *& root, std::vector<int> & ref )
+{
+    for ( int i = 0; i < this->dimInfo.dimList.size(); ++ i )
+    {
+        ref[ i ] += this->dimInfo.oriPoint[ i ];
+    }
+
+    if ( this->parent )
+    {
+        this->parent->GetRootInfo( root, ref );
+    }
+    else
+    {
+        root = this;
+    }
+}
+
+
+int SplitZone::GetNCell()
+{
+    int numberOfCells = 1;
+    for ( int i = 0; i < this->dimInfo.dim; ++ i )
+    {
+        numberOfCells *= std::max( 1, ( this->dimInfo.dimList[ i ] - 1 ) );
+    }
+
+    return numberOfCells; 
+}
+
+void SplitZone::GetLeafBcList( std::vector< SplitBc * > & leafBcList )
+{
+    int nSplitBcs = this->splitBcList.size();
+
+    for ( int iSplitBcs = 0; iSplitBcs < nSplitBcs; ++ iSplitBcs )
+    {
+        SplitBc * splitBc = splitBcList[ iSplitBcs ];
+
+        std::vector< SplitBc * > leafBcs;
+        splitBc->GetLeafBcs( leafBcs );
+        for ( int j = 0; j < leafBcs.size(); ++ j )
+        {
+            leafBcList.push_back( leafBcs[ j ] );
+        }
+    }
+}
+
+void SplitZone::SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int leftStart = 0;
+    int leftWidth = iSplit - 0;
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, leftStart , leftWidth  );
+}
+
+void SplitZone::SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int rightStart = iSplit - 1;
+    int rightWidth = dimList[ axisNeedSplit ] - ( iSplit - 1 );
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, rightStart, rightWidth );
+}
+
+void SplitZone::Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell )
+{
+    //Find the longest axis
+    int axisNeedSplit = this->FindAxisNeedSplit();
+    int iSplit        = this->FindSplitPosition( axisNeedSplit, nCell );
+
+    zoneL->SetLeftDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+    zoneR->SetRightDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+
+    zoneL->CreateBcFromParent();
+    zoneR->CreateBcFromParent();
+    
+    CreateInterfaceBc( zoneL, zoneR );
+}
+
+void SplitZone::CreateBcFromParent()
+{
+    this->CreatePhysicalBcFromParent();
+    this->CreateInterfaceBcFromParent();
+}
+
+void SplitZone::CreatePhysicalBcFromParent()
+{
+    int nParentPhysicalBcs = this->parent->physicalSplitBcList.size();
+
+    for ( int iParentPhysicalBcs = 0; iParentPhysicalBcs < nParentPhysicalBcs; ++ iParentPhysicalBcs )
+    {
+        PhysicalSplitBc * parentPhysicalSplitBc = this->parent->physicalSplitBcList[ iParentPhysicalBcs ];
+
+        this->CreatePhysicalBcFromParent( parentPhysicalSplitBc );
+    }
+}
+
+void SplitZone::CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentPhysicalSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreatePhysicalBc( overlapRegion, parentPhysicalSplitBc->bcType );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent()
+{
+    int nInterfaceSplitBcs = this->parent->interfaceSplitBcList.size();
+
+    for ( int iInterfaceSplitBcs = 0; iInterfaceSplitBcs < nInterfaceSplitBcs; ++ iInterfaceSplitBcs )
+    {
+        InterfaceSplitBc * parentInterfaceSplitBc = this->parent->interfaceSplitBcList[ iInterfaceSplitBcs ];
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc );
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentInterfaceSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc, overlapRegion );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion )
+{
+    InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+    interfaceSplitBc->region = overlapRegion;
+    interfaceSplitBc->zone = this;
+    interfaceSplitBc->donor_zone = parentInterfaceSplitBc->donor_zone;
+    interfaceSplitBc->CopyMatrix( parentInterfaceSplitBc );
+    RangeRegion subDonorRegion( Dim::dim );
+    parentInterfaceSplitBc->CalcSubDonorRegion( overlapRegion, subDonorRegion );
+    interfaceSplitBc->ChangeRegionToLocalCoordinate();
+    interfaceSplitBc->donor_region = subDonorRegion;
+
+    SplitZone * donor_zone = interfaceSplitBc->donor_zone;
+    interfaceSplitBc->donor_bc = donor_zone->FindDonorInterface( interfaceSplitBc );
+    int kkk = 1;
+}
+
+void SplitZone::AddSplitBc( SplitBc * splitBc )
+{
+    if ( ! splitBc ) return;
+    this->splitBcList.push_back( splitBc );
+}
+
+
+void SplitZone::CreatePhysicalBc( RangeRegion & overlapRegion, int bcType )
+{
+    PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+    this->physicalSplitBcList.push_back( physicalSplitBc );
+    physicalSplitBc->SetRegion( overlapRegion );
+    physicalSplitBc->bcType = bcType;
+    physicalSplitBc->splitZone = this;
+    physicalSplitBc->ChangeRegionToLocalCoordinate();
+}
+
+int SplitZone::FindAxisNeedSplit()
+{
+    //Find the longest axis
+    int axisNeedSplit = 0;
+    int maxN = this->dimInfo.dimList[ 0 ];
+
+    for ( int m = 1; m < this->dimInfo.dimList.size(); ++ m )
+    {
+        if ( this->IsPoleBc( m ) )
+        {
+            continue;
+        }
+        int Nm = this->dimInfo.dimList[ m ];
+        if ( maxN < Nm )
+        {
+            maxN = Nm;
+            axisNeedSplit = m;
+        }
+    }
+
+    return axisNeedSplit;
+}
+
+int SplitZone::GetCrossSection( int axis )
+{
+    int nDim = this->dimInfo.dimList.size();
+    int crossSection = 1;
+    int N = nDim - 1;
+    for ( int m = 0; m < N; ++ m )
+    {
+         int mm = ( axis + 1 ) % nDim;
+         int nLineElements = std::max( 1, ( this->dimInfo.dimList[ mm ] - 1 ) );
+         crossSection *= nLineElements;
+    }
+    return crossSection;
+}
+
+int SplitZone::FindSplitPosition( int axisNeedSplit, double nCell )
+{
+    int nDim = this->dimInfo.dimList.size();
+    std::vector<int> crossSections( nDim );
+    for ( int m = 0; m < nDim; ++ m )
+    {
+        crossSections[ m ] = this->GetCrossSection( m );
+    }
+
+    //guess the value
+    double dSplit = nCell / crossSections[ axisNeedSplit ];
+    int  iSplit = 1 + static_cast< int >( std::floor( dSplit + 0.5 ) );
+    return iSplit;
+}
+
+
+bool SplitZone::IsPoleBc( int splitDirection )
+{
+    return false;
+}
+
diff --git a/example/partition/struct/2d/stage1/01f/SplitZone.h b/example/partition/struct/2d/stage1/01f/SplitZone.h
new file mode 100644
index 00000000..a78207bf
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01f/SplitZone.h
@@ -0,0 +1,212 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class Dim
+{
+public:
+    static int dim;
+};
+
+class SplitZone;
+class RangeRegion;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox );
+
+class DimInfo
+{
+public:
+    DimInfo();
+    ~DimInfo();
+public:
+    int dim;
+    std::vector<int> dimList;
+    std::vector<int> oriPoint;
+    std::vector<int> isize;
+    std::vector<int> rmin;
+    std::vector<int> rmax;
+public:
+    int GetSize() const { return dim; }
+    DimInfo & operator = ( const DimInfo & rhs );
+public:
+    int ComputeNumNodes();
+    void ComputeISize();
+    void ComputeRminmax( std::vector<int> & ref );
+    void Init( int dim );
+    void Init( std::vector<int> & dimList );
+    void SetNewDimension( int axis, int newStart, int newWidth );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+};
+
+class SplitZone;
+class SplitBcPatch;
+
+class RangeRegion
+{
+public:
+    RangeRegion( int nSize = 1 );
+    ~RangeRegion();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    void Init( int nSize );
+    RangeRegion & operator = ( const RangeRegion & rhs );
+    bool operator == ( const RangeRegion & rhs ) const;
+    bool InRegion( const RangeRegion & region );
+    void SetRegion( std::vector<int> &pnts );
+    void Normalize();
+    void Localize( std::vector<int> & oriPoint );
+};
+
+class PhysicalSplitBc
+{
+public:
+    PhysicalSplitBc();
+    ~PhysicalSplitBc();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class SplitBc
+{
+public:
+    SplitBc();
+    ~SplitBc();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone = nullptr;
+    SplitBcPatch * patch = nullptr;
+    std::vector< SplitBc * > * child = nullptr;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+    void ChangeRegionToLocalCoordinate();
+public:
+    void GetLeafBcs( std::vector< SplitBc * > & leafBcs );
+};
+
+class SplitBcPatch
+{
+public:
+    SplitBcPatch ();
+    ~SplitBcPatch();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+};
+
+class BasicSplitBc
+{
+public:
+    BasicSplitBc();
+    ~BasicSplitBc();
+public:
+    RangeRegion region;
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> & pnts );
+    void SetRegion( RangeRegion & region );
+};
+
+class trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class InterfaceSplitBc
+{
+public:
+    InterfaceSplitBc();
+    ~InterfaceSplitBc();
+public:
+    std::vector<int> transform;
+    int Mt[ 3 ][ 3 ];
+    RangeRegion region;
+    SplitZone * zone = nullptr;
+    RangeRegion donor_region;
+    SplitZone * donor_zone = nullptr;
+    InterfaceSplitBc * donor_bc = nullptr;
+public:
+    std::vector<InterfaceSplitBc *> child;
+public:
+    void CopyMatrix( InterfaceSplitBc * interfaceSplitBc );
+    void CalcTransformMatrix();
+    void CalcSubDonorRegion( RangeRegion & subRegion, RangeRegion & subDonorRegion );
+    void mapindex( std::vector<int> & begin1, std::vector<int> & begin2, std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( int Mt[][ 3 ], std::vector<int> & a, std::vector<int> & b );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class SplitZone
+{
+public:
+    SplitZone();
+    ~SplitZone();
+public:
+    DimInfo dimInfo;
+    int zoneIndex, iProc;
+    int newIndex;
+protected:
+    SplitZone * parent;
+public:
+    std::vector< SplitBc * > splitBcList;
+    std::vector< PhysicalSplitBc * > physicalSplitBcList;
+    std::vector< InterfaceSplitBc * > interfaceSplitBcList;
+public:
+    int GetNCell();
+    void ComputeRminmax();
+    void GetRootInfo( SplitZone *& root, std::vector<int> & ref );
+    void SetZoneIndex( int zoneIndex ) { this->zoneIndex = zoneIndex; }
+    int  GetZoneIndex() { return zoneIndex; }
+    void SetProcId( int iProc ) { this->iProc = iProc; }
+    void SetParent( SplitZone * parent ) { this->parent = parent; };
+    std::vector< SplitBc * > & GetSplitBcList() { return this->splitBcList; };
+    InterfaceSplitBc * FindDonorInterface( InterfaceSplitBc * interfaceSplitBc );
+public:
+    void CreateBcFromParent();
+    void CreatePhysicalBcFromParent();
+    void CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc );
+    void CreatePhysicalBc( RangeRegion & overlapRegion, int bcType );
+    void CreateInterfaceBcFromParent();
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc );
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion );
+
+    void AddSplitBc( SplitBc * splitBc );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+    SplitZone * GetRootZone();
+    void GetLeafBcList( std::vector< SplitBc * > & leafBcList );
+public:
+    void Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell );
+    void SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+    void SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+private:
+    int FindAxisNeedSplit();
+    int FindSplitPosition( int axisNeedSplit, double nCell );
+    bool IsPoleBc( int splitDirection );
+    int GetCrossSection( int axis );
+};
+
diff --git a/example/partition/struct/2d/stage1/01f/heat2d2blocks.cgns b/example/partition/struct/2d/stage1/01f/heat2d2blocks.cgns
new file mode 100644
index 00000000..ab4dcea5
Binary files /dev/null and b/example/partition/struct/2d/stage1/01f/heat2d2blocks.cgns differ
diff --git a/example/partition/struct/2d/stage1/01f/main.cpp b/example/partition/struct/2d/stage1/01f/main.cpp
new file mode 100644
index 00000000..5da1de7c
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01f/main.cpp
@@ -0,0 +1,18 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include "Partition.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip>
+
+int main(int argc, char **argv)
+{
+    Partition * partition = new Partition();
+    partition->Solve();
+    delete partition;
+
+    return 0;
+}
diff --git a/example/partition/struct/2d/stage1/01g/CMakeLists.txt b/example/partition/struct/2d/stage1/01g/CMakeLists.txt
new file mode 100644
index 00000000..74ceea7d
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01g/CMakeLists.txt
@@ -0,0 +1,78 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	Partition.h Partition.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	SplitZone.h SplitZone.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/partition/struct/2d/stage1/01g/CgnsGrid.cpp b/example/partition/struct/2d/stage1/01g/CgnsGrid.cpp
new file mode 100644
index 00000000..dfe750bd
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01g/CgnsGrid.cpp
@@ -0,0 +1,349 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include <map>
+
+Grid::Grid()
+{
+    ;
+}
+
+Grid::~Grid()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if( (i+1)%5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+    delete this->patch;
+}
+
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+ZoneBcPatch::ZoneBcPatch()
+{
+    ;
+}
+
+ZoneBcPatch::~ZoneBcPatch()
+{
+}
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+Global::Global()
+{
+    ;
+}
+
+Global::~Global()
+{
+}
+
+void Global::FreeData()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+    zones.resize( 0 );
+}
+
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            //baseZone.baseId = baseId;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin( index_dim );
+            std::vector<cgsize_t> irmax( index_dim );
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                std::vector<char> coord( nNodes * sizeof(double) );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+                coor->DumpCoor();
+            }
+
+            int nbocos = -1;
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+                int kkk = 1;
+            }
+        }
+        int kkk = 1;
+    }
+    int kkk = 1;
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage1/01g/CgnsGrid.h b/example/partition/struct/2d/stage1/01g/CgnsGrid.h
new file mode 100644
index 00000000..053c467b
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01g/CgnsGrid.h
@@ -0,0 +1,140 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <map>
+
+class Grid;
+
+class Zone;
+
+class Grid
+{
+public:
+    Grid();
+    ~Grid();
+public:
+    int nZone;
+    std::vector<double> x;
+    std::vector<Zone *> zones;
+};
+
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+};
+
+class ZoneBc;
+class ZoneBc1To1;
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class ZoneBcPatch;
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+    ZoneBcPatch * patch = nullptr;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+class ZoneBcPatch
+{
+public:
+    ZoneBcPatch();
+    ~ZoneBcPatch();
+public:
+    int donor_zoneid;
+    std::vector<int> transform;
+    std::vector<int> donor_pnts;
+};
+
+class BaseZone
+{
+public:
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Global
+{
+public:
+    Global();
+    ~Global();
+public:
+    static int cell_dim;
+    static int phys_dim;
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+public:
+    static void FreeData();
+};
+
+void ReadCgnsGrid( const std::string & filename );
+void ReadCgnsGridBaseZone( const std::string & filename );
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage1/01g/Partition.cpp b/example/partition/struct/2d/stage1/01g/Partition.cpp
new file mode 100644
index 00000000..344fcb5b
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01g/Partition.cpp
@@ -0,0 +1,612 @@
+#include "Partition.h"
+#include "CgnsGrid.h"
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+double CalSumOfProcSpeed( std::vector<double> & procSpeed );
+double CalSumOfProcSpeed( std::vector<double> & procSpeed )
+{
+    int nProc = procSpeed.size();
+    double sumOfProcSpeed = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        sumOfProcSpeed += procSpeed[ iProc ];
+    }
+    return sumOfProcSpeed;
+}
+
+Partition::Partition()
+{
+    this->inputName = "../heat2d2blocks.cgns";
+    this->outName =  "../heat2dpart.cgns";
+}
+
+Partition::~Partition()
+{
+    ;
+}
+
+int Partition::GetMinValueIndex( double * data, int numberOfData )
+{
+    double minValue = data[ 0 ];
+    int minimumValueIndex = 0;
+
+    for ( int iData = 1; iData < numberOfData; ++ iData )
+    {
+        if ( minValue > data[ iData ] )
+        {
+            minValue      = data[ iData ];
+            minimumValueIndex = iData;
+        }
+    }
+    return minimumValueIndex;
+}
+
+int Partition::GetMinLoadProc()
+{
+    return this->GetMinValueIndex( this->timeProc.data(), this->nProc );
+}
+
+SplitZone * Partition::GetLargestZone()
+{
+    SplitZone * largestZone = 0;
+
+    double nMaxCell = 0.0;
+
+    for ( std::set< SplitZone * >::iterator iter = unsignedZoneGroup.begin(); iter != unsignedZoneGroup.end(); ++ iter )
+    {
+        double nSize = ( * iter )->GetNCell();
+        if ( nMaxCell < nSize )
+        {
+            nMaxCell    = nSize;
+            largestZone = * iter;
+        }
+    }
+
+    return largestZone;
+}
+
+void Partition::Solve()
+{
+    std::cout << "Partition::Split()\n";
+    //this->nProc = 2;
+    this->nProc = 4;
+    this->ReadGrid();
+    this->Split();
+    this->DumpPartitionedGridFile();
+    this->FreeAllZones();
+}
+
+void Partition::ReadGrid()
+{
+    ReadCgnsGridBaseZone( this->inputName );
+    ReadCgnsGrid( this->inputName );
+
+    this->nOriZone = ::Global::zones.size();
+    Dim::dim = Global::cell_dim;
+
+    std::cout << "numberOfBlocks = " << nOriZone << "\n";
+
+    this->refZone.resize( nOriZone );
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = new SplitZone();
+        refZone[ iZone ] = splitZone;
+
+        splitZone->SetZoneIndex( iZone );
+        splitZone->SetProcId( 0 );
+        splitZone->SetParent( 0 );
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        Zone * zone = ::Global::zones[ iZone ];
+
+        splitZone->dimInfo.dimList = zone->nijk;
+
+        int nbccos = zone->bccos.size();
+        std::cout << "nbccos = " << nbccos << "\n";
+
+        for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+        {
+            ZoneBc * zoneBc = zone->bccos[ ibcco ];
+
+            PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+            splitZone->physicalSplitBcList.push_back( physicalSplitBc );
+            physicalSplitBc->bcType = zoneBc->bcType;
+            physicalSplitBc->SetRegion( zoneBc->pnts );
+            physicalSplitBc->splitZone = splitZone;
+        }
+
+        int nbc1to1s = zone->bc1to1s.size();
+
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * zoneBc1To1 = zone->bc1to1s[ ibc1to1 ];
+
+            InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+            splitZone->interfaceSplitBcList.push_back( interfaceSplitBc );
+            interfaceSplitBc->zone = splitZone;
+            interfaceSplitBc->region.SetRegion( zoneBc1To1->pnts );
+
+            interfaceSplitBc->transform = zoneBc1To1->transform;
+            interfaceSplitBc->CalcTransformMatrix();
+
+            interfaceSplitBc->donor_zone = refZone[ zoneBc1To1->donor_zoneid ];
+            interfaceSplitBc->donor_region.SetRegion( zoneBc1To1->donor_pnts );
+        }
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        int nbc1to1s = splitZone->interfaceSplitBcList.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            InterfaceSplitBc * interfaceSplitBc = splitZone->interfaceSplitBcList[ ibc1to1 ];
+            InterfaceSplitBc * donorInterface = interfaceSplitBc->donor_zone->FindDonorInterface( interfaceSplitBc );
+            interfaceSplitBc->donor_bc = donorInterface;
+        }
+    }
+}
+
+void Partition::Split()
+{
+    this->InitSplit();
+    this->BinarySplit();
+    this->ModifyZoneIndex();
+    int kkk = 1;
+}
+
+void Partition::InitSplit()
+{
+    //nZone is the number of zones in the original grid
+    //nProc is not the number of blocks in the end, but the number of processes that need to be divided.
+    //This difference occurs because the structure grid can have many blocks per process.
+
+    //this->nProc    = nProc;
+    //this->nPhyBlocks = referenceBlock.size();
+    //this->nZone  = this->nPhyBlocks;
+
+    //tj Computation time on processor j
+    //Nk Number of internal grid-cells for zone j
+    //aveFloatOp:  Number of Real operations per gridcell
+    //Gj The set of blocks allocated to process j
+    //Pj Real operations per second for process j
+
+    //The Greedy Load Balancing Algorithm
+    //1.Compute an "ideal" uniprocessor time, Tuni = sum ( Nk * aveFloatOp )/ sum( Pj ).
+    //2.Set the group of unassigned blocks, Gu, to contain all blocks. The number of blocks in Nu=M, where M is the total number of blocks in the mesh.
+    //3.Start all processors with a very small fictitious zone to get a start tj=delt aveFloatOp/Pj, where delt<<1 is the size of the very small fictious zone.
+    //This is used to find the fastest processor in a heterogeneous system, tj could otherwise be set to 0 in the homogeneous case.
+    this->aveFloatOp = 1.0;
+    this->delta      = 1.0e-5;
+    this->procSpeed.resize( nProc );
+    this->timeProc.resize( nProc );
+
+    this->nTZone = this->nOriZone;
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        procSpeed[ iProc ] = 1.0;
+    }
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        timeProc[ iProc ] = delta * aveFloatOp / procSpeed[ iProc ];
+    }
+
+    double sumProcSpeed = CalSumOfProcSpeed( procSpeed );
+
+    double sumProcOp = 0.0;
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        sumProcOp += refZone[ iZone ]->GetNCell() * aveFloatOp;
+    }
+
+    this->idealUniProcTime = sumProcOp / sumProcSpeed;
+
+    this->eps = 0.05;
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        unsignedZoneGroup.insert( refZone[ iZone ] );
+    }
+
+    //Init zoneStorage
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        zoneStorage.insert( refZone[ iZone ] );
+    }
+
+    //Assign procSplitZone to each process
+    procSplitZone.resize( nProc );
+
+    this->minNumberCell = 1;
+    for ( int m = 0; m < Dim::dim; ++ m )
+    {
+        this->minNumberCell *= 1;
+    }
+
+    int kkk = 1;
+
+}
+
+void Partition::FreeAllZones()
+{
+    int iCount = 0;
+    for ( std::set < SplitZone * >::iterator iter = zoneStorage.begin(); iter != zoneStorage.end(); ++ iter )
+    {
+        //cout << "iCount = " << iCount << "\n";
+        ++ iCount;
+        delete * iter;
+    }
+}
+
+int Partition::GetNZones( int iProc )
+{
+    return this->procSplitZone[ iProc ].size();
+}
+
+SplitZone * Partition::GetSplitZone( int iProc, int zoneId )
+{
+    return this->procSplitZone[ iProc ][ zoneId ];
+}
+
+void Partition::AddZoneToUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.insert( zone );
+}
+
+void Partition::RemoveZoneFromUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.erase( zone );
+}
+
+void Partition::AddZoneToProcess( int iProc, SplitZone * zone )
+{
+    this->procSplitZone[ iProc ].push_back( zone );
+}
+
+void Partition::AddNewZone( SplitZone * zone )
+{
+    zone->SetZoneIndex( nTZone ++ );
+
+    this->AddZoneToUnsignedGroup( zone );
+
+    this->zoneStorage.insert( zone );
+}
+
+SplitZone * Partition::Split( SplitZone * zone, double nCell )
+{
+    SplitZone * zoneL = new SplitZone();
+    zoneL->SetParent( zone );
+
+    SplitZone * zoneR = new SplitZone();
+    zoneR->SetParent( zone );
+
+    //Remove the original block from the UnsignedGroup
+    this->RemoveZoneFromUnsignedGroup( zone );
+
+    this->AddNewZone( zoneL );
+    this->AddNewZone( zoneR );
+
+    zone->Split( zoneL, zoneR, nCell );
+
+    return zoneL;
+}
+
+void Partition::BinarySplit()
+{
+    while ( ! unsignedZoneGroup.empty() )
+    {
+        std::cout << "number of unsigned zone = " << unsignedZoneGroup.size() << "\n";
+        int iProc = this->GetMinLoadProc();
+
+        //Get the block with the largest number of grids and its size
+        SplitZone * largestZone = this->GetLargestZone();
+
+        double nMaxCell = largestZone->GetNCell();
+
+        double aveFloatOp = this->aveFloatOp;
+        double tau = timeProc[ iProc ] + nMaxCell * aveFloatOp / procSpeed[ iProc ];
+
+        int kkk = 1;
+
+        //It seems that EPS is still necessary
+        //The idea here is as follows. For the candidate blocks which can be divided into blocks, 
+        //if the difference between the target blocks and the candidate blocks is too wide, 
+        //the binarySplit method is adopted. The binarySplit blocks do not directly join the process,
+        //but enter the next round of screening.
+
+        if ( tau > idealUniProcTime * ( 1.0 + eps ) )
+        {
+            double nRest = ( tau - idealUniProcTime ) * procSpeed[ iProc ] / aveFloatOp;
+
+            double nTarget = nMaxCell - nRest;
+            if ( nRest > this->minNumberCell && nTarget > this->minNumberCell )
+            {
+                //It is necessary to divide blocks only when a certain number of points are satisfied.
+                double nHalf = nMaxCell / 2.0;
+                nMaxCell = nTarget;
+                double ratio = nMaxCell / nRest;
+                double oRatio = 1.0 / ratio;
+
+                if ( std::max( ratio, oRatio ) < 3.0 )
+                {
+                    int kkk = 1;
+                    largestZone = this->Split( largestZone, nMaxCell );
+                    timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                    this->RemoveZoneFromUnsignedGroup( largestZone );
+                    this->AddZoneToProcess( iProc, largestZone );
+                }
+                else
+                {
+                    this->Split( largestZone, nHalf );
+                }
+            }
+            else
+            {
+                //If the block is of the right size, join the process directly, and there is no need to split it.
+                timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                this->RemoveZoneFromUnsignedGroup( largestZone );
+                this->AddZoneToProcess( iProc, largestZone );
+            }
+        }
+        else
+        {
+            //If the block is of the right size, join the process directly, and there is no need to split it.
+            timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+            this->RemoveZoneFromUnsignedGroup( largestZone );
+            this->AddZoneToProcess( iProc, largestZone );
+        }
+    }
+}
+
+void Partition::ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord )
+{
+    SplitZone * rootSplitZone = splitZone->GetRootZone();
+    Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+    int nNodes = splitZone->dimInfo.ComputeNumNodes();
+    std::cout << "nNodes = " << nNodes << "\n";
+
+    coord.resize( nNodes * sizeof(double) );
+
+    int index_dim = splitZone->dimInfo.dimList.size();
+    Coor * coor = zone->coors[ icoord ];
+
+    double * xlocal = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    double * xglobal = reinterpret_cast<double *>( const_cast<char *>( coor->coord.data() ) );
+    if ( index_dim == 1 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        for ( int i = imin; i < imax; ++ i )
+        {
+            xlocal[ icount++ ] = xglobal[ i ];
+        }
+    }
+    else if ( index_dim == 2 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        int jmin = splitZone->dimInfo.rmin[ 1 ] - 1;
+        int jmax = splitZone->dimInfo.rmax[ 1 ];
+        int ni = rootSplitZone->dimInfo.dimList[ 0 ];
+        int nj = rootSplitZone->dimInfo.dimList[ 1 ];
+        for ( int j = jmin; j < jmax; ++ j )
+        {
+            int jstride = j * ni;
+            for ( int i = imin; i < imax; ++ i )
+            {
+                xlocal[ icount++ ] = xglobal[ jstride + i ];
+            }
+        }
+    }
+}
+
+void Partition::DumpBc( SplitZone * splitZone )
+{
+}
+
+void Partition::DumpPartitionedGridFile()
+{
+    std::cout << "\n";
+    std::cout << "DumpPartitionedGridFile -------------------------------" << "\n";
+    std::cout << "\n";
+    int fileId = -1;
+    std::string filename = this->outName;
+    int ierr = cg_open( filename.c_str(), CG_MODE_WRITE, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+
+    std::vector<std::string> coordnames;
+    coordnames.push_back( "CoordinateX" );
+    coordnames.push_back( "CoordinateY" );
+    coordnames.push_back( "CoordinateZ" );
+
+    std::string basename = "Base";
+    int baseId = -1;
+    int icelldim = Global::cell_dim;
+    int iphysdim = Global::phys_dim;
+    cg_base_write( fileId, basename.c_str(), icelldim, iphysdim, &baseId );
+
+    std::cout << "baseId = " << baseId << "\n";
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        int nZones = this->GetNZones( iProc );
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            ZoneType_t zoneType = Structured;
+
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+
+            int index_dim = splitZone->dimInfo.dimList.size();
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            splitZone->dimInfo.ComputeISize();
+
+            int isize_dim = index_dim * 3;
+
+            std::vector<cgsize_t> isize( index_dim * 3, 0 );
+            for ( int m = 0; m < isize_dim; ++ m )
+            {
+                isize[ m ] = splitZone->dimInfo.isize[ m ];
+            }
+
+            int zoneId = -1;
+
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+
+            std::string zonename = "Zone" + std::to_string( splitZone->newIndex );
+
+            cg_zone_write( fileId, baseId, zonename.c_str(), isize.data(), zoneType, &zoneId );
+
+            std::cout << "zoneId = " << zoneId << "\n";
+            std::cout << "zonename = " << zonename << "\n";
+                
+            splitZone->ComputeRminmax();
+
+            SplitZone * rootSplitZone = splitZone->GetRootZone();
+
+            Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+            int ncoords = zone->coors.size();
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = -1;
+                DataType_t dataType = RealDouble;
+                std::string coordname = coordnames[ icoord ];
+                Coor * coor = zone->coors[ icoord ];
+
+                int nNodes = splitZone->dimInfo.ComputeNumNodes();
+                std::cout << "nNodes = " << nNodes << "\n";
+
+                std::vector<char> coord;
+                ComputeCoor( splitZone, icoord, coord );
+
+                cg_coord_write( fileId, baseId, zoneId, dataType, coordname.c_str(), coord.data(), &coorId );
+
+                std::cout << "fileId = " << fileId  << " baseId = " << baseId << " zoneId = " << zoneId  << " coorId = " << coorId << "\n";
+            }
+
+            std::vector< PhysicalSplitBc * > &bccoList = splitZone->physicalSplitBcList;
+
+            int nbocos = bccoList.size();
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = -1;
+                GridLocation_t location = Vertex;
+
+                std::string boconame = "BC" + std::to_string( iboco + 1 );
+
+                PhysicalSplitBc * physicalSplitBc = bccoList[ iboco ];
+                BCType_t bocotype = static_cast<BCType_t>( physicalSplitBc->bcType );
+                PointSetType_t ptset_type = PointRange;
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> pnts;
+                int nSize = physicalSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.end[ i ] );
+                }
+
+                cg_boco_write( fileId, baseId, zoneId, boconame.c_str(), bocotype, ptset_type, npnts, pnts.data(), & bccoId );
+            }
+
+            std::vector< InterfaceSplitBc * > & bc1to1List = splitZone->interfaceSplitBcList;
+
+            int n1to1 = bc1to1List.size();
+            std::cout << "n1to1 = " << n1to1 << "\n";
+
+            std::vector<int> itranfrm( index_dim );
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                itranfrm[ m ] = m + 1;
+            }
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int index_conn = -1;
+
+                InterfaceSplitBc * interfaceSplitBc = bc1to1List[ i1to1 ];
+
+                std::vector<cgsize_t> pnts;
+                std::vector<cgsize_t> pntsdonor;
+                int nSize = interfaceSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.end[ i ] );
+                }
+
+                int nPatchSize = interfaceSplitBc->donor_region.start.size();
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.start[ i ] );
+                }
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.end[ i ] );
+                }
+                int id = interfaceSplitBc->donor_zone->newIndex;
+                int oldZoneIndex = interfaceSplitBc->donor_zone->zoneIndex;
+                std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+                std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+                std::cout << "donor zone id = " << id << "\n";
+                std::cout << "donor zone oldZoneIndex = " << oldZoneIndex << "\n";
+                std::string donorname = "Zone" + std::to_string( id );
+                std::string connectname = "Interface" + std::to_string( i1to1 );
+
+                std::cout << "donorname = " << donorname << "\n";
+                std::cout << "connectname = " << connectname << "\n";
+
+                std::vector<int> & itranfrm = interfaceSplitBc->transform;
+
+                cg_1to1_write( fileId, baseId, zoneId, connectname.c_str(), donorname.c_str(), pnts.data(), pntsdonor.data(), itranfrm.data(), &index_conn );
+                std::cout << "index_conn = " << index_conn << "\n";
+            }
+        }
+    }
+    cg_close( fileId );
+}
+
+void Partition::ModifyZoneIndex()
+{
+    std::cout << "ModifyZoneIndex +++++++++++++++++++++++++ " << "\n";
+    int globalZoneId = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        std::cout << "iProc = " << iProc << "\n";
+        int nZones = this->GetNZones( iProc );
+        std::cout << "nZones in Proc " << iProc << "  = " << nZones << "\n";
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+            //splitZone->SetZoneIndex( globalZoneId++ );
+            splitZone->newIndex = ( globalZoneId++ );
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+        }
+    }
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage1/01g/Partition.h b/example/partition/struct/2d/stage1/01g/Partition.h
new file mode 100644
index 00000000..257548f7
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01g/Partition.h
@@ -0,0 +1,54 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class SplitZone;
+
+class Partition
+{
+public:
+    Partition();
+    ~Partition();
+protected:
+    std::set < SplitZone * > zoneStorage;
+    std::set < SplitZone * > unsignedZoneGroup;
+    std::vector< SplitZone * > refZone;
+    std::vector< std::vector< SplitZone * > > procSplitZone;
+    std::vector<double> procSpeed;
+    std::vector<double> timeProc;
+    double aveFloatOp, delta;
+    double idealUniProcTime, eps;
+    int minNumberCell;
+    int nTZone;
+    int nOriZone;
+    int nProc;
+public:
+    std::string inputName;
+    std::string outName;
+public:
+    void Solve();
+    void ReadGrid();
+    void Split();
+    void InitSplit();
+    void BinarySplit();
+    //void GreedySplit();
+public:
+    void AddNewZone( SplitZone * zone );
+    void AddZoneToUnsignedGroup( SplitZone * zone );
+    void RemoveZoneFromUnsignedGroup( SplitZone * zone );
+    void AddZoneToProcess( int iProc, SplitZone * zone );
+    void DumpPartitionedGridFile();
+    void ModifyZoneIndex();
+    void FreeAllZones();
+    int GetNZones( int iProc );
+    SplitZone * GetSplitZone( int iProc, int zoneId );
+    void ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord );
+    void DumpBc( SplitZone * splitZone );
+private:
+    int GetMinValueIndex( double * data, int numberOfData );
+    int GetMinLoadProc();
+    SplitZone * GetLargestZone();
+    SplitZone * Split( SplitZone * zone, double nCell );
+};
+
diff --git a/example/partition/struct/2d/stage1/01g/README.txt b/example/partition/struct/2d/stage1/01g/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01g/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/partition/struct/2d/stage1/01g/SplitZone.cpp b/example/partition/struct/2d/stage1/01g/SplitZone.cpp
new file mode 100644
index 00000000..1168656d
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01g/SplitZone.cpp
@@ -0,0 +1,903 @@
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+int Dim::dim = -1;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox  )
+{
+    domainBox.start = zoneBox.start;
+    domainBox.end = zoneBox.end;
+
+    int axis = iDomain / 2;
+    int direction = iDomain % 2;
+
+    if ( direction == 0 )
+    {
+        domainBox.end[ axis ] = domainBox.start[ axis ];
+    }
+    else if ( direction == 1 )
+    {
+        domainBox.start[ axis ] = domainBox.end[ axis ];
+    }
+}
+
+DimInfo::DimInfo()
+{
+    this->Init( 1 );
+}
+
+DimInfo::~DimInfo()
+{
+}
+
+void DimInfo::Init( int dim )
+{
+    this->dim = dim;
+    dimList.resize( this->dim, 1 );
+    oriPoint.resize( this->dim, 0 );
+}
+
+DimInfo & DimInfo::operator = ( const DimInfo & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->dim = rhs.dim;
+    this->dimList = rhs.dimList;
+    this->oriPoint = rhs.oriPoint;
+
+    return * this;
+}
+
+int DimInfo::ComputeNumNodes()
+{
+    int nNodes = 1;
+    for ( int m = 0; m < this->dimList.size(); ++ m )
+    {
+        nNodes *= this->dimList[ m ];
+    }
+    return nNodes;
+}
+
+void DimInfo::ComputeISize()
+{
+    int index_dim = this->dimList.size();
+    this->isize.resize( index_dim * 3, 0 );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        isize[ m ] = this->dimList[ m ];
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 1;
+        isize[ start + m ] = this->dimList[ m ] - 1;
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 2;
+        isize[ start + m ] = 0;
+    }
+
+    for ( int i = 0; i < isize.size(); ++ i )
+    {
+        std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+    }
+}
+
+void DimInfo::ComputeRminmax( std::vector<int> & ref )
+{
+    int index_dim = this->dimList.size();
+    this->rmin.resize( index_dim );
+    this->rmax.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        rmin[ m ] = ref[ m ] + 1;
+        rmax[ m ] = ref[ m ] + this->dimList[ m ];
+    }
+
+    std::cout << "rmin, rmax = \n";
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        std::cout << rmin[ m ] << " " << rmax[ m ] << "\n";
+    }
+}
+
+void DimInfo::Init( std::vector<int> & dimList )
+{
+    this->dim = dimList.size();
+    this->dimList = dimList;
+    std::vector<int> zero( dimList.size(), 0 );
+    this->oriPoint = zero;
+}
+
+void DimInfo::SetNewDimension( int axis, int newStart, int newWidth )
+{
+    this->oriPoint[ axis ] = newStart;
+    this->dimList [ axis ] = newWidth;
+}
+
+void DimInfo::GetZoneGlobalBox( RangeRegion &zoneBox )
+{
+    int index_dim = this->dimList.size();
+    zoneBox.start.resize( index_dim );
+    zoneBox.end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        zoneBox.start[ m ] = this->oriPoint[ m ] + 1;
+        zoneBox.end[ m ] = this->oriPoint[ m ] + this->dimList[ m ];
+    }
+}
+
+void DimInfo::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    int index_dim = this->dimList.size();
+    localBox.start.resize( index_dim );
+    localBox.end.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        localBox.start[ m ] = globalBox.start[ m ] - this->oriPoint[ m ];
+        localBox.end[ m ] = globalBox.end[ m ] - this->oriPoint[ m ];
+    }
+}
+
+RangeRegion::RangeRegion( int nSize )
+{
+    this->Init( nSize );
+}
+
+RangeRegion::~RangeRegion()
+{
+}
+
+void RangeRegion::Init( int nSize )
+{
+    this->start.resize( nSize );
+    this->end.resize( nSize );
+}
+
+RangeRegion & RangeRegion::operator = ( const RangeRegion & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+bool RangeRegion::operator == ( const RangeRegion & rhs ) const
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] != rhs.start[ m ] || 
+            this->end  [ m ] != rhs.end  [ m ] )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+bool RangeRegion::InRegion( const RangeRegion & region )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( ( this->start[ m ] < region.start[ m ] ) || ( this->end[ m ] > region.end[ m ] ) )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::Normalize()
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        int minv = std::min( this->start[ m ], this->end[ m ] );
+        int maxv = std::max( this->start[ m ], this->end[ m ] );
+        this->start[ m ] = minv;
+        this->end[ m ] = maxv;
+    }
+}
+
+void RangeRegion::Localize( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] -= oriPoint[ m ];
+        this->end[ m ] -= oriPoint[ m ];
+    }
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion );
+
+bool ComputeOverlapRegion( RangeRegion & region1, RangeRegion & region2, RangeRegion & overlapRegion )
+{
+    int index_dim = region1.start.size();
+    overlapRegion.Init( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int ijkmin1 = std::min( region1.start[ m ], region1.end[ m ] );
+        int ijkmax1 = std::max( region1.start[ m ], region1.end[ m ] );
+        int ijkmin2 = std::min( region2.start[ m ], region2.end[ m ] );
+        int ijkmax2 = std::max( region2.start[ m ], region2.end[ m ] );
+        if ( ( ijkmax1 < ijkmin2 ) || ( ijkmin1 > ijkmax2 ) )
+        {
+            return false;
+        }
+
+        int ijkmin = std::max( ijkmin1, ijkmin2 );
+        int ijkmax = std::min( ijkmax1, ijkmax2 );
+
+        overlapRegion.start[ m ] = ijkmin;
+        overlapRegion.end  [ m ] = ijkmax;
+    }
+
+    return CheckOverLapping( overlapRegion );
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion )
+{
+    int index_dim = overlapRegion.start.size();
+    int iCount = 0;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        if ( overlapRegion.start[ m ] == overlapRegion.end[ m ] )
+        {
+            ++ iCount;
+        }
+    }
+
+    return ( iCount == 1 );
+}
+
+bool GetInterfaceRegion( RangeRegion & zoneBoxL, RangeRegion & zoneBoxR, RangeRegion & interfaceRegion )
+{
+    int index_dim = zoneBoxL.start.size();
+    int nDomains = 2 * index_dim;
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegionL;
+        GetDomainRegion( zoneBoxL, iDomain, domainRegionL );
+
+        for ( int jDomain = 0; jDomain < nDomains; ++ jDomain )
+        {
+            RangeRegion domainRegionR;
+            GetDomainRegion( zoneBoxR, jDomain, domainRegionR );
+
+            if ( domainRegionL == domainRegionR )
+            {
+                interfaceRegion = domainRegionL;
+                return true;
+            }
+        }
+    }
+    return false;
+}
+
+void CreateInterfaceBc( SplitZone * zoneL, SplitZone * zoneR )
+{
+    RangeRegion globalBoxL, globalBoxR, globalInterfaceRegion;
+
+    zoneL->GetZoneGlobalBox( globalBoxL );
+    zoneR->GetZoneGlobalBox( globalBoxR );
+
+    if ( ! GetInterfaceRegion( globalBoxL, globalBoxR, globalInterfaceRegion ) )
+    {
+        return;
+    }
+
+    RangeRegion localInterfaceRegionL, localInterfaceRegionR;
+
+    zoneL->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionL );
+    zoneR->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionR );
+
+    int kkk = 1;
+
+    InterfaceSplitBc * interfaceSplitBcL = new InterfaceSplitBc();
+    zoneL->interfaceSplitBcList.push_back( interfaceSplitBcL );
+    interfaceSplitBcL->zone = zoneL;
+    interfaceSplitBcL->region = localInterfaceRegionL;
+
+    int nSize = localInterfaceRegionL.start.size();
+
+    std::vector<int> transform;
+
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        transform.push_back( m + 1 );
+    }
+
+    interfaceSplitBcL->transform = transform;
+    interfaceSplitBcL->CalcTransformMatrix();
+
+    interfaceSplitBcL->donor_zone = zoneR;
+    interfaceSplitBcL->donor_region = localInterfaceRegionR;
+
+    InterfaceSplitBc * interfaceSplitBcR = new InterfaceSplitBc();
+    zoneR->interfaceSplitBcList.push_back( interfaceSplitBcR );
+
+    interfaceSplitBcR->zone = zoneR;
+    interfaceSplitBcR->region = localInterfaceRegionR;
+
+    interfaceSplitBcR->transform = transform;
+    interfaceSplitBcR->CalcTransformMatrix();
+
+    interfaceSplitBcR->donor_zone = zoneL;
+    interfaceSplitBcR->donor_region = localInterfaceRegionL;
+}
+
+
+PhysicalSplitBc::PhysicalSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+PhysicalSplitBc::~PhysicalSplitBc()
+{
+}
+
+void PhysicalSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void PhysicalSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+void PhysicalSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = splitZone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+BasicSplitBc::BasicSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+BasicSplitBc::~BasicSplitBc()
+{
+    ;
+}
+
+void BasicSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void BasicSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+int trans::M[ 3 ][ 3 ];
+std::vector<int> trans::transform;
+
+int trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void trans::CalcTransformMatrix()
+{
+    int dim = trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = trans::transform[ 0 ];
+        int sgna = trans::sgn( a );
+        int a1 = trans::del( a, 1 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int c = trans::transform[ 2 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int sgnc = trans::sgn( c );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int a3 = trans::del( a, 3 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        int b3 = trans::del( b, 3 );
+        int c1 = trans::del( c, 1 );
+        int c2 = trans::del( c, 2 );
+        int c3 = trans::del( c, 3 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 2 ][ 0 ] = sgna * a3;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+        trans::M[ 2 ][ 1 ] = sgnb * b3;
+        trans::M[ 0 ][ 2 ] = sgnc * c1;
+        trans::M[ 1 ][ 2 ] = sgnc * c2;
+        trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+InterfaceSplitBc::InterfaceSplitBc()
+{
+    this->region.Init( Dim::dim );
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceSplitBc::~InterfaceSplitBc()
+{
+}
+
+void InterfaceSplitBc::CopyMatrix( InterfaceSplitBc * interfaceSplitBc )
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = interfaceSplitBc->Mt[ i ][ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::CalcTransformMatrix()
+{
+    trans::ZeroMatrix();
+    trans::transform = this->transform;
+    trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = trans::M[ i ][ j ];
+        }
+    }
+
+}
+
+void InterfaceSplitBc::mapindex( std::vector<int> & begin1, std::vector<int> & begin2,  std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = Dim::dim;
+    std::vector<int> diff( dim );
+    for ( int m = 0; m < dim; ++ m )
+    {
+        diff[ m ] = index1[ m ] - begin1[ m ];
+    }
+
+    std::vector<int> mul( dim );
+
+    Multiply( Mt, diff, mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = mul[ m ] + begin2[ m ];
+    }
+}
+
+void InterfaceSplitBc::Multiply( int Mt[][3], std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = Dim::dim;
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = this->zone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void InterfaceSplitBc::CalcSubDonorRegion( RangeRegion &subRegion, RangeRegion &subDonorRegion )
+{
+    std::vector<int> begin1 = this->region.start;
+    std::vector<int> end1 = this->region.end;
+    std::vector<int> begin2 = this->donor_region.start;
+    std::vector<int> end2 = this->donor_region.end;
+
+    std::vector<int> new_begin1 = subRegion.start;
+    std::vector<int> new_end1 = subRegion.end;
+
+    int dim = Dim::dim;
+    std::vector<int> new_begin2( dim );
+    std::vector<int> new_end2( dim );
+
+    mapindex( begin1, begin2, new_begin1, new_begin2 );
+    mapindex( begin1, begin2, new_end1, new_end2 );
+
+    subDonorRegion.start = new_begin2;
+    subDonorRegion.end = new_end2;
+}
+
+SplitZone::SplitZone()
+{
+    this->parent  = 0;
+    this->zoneIndex = 0;
+    this->iProc = 0;
+    dimInfo.Init( Dim::dim );
+    int kk = 1;
+}
+
+SplitZone::~SplitZone()
+{
+    ;
+}
+
+void SplitZone::GetZoneGlobalBox( RangeRegion & zoneBox )
+{
+    this->dimInfo.GetZoneGlobalBox( zoneBox );
+}
+
+void SplitZone::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    this->dimInfo.GetZoneLocalBox( globalBox, localBox );
+}
+
+
+void SplitZone::ComputeRminmax()
+{
+    int index_dim = this->dimInfo.dimList.size();
+    std::vector<int> ref( index_dim, 0 );
+
+    SplitZone * rootSplitZone = 0;
+    this->GetRootInfo( rootSplitZone, ref );
+
+    this->dimInfo.ComputeRminmax( ref );
+}
+
+InterfaceSplitBc * SplitZone::FindDonorInterface( InterfaceSplitBc * interfaceSplitBc )
+{
+    RangeRegion donor_region = interfaceSplitBc->donor_region;
+    donor_region.Normalize();
+    for ( int iInterface = 0; iInterface < interfaceSplitBcList.size(); ++ iInterface )
+    {
+        InterfaceSplitBc * candidateDonorBc = interfaceSplitBcList[ iInterface ];
+        bool flag = donor_region.InRegion( candidateDonorBc->region );
+        if ( flag )
+        {
+            if ( donor_region == candidateDonorBc->region )
+            {
+                return candidateDonorBc;
+            }
+            else
+            {
+                InterfaceSplitBc * donorBc = new InterfaceSplitBc();
+                candidateDonorBc->child.push_back( donorBc );
+                donorBc->region = donor_region;
+                donorBc->zone = candidateDonorBc->zone;
+                donorBc->donor_zone = interfaceSplitBc->zone;
+                donorBc->transform = candidateDonorBc->transform;
+                donorBc->CopyMatrix( candidateDonorBc );
+                RangeRegion subDonorRegion( Dim::dim );
+                candidateDonorBc->CalcSubDonorRegion( donorBc->region, subDonorRegion );
+                std::vector<int> & oriPoint = interfaceSplitBc->zone->dimInfo.oriPoint;
+                subDonorRegion.Localize( oriPoint );
+                donorBc->donor_region = subDonorRegion;
+                donorBc->donor_bc = interfaceSplitBc;
+                return donorBc;
+            }
+        }
+    }
+    return nullptr;
+}
+
+SplitZone * SplitZone::GetRootZone()
+{
+    SplitZone * root = this;
+
+    while ( true )
+    {
+        if ( root->parent )
+        {
+            root = root->parent;
+        }
+        else
+        {
+            return root;
+        }
+    };
+}
+
+void SplitZone::GetRootInfo( SplitZone *& root, std::vector<int> & ref )
+{
+    for ( int i = 0; i < this->dimInfo.dimList.size(); ++ i )
+    {
+        ref[ i ] += this->dimInfo.oriPoint[ i ];
+    }
+
+    if ( this->parent )
+    {
+        this->parent->GetRootInfo( root, ref );
+    }
+    else
+    {
+        root = this;
+    }
+}
+
+
+int SplitZone::GetNCell()
+{
+    int numberOfCells = 1;
+    for ( int i = 0; i < this->dimInfo.dim; ++ i )
+    {
+        numberOfCells *= std::max( 1, ( this->dimInfo.dimList[ i ] - 1 ) );
+    }
+
+    return numberOfCells; 
+}
+
+void SplitZone::SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int leftStart = 0;
+    int leftWidth = iSplit - 0;
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, leftStart , leftWidth  );
+}
+
+void SplitZone::SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int rightStart = iSplit - 1;
+    int rightWidth = dimList[ axisNeedSplit ] - ( iSplit - 1 );
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, rightStart, rightWidth );
+}
+
+void SplitZone::Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell )
+{
+    //Find the longest axis
+    int axisNeedSplit = this->FindAxisNeedSplit();
+    int iSplit        = this->FindSplitPosition( axisNeedSplit, nCell );
+
+    zoneL->SetLeftDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+    zoneR->SetRightDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+
+    zoneL->CreateBcFromParent();
+    zoneR->CreateBcFromParent();
+    
+    CreateInterfaceBc( zoneL, zoneR );
+}
+
+void SplitZone::CreateBcFromParent()
+{
+    this->CreatePhysicalBcFromParent();
+    this->CreateInterfaceBcFromParent();
+}
+
+void SplitZone::CreatePhysicalBcFromParent()
+{
+    int nParentPhysicalBcs = this->parent->physicalSplitBcList.size();
+
+    for ( int iParentPhysicalBcs = 0; iParentPhysicalBcs < nParentPhysicalBcs; ++ iParentPhysicalBcs )
+    {
+        PhysicalSplitBc * parentPhysicalSplitBc = this->parent->physicalSplitBcList[ iParentPhysicalBcs ];
+
+        this->CreatePhysicalBcFromParent( parentPhysicalSplitBc );
+    }
+}
+
+void SplitZone::CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentPhysicalSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreatePhysicalBc( overlapRegion, parentPhysicalSplitBc->bcType );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent()
+{
+    int nInterfaceSplitBcs = this->parent->interfaceSplitBcList.size();
+
+    for ( int iInterfaceSplitBcs = 0; iInterfaceSplitBcs < nInterfaceSplitBcs; ++ iInterfaceSplitBcs )
+    {
+        InterfaceSplitBc * parentInterfaceSplitBc = this->parent->interfaceSplitBcList[ iInterfaceSplitBcs ];
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc );
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentInterfaceSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc, overlapRegion );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion )
+{
+    InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+    interfaceSplitBc->region = overlapRegion;
+    interfaceSplitBc->zone = this;
+    interfaceSplitBc->donor_zone = parentInterfaceSplitBc->donor_zone;
+    interfaceSplitBc->CopyMatrix( parentInterfaceSplitBc );
+    RangeRegion subDonorRegion( Dim::dim );
+    parentInterfaceSplitBc->CalcSubDonorRegion( overlapRegion, subDonorRegion );
+    interfaceSplitBc->ChangeRegionToLocalCoordinate();
+    interfaceSplitBc->donor_region = subDonorRegion;
+
+    SplitZone * donor_zone = interfaceSplitBc->donor_zone;
+    interfaceSplitBc->donor_bc = donor_zone->FindDonorInterface( interfaceSplitBc );
+    int kkk = 1;
+}
+
+void SplitZone::CreatePhysicalBc( RangeRegion & overlapRegion, int bcType )
+{
+    PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+    this->physicalSplitBcList.push_back( physicalSplitBc );
+    physicalSplitBc->SetRegion( overlapRegion );
+    physicalSplitBc->bcType = bcType;
+    physicalSplitBc->splitZone = this;
+    physicalSplitBc->ChangeRegionToLocalCoordinate();
+}
+
+int SplitZone::FindAxisNeedSplit()
+{
+    //Find the longest axis
+    int axisNeedSplit = 0;
+    int maxN = this->dimInfo.dimList[ 0 ];
+
+    for ( int m = 1; m < this->dimInfo.dimList.size(); ++ m )
+    {
+        if ( this->IsPoleBc( m ) )
+        {
+            continue;
+        }
+        int Nm = this->dimInfo.dimList[ m ];
+        if ( maxN < Nm )
+        {
+            maxN = Nm;
+            axisNeedSplit = m;
+        }
+    }
+
+    return axisNeedSplit;
+}
+
+int SplitZone::GetCrossSection( int axis )
+{
+    int nDim = this->dimInfo.dimList.size();
+    int crossSection = 1;
+    int N = nDim - 1;
+    for ( int m = 0; m < N; ++ m )
+    {
+         int mm = ( axis + 1 ) % nDim;
+         int nLineElements = std::max( 1, ( this->dimInfo.dimList[ mm ] - 1 ) );
+         crossSection *= nLineElements;
+    }
+    return crossSection;
+}
+
+int SplitZone::FindSplitPosition( int axisNeedSplit, double nCell )
+{
+    int nDim = this->dimInfo.dimList.size();
+    std::vector<int> crossSections( nDim );
+    for ( int m = 0; m < nDim; ++ m )
+    {
+        crossSections[ m ] = this->GetCrossSection( m );
+    }
+
+    //guess the value
+    double dSplit = nCell / crossSections[ axisNeedSplit ];
+    int  iSplit = 1 + static_cast< int >( std::floor( dSplit + 0.5 ) );
+    return iSplit;
+}
+
+
+bool SplitZone::IsPoleBc( int splitDirection )
+{
+    return false;
+}
+
diff --git a/example/partition/struct/2d/stage1/01g/SplitZone.h b/example/partition/struct/2d/stage1/01g/SplitZone.h
new file mode 100644
index 00000000..4c7ae07c
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01g/SplitZone.h
@@ -0,0 +1,173 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class Dim
+{
+public:
+    static int dim;
+};
+
+class SplitZone;
+class RangeRegion;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox );
+
+class DimInfo
+{
+public:
+    DimInfo();
+    ~DimInfo();
+public:
+    int dim;
+    std::vector<int> dimList;
+    std::vector<int> oriPoint;
+    std::vector<int> isize;
+    std::vector<int> rmin;
+    std::vector<int> rmax;
+public:
+    int GetSize() const { return dim; }
+    DimInfo & operator = ( const DimInfo & rhs );
+public:
+    int ComputeNumNodes();
+    void ComputeISize();
+    void ComputeRminmax( std::vector<int> & ref );
+    void Init( int dim );
+    void Init( std::vector<int> & dimList );
+    void SetNewDimension( int axis, int newStart, int newWidth );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+};
+
+class SplitZone;
+class SplitBcPatch;
+
+class RangeRegion
+{
+public:
+    RangeRegion( int nSize = 1 );
+    ~RangeRegion();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    void Init( int nSize );
+    RangeRegion & operator = ( const RangeRegion & rhs );
+    bool operator == ( const RangeRegion & rhs ) const;
+    bool InRegion( const RangeRegion & region );
+    void SetRegion( std::vector<int> &pnts );
+    void Normalize();
+    void Localize( std::vector<int> & oriPoint );
+};
+
+class PhysicalSplitBc
+{
+public:
+    PhysicalSplitBc();
+    ~PhysicalSplitBc();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class BasicSplitBc
+{
+public:
+    BasicSplitBc();
+    ~BasicSplitBc();
+public:
+    RangeRegion region;
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> & pnts );
+    void SetRegion( RangeRegion & region );
+};
+
+class trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class InterfaceSplitBc
+{
+public:
+    InterfaceSplitBc();
+    ~InterfaceSplitBc();
+public:
+    std::vector<int> transform;
+    int Mt[ 3 ][ 3 ];
+    RangeRegion region;
+    SplitZone * zone = nullptr;
+    RangeRegion donor_region;
+    SplitZone * donor_zone = nullptr;
+    InterfaceSplitBc * donor_bc = nullptr;
+public:
+    std::vector<InterfaceSplitBc *> child;
+public:
+    void CopyMatrix( InterfaceSplitBc * interfaceSplitBc );
+    void CalcTransformMatrix();
+    void CalcSubDonorRegion( RangeRegion & subRegion, RangeRegion & subDonorRegion );
+    void mapindex( std::vector<int> & begin1, std::vector<int> & begin2, std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( int Mt[][ 3 ], std::vector<int> & a, std::vector<int> & b );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class SplitZone
+{
+public:
+    SplitZone();
+    ~SplitZone();
+public:
+    DimInfo dimInfo;
+    int zoneIndex, iProc;
+    int newIndex;
+protected:
+    SplitZone * parent;
+public:
+    std::vector< PhysicalSplitBc * > physicalSplitBcList;
+    std::vector< InterfaceSplitBc * > interfaceSplitBcList;
+public:
+    int GetNCell();
+    void ComputeRminmax();
+    void GetRootInfo( SplitZone *& root, std::vector<int> & ref );
+    void SetZoneIndex( int zoneIndex ) { this->zoneIndex = zoneIndex; }
+    int  GetZoneIndex() { return zoneIndex; }
+    void SetProcId( int iProc ) { this->iProc = iProc; }
+    void SetParent( SplitZone * parent ) { this->parent = parent; };
+    InterfaceSplitBc * FindDonorInterface( InterfaceSplitBc * interfaceSplitBc );
+public:
+    void CreateBcFromParent();
+    void CreatePhysicalBcFromParent();
+    void CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc );
+    void CreatePhysicalBc( RangeRegion & overlapRegion, int bcType );
+    void CreateInterfaceBcFromParent();
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc );
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion );
+
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+    SplitZone * GetRootZone();
+public:
+    void Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell );
+    void SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+    void SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+private:
+    int FindAxisNeedSplit();
+    int FindSplitPosition( int axisNeedSplit, double nCell );
+    bool IsPoleBc( int splitDirection );
+    int GetCrossSection( int axis );
+};
+
diff --git a/example/partition/struct/2d/stage1/01g/heat2d2blocks.cgns b/example/partition/struct/2d/stage1/01g/heat2d2blocks.cgns
new file mode 100644
index 00000000..ab4dcea5
Binary files /dev/null and b/example/partition/struct/2d/stage1/01g/heat2d2blocks.cgns differ
diff --git a/example/partition/struct/2d/stage1/01g/main.cpp b/example/partition/struct/2d/stage1/01g/main.cpp
new file mode 100644
index 00000000..5da1de7c
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01g/main.cpp
@@ -0,0 +1,18 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include "Partition.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip>
+
+int main(int argc, char **argv)
+{
+    Partition * partition = new Partition();
+    partition->Solve();
+    delete partition;
+
+    return 0;
+}
diff --git a/example/partition/struct/2d/stage1/01h/CMakeLists.txt b/example/partition/struct/2d/stage1/01h/CMakeLists.txt
new file mode 100644
index 00000000..74ceea7d
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01h/CMakeLists.txt
@@ -0,0 +1,78 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	Partition.h Partition.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	SplitZone.h SplitZone.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/partition/struct/2d/stage1/01h/CgnsGrid.cpp b/example/partition/struct/2d/stage1/01h/CgnsGrid.cpp
new file mode 100644
index 00000000..dfe750bd
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01h/CgnsGrid.cpp
@@ -0,0 +1,349 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include <map>
+
+Grid::Grid()
+{
+    ;
+}
+
+Grid::~Grid()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if( (i+1)%5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+    delete this->patch;
+}
+
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+ZoneBcPatch::ZoneBcPatch()
+{
+    ;
+}
+
+ZoneBcPatch::~ZoneBcPatch()
+{
+}
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+Global::Global()
+{
+    ;
+}
+
+Global::~Global()
+{
+}
+
+void Global::FreeData()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+    zones.resize( 0 );
+}
+
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            //baseZone.baseId = baseId;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin( index_dim );
+            std::vector<cgsize_t> irmax( index_dim );
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                std::vector<char> coord( nNodes * sizeof(double) );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+                coor->DumpCoor();
+            }
+
+            int nbocos = -1;
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+                int kkk = 1;
+            }
+        }
+        int kkk = 1;
+    }
+    int kkk = 1;
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage1/01h/CgnsGrid.h b/example/partition/struct/2d/stage1/01h/CgnsGrid.h
new file mode 100644
index 00000000..053c467b
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01h/CgnsGrid.h
@@ -0,0 +1,140 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <map>
+
+class Grid;
+
+class Zone;
+
+class Grid
+{
+public:
+    Grid();
+    ~Grid();
+public:
+    int nZone;
+    std::vector<double> x;
+    std::vector<Zone *> zones;
+};
+
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+};
+
+class ZoneBc;
+class ZoneBc1To1;
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class ZoneBcPatch;
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+    ZoneBcPatch * patch = nullptr;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+class ZoneBcPatch
+{
+public:
+    ZoneBcPatch();
+    ~ZoneBcPatch();
+public:
+    int donor_zoneid;
+    std::vector<int> transform;
+    std::vector<int> donor_pnts;
+};
+
+class BaseZone
+{
+public:
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Global
+{
+public:
+    Global();
+    ~Global();
+public:
+    static int cell_dim;
+    static int phys_dim;
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+public:
+    static void FreeData();
+};
+
+void ReadCgnsGrid( const std::string & filename );
+void ReadCgnsGridBaseZone( const std::string & filename );
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage1/01h/Partition.cpp b/example/partition/struct/2d/stage1/01h/Partition.cpp
new file mode 100644
index 00000000..77a9fb3a
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01h/Partition.cpp
@@ -0,0 +1,616 @@
+#include "Partition.h"
+#include "CgnsGrid.h"
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+bool CmpSplitZone::operator() ( SplitZone * a, SplitZone * b ) const
+{
+    return a->zoneIndex < b->zoneIndex;
+};
+
+
+double CalSumOfProcSpeed( std::vector<double> & procSpeed );
+double CalSumOfProcSpeed( std::vector<double> & procSpeed )
+{
+    int nProc = procSpeed.size();
+    double sumOfProcSpeed = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        sumOfProcSpeed += procSpeed[ iProc ];
+    }
+    return sumOfProcSpeed;
+}
+
+Partition::Partition()
+{
+    this->inputName = "../heat2d2blocks.cgns";
+    this->outName =  "../heat2dpart.cgns";
+}
+
+Partition::~Partition()
+{
+    ;
+}
+
+int Partition::GetMinValueIndex( double * data, int numberOfData )
+{
+    double minValue = data[ 0 ];
+    int minimumValueIndex = 0;
+
+    for ( int iData = 1; iData < numberOfData; ++ iData )
+    {
+        if ( minValue > data[ iData ] )
+        {
+            minValue      = data[ iData ];
+            minimumValueIndex = iData;
+        }
+    }
+    return minimumValueIndex;
+}
+
+int Partition::GetMinLoadProc()
+{
+    return this->GetMinValueIndex( this->timeProc.data(), this->nProc );
+}
+
+SplitZone * Partition::GetLargestZone()
+{
+    SplitZone * largestZone = 0;
+
+    double nMaxCell = 0.0;
+
+    for ( std::set< SplitZone * >::iterator iter = unsignedZoneGroup.begin(); iter != unsignedZoneGroup.end(); ++ iter )
+    {
+        double nSize = ( * iter )->GetNCell();
+        if ( nMaxCell < nSize )
+        {
+            nMaxCell    = nSize;
+            largestZone = * iter;
+        }
+    }
+
+    return largestZone;
+}
+
+void Partition::Solve()
+{
+    std::cout << "Partition::Split()\n";
+    //this->nProc = 2;
+    this->nProc = 4;
+    this->ReadGrid();
+    this->Split();
+    this->DumpPartitionedGridFile();
+    this->FreeAllZones();
+}
+
+void Partition::ReadGrid()
+{
+    ReadCgnsGridBaseZone( this->inputName );
+    ReadCgnsGrid( this->inputName );
+
+    this->nOriZone = ::Global::zones.size();
+    Dim::dim = Global::cell_dim;
+
+    std::cout << "numberOfBlocks = " << nOriZone << "\n";
+
+    this->refZone.resize( nOriZone );
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = new SplitZone();
+        refZone[ iZone ] = splitZone;
+
+        splitZone->SetZoneIndex( iZone );
+        splitZone->SetProcId( 0 );
+        splitZone->SetParentAndChild( 0 );
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        Zone * zone = ::Global::zones[ iZone ];
+
+        splitZone->dimInfo.dimList = zone->nijk;
+
+        int nbccos = zone->bccos.size();
+        std::cout << "nbccos = " << nbccos << "\n";
+
+        for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+        {
+            ZoneBc * zoneBc = zone->bccos[ ibcco ];
+
+            PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+            splitZone->physicalSplitBcList.push_back( physicalSplitBc );
+            physicalSplitBc->bcType = zoneBc->bcType;
+            physicalSplitBc->SetRegion( zoneBc->pnts );
+            physicalSplitBc->splitZone = splitZone;
+        }
+
+        int nbc1to1s = zone->bc1to1s.size();
+
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * zoneBc1To1 = zone->bc1to1s[ ibc1to1 ];
+
+            InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+            splitZone->interfaceSplitBcList.push_back( interfaceSplitBc );
+            interfaceSplitBc->zone = splitZone;
+            interfaceSplitBc->region.SetRegion( zoneBc1To1->pnts );
+
+            interfaceSplitBc->transform = zoneBc1To1->transform;
+            interfaceSplitBc->CalcTransformMatrix();
+
+            interfaceSplitBc->donor_zone = refZone[ zoneBc1To1->donor_zoneid ];
+            interfaceSplitBc->donor_region.SetRegion( zoneBc1To1->donor_pnts );
+        }
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        int nbc1to1s = splitZone->interfaceSplitBcList.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            InterfaceSplitBc * interfaceSplitBc = splitZone->interfaceSplitBcList[ ibc1to1 ];
+            InterfaceSplitBc * donorInterface = interfaceSplitBc->donor_zone->FindDonorInterface( interfaceSplitBc );
+            interfaceSplitBc->donor_bc = donorInterface;
+        }
+    }
+}
+
+void Partition::Split()
+{
+    this->InitSplit();
+    this->BinarySplit();
+    this->ModifyZoneIndex();
+    int kkk = 1;
+}
+
+void Partition::InitSplit()
+{
+    //nZone is the number of zones in the original grid
+    //nProc is not the number of blocks in the end, but the number of processes that need to be divided.
+    //This difference occurs because the structure grid can have many blocks per process.
+
+    //this->nProc    = nProc;
+    //this->nPhyBlocks = referenceBlock.size();
+    //this->nZone  = this->nPhyBlocks;
+
+    //tj Computation time on processor j
+    //Nk Number of internal grid-cells for zone j
+    //aveFloatOp:  Number of Real operations per gridcell
+    //Gj The set of blocks allocated to process j
+    //Pj Real operations per second for process j
+
+    //The Greedy Load Balancing Algorithm
+    //1.Compute an "ideal" uniprocessor time, Tuni = sum ( Nk * aveFloatOp )/ sum( Pj ).
+    //2.Set the group of unassigned blocks, Gu, to contain all blocks. The number of blocks in Nu=M, where M is the total number of blocks in the mesh.
+    //3.Start all processors with a very small fictitious zone to get a start tj=delt aveFloatOp/Pj, where delt<<1 is the size of the very small fictious zone.
+    //This is used to find the fastest processor in a heterogeneous system, tj could otherwise be set to 0 in the homogeneous case.
+    this->aveFloatOp = 1.0;
+    this->delta      = 1.0e-5;
+    this->procSpeed.resize( nProc );
+    this->timeProc.resize( nProc );
+
+    this->nTZone = this->nOriZone;
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        procSpeed[ iProc ] = 1.0;
+    }
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        timeProc[ iProc ] = delta * aveFloatOp / procSpeed[ iProc ];
+    }
+
+    double sumProcSpeed = CalSumOfProcSpeed( procSpeed );
+
+    double sumProcOp = 0.0;
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        sumProcOp += refZone[ iZone ]->GetNCell() * aveFloatOp;
+    }
+
+    this->idealUniProcTime = sumProcOp / sumProcSpeed;
+
+    this->eps = 0.05;
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        unsignedZoneGroup.insert( refZone[ iZone ] );
+    }
+
+    //Init zoneStorage
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        zoneStorage.insert( refZone[ iZone ] );
+    }
+
+    //Assign procSplitZone to each process
+    procSplitZone.resize( nProc );
+
+    this->minNumberCell = 1;
+    for ( int m = 0; m < Dim::dim; ++ m )
+    {
+        this->minNumberCell *= 1;
+    }
+
+    int kkk = 1;
+
+}
+
+void Partition::FreeAllZones()
+{
+    int iCount = 0;
+    for ( std::set < SplitZone * >::iterator iter = zoneStorage.begin(); iter != zoneStorage.end(); ++ iter )
+    {
+        //cout << "iCount = " << iCount << "\n";
+        ++ iCount;
+        delete * iter;
+    }
+}
+
+int Partition::GetNZones( int iProc )
+{
+    return this->procSplitZone[ iProc ].size();
+}
+
+SplitZone * Partition::GetSplitZone( int iProc, int zoneId )
+{
+    return this->procSplitZone[ iProc ][ zoneId ];
+}
+
+void Partition::AddZoneToUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.insert( zone );
+}
+
+void Partition::RemoveZoneFromUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.erase( zone );
+}
+
+void Partition::AddZoneToProcess( int iProc, SplitZone * zone )
+{
+    this->procSplitZone[ iProc ].push_back( zone );
+}
+
+void Partition::AddNewZone( SplitZone * zone )
+{
+    zone->SetZoneIndex( nTZone ++ );
+
+    this->AddZoneToUnsignedGroup( zone );
+
+    this->zoneStorage.insert( zone );
+}
+
+SplitZone * Partition::Split( SplitZone * zone, double nCell )
+{
+    SplitZone * zoneL = new SplitZone();
+    zoneL->SetParentAndChild( zone );
+
+    SplitZone * zoneR = new SplitZone();
+    zoneR->SetParentAndChild( zone );
+
+    //Remove the original block from the UnsignedGroup
+    this->RemoveZoneFromUnsignedGroup( zone );
+
+    this->AddNewZone( zoneL );
+    this->AddNewZone( zoneR );
+
+    zone->Split( zoneL, zoneR, nCell );
+
+    return zoneL;
+}
+
+void Partition::BinarySplit()
+{
+    while ( ! unsignedZoneGroup.empty() )
+    {
+        std::cout << "number of unsigned zone = " << unsignedZoneGroup.size() << "\n";
+        int iProc = this->GetMinLoadProc();
+
+        //Get the block with the largest number of grids and its size
+        SplitZone * largestZone = this->GetLargestZone();
+
+        double nMaxCell = largestZone->GetNCell();
+
+        double aveFloatOp = this->aveFloatOp;
+        double tau = timeProc[ iProc ] + nMaxCell * aveFloatOp / procSpeed[ iProc ];
+
+        //It seems that EPS is still necessary
+        //The idea here is as follows. For the candidate blocks which can be divided into blocks, 
+        //if the difference between the target blocks and the candidate blocks is too wide, 
+        //the binarySplit method is adopted. The binarySplit blocks do not directly join the process,
+        //but enter the next round of screening.
+
+        if ( tau > idealUniProcTime * ( 1.0 + eps ) )
+        {
+            double nRest = ( tau - idealUniProcTime ) * procSpeed[ iProc ] / aveFloatOp;
+
+            double nTarget = nMaxCell - nRest;
+            if ( nRest > this->minNumberCell && nTarget > this->minNumberCell )
+            {
+                //It is necessary to divide blocks only when a certain number of points are satisfied.
+                double nHalf = nMaxCell / 2.0;
+                nMaxCell = nTarget;
+                double ratio = nMaxCell / nRest;
+                double oRatio = 1.0 / ratio;
+
+                if ( std::max( ratio, oRatio ) < 3.0 )
+                {
+                    int kkk = 1;
+                    largestZone = this->Split( largestZone, nMaxCell );
+                    timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                    this->RemoveZoneFromUnsignedGroup( largestZone );
+                    this->AddZoneToProcess( iProc, largestZone );
+                }
+                else
+                {
+                    this->Split( largestZone, nHalf );
+                }
+            }
+            else
+            {
+                //If the block is of the right size, join the process directly, and there is no need to split it.
+                timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                this->RemoveZoneFromUnsignedGroup( largestZone );
+                this->AddZoneToProcess( iProc, largestZone );
+            }
+        }
+        else
+        {
+            //If the block is of the right size, join the process directly, and there is no need to split it.
+            timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+            this->RemoveZoneFromUnsignedGroup( largestZone );
+            this->AddZoneToProcess( iProc, largestZone );
+        }
+    }
+}
+
+void Partition::ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord )
+{
+    SplitZone * rootSplitZone = splitZone->GetRootZone();
+    Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+    int nNodes = splitZone->dimInfo.ComputeNumNodes();
+    std::cout << "nNodes = " << nNodes << "\n";
+
+    coord.resize( nNodes * sizeof(double) );
+
+    int index_dim = splitZone->dimInfo.dimList.size();
+    Coor * coor = zone->coors[ icoord ];
+
+    double * xlocal = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    double * xglobal = reinterpret_cast<double *>( const_cast<char *>( coor->coord.data() ) );
+    if ( index_dim == 1 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        for ( int i = imin; i < imax; ++ i )
+        {
+            xlocal[ icount++ ] = xglobal[ i ];
+        }
+    }
+    else if ( index_dim == 2 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        int jmin = splitZone->dimInfo.rmin[ 1 ] - 1;
+        int jmax = splitZone->dimInfo.rmax[ 1 ];
+        int ni = rootSplitZone->dimInfo.dimList[ 0 ];
+        int nj = rootSplitZone->dimInfo.dimList[ 1 ];
+        for ( int j = jmin; j < jmax; ++ j )
+        {
+            int jstride = j * ni;
+            for ( int i = imin; i < imax; ++ i )
+            {
+                xlocal[ icount++ ] = xglobal[ jstride + i ];
+            }
+        }
+    }
+}
+
+void Partition::DumpBc( SplitZone * splitZone )
+{
+}
+
+void Partition::DumpPartitionedGridFile()
+{
+    std::cout << "\n";
+    std::cout << "DumpPartitionedGridFile -------------------------------" << "\n";
+    std::cout << "\n";
+    int fileId = -1;
+    std::string filename = this->outName;
+    int ierr = cg_open( filename.c_str(), CG_MODE_WRITE, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+
+    std::vector<std::string> coordnames;
+    coordnames.push_back( "CoordinateX" );
+    coordnames.push_back( "CoordinateY" );
+    coordnames.push_back( "CoordinateZ" );
+
+    std::string basename = "Base";
+    int baseId = -1;
+    int icelldim = Global::cell_dim;
+    int iphysdim = Global::phys_dim;
+    cg_base_write( fileId, basename.c_str(), icelldim, iphysdim, &baseId );
+
+    std::cout << "baseId = " << baseId << "\n";
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        int nZones = this->GetNZones( iProc );
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            ZoneType_t zoneType = Structured;
+
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+
+            int index_dim = splitZone->dimInfo.dimList.size();
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            splitZone->dimInfo.ComputeISize();
+
+            int isize_dim = index_dim * 3;
+
+            std::vector<cgsize_t> isize( index_dim * 3, 0 );
+            for ( int m = 0; m < isize_dim; ++ m )
+            {
+                isize[ m ] = splitZone->dimInfo.isize[ m ];
+            }
+
+            int zoneId = -1;
+
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+
+            std::string zonename = "Zone" + std::to_string( splitZone->newIndex );
+
+            cg_zone_write( fileId, baseId, zonename.c_str(), isize.data(), zoneType, &zoneId );
+
+            std::cout << "zoneId = " << zoneId << "\n";
+            std::cout << "zonename = " << zonename << "\n";
+                
+            splitZone->ComputeRminmax();
+
+            SplitZone * rootSplitZone = splitZone->GetRootZone();
+
+            Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+            int ncoords = zone->coors.size();
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = -1;
+                DataType_t dataType = RealDouble;
+                std::string coordname = coordnames[ icoord ];
+                Coor * coor = zone->coors[ icoord ];
+
+                int nNodes = splitZone->dimInfo.ComputeNumNodes();
+                std::cout << "nNodes = " << nNodes << "\n";
+
+                std::vector<char> coord;
+                ComputeCoor( splitZone, icoord, coord );
+
+                cg_coord_write( fileId, baseId, zoneId, dataType, coordname.c_str(), coord.data(), &coorId );
+
+                std::cout << "fileId = " << fileId  << " baseId = " << baseId << " zoneId = " << zoneId  << " coorId = " << coorId << "\n";
+            }
+
+            std::vector< PhysicalSplitBc * > &bccoList = splitZone->physicalSplitBcList;
+
+            int nbocos = bccoList.size();
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = -1;
+                GridLocation_t location = Vertex;
+
+                std::string boconame = "BC" + std::to_string( iboco + 1 );
+
+                PhysicalSplitBc * physicalSplitBc = bccoList[ iboco ];
+                BCType_t bocotype = static_cast<BCType_t>( physicalSplitBc->bcType );
+                PointSetType_t ptset_type = PointRange;
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> pnts;
+                int nSize = physicalSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.end[ i ] );
+                }
+
+                cg_boco_write( fileId, baseId, zoneId, boconame.c_str(), bocotype, ptset_type, npnts, pnts.data(), & bccoId );
+            }
+
+            std::vector< InterfaceSplitBc * > & bc1to1List = splitZone->interfaceSplitBcList;
+
+            int n1to1 = bc1to1List.size();
+            std::cout << "n1to1 = " << n1to1 << "\n";
+
+            std::vector<int> itranfrm( index_dim );
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                itranfrm[ m ] = m + 1;
+            }
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int index_conn = -1;
+
+                InterfaceSplitBc * interfaceSplitBc = bc1to1List[ i1to1 ];
+
+                std::vector<cgsize_t> pnts;
+                std::vector<cgsize_t> pntsdonor;
+                int nSize = interfaceSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.end[ i ] );
+                }
+
+                int nPatchSize = interfaceSplitBc->donor_region.start.size();
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.start[ i ] );
+                }
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.end[ i ] );
+                }
+                int id = interfaceSplitBc->donor_zone->newIndex;
+                int oldZoneIndex = interfaceSplitBc->donor_zone->zoneIndex;
+                std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+                std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+                std::cout << "donor zone id = " << id << "\n";
+                std::cout << "donor zone oldZoneIndex = " << oldZoneIndex << "\n";
+                std::string donorname = "Zone" + std::to_string( id );
+                std::string connectname = "Interface" + std::to_string( i1to1 );
+
+                std::cout << "donorname = " << donorname << "\n";
+                std::cout << "connectname = " << connectname << "\n";
+
+                std::vector<int> & itranfrm = interfaceSplitBc->transform;
+
+                cg_1to1_write( fileId, baseId, zoneId, connectname.c_str(), donorname.c_str(), pnts.data(), pntsdonor.data(), itranfrm.data(), &index_conn );
+                std::cout << "index_conn = " << index_conn << "\n";
+            }
+        }
+    }
+    cg_close( fileId );
+}
+
+void Partition::ModifyZoneIndex()
+{
+    std::cout << "ModifyZoneIndex +++++++++++++++++++++++++ " << "\n";
+    int globalZoneId = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        std::cout << "iProc = " << iProc << "\n";
+        int nZones = this->GetNZones( iProc );
+        std::cout << "nZones in Proc " << iProc << "  = " << nZones << "\n";
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+            //splitZone->SetZoneIndex( globalZoneId++ );
+            splitZone->newIndex = ( globalZoneId++ );
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+        }
+    }
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage1/01h/Partition.h b/example/partition/struct/2d/stage1/01h/Partition.h
new file mode 100644
index 00000000..8a4a9731
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01h/Partition.h
@@ -0,0 +1,59 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class SplitZone;
+
+struct CmpSplitZone 
+{
+    bool operator() ( SplitZone * a, SplitZone * b ) const;
+};
+
+class Partition
+{
+public:
+    Partition();
+    ~Partition();
+protected:
+    std::set < SplitZone * > zoneStorage;
+    std::set < SplitZone *, CmpSplitZone > unsignedZoneGroup;
+    std::vector< SplitZone * > refZone;
+    std::vector< std::vector< SplitZone * > > procSplitZone;
+    std::vector<double> procSpeed;
+    std::vector<double> timeProc;
+    double aveFloatOp, delta;
+    double idealUniProcTime, eps;
+    int minNumberCell;
+    int nTZone;
+    int nOriZone;
+    int nProc;
+public:
+    std::string inputName;
+    std::string outName;
+public:
+    void Solve();
+    void ReadGrid();
+    void Split();
+    void InitSplit();
+    void BinarySplit();
+    //void GreedySplit();
+public:
+    void AddNewZone( SplitZone * zone );
+    void AddZoneToUnsignedGroup( SplitZone * zone );
+    void RemoveZoneFromUnsignedGroup( SplitZone * zone );
+    void AddZoneToProcess( int iProc, SplitZone * zone );
+    void DumpPartitionedGridFile();
+    void ModifyZoneIndex();
+    void FreeAllZones();
+    int GetNZones( int iProc );
+    SplitZone * GetSplitZone( int iProc, int zoneId );
+    void ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord );
+    void DumpBc( SplitZone * splitZone );
+private:
+    int GetMinValueIndex( double * data, int numberOfData );
+    int GetMinLoadProc();
+    SplitZone * GetLargestZone();
+    SplitZone * Split( SplitZone * zone, double nCell );
+};
+
diff --git a/example/partition/struct/2d/stage1/01h/README.txt b/example/partition/struct/2d/stage1/01h/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01h/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/partition/struct/2d/stage1/01h/SplitZone.cpp b/example/partition/struct/2d/stage1/01h/SplitZone.cpp
new file mode 100644
index 00000000..4f262fd7
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01h/SplitZone.cpp
@@ -0,0 +1,1018 @@
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+int Dim::dim = -1;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox  )
+{
+    domainBox.start = zoneBox.start;
+    domainBox.end = zoneBox.end;
+
+    int axis = iDomain / 2;
+    int direction = iDomain % 2;
+
+    if ( direction == 0 )
+    {
+        domainBox.end[ axis ] = domainBox.start[ axis ];
+    }
+    else if ( direction == 1 )
+    {
+        domainBox.start[ axis ] = domainBox.end[ axis ];
+    }
+}
+
+DimInfo::DimInfo()
+{
+    this->Init( 1 );
+}
+
+DimInfo::~DimInfo()
+{
+}
+
+void DimInfo::Init( int dim )
+{
+    this->dim = dim;
+    dimList.resize( this->dim, 1 );
+    oriPoint.resize( this->dim, 0 );
+}
+
+DimInfo & DimInfo::operator = ( const DimInfo & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->dim = rhs.dim;
+    this->dimList = rhs.dimList;
+    this->oriPoint = rhs.oriPoint;
+
+    return * this;
+}
+
+int DimInfo::ComputeNumNodes()
+{
+    int nNodes = 1;
+    for ( int m = 0; m < this->dimList.size(); ++ m )
+    {
+        nNodes *= this->dimList[ m ];
+    }
+    return nNodes;
+}
+
+void DimInfo::ComputeISize()
+{
+    int index_dim = this->dimList.size();
+    this->isize.resize( index_dim * 3, 0 );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        isize[ m ] = this->dimList[ m ];
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 1;
+        isize[ start + m ] = this->dimList[ m ] - 1;
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 2;
+        isize[ start + m ] = 0;
+    }
+
+    for ( int i = 0; i < isize.size(); ++ i )
+    {
+        std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+    }
+}
+
+void DimInfo::ComputeRminmax( std::vector<int> & ref )
+{
+    int index_dim = this->dimList.size();
+    this->rmin.resize( index_dim );
+    this->rmax.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        rmin[ m ] = ref[ m ] + 1;
+        rmax[ m ] = ref[ m ] + this->dimList[ m ];
+    }
+
+    std::cout << "rmin, rmax = \n";
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        std::cout << rmin[ m ] << " " << rmax[ m ] << "\n";
+    }
+}
+
+void DimInfo::Init( std::vector<int> & dimList )
+{
+    this->dim = dimList.size();
+    this->dimList = dimList;
+    std::vector<int> zero( dimList.size(), 0 );
+    this->oriPoint = zero;
+}
+
+void DimInfo::SetNewDimension( int axis, int newStart, int newWidth )
+{
+    this->oriPoint[ axis ] = newStart;
+    this->dimList [ axis ] = newWidth;
+}
+
+void DimInfo::GetZoneGlobalBox( RangeRegion &zoneBox )
+{
+    int index_dim = this->dimList.size();
+    zoneBox.start.resize( index_dim );
+    zoneBox.end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        zoneBox.start[ m ] = this->oriPoint[ m ] + 1;
+        zoneBox.end[ m ] = this->oriPoint[ m ] + this->dimList[ m ];
+    }
+}
+
+void DimInfo::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    int index_dim = this->dimList.size();
+    localBox.start.resize( index_dim );
+    localBox.end.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        localBox.start[ m ] = globalBox.start[ m ] - this->oriPoint[ m ];
+        localBox.end[ m ] = globalBox.end[ m ] - this->oriPoint[ m ];
+    }
+}
+
+RangeRegion::RangeRegion( int nSize )
+{
+    this->Init( nSize );
+}
+
+RangeRegion::~RangeRegion()
+{
+}
+
+void RangeRegion::Init( int nSize )
+{
+    this->start.resize( nSize );
+    this->end.resize( nSize );
+}
+
+RangeRegion & RangeRegion::operator = ( const RangeRegion & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+bool RangeRegion::operator == ( const RangeRegion & rhs ) const
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] != rhs.start[ m ] || 
+            this->end  [ m ] != rhs.end  [ m ] )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+bool RangeRegion::InRegion( const RangeRegion & region )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( ( this->start[ m ] < region.start[ m ] ) || ( this->end[ m ] > region.end[ m ] ) )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::Normalize()
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        int minv = std::min( this->start[ m ], this->end[ m ] );
+        int maxv = std::max( this->start[ m ], this->end[ m ] );
+        this->start[ m ] = minv;
+        this->end[ m ] = maxv;
+    }
+}
+
+void RangeRegion::Localize( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] -= oriPoint[ m ];
+        this->end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void RangeRegion::AddShift( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] += oriPoint[ m ];
+        this->end[ m ] += oriPoint[ m ];
+    }
+}
+
+void RangeRegion::PrintGlobal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    std::cout << "global start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ] + oriPoint[m];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "global end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ] + oriPoint[m];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+void RangeRegion::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion );
+
+bool ComputeOverlapRegion( RangeRegion & region1, RangeRegion & region2, RangeRegion & overlapRegion )
+{
+    int index_dim = region1.start.size();
+    overlapRegion.Init( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int ijkmin1 = std::min( region1.start[ m ], region1.end[ m ] );
+        int ijkmax1 = std::max( region1.start[ m ], region1.end[ m ] );
+        int ijkmin2 = std::min( region2.start[ m ], region2.end[ m ] );
+        int ijkmax2 = std::max( region2.start[ m ], region2.end[ m ] );
+        if ( ( ijkmax1 < ijkmin2 ) || ( ijkmin1 > ijkmax2 ) )
+        {
+            return false;
+        }
+
+        int ijkmin = std::max( ijkmin1, ijkmin2 );
+        int ijkmax = std::min( ijkmax1, ijkmax2 );
+
+        overlapRegion.start[ m ] = ijkmin;
+        overlapRegion.end  [ m ] = ijkmax;
+    }
+
+    return CheckOverLapping( overlapRegion );
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion )
+{
+    int index_dim = overlapRegion.start.size();
+    int iCount = 0;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        if ( overlapRegion.start[ m ] == overlapRegion.end[ m ] )
+        {
+            ++ iCount;
+        }
+    }
+
+    return ( iCount == 1 );
+}
+
+bool GetInterfaceRegion( RangeRegion & zoneBoxL, RangeRegion & zoneBoxR, RangeRegion & interfaceRegion )
+{
+    int index_dim = zoneBoxL.start.size();
+    int nDomains = 2 * index_dim;
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegionL;
+        GetDomainRegion( zoneBoxL, iDomain, domainRegionL );
+
+        for ( int jDomain = 0; jDomain < nDomains; ++ jDomain )
+        {
+            RangeRegion domainRegionR;
+            GetDomainRegion( zoneBoxR, jDomain, domainRegionR );
+
+            if ( domainRegionL == domainRegionR )
+            {
+                interfaceRegion = domainRegionL;
+                return true;
+            }
+        }
+    }
+    return false;
+}
+
+void CreateInterfaceBc( SplitZone * zoneL, SplitZone * zoneR )
+{
+    RangeRegion globalBoxL, globalBoxR, globalInterfaceRegion;
+
+    zoneL->GetZoneGlobalBox( globalBoxL );
+    zoneR->GetZoneGlobalBox( globalBoxR );
+
+    if ( ! GetInterfaceRegion( globalBoxL, globalBoxR, globalInterfaceRegion ) )
+    {
+        return;
+    }
+
+    RangeRegion localInterfaceRegionL, localInterfaceRegionR;
+
+    zoneL->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionL );
+    zoneR->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionR );
+
+    int kkk = 1;
+
+    InterfaceSplitBc * interfaceSplitBcL = new InterfaceSplitBc();
+    zoneL->interfaceSplitBcList.push_back( interfaceSplitBcL );
+    interfaceSplitBcL->zone = zoneL;
+    interfaceSplitBcL->region = localInterfaceRegionL;
+
+    int nSize = localInterfaceRegionL.start.size();
+
+    std::vector<int> transform;
+
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        transform.push_back( m + 1 );
+    }
+
+    interfaceSplitBcL->transform = transform;
+    interfaceSplitBcL->CalcTransformMatrix();
+
+    interfaceSplitBcL->donor_zone = zoneR;
+    interfaceSplitBcL->donor_region = localInterfaceRegionR;
+
+    InterfaceSplitBc * interfaceSplitBcR = new InterfaceSplitBc();
+    zoneR->interfaceSplitBcList.push_back( interfaceSplitBcR );
+
+    interfaceSplitBcR->zone = zoneR;
+    interfaceSplitBcR->region = localInterfaceRegionR;
+
+    interfaceSplitBcR->transform = transform;
+    interfaceSplitBcR->CalcTransformMatrix();
+
+    interfaceSplitBcR->donor_zone = zoneL;
+    interfaceSplitBcR->donor_region = localInterfaceRegionL;
+}
+
+
+PhysicalSplitBc::PhysicalSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+PhysicalSplitBc::~PhysicalSplitBc()
+{
+}
+
+void PhysicalSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void PhysicalSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+void PhysicalSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = splitZone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+BasicSplitBc::BasicSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+BasicSplitBc::~BasicSplitBc()
+{
+    ;
+}
+
+void BasicSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void BasicSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+int trans::M[ 3 ][ 3 ];
+std::vector<int> trans::transform;
+
+int trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void trans::CalcTransformMatrix()
+{
+    int dim = trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = trans::transform[ 0 ];
+        int sgna = trans::sgn( a );
+        int a1 = trans::del( a, 1 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int c = trans::transform[ 2 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int sgnc = trans::sgn( c );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int a3 = trans::del( a, 3 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        int b3 = trans::del( b, 3 );
+        int c1 = trans::del( c, 1 );
+        int c2 = trans::del( c, 2 );
+        int c3 = trans::del( c, 3 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 2 ][ 0 ] = sgna * a3;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+        trans::M[ 2 ][ 1 ] = sgnb * b3;
+        trans::M[ 0 ][ 2 ] = sgnc * c1;
+        trans::M[ 1 ][ 2 ] = sgnc * c2;
+        trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+InterfaceSplitBc::InterfaceSplitBc()
+{
+    this->region.Init( Dim::dim );
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceSplitBc::~InterfaceSplitBc()
+{
+}
+
+void InterfaceSplitBc::CopyMatrix( InterfaceSplitBc * interfaceSplitBc )
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = interfaceSplitBc->Mt[ i ][ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::CalcTransformMatrix()
+{
+    trans::ZeroMatrix();
+    trans::transform = this->transform;
+    trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = trans::M[ i ][ j ];
+        }
+    }
+
+}
+
+void InterfaceSplitBc::mapindex( std::vector<int> & begin1, std::vector<int> & begin2,  std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = Dim::dim;
+    std::vector<int> diff( dim );
+    for ( int m = 0; m < dim; ++ m )
+    {
+        diff[ m ] = index1[ m ] - begin1[ m ];
+    }
+
+    std::vector<int> mul( dim );
+
+    Multiply( Mt, diff, mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = mul[ m ] + begin2[ m ];
+    }
+}
+
+void InterfaceSplitBc::Multiply( int Mt[][3], std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = Dim::dim;
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = this->zone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void InterfaceSplitBc::CalcSubDonorRegion( RangeRegion &subRegion, RangeRegion &subDonorRegion )
+{
+    std::vector<int> begin1 = this->region.start;
+    std::vector<int> end1 = this->region.end;
+    std::vector<int> begin2 = this->donor_region.start;
+    std::vector<int> end2 = this->donor_region.end;
+
+    std::vector<int> new_begin1 = subRegion.start;
+    std::vector<int> new_end1 = subRegion.end;
+
+    int dim = Dim::dim;
+    std::vector<int> new_begin2( dim );
+    std::vector<int> new_end2( dim );
+
+    mapindex( begin1, begin2, new_begin1, new_begin2 );
+    mapindex( begin1, begin2, new_end1, new_end2 );
+
+    subDonorRegion.start = new_begin2;
+    subDonorRegion.end = new_end2;
+}
+
+SplitZone::SplitZone()
+{
+    this->parent  = 0;
+    this->zoneIndex = 0;
+    this->iProc = 0;
+    dimInfo.Init( Dim::dim );
+    int kk = 1;
+}
+
+SplitZone::~SplitZone()
+{
+    ;
+}
+
+void SplitZone::GetZoneGlobalBox( RangeRegion & zoneBox )
+{
+    this->dimInfo.GetZoneGlobalBox( zoneBox );
+}
+
+void SplitZone::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    this->dimInfo.GetZoneLocalBox( globalBox, localBox );
+}
+
+
+void SplitZone::ComputeRminmax()
+{
+    int index_dim = this->dimInfo.dimList.size();
+    std::vector<int> ref( index_dim, 0 );
+
+    SplitZone * rootSplitZone = 0;
+    this->GetRootInfo( rootSplitZone, ref );
+
+    this->dimInfo.ComputeRminmax( ref );
+}
+
+InterfaceSplitBc * SplitZone::FindDonorInterface( InterfaceSplitBc * interfaceSplitBc )
+{
+    RangeRegion donor_region = interfaceSplitBc->donor_region;
+    donor_region.Normalize();
+    for ( int iInterface = 0; iInterface < interfaceSplitBcList.size(); ++ iInterface )
+    {
+        InterfaceSplitBc * candidateDonorBc = interfaceSplitBcList[ iInterface ];
+        bool flag = donor_region.InRegion( candidateDonorBc->region );
+        if ( flag )
+        {
+            if ( donor_region == candidateDonorBc->region )
+            {
+                return candidateDonorBc;
+            }
+            else
+            {
+                InterfaceSplitBc * donorBc = new InterfaceSplitBc();
+                candidateDonorBc->child.push_back( donorBc );
+                donorBc->region = donor_region;
+                donorBc->zone = candidateDonorBc->zone;
+                donorBc->donor_zone = interfaceSplitBc->zone;
+                donorBc->transform = candidateDonorBc->transform;
+                donorBc->CopyMatrix( candidateDonorBc );
+                RangeRegion subDonorRegion( Dim::dim );
+                candidateDonorBc->CalcSubDonorRegion( donorBc->region, subDonorRegion );
+                std::vector<int> & oriPoint = interfaceSplitBc->zone->dimInfo.oriPoint;
+                subDonorRegion.Localize( oriPoint );
+                donorBc->donor_region = subDonorRegion;
+                donorBc->donor_bc = interfaceSplitBc;
+                return donorBc;
+            }
+        }
+    }
+    return nullptr;
+}
+
+SplitZone * SplitZone::GetRootZone()
+{
+    SplitZone * root = this;
+
+    while ( true )
+    {
+        if ( root->parent )
+        {
+            root = root->parent;
+        }
+        else
+        {
+            return root;
+        }
+    };
+}
+
+void SplitZone::GetRootInfo( SplitZone *& root, std::vector<int> & ref )
+{
+    for ( int i = 0; i < this->dimInfo.dimList.size(); ++ i )
+    {
+        ref[ i ] += this->dimInfo.oriPoint[ i ];
+    }
+
+    if ( this->parent )
+    {
+        this->parent->GetRootInfo( root, ref );
+    }
+    else
+    {
+        root = this;
+    }
+}
+
+void SplitZone::SetParentAndChild( SplitZone * parent )
+{
+    this->parent = parent;
+    if ( parent )
+    {
+        parent->child.push_back( this );
+    }
+}
+
+
+int SplitZone::GetNCell()
+{
+    int numberOfCells = 1;
+    for ( int i = 0; i < this->dimInfo.dim; ++ i )
+    {
+        numberOfCells *= std::max( 1, ( this->dimInfo.dimList[ i ] - 1 ) );
+    }
+
+    return numberOfCells; 
+}
+
+void SplitZone::SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int leftStart = 0;
+    int leftWidth = iSplit - 0;
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, leftStart , leftWidth  );
+}
+
+void SplitZone::SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int rightStart = iSplit - 1;
+    int rightWidth = dimList[ axisNeedSplit ] - ( iSplit - 1 );
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, rightStart, rightWidth );
+}
+
+void SplitZone::Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell )
+{
+    //Find the longest axis
+    int axisNeedSplit = this->FindAxisNeedSplit();
+    int iSplit        = this->FindSplitPosition( axisNeedSplit, nCell );
+
+    zoneL->SetLeftDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+    zoneR->SetRightDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+
+    zoneL->CreateBcFromParent();
+    zoneR->CreateBcFromParent();
+    
+    CreateInterfaceBc( zoneL, zoneR );
+}
+
+void SplitZone::CreateBcFromParent()
+{
+    this->CreatePhysicalBcFromParent();
+    this->CreateInterfaceBcFromParent();
+}
+
+void SplitZone::CreatePhysicalBcFromParent()
+{
+    int nParentPhysicalBcs = this->parent->physicalSplitBcList.size();
+
+    for ( int iParentPhysicalBcs = 0; iParentPhysicalBcs < nParentPhysicalBcs; ++ iParentPhysicalBcs )
+    {
+        PhysicalSplitBc * parentPhysicalSplitBc = this->parent->physicalSplitBcList[ iParentPhysicalBcs ];
+
+        this->CreatePhysicalBcFromParent( parentPhysicalSplitBc );
+    }
+}
+
+void SplitZone::CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentPhysicalSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreatePhysicalBc( overlapRegion, parentPhysicalSplitBc->bcType );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent()
+{
+    int nInterfaceSplitBcs = this->parent->interfaceSplitBcList.size();
+
+    for ( int iInterfaceSplitBcs = 0; iInterfaceSplitBcs < nInterfaceSplitBcs; ++ iInterfaceSplitBcs )
+    {
+        InterfaceSplitBc * parentInterfaceSplitBc = this->parent->interfaceSplitBcList[ iInterfaceSplitBcs ];
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc );
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentInterfaceSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc, overlapRegion );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::GetChildDonorRegion( RangeRegion & subDonorRegion, InterfaceInfo & interfaceInfo )
+{
+    std::cout << "subDonorRegion = \n";
+    subDonorRegion.Print();
+    int nChild = this->child.size();
+    for ( int ichild = 0; ichild < nChild; ++ ichild )
+    {
+        std::cout << " iChild = " << ichild << " nChild = " << nChild << "\n";
+        SplitZone * sub_zone = this->child[ ichild ];
+        std::cout << " zoneIndex = " << sub_zone->zoneIndex << "\n";
+        int nInters = sub_zone->interfaceSplitBcList.size();
+        for ( int iInter = 0; iInter < nInters; ++ iInter )
+        {
+            std::cout << " iInter = " << iInter << "\n";
+            InterfaceSplitBc * interfaceSplitBc = sub_zone->interfaceSplitBcList[ iInter ];
+            std::cout << "interfaceSplitBc local = \n";
+            interfaceSplitBc->region.Print();
+            std::cout << "interfaceSplitBc global = \n";
+            interfaceSplitBc->region.PrintGlobal( sub_zone->dimInfo.oriPoint );
+            RangeRegion g_region = interfaceSplitBc->region;
+            g_region.AddShift( sub_zone->dimInfo.oriPoint );
+            if ( g_region == subDonorRegion )
+            {
+                interfaceInfo.donor_zone = sub_zone;
+                interfaceInfo.donor_interface = interfaceSplitBc;
+                return;
+            }
+        }
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion )
+{
+    InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+    this->interfaceSplitBcList.push_back( interfaceSplitBc );
+
+    interfaceSplitBc->region = overlapRegion;
+    interfaceSplitBc->zone = this;
+    interfaceSplitBc->transform = parentInterfaceSplitBc->transform;
+    interfaceSplitBc->CopyMatrix( parentInterfaceSplitBc );
+    RangeRegion subDonorRegion( Dim::dim );
+    parentInterfaceSplitBc->CalcSubDonorRegion( overlapRegion, subDonorRegion );
+    interfaceSplitBc->ChangeRegionToLocalCoordinate();
+    interfaceSplitBc->donor_region = subDonorRegion;
+    SplitZone * donor_zone = parentInterfaceSplitBc->donor_zone;
+    std::cout << " parentInterfaceSplitBc->zone->zoneIndex " << parentInterfaceSplitBc->zone->zoneIndex << "\n";
+    std::cout << " parentInterfaceSplitBc->donor_zone->zoneIndex " << donor_zone->zoneIndex << "\n";
+    if ( donor_zone->child.size() > 0 )
+    {
+        InterfaceInfo interfaceInfo;
+        donor_zone->GetChildDonorRegion( subDonorRegion, interfaceInfo );
+        interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+        interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+    }
+    else
+    {
+        interfaceSplitBc->donor_zone = donor_zone;
+        interfaceSplitBc->donor_bc = donor_zone->FindDonorInterface( interfaceSplitBc );
+    }
+    
+    int kkk = 1;
+}
+
+void SplitZone::CreatePhysicalBc( RangeRegion & overlapRegion, int bcType )
+{
+    PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+    this->physicalSplitBcList.push_back( physicalSplitBc );
+    physicalSplitBc->SetRegion( overlapRegion );
+    physicalSplitBc->bcType = bcType;
+    physicalSplitBc->splitZone = this;
+    physicalSplitBc->ChangeRegionToLocalCoordinate();
+}
+
+int SplitZone::FindAxisNeedSplit()
+{
+    //Find the longest axis
+    int axisNeedSplit = 0;
+    int maxN = this->dimInfo.dimList[ 0 ];
+
+    for ( int m = 1; m < this->dimInfo.dimList.size(); ++ m )
+    {
+        if ( this->IsPoleBc( m ) )
+        {
+            continue;
+        }
+        int Nm = this->dimInfo.dimList[ m ];
+        if ( maxN < Nm )
+        {
+            maxN = Nm;
+            axisNeedSplit = m;
+        }
+    }
+
+    return axisNeedSplit;
+}
+
+int SplitZone::GetCrossSection( int axis )
+{
+    int nDim = this->dimInfo.dimList.size();
+    int crossSection = 1;
+    int N = nDim - 1;
+    for ( int m = 0; m < N; ++ m )
+    {
+         int mm = ( axis + 1 ) % nDim;
+         int nLineElements = std::max( 1, ( this->dimInfo.dimList[ mm ] - 1 ) );
+         crossSection *= nLineElements;
+    }
+    return crossSection;
+}
+
+int SplitZone::FindSplitPosition( int axisNeedSplit, double nCell )
+{
+    int nDim = this->dimInfo.dimList.size();
+    std::vector<int> crossSections( nDim );
+    for ( int m = 0; m < nDim; ++ m )
+    {
+        crossSections[ m ] = this->GetCrossSection( m );
+    }
+
+    //guess the value
+    double dSplit = nCell / crossSections[ axisNeedSplit ];
+    int  iSplit = 1 + static_cast< int >( std::floor( dSplit + 0.5 ) );
+    return iSplit;
+}
+
+
+bool SplitZone::IsPoleBc( int splitDirection )
+{
+    return false;
+}
+
diff --git a/example/partition/struct/2d/stage1/01h/SplitZone.h b/example/partition/struct/2d/stage1/01h/SplitZone.h
new file mode 100644
index 00000000..b76fb88b
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01h/SplitZone.h
@@ -0,0 +1,189 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class Dim
+{
+public:
+    static int dim;
+};
+
+class SplitZone;
+class RangeRegion;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox );
+
+class DimInfo
+{
+public:
+    DimInfo();
+    ~DimInfo();
+public:
+    int dim;
+    std::vector<int> dimList;
+    std::vector<int> oriPoint;
+    std::vector<int> isize;
+    std::vector<int> rmin;
+    std::vector<int> rmax;
+public:
+    int GetSize() const { return dim; }
+    DimInfo & operator = ( const DimInfo & rhs );
+public:
+    int ComputeNumNodes();
+    void ComputeISize();
+    void ComputeRminmax( std::vector<int> & ref );
+    void Init( int dim );
+    void Init( std::vector<int> & dimList );
+    void SetNewDimension( int axis, int newStart, int newWidth );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+};
+
+class SplitZone;
+class SplitBcPatch;
+
+class RangeRegion
+{
+public:
+    RangeRegion( int nSize = 1 );
+    ~RangeRegion();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    void Init( int nSize );
+    RangeRegion & operator = ( const RangeRegion & rhs );
+    bool operator == ( const RangeRegion & rhs ) const;
+    bool InRegion( const RangeRegion & region );
+    void SetRegion( std::vector<int> &pnts );
+    void Normalize();
+    void Localize( std::vector<int> & oriPoint );
+    void AddShift( std::vector<int> & oriPoint );
+    void PrintGlobal( std::vector<int> & oriPoint );
+    void Print();
+};
+
+class PhysicalSplitBc
+{
+public:
+    PhysicalSplitBc();
+    ~PhysicalSplitBc();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class BasicSplitBc
+{
+public:
+    BasicSplitBc();
+    ~BasicSplitBc();
+public:
+    RangeRegion region;
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> & pnts );
+    void SetRegion( RangeRegion & region );
+};
+
+class trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class InterfaceSplitBc;
+class SplitZone;
+
+class InterfaceInfo
+{
+public:
+    InterfaceSplitBc * donor_interface = nullptr;
+    SplitZone * donor_zone = nullptr;
+};
+
+class InterfaceSplitBc
+{
+public:
+    InterfaceSplitBc();
+    ~InterfaceSplitBc();
+public:
+    std::vector<int> transform;
+    int Mt[ 3 ][ 3 ];
+    RangeRegion region;
+    SplitZone * zone = nullptr;
+    RangeRegion donor_region;
+    SplitZone * donor_zone = nullptr;
+    InterfaceSplitBc * donor_bc = nullptr;
+public:
+    std::vector<InterfaceSplitBc *> child;
+public:
+    void CopyMatrix( InterfaceSplitBc * interfaceSplitBc );
+    void CalcTransformMatrix();
+    void CalcSubDonorRegion( RangeRegion & subRegion, RangeRegion & subDonorRegion );
+    void mapindex( std::vector<int> & begin1, std::vector<int> & begin2, std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( int Mt[][ 3 ], std::vector<int> & a, std::vector<int> & b );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class SplitZone
+{
+public:
+    SplitZone();
+    ~SplitZone();
+public:
+    DimInfo dimInfo;
+    int zoneIndex, iProc;
+    int newIndex;
+protected:
+    SplitZone * parent;
+    std::vector<SplitZone *> child;
+public:
+    std::vector< PhysicalSplitBc * > physicalSplitBcList;
+    std::vector< InterfaceSplitBc * > interfaceSplitBcList;
+public:
+    int GetNCell();
+    void ComputeRminmax();
+    void GetRootInfo( SplitZone *& root, std::vector<int> & ref );
+    void SetZoneIndex( int zoneIndex ) { this->zoneIndex = zoneIndex; }
+    int  GetZoneIndex() { return zoneIndex; }
+    void SetProcId( int iProc ) { this->iProc = iProc; }
+    void SetParent( SplitZone * parent ) { this->parent = parent; };
+    void SetParentAndChild( SplitZone * parent );
+    InterfaceSplitBc * FindDonorInterface( InterfaceSplitBc * interfaceSplitBc );
+    void GetChildDonorRegion( RangeRegion & subDonorRegion, InterfaceInfo & interfaceInfo );
+public:
+    void CreateBcFromParent();
+    void CreatePhysicalBcFromParent();
+    void CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc );
+    void CreatePhysicalBc( RangeRegion & overlapRegion, int bcType );
+    void CreateInterfaceBcFromParent();
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc );
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion );
+
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+    SplitZone * GetRootZone();
+public:
+    void Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell );
+    void SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+    void SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+private:
+    int FindAxisNeedSplit();
+    int FindSplitPosition( int axisNeedSplit, double nCell );
+    bool IsPoleBc( int splitDirection );
+    int GetCrossSection( int axis );
+};
+
diff --git a/example/partition/struct/2d/stage1/01h/heat2d2blocks.cgns b/example/partition/struct/2d/stage1/01h/heat2d2blocks.cgns
new file mode 100644
index 00000000..ab4dcea5
Binary files /dev/null and b/example/partition/struct/2d/stage1/01h/heat2d2blocks.cgns differ
diff --git a/example/partition/struct/2d/stage1/01h/main.cpp b/example/partition/struct/2d/stage1/01h/main.cpp
new file mode 100644
index 00000000..5da1de7c
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01h/main.cpp
@@ -0,0 +1,18 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include "Partition.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip>
+
+int main(int argc, char **argv)
+{
+    Partition * partition = new Partition();
+    partition->Solve();
+    delete partition;
+
+    return 0;
+}
diff --git a/example/partition/struct/2d/stage1/01i/CMakeLists.txt b/example/partition/struct/2d/stage1/01i/CMakeLists.txt
new file mode 100644
index 00000000..74ceea7d
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01i/CMakeLists.txt
@@ -0,0 +1,78 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	Partition.h Partition.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	SplitZone.h SplitZone.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/partition/struct/2d/stage1/01i/CgnsGrid.cpp b/example/partition/struct/2d/stage1/01i/CgnsGrid.cpp
new file mode 100644
index 00000000..dfe750bd
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01i/CgnsGrid.cpp
@@ -0,0 +1,349 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include <map>
+
+Grid::Grid()
+{
+    ;
+}
+
+Grid::~Grid()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if( (i+1)%5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+    delete this->patch;
+}
+
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+ZoneBcPatch::ZoneBcPatch()
+{
+    ;
+}
+
+ZoneBcPatch::~ZoneBcPatch()
+{
+}
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+Global::Global()
+{
+    ;
+}
+
+Global::~Global()
+{
+}
+
+void Global::FreeData()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+    zones.resize( 0 );
+}
+
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            //baseZone.baseId = baseId;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin( index_dim );
+            std::vector<cgsize_t> irmax( index_dim );
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                std::vector<char> coord( nNodes * sizeof(double) );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+                coor->DumpCoor();
+            }
+
+            int nbocos = -1;
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+                int kkk = 1;
+            }
+        }
+        int kkk = 1;
+    }
+    int kkk = 1;
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage1/01i/CgnsGrid.h b/example/partition/struct/2d/stage1/01i/CgnsGrid.h
new file mode 100644
index 00000000..053c467b
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01i/CgnsGrid.h
@@ -0,0 +1,140 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <map>
+
+class Grid;
+
+class Zone;
+
+class Grid
+{
+public:
+    Grid();
+    ~Grid();
+public:
+    int nZone;
+    std::vector<double> x;
+    std::vector<Zone *> zones;
+};
+
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+};
+
+class ZoneBc;
+class ZoneBc1To1;
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class ZoneBcPatch;
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+    ZoneBcPatch * patch = nullptr;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+class ZoneBcPatch
+{
+public:
+    ZoneBcPatch();
+    ~ZoneBcPatch();
+public:
+    int donor_zoneid;
+    std::vector<int> transform;
+    std::vector<int> donor_pnts;
+};
+
+class BaseZone
+{
+public:
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Global
+{
+public:
+    Global();
+    ~Global();
+public:
+    static int cell_dim;
+    static int phys_dim;
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+public:
+    static void FreeData();
+};
+
+void ReadCgnsGrid( const std::string & filename );
+void ReadCgnsGridBaseZone( const std::string & filename );
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage1/01i/Partition.cpp b/example/partition/struct/2d/stage1/01i/Partition.cpp
new file mode 100644
index 00000000..28a6b9d9
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01i/Partition.cpp
@@ -0,0 +1,617 @@
+#include "Partition.h"
+#include "CgnsGrid.h"
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+bool CmpSplitZone::operator() ( SplitZone * a, SplitZone * b ) const
+{
+    return a->zoneIndex < b->zoneIndex;
+};
+
+
+double CalSumOfProcSpeed( std::vector<double> & procSpeed );
+double CalSumOfProcSpeed( std::vector<double> & procSpeed )
+{
+    int nProc = procSpeed.size();
+    double sumOfProcSpeed = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        sumOfProcSpeed += procSpeed[ iProc ];
+    }
+    return sumOfProcSpeed;
+}
+
+Partition::Partition()
+{
+    this->inputName = "../heat2d2blocks.cgns";
+    this->outName =  "../heat2dpart.cgns";
+}
+
+Partition::~Partition()
+{
+    ;
+}
+
+int Partition::GetMinValueIndex( double * data, int numberOfData )
+{
+    double minValue = data[ 0 ];
+    int minimumValueIndex = 0;
+
+    for ( int iData = 1; iData < numberOfData; ++ iData )
+    {
+        if ( minValue > data[ iData ] )
+        {
+            minValue      = data[ iData ];
+            minimumValueIndex = iData;
+        }
+    }
+    return minimumValueIndex;
+}
+
+int Partition::GetMinLoadProc()
+{
+    return this->GetMinValueIndex( this->timeProc.data(), this->nProc );
+}
+
+SplitZone * Partition::GetLargestZone()
+{
+    SplitZone * largestZone = 0;
+
+    double nMaxCell = 0.0;
+
+    for ( std::set< SplitZone * >::iterator iter = unsignedZoneGroup.begin(); iter != unsignedZoneGroup.end(); ++ iter )
+    {
+        double nSize = ( * iter )->GetNCell();
+        if ( nMaxCell < nSize )
+        {
+            nMaxCell    = nSize;
+            largestZone = * iter;
+        }
+    }
+
+    return largestZone;
+}
+
+void Partition::Solve()
+{
+    std::cout << "Partition::Split()\n";
+    //this->nProc = 2;
+    this->nProc = 4;
+    this->ReadGrid();
+    this->Split();
+    this->DumpPartitionedGridFile();
+    this->FreeAllZones();
+}
+
+void Partition::ReadGrid()
+{
+    ReadCgnsGridBaseZone( this->inputName );
+    ReadCgnsGrid( this->inputName );
+
+    this->nOriZone = ::Global::zones.size();
+    Dim::dim = Global::cell_dim;
+
+    std::cout << "numberOfBlocks = " << nOriZone << "\n";
+
+    this->refZone.resize( nOriZone );
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = new SplitZone();
+        refZone[ iZone ] = splitZone;
+
+        splitZone->SetZoneIndex( iZone );
+        splitZone->SetProcId( 0 );
+        splitZone->SetParentAndChild( 0 );
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        Zone * zone = ::Global::zones[ iZone ];
+
+        splitZone->dimInfo.dimList = zone->nijk;
+
+        int nbccos = zone->bccos.size();
+        std::cout << "nbccos = " << nbccos << "\n";
+
+        for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+        {
+            ZoneBc * zoneBc = zone->bccos[ ibcco ];
+
+            PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+            splitZone->physicalSplitBcList.push_back( physicalSplitBc );
+            physicalSplitBc->bcType = zoneBc->bcType;
+            physicalSplitBc->SetRegion( zoneBc->pnts );
+            physicalSplitBc->splitZone = splitZone;
+        }
+
+        int nbc1to1s = zone->bc1to1s.size();
+
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * zoneBc1To1 = zone->bc1to1s[ ibc1to1 ];
+
+            InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+            splitZone->interfaceSplitBcList.push_back( interfaceSplitBc );
+            interfaceSplitBc->zone = splitZone;
+            interfaceSplitBc->region.SetRegion( zoneBc1To1->pnts );
+
+            interfaceSplitBc->transform = zoneBc1To1->transform;
+            interfaceSplitBc->CalcTransformMatrix();
+
+            interfaceSplitBc->donor_zone = refZone[ zoneBc1To1->donor_zoneid ];
+            interfaceSplitBc->donor_region.SetRegion( zoneBc1To1->donor_pnts );
+        }
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        int nbc1to1s = splitZone->interfaceSplitBcList.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            InterfaceSplitBc * interfaceSplitBc = splitZone->interfaceSplitBcList[ ibc1to1 ];
+            InterfaceInfo interfaceInfo;
+            interfaceSplitBc->donor_zone->FindDonorInterface( interfaceSplitBc, interfaceInfo );
+            interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+        }
+    }
+}
+
+void Partition::Split()
+{
+    this->InitSplit();
+    this->BinarySplit();
+    this->ModifyZoneIndex();
+    int kkk = 1;
+}
+
+void Partition::InitSplit()
+{
+    //nZone is the number of zones in the original grid
+    //nProc is not the number of blocks in the end, but the number of processes that need to be divided.
+    //This difference occurs because the structure grid can have many blocks per process.
+
+    //this->nProc    = nProc;
+    //this->nPhyBlocks = referenceBlock.size();
+    //this->nZone  = this->nPhyBlocks;
+
+    //tj Computation time on processor j
+    //Nk Number of internal grid-cells for zone j
+    //aveFloatOp:  Number of Real operations per gridcell
+    //Gj The set of blocks allocated to process j
+    //Pj Real operations per second for process j
+
+    //The Greedy Load Balancing Algorithm
+    //1.Compute an "ideal" uniprocessor time, Tuni = sum ( Nk * aveFloatOp )/ sum( Pj ).
+    //2.Set the group of unassigned blocks, Gu, to contain all blocks. The number of blocks in Nu=M, where M is the total number of blocks in the mesh.
+    //3.Start all processors with a very small fictitious zone to get a start tj=delt aveFloatOp/Pj, where delt<<1 is the size of the very small fictious zone.
+    //This is used to find the fastest processor in a heterogeneous system, tj could otherwise be set to 0 in the homogeneous case.
+    this->aveFloatOp = 1.0;
+    this->delta      = 1.0e-5;
+    this->procSpeed.resize( nProc );
+    this->timeProc.resize( nProc );
+
+    this->nTZone = this->nOriZone;
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        procSpeed[ iProc ] = 1.0;
+    }
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        timeProc[ iProc ] = delta * aveFloatOp / procSpeed[ iProc ];
+    }
+
+    double sumProcSpeed = CalSumOfProcSpeed( procSpeed );
+
+    double sumProcOp = 0.0;
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        sumProcOp += refZone[ iZone ]->GetNCell() * aveFloatOp;
+    }
+
+    this->idealUniProcTime = sumProcOp / sumProcSpeed;
+
+    this->eps = 0.05;
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        unsignedZoneGroup.insert( refZone[ iZone ] );
+    }
+
+    //Init zoneStorage
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        zoneStorage.insert( refZone[ iZone ] );
+    }
+
+    //Assign procSplitZone to each process
+    procSplitZone.resize( nProc );
+
+    this->minNumberCell = 1;
+    for ( int m = 0; m < Dim::dim; ++ m )
+    {
+        this->minNumberCell *= 1;
+    }
+
+    int kkk = 1;
+
+}
+
+void Partition::FreeAllZones()
+{
+    int iCount = 0;
+    for ( std::set < SplitZone * >::iterator iter = zoneStorage.begin(); iter != zoneStorage.end(); ++ iter )
+    {
+        //cout << "iCount = " << iCount << "\n";
+        ++ iCount;
+        delete * iter;
+    }
+}
+
+int Partition::GetNZones( int iProc )
+{
+    return this->procSplitZone[ iProc ].size();
+}
+
+SplitZone * Partition::GetSplitZone( int iProc, int zoneId )
+{
+    return this->procSplitZone[ iProc ][ zoneId ];
+}
+
+void Partition::AddZoneToUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.insert( zone );
+}
+
+void Partition::RemoveZoneFromUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.erase( zone );
+}
+
+void Partition::AddZoneToProcess( int iProc, SplitZone * zone )
+{
+    this->procSplitZone[ iProc ].push_back( zone );
+}
+
+void Partition::AddNewZone( SplitZone * zone )
+{
+    zone->SetZoneIndex( nTZone ++ );
+
+    this->AddZoneToUnsignedGroup( zone );
+
+    this->zoneStorage.insert( zone );
+}
+
+SplitZone * Partition::Split( SplitZone * zone, double nCell )
+{
+    SplitZone * zoneL = new SplitZone();
+    zoneL->SetParentAndChild( zone );
+
+    SplitZone * zoneR = new SplitZone();
+    zoneR->SetParentAndChild( zone );
+
+    //Remove the original block from the UnsignedGroup
+    this->RemoveZoneFromUnsignedGroup( zone );
+
+    this->AddNewZone( zoneL );
+    this->AddNewZone( zoneR );
+
+    zone->Split( zoneL, zoneR, nCell );
+
+    return zoneL;
+}
+
+void Partition::BinarySplit()
+{
+    while ( ! unsignedZoneGroup.empty() )
+    {
+        std::cout << "number of unsigned zone = " << unsignedZoneGroup.size() << "\n";
+        int iProc = this->GetMinLoadProc();
+
+        //Get the block with the largest number of grids and its size
+        SplitZone * largestZone = this->GetLargestZone();
+
+        double nMaxCell = largestZone->GetNCell();
+
+        double aveFloatOp = this->aveFloatOp;
+        double tau = timeProc[ iProc ] + nMaxCell * aveFloatOp / procSpeed[ iProc ];
+
+        //It seems that EPS is still necessary
+        //The idea here is as follows. For the candidate blocks which can be divided into blocks, 
+        //if the difference between the target blocks and the candidate blocks is too wide, 
+        //the binarySplit method is adopted. The binarySplit blocks do not directly join the process,
+        //but enter the next round of screening.
+
+        if ( tau > idealUniProcTime * ( 1.0 + eps ) )
+        {
+            double nRest = ( tau - idealUniProcTime ) * procSpeed[ iProc ] / aveFloatOp;
+
+            double nTarget = nMaxCell - nRest;
+            if ( nRest > this->minNumberCell && nTarget > this->minNumberCell )
+            {
+                //It is necessary to divide blocks only when a certain number of points are satisfied.
+                double nHalf = nMaxCell / 2.0;
+                nMaxCell = nTarget;
+                double ratio = nMaxCell / nRest;
+                double oRatio = 1.0 / ratio;
+
+                if ( std::max( ratio, oRatio ) < 3.0 )
+                {
+                    int kkk = 1;
+                    largestZone = this->Split( largestZone, nMaxCell );
+                    timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                    this->RemoveZoneFromUnsignedGroup( largestZone );
+                    this->AddZoneToProcess( iProc, largestZone );
+                }
+                else
+                {
+                    this->Split( largestZone, nHalf );
+                }
+            }
+            else
+            {
+                //If the block is of the right size, join the process directly, and there is no need to split it.
+                timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                this->RemoveZoneFromUnsignedGroup( largestZone );
+                this->AddZoneToProcess( iProc, largestZone );
+            }
+        }
+        else
+        {
+            //If the block is of the right size, join the process directly, and there is no need to split it.
+            timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+            this->RemoveZoneFromUnsignedGroup( largestZone );
+            this->AddZoneToProcess( iProc, largestZone );
+        }
+    }
+}
+
+void Partition::ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord )
+{
+    SplitZone * rootSplitZone = splitZone->GetRootZone();
+    Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+    int nNodes = splitZone->dimInfo.ComputeNumNodes();
+    std::cout << "nNodes = " << nNodes << "\n";
+
+    coord.resize( nNodes * sizeof(double) );
+
+    int index_dim = splitZone->dimInfo.dimList.size();
+    Coor * coor = zone->coors[ icoord ];
+
+    double * xlocal = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    double * xglobal = reinterpret_cast<double *>( const_cast<char *>( coor->coord.data() ) );
+    if ( index_dim == 1 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        for ( int i = imin; i < imax; ++ i )
+        {
+            xlocal[ icount++ ] = xglobal[ i ];
+        }
+    }
+    else if ( index_dim == 2 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        int jmin = splitZone->dimInfo.rmin[ 1 ] - 1;
+        int jmax = splitZone->dimInfo.rmax[ 1 ];
+        int ni = rootSplitZone->dimInfo.dimList[ 0 ];
+        int nj = rootSplitZone->dimInfo.dimList[ 1 ];
+        for ( int j = jmin; j < jmax; ++ j )
+        {
+            int jstride = j * ni;
+            for ( int i = imin; i < imax; ++ i )
+            {
+                xlocal[ icount++ ] = xglobal[ jstride + i ];
+            }
+        }
+    }
+}
+
+void Partition::DumpBc( SplitZone * splitZone )
+{
+}
+
+void Partition::DumpPartitionedGridFile()
+{
+    std::cout << "\n";
+    std::cout << "DumpPartitionedGridFile -------------------------------" << "\n";
+    std::cout << "\n";
+    int fileId = -1;
+    std::string filename = this->outName;
+    int ierr = cg_open( filename.c_str(), CG_MODE_WRITE, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+
+    std::vector<std::string> coordnames;
+    coordnames.push_back( "CoordinateX" );
+    coordnames.push_back( "CoordinateY" );
+    coordnames.push_back( "CoordinateZ" );
+
+    std::string basename = "Base";
+    int baseId = -1;
+    int icelldim = Global::cell_dim;
+    int iphysdim = Global::phys_dim;
+    cg_base_write( fileId, basename.c_str(), icelldim, iphysdim, &baseId );
+
+    std::cout << "baseId = " << baseId << "\n";
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        int nZones = this->GetNZones( iProc );
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            ZoneType_t zoneType = Structured;
+
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+
+            int index_dim = splitZone->dimInfo.dimList.size();
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            splitZone->dimInfo.ComputeISize();
+
+            int isize_dim = index_dim * 3;
+
+            std::vector<cgsize_t> isize( index_dim * 3, 0 );
+            for ( int m = 0; m < isize_dim; ++ m )
+            {
+                isize[ m ] = splitZone->dimInfo.isize[ m ];
+            }
+
+            int zoneId = -1;
+
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+
+            std::string zonename = "Zone" + std::to_string( splitZone->newIndex );
+
+            cg_zone_write( fileId, baseId, zonename.c_str(), isize.data(), zoneType, &zoneId );
+
+            std::cout << "zoneId = " << zoneId << "\n";
+            std::cout << "zonename = " << zonename << "\n";
+                
+            splitZone->ComputeRminmax();
+
+            SplitZone * rootSplitZone = splitZone->GetRootZone();
+
+            Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+            int ncoords = zone->coors.size();
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = -1;
+                DataType_t dataType = RealDouble;
+                std::string coordname = coordnames[ icoord ];
+                Coor * coor = zone->coors[ icoord ];
+
+                int nNodes = splitZone->dimInfo.ComputeNumNodes();
+                std::cout << "nNodes = " << nNodes << "\n";
+
+                std::vector<char> coord;
+                ComputeCoor( splitZone, icoord, coord );
+
+                cg_coord_write( fileId, baseId, zoneId, dataType, coordname.c_str(), coord.data(), &coorId );
+
+                std::cout << "fileId = " << fileId  << " baseId = " << baseId << " zoneId = " << zoneId  << " coorId = " << coorId << "\n";
+            }
+
+            std::vector< PhysicalSplitBc * > &bccoList = splitZone->physicalSplitBcList;
+
+            int nbocos = bccoList.size();
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = -1;
+                GridLocation_t location = Vertex;
+
+                std::string boconame = "BC" + std::to_string( iboco + 1 );
+
+                PhysicalSplitBc * physicalSplitBc = bccoList[ iboco ];
+                BCType_t bocotype = static_cast<BCType_t>( physicalSplitBc->bcType );
+                PointSetType_t ptset_type = PointRange;
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> pnts;
+                int nSize = physicalSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.end[ i ] );
+                }
+
+                cg_boco_write( fileId, baseId, zoneId, boconame.c_str(), bocotype, ptset_type, npnts, pnts.data(), & bccoId );
+            }
+
+            std::vector< InterfaceSplitBc * > & bc1to1List = splitZone->interfaceSplitBcList;
+
+            int n1to1 = bc1to1List.size();
+            std::cout << "n1to1 = " << n1to1 << "\n";
+
+            std::vector<int> itranfrm( index_dim );
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                itranfrm[ m ] = m + 1;
+            }
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int index_conn = -1;
+
+                InterfaceSplitBc * interfaceSplitBc = bc1to1List[ i1to1 ];
+
+                std::vector<cgsize_t> pnts;
+                std::vector<cgsize_t> pntsdonor;
+                int nSize = interfaceSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.end[ i ] );
+                }
+
+                int nPatchSize = interfaceSplitBc->donor_region.start.size();
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.start[ i ] );
+                }
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.end[ i ] );
+                }
+                int id = interfaceSplitBc->donor_zone->newIndex;
+                int oldZoneIndex = interfaceSplitBc->donor_zone->zoneIndex;
+                std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+                std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+                std::cout << "donor zone id = " << id << "\n";
+                std::cout << "donor zone oldZoneIndex = " << oldZoneIndex << "\n";
+                std::string donorname = "Zone" + std::to_string( id );
+                std::string connectname = "Interface" + std::to_string( i1to1 );
+
+                std::cout << "donorname = " << donorname << "\n";
+                std::cout << "connectname = " << connectname << "\n";
+
+                std::vector<int> & itranfrm = interfaceSplitBc->transform;
+
+                cg_1to1_write( fileId, baseId, zoneId, connectname.c_str(), donorname.c_str(), pnts.data(), pntsdonor.data(), itranfrm.data(), &index_conn );
+                std::cout << "index_conn = " << index_conn << "\n";
+            }
+        }
+    }
+    cg_close( fileId );
+}
+
+void Partition::ModifyZoneIndex()
+{
+    std::cout << "ModifyZoneIndex +++++++++++++++++++++++++ " << "\n";
+    int globalZoneId = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        std::cout << "iProc = " << iProc << "\n";
+        int nZones = this->GetNZones( iProc );
+        std::cout << "nZones in Proc " << iProc << "  = " << nZones << "\n";
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+            //splitZone->SetZoneIndex( globalZoneId++ );
+            splitZone->newIndex = ( globalZoneId++ );
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+        }
+    }
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage1/01i/Partition.h b/example/partition/struct/2d/stage1/01i/Partition.h
new file mode 100644
index 00000000..8a4a9731
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01i/Partition.h
@@ -0,0 +1,59 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class SplitZone;
+
+struct CmpSplitZone 
+{
+    bool operator() ( SplitZone * a, SplitZone * b ) const;
+};
+
+class Partition
+{
+public:
+    Partition();
+    ~Partition();
+protected:
+    std::set < SplitZone * > zoneStorage;
+    std::set < SplitZone *, CmpSplitZone > unsignedZoneGroup;
+    std::vector< SplitZone * > refZone;
+    std::vector< std::vector< SplitZone * > > procSplitZone;
+    std::vector<double> procSpeed;
+    std::vector<double> timeProc;
+    double aveFloatOp, delta;
+    double idealUniProcTime, eps;
+    int minNumberCell;
+    int nTZone;
+    int nOriZone;
+    int nProc;
+public:
+    std::string inputName;
+    std::string outName;
+public:
+    void Solve();
+    void ReadGrid();
+    void Split();
+    void InitSplit();
+    void BinarySplit();
+    //void GreedySplit();
+public:
+    void AddNewZone( SplitZone * zone );
+    void AddZoneToUnsignedGroup( SplitZone * zone );
+    void RemoveZoneFromUnsignedGroup( SplitZone * zone );
+    void AddZoneToProcess( int iProc, SplitZone * zone );
+    void DumpPartitionedGridFile();
+    void ModifyZoneIndex();
+    void FreeAllZones();
+    int GetNZones( int iProc );
+    SplitZone * GetSplitZone( int iProc, int zoneId );
+    void ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord );
+    void DumpBc( SplitZone * splitZone );
+private:
+    int GetMinValueIndex( double * data, int numberOfData );
+    int GetMinLoadProc();
+    SplitZone * GetLargestZone();
+    SplitZone * Split( SplitZone * zone, double nCell );
+};
+
diff --git a/example/partition/struct/2d/stage1/01i/README.txt b/example/partition/struct/2d/stage1/01i/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01i/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/partition/struct/2d/stage1/01i/SplitZone.cpp b/example/partition/struct/2d/stage1/01i/SplitZone.cpp
new file mode 100644
index 00000000..25fea184
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01i/SplitZone.cpp
@@ -0,0 +1,1046 @@
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+int Dim::dim = -1;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox  )
+{
+    domainBox.start = zoneBox.start;
+    domainBox.end = zoneBox.end;
+
+    int axis = iDomain / 2;
+    int direction = iDomain % 2;
+
+    if ( direction == 0 )
+    {
+        domainBox.end[ axis ] = domainBox.start[ axis ];
+    }
+    else if ( direction == 1 )
+    {
+        domainBox.start[ axis ] = domainBox.end[ axis ];
+    }
+}
+
+DimInfo::DimInfo()
+{
+    this->Init( 1 );
+}
+
+DimInfo::~DimInfo()
+{
+}
+
+void DimInfo::Init( int dim )
+{
+    this->dim = dim;
+    dimList.resize( this->dim, 1 );
+    oriPoint.resize( this->dim, 0 );
+}
+
+DimInfo & DimInfo::operator = ( const DimInfo & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->dim = rhs.dim;
+    this->dimList = rhs.dimList;
+    this->oriPoint = rhs.oriPoint;
+
+    return * this;
+}
+
+int DimInfo::ComputeNumNodes()
+{
+    int nNodes = 1;
+    for ( int m = 0; m < this->dimList.size(); ++ m )
+    {
+        nNodes *= this->dimList[ m ];
+    }
+    return nNodes;
+}
+
+void DimInfo::ComputeISize()
+{
+    int index_dim = this->dimList.size();
+    this->isize.resize( index_dim * 3, 0 );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        isize[ m ] = this->dimList[ m ];
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 1;
+        isize[ start + m ] = this->dimList[ m ] - 1;
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 2;
+        isize[ start + m ] = 0;
+    }
+
+    for ( int i = 0; i < isize.size(); ++ i )
+    {
+        std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+    }
+}
+
+void DimInfo::ComputeRminmax( std::vector<int> & ref )
+{
+    int index_dim = this->dimList.size();
+    this->rmin.resize( index_dim );
+    this->rmax.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        rmin[ m ] = ref[ m ] + 1;
+        rmax[ m ] = ref[ m ] + this->dimList[ m ];
+    }
+
+    std::cout << "rmin, rmax = \n";
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        std::cout << rmin[ m ] << " " << rmax[ m ] << "\n";
+    }
+}
+
+void DimInfo::Init( std::vector<int> & dimList )
+{
+    this->dim = dimList.size();
+    this->dimList = dimList;
+    std::vector<int> zero( dimList.size(), 0 );
+    this->oriPoint = zero;
+}
+
+void DimInfo::SetNewDimension( int axis, int newStart, int newWidth )
+{
+    this->oriPoint[ axis ] = newStart;
+    this->dimList [ axis ] = newWidth;
+}
+
+void DimInfo::GetZoneGlobalBox( RangeRegion &zoneBox )
+{
+    int index_dim = this->dimList.size();
+    zoneBox.start.resize( index_dim );
+    zoneBox.end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        zoneBox.start[ m ] = this->oriPoint[ m ] + 1;
+        zoneBox.end[ m ] = this->oriPoint[ m ] + this->dimList[ m ];
+    }
+}
+
+void DimInfo::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    int index_dim = this->dimList.size();
+    localBox.start.resize( index_dim );
+    localBox.end.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        localBox.start[ m ] = globalBox.start[ m ] - this->oriPoint[ m ];
+        localBox.end[ m ] = globalBox.end[ m ] - this->oriPoint[ m ];
+    }
+}
+
+RangeRegion::RangeRegion( int nSize )
+{
+    this->Init( nSize );
+}
+
+RangeRegion::~RangeRegion()
+{
+}
+
+void RangeRegion::Init( int nSize )
+{
+    this->start.resize( nSize );
+    this->end.resize( nSize );
+}
+
+RangeRegion & RangeRegion::operator = ( const RangeRegion & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+bool RangeRegion::operator == ( const RangeRegion & rhs ) const
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] != rhs.start[ m ] || 
+            this->end  [ m ] != rhs.end  [ m ] )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+bool RangeRegion::InRegion( const RangeRegion & region )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( ( this->start[ m ] < region.start[ m ] ) || ( this->end[ m ] > region.end[ m ] ) )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::Normalize()
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        int minv = std::min( this->start[ m ], this->end[ m ] );
+        int maxv = std::max( this->start[ m ], this->end[ m ] );
+        this->start[ m ] = minv;
+        this->end[ m ] = maxv;
+    }
+}
+
+void RangeRegion::Localize( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] -= oriPoint[ m ];
+        this->end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void RangeRegion::AddShift( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] += oriPoint[ m ];
+        this->end[ m ] += oriPoint[ m ];
+    }
+}
+
+void RangeRegion::PrintGlobal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    std::cout << "global start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ] + oriPoint[m];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "global end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ] + oriPoint[m];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+void RangeRegion::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion );
+
+bool ComputeOverlapRegion( RangeRegion & region1, RangeRegion & region2, RangeRegion & overlapRegion )
+{
+    int index_dim = region1.start.size();
+    overlapRegion.Init( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int ijkmin1 = std::min( region1.start[ m ], region1.end[ m ] );
+        int ijkmax1 = std::max( region1.start[ m ], region1.end[ m ] );
+        int ijkmin2 = std::min( region2.start[ m ], region2.end[ m ] );
+        int ijkmax2 = std::max( region2.start[ m ], region2.end[ m ] );
+        if ( ( ijkmax1 < ijkmin2 ) || ( ijkmin1 > ijkmax2 ) )
+        {
+            return false;
+        }
+
+        int ijkmin = std::max( ijkmin1, ijkmin2 );
+        int ijkmax = std::min( ijkmax1, ijkmax2 );
+
+        overlapRegion.start[ m ] = ijkmin;
+        overlapRegion.end  [ m ] = ijkmax;
+    }
+
+    return CheckOverLapping( overlapRegion );
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion )
+{
+    int index_dim = overlapRegion.start.size();
+    int iCount = 0;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        if ( overlapRegion.start[ m ] == overlapRegion.end[ m ] )
+        {
+            ++ iCount;
+        }
+    }
+
+    return ( iCount == 1 );
+}
+
+bool GetInterfaceRegion( RangeRegion & zoneBoxL, RangeRegion & zoneBoxR, RangeRegion & interfaceRegion )
+{
+    int index_dim = zoneBoxL.start.size();
+    int nDomains = 2 * index_dim;
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegionL;
+        GetDomainRegion( zoneBoxL, iDomain, domainRegionL );
+
+        for ( int jDomain = 0; jDomain < nDomains; ++ jDomain )
+        {
+            RangeRegion domainRegionR;
+            GetDomainRegion( zoneBoxR, jDomain, domainRegionR );
+
+            if ( domainRegionL == domainRegionR )
+            {
+                interfaceRegion = domainRegionL;
+                return true;
+            }
+        }
+    }
+    return false;
+}
+
+void CreateInterfaceBc( SplitZone * zoneL, SplitZone * zoneR )
+{
+    RangeRegion globalBoxL, globalBoxR, globalInterfaceRegion;
+
+    zoneL->GetZoneGlobalBox( globalBoxL );
+    zoneR->GetZoneGlobalBox( globalBoxR );
+
+    if ( ! GetInterfaceRegion( globalBoxL, globalBoxR, globalInterfaceRegion ) )
+    {
+        return;
+    }
+
+    RangeRegion localInterfaceRegionL, localInterfaceRegionR;
+
+    zoneL->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionL );
+    zoneR->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionR );
+
+    int kkk = 1;
+
+    InterfaceSplitBc * interfaceSplitBcL = new InterfaceSplitBc();
+    zoneL->interfaceSplitBcList.push_back( interfaceSplitBcL );
+    interfaceSplitBcL->zone = zoneL;
+    interfaceSplitBcL->region = localInterfaceRegionL;
+
+    int nSize = localInterfaceRegionL.start.size();
+
+    std::vector<int> transform;
+
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        transform.push_back( m + 1 );
+    }
+
+    interfaceSplitBcL->transform = transform;
+    interfaceSplitBcL->CalcTransformMatrix();
+
+    interfaceSplitBcL->donor_zone = zoneR;
+    interfaceSplitBcL->donor_region = localInterfaceRegionR;
+
+    InterfaceSplitBc * interfaceSplitBcR = new InterfaceSplitBc();
+    zoneR->interfaceSplitBcList.push_back( interfaceSplitBcR );
+
+    interfaceSplitBcR->zone = zoneR;
+    interfaceSplitBcR->region = localInterfaceRegionR;
+
+    interfaceSplitBcR->transform = transform;
+    interfaceSplitBcR->CalcTransformMatrix();
+
+    interfaceSplitBcR->donor_zone = zoneL;
+    interfaceSplitBcR->donor_region = localInterfaceRegionL;
+}
+
+
+PhysicalSplitBc::PhysicalSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+PhysicalSplitBc::~PhysicalSplitBc()
+{
+}
+
+void PhysicalSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void PhysicalSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+void PhysicalSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = splitZone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+BasicSplitBc::BasicSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+BasicSplitBc::~BasicSplitBc()
+{
+    ;
+}
+
+void BasicSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void BasicSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+int trans::M[ 3 ][ 3 ];
+std::vector<int> trans::transform;
+
+int trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void trans::CalcTransformMatrix()
+{
+    int dim = trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = trans::transform[ 0 ];
+        int sgna = trans::sgn( a );
+        int a1 = trans::del( a, 1 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int c = trans::transform[ 2 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int sgnc = trans::sgn( c );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int a3 = trans::del( a, 3 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        int b3 = trans::del( b, 3 );
+        int c1 = trans::del( c, 1 );
+        int c2 = trans::del( c, 2 );
+        int c3 = trans::del( c, 3 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 2 ][ 0 ] = sgna * a3;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+        trans::M[ 2 ][ 1 ] = sgnb * b3;
+        trans::M[ 0 ][ 2 ] = sgnc * c1;
+        trans::M[ 1 ][ 2 ] = sgnc * c2;
+        trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+InterfaceInfo::InterfaceInfo()
+{
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceInfo::~InterfaceInfo()
+{
+}
+
+InterfaceSplitBc::InterfaceSplitBc()
+{
+    this->region.Init( Dim::dim );
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceSplitBc::~InterfaceSplitBc()
+{
+}
+
+void InterfaceSplitBc::CopyMatrix( InterfaceSplitBc * interfaceSplitBc )
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = interfaceSplitBc->Mt[ i ][ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::CalcTransformMatrix()
+{
+    trans::ZeroMatrix();
+    trans::transform = this->transform;
+    trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = trans::M[ i ][ j ];
+        }
+    }
+
+}
+
+void InterfaceSplitBc::mapindex( std::vector<int> & begin1, std::vector<int> & begin2,  std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = Dim::dim;
+    std::vector<int> diff( dim );
+    for ( int m = 0; m < dim; ++ m )
+    {
+        diff[ m ] = index1[ m ] - begin1[ m ];
+    }
+
+    std::vector<int> mul( dim );
+
+    Multiply( Mt, diff, mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = mul[ m ] + begin2[ m ];
+    }
+}
+
+void InterfaceSplitBc::Multiply( int Mt[][3], std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = Dim::dim;
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = this->zone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void InterfaceSplitBc::CalcSubDonorRegion( RangeRegion &subRegion, RangeRegion &subDonorRegion )
+{
+    std::vector<int> begin1 = this->region.start;
+    std::vector<int> end1 = this->region.end;
+    std::vector<int> begin2 = this->donor_region.start;
+    std::vector<int> end2 = this->donor_region.end;
+
+    std::vector<int> new_begin1 = subRegion.start;
+    std::vector<int> new_end1 = subRegion.end;
+
+    int dim = Dim::dim;
+    std::vector<int> new_begin2( dim );
+    std::vector<int> new_end2( dim );
+
+    mapindex( begin1, begin2, new_begin1, new_begin2 );
+    mapindex( begin1, begin2, new_end1, new_end2 );
+
+    subDonorRegion.start = new_begin2;
+    subDonorRegion.end = new_end2;
+}
+
+SplitZone::SplitZone()
+{
+    this->parent  = 0;
+    this->zoneIndex = 0;
+    this->iProc = 0;
+    dimInfo.Init( Dim::dim );
+    int kk = 1;
+}
+
+SplitZone::~SplitZone()
+{
+    ;
+}
+
+void SplitZone::GetZoneGlobalBox( RangeRegion & zoneBox )
+{
+    this->dimInfo.GetZoneGlobalBox( zoneBox );
+}
+
+void SplitZone::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    this->dimInfo.GetZoneLocalBox( globalBox, localBox );
+}
+
+
+void SplitZone::ComputeRminmax()
+{
+    int index_dim = this->dimInfo.dimList.size();
+    std::vector<int> ref( index_dim, 0 );
+
+    SplitZone * rootSplitZone = 0;
+    this->GetRootInfo( rootSplitZone, ref );
+
+    this->dimInfo.ComputeRminmax( ref );
+}
+
+SplitZone * SplitZone::GetRootZone()
+{
+    SplitZone * root = this;
+
+    while ( true )
+    {
+        if ( root->parent )
+        {
+            root = root->parent;
+        }
+        else
+        {
+            return root;
+        }
+    };
+}
+
+void SplitZone::GetRootInfo( SplitZone *& root, std::vector<int> & ref )
+{
+    for ( int i = 0; i < this->dimInfo.dimList.size(); ++ i )
+    {
+        ref[ i ] += this->dimInfo.oriPoint[ i ];
+    }
+
+    if ( this->parent )
+    {
+        this->parent->GetRootInfo( root, ref );
+    }
+    else
+    {
+        root = this;
+    }
+}
+
+void SplitZone::SetParentAndChild( SplitZone * parent )
+{
+    this->parent = parent;
+    if ( parent )
+    {
+        parent->child.push_back( this );
+    }
+}
+
+
+int SplitZone::GetNCell()
+{
+    int numberOfCells = 1;
+    for ( int i = 0; i < this->dimInfo.dim; ++ i )
+    {
+        numberOfCells *= std::max( 1, ( this->dimInfo.dimList[ i ] - 1 ) );
+    }
+
+    return numberOfCells; 
+}
+
+void SplitZone::SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int leftStart = 0;
+    int leftWidth = iSplit - 0;
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, leftStart , leftWidth  );
+}
+
+void SplitZone::SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int rightStart = iSplit - 1;
+    int rightWidth = dimList[ axisNeedSplit ] - ( iSplit - 1 );
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, rightStart, rightWidth );
+}
+
+void SplitZone::Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell )
+{
+    //Find the longest axis
+    int axisNeedSplit = this->FindAxisNeedSplit();
+    int iSplit        = this->FindSplitPosition( axisNeedSplit, nCell );
+
+    zoneL->SetLeftDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+    zoneR->SetRightDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+
+    zoneL->CreateBcFromParent();
+    zoneR->CreateBcFromParent();
+    
+    CreateInterfaceBc( zoneL, zoneR );
+}
+
+void SplitZone::CreateBcFromParent()
+{
+    this->CreatePhysicalBcFromParent();
+    this->CreateInterfaceBcFromParent();
+}
+
+void SplitZone::CreatePhysicalBcFromParent()
+{
+    int nParentPhysicalBcs = this->parent->physicalSplitBcList.size();
+
+    for ( int iParentPhysicalBcs = 0; iParentPhysicalBcs < nParentPhysicalBcs; ++ iParentPhysicalBcs )
+    {
+        PhysicalSplitBc * parentPhysicalSplitBc = this->parent->physicalSplitBcList[ iParentPhysicalBcs ];
+
+        this->CreatePhysicalBcFromParent( parentPhysicalSplitBc );
+    }
+}
+
+void SplitZone::CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentPhysicalSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreatePhysicalBc( overlapRegion, parentPhysicalSplitBc->bcType );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent()
+{
+    int nInterfaceSplitBcs = this->parent->interfaceSplitBcList.size();
+
+    for ( int iInterfaceSplitBcs = 0; iInterfaceSplitBcs < nInterfaceSplitBcs; ++ iInterfaceSplitBcs )
+    {
+        InterfaceSplitBc * parentInterfaceSplitBc = this->parent->interfaceSplitBcList[ iInterfaceSplitBcs ];
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc );
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentInterfaceSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc, overlapRegion );
+
+        int kkk = 1;
+    }
+}
+
+InterfaceSplitBc * SplitZone::FindDonorInterface( InterfaceSplitBc * interfaceSplitBc, InterfaceInfo & interfaceInfo )
+{
+    RangeRegion donor_region = interfaceSplitBc->donor_region;
+    donor_region.Normalize();
+    interfaceInfo.donor_zone = this;
+    for ( int iInterface = 0; iInterface < interfaceSplitBcList.size(); ++ iInterface )
+    {
+        InterfaceSplitBc * candidateDonorBc = interfaceSplitBcList[ iInterface ];
+        bool flag = donor_region.InRegion( candidateDonorBc->region );
+        if ( flag )
+        {
+            if ( donor_region == candidateDonorBc->region )
+            {
+                interfaceInfo.donor_interface = candidateDonorBc;
+                return candidateDonorBc;
+            }
+            else
+            {
+                InterfaceSplitBc * donorBc = new InterfaceSplitBc();
+                candidateDonorBc->child.push_back( donorBc );
+                donorBc->region = donor_region;
+                donorBc->zone = candidateDonorBc->zone;
+                donorBc->donor_zone = interfaceSplitBc->zone;
+                donorBc->transform = candidateDonorBc->transform;
+                donorBc->CopyMatrix( candidateDonorBc );
+                RangeRegion subDonorRegion( Dim::dim );
+                candidateDonorBc->CalcSubDonorRegion( donorBc->region, subDonorRegion );
+                std::vector<int> & oriPoint = interfaceSplitBc->zone->dimInfo.oriPoint;
+                subDonorRegion.Localize( oriPoint );
+                donorBc->donor_region = subDonorRegion;
+                donorBc->donor_bc = interfaceSplitBc;
+                interfaceInfo.donor_interface = donorBc;
+                return donorBc;
+            }
+        }
+    }
+    return nullptr;
+}
+
+void SplitZone::GetChildDonorRegion( RangeRegion & subDonorRegion, InterfaceInfo & interfaceInfo )
+{
+    std::cout << "subDonorRegion = \n";
+    subDonorRegion.Print();
+    int nChild = this->child.size();
+    for ( int ichild = 0; ichild < nChild; ++ ichild )
+    {
+        std::cout << " iChild = " << ichild << " nChild = " << nChild << "\n";
+        SplitZone * sub_zone = this->child[ ichild ];
+        std::cout << " zoneIndex = " << sub_zone->zoneIndex << "\n";
+        int nInters = sub_zone->interfaceSplitBcList.size();
+        for ( int iInter = 0; iInter < nInters; ++ iInter )
+        {
+            std::cout << " iInter = " << iInter << "\n";
+            InterfaceSplitBc * interfaceSplitBc = sub_zone->interfaceSplitBcList[ iInter ];
+            std::cout << "interfaceSplitBc local = \n";
+            interfaceSplitBc->region.Print();
+            std::cout << "interfaceSplitBc global = \n";
+            interfaceSplitBc->region.PrintGlobal( sub_zone->dimInfo.oriPoint );
+            RangeRegion g_region = interfaceSplitBc->region;
+            g_region.AddShift( sub_zone->dimInfo.oriPoint );
+            if ( g_region == subDonorRegion )
+            {
+                interfaceInfo.donor_zone = sub_zone;
+                interfaceInfo.donor_interface = interfaceSplitBc;
+                interfaceInfo.donor_region = interfaceSplitBc->region;
+                return;
+            }
+        }
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion )
+{
+    InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+    this->interfaceSplitBcList.push_back( interfaceSplitBc );
+
+    interfaceSplitBc->region = overlapRegion;
+    interfaceSplitBc->zone = this;
+    interfaceSplitBc->transform = parentInterfaceSplitBc->transform;
+    interfaceSplitBc->CopyMatrix( parentInterfaceSplitBc );
+    RangeRegion subDonorRegion( Dim::dim );
+    parentInterfaceSplitBc->CalcSubDonorRegion( overlapRegion, subDonorRegion );
+    interfaceSplitBc->ChangeRegionToLocalCoordinate();
+    interfaceSplitBc->donor_region = subDonorRegion;
+    SplitZone * parent_donor_zone = parentInterfaceSplitBc->donor_zone;
+    std::cout << " parentInterfaceSplitBc->zone->zoneIndex " << parentInterfaceSplitBc->zone->zoneIndex << "\n";
+    std::cout << " parentInterfaceSplitBc->donor_zone->zoneIndex " << parent_donor_zone->zoneIndex << "\n";
+    if ( parent_donor_zone->child.size() > 0 )
+    {
+        InterfaceInfo interfaceInfo;
+        parent_donor_zone->GetChildDonorRegion( subDonorRegion, interfaceInfo );
+        interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+        interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+        interfaceSplitBc->donor_region = interfaceInfo.donor_region;
+        //compatibility
+        InterfaceSplitBc * donor_bc = interfaceSplitBc->donor_bc;
+        SplitZone * donor_zone = interfaceSplitBc->donor_zone;
+        //if ( donor_bc->donor_zone->zoneIndex == interfaceSplitBc->zone->zoneIndex )
+        if ( interfaceSplitBc->zone != donor_bc->donor_zone )
+        {
+            donor_bc->donor_zone = interfaceSplitBc->zone;
+            donor_bc->donor_region = interfaceSplitBc->region;
+           
+            int kkk = 1;
+        }
+        int kkk = 1;
+    }
+    else
+    {
+        InterfaceInfo interfaceInfo;
+        parent_donor_zone->FindDonorInterface( interfaceSplitBc, interfaceInfo );
+        interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+        interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+    }
+    
+    int kkk = 1;
+}
+
+void SplitZone::CreatePhysicalBc( RangeRegion & overlapRegion, int bcType )
+{
+    PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+    this->physicalSplitBcList.push_back( physicalSplitBc );
+    physicalSplitBc->SetRegion( overlapRegion );
+    physicalSplitBc->bcType = bcType;
+    physicalSplitBc->splitZone = this;
+    physicalSplitBc->ChangeRegionToLocalCoordinate();
+}
+
+int SplitZone::FindAxisNeedSplit()
+{
+    //Find the longest axis
+    int axisNeedSplit = 0;
+    int maxN = this->dimInfo.dimList[ 0 ];
+
+    for ( int m = 1; m < this->dimInfo.dimList.size(); ++ m )
+    {
+        if ( this->IsPoleBc( m ) )
+        {
+            continue;
+        }
+        int Nm = this->dimInfo.dimList[ m ];
+        if ( maxN < Nm )
+        {
+            maxN = Nm;
+            axisNeedSplit = m;
+        }
+    }
+
+    return axisNeedSplit;
+}
+
+int SplitZone::GetCrossSection( int axis )
+{
+    int nDim = this->dimInfo.dimList.size();
+    int crossSection = 1;
+    int N = nDim - 1;
+    for ( int m = 0; m < N; ++ m )
+    {
+         int mm = ( axis + 1 ) % nDim;
+         int nLineElements = std::max( 1, ( this->dimInfo.dimList[ mm ] - 1 ) );
+         crossSection *= nLineElements;
+    }
+    return crossSection;
+}
+
+int SplitZone::FindSplitPosition( int axisNeedSplit, double nCell )
+{
+    int nDim = this->dimInfo.dimList.size();
+    std::vector<int> crossSections( nDim );
+    for ( int m = 0; m < nDim; ++ m )
+    {
+        crossSections[ m ] = this->GetCrossSection( m );
+    }
+
+    //guess the value
+    double dSplit = nCell / crossSections[ axisNeedSplit ];
+    int  iSplit = 1 + static_cast< int >( std::floor( dSplit + 0.5 ) );
+    return iSplit;
+}
+
+
+bool SplitZone::IsPoleBc( int splitDirection )
+{
+    return false;
+}
+
diff --git a/example/partition/struct/2d/stage1/01i/SplitZone.h b/example/partition/struct/2d/stage1/01i/SplitZone.h
new file mode 100644
index 00000000..d387037e
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01i/SplitZone.h
@@ -0,0 +1,193 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class Dim
+{
+public:
+    static int dim;
+};
+
+class SplitZone;
+class RangeRegion;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox );
+
+class DimInfo
+{
+public:
+    DimInfo();
+    ~DimInfo();
+public:
+    int dim;
+    std::vector<int> dimList;
+    std::vector<int> oriPoint;
+    std::vector<int> isize;
+    std::vector<int> rmin;
+    std::vector<int> rmax;
+public:
+    int GetSize() const { return dim; }
+    DimInfo & operator = ( const DimInfo & rhs );
+public:
+    int ComputeNumNodes();
+    void ComputeISize();
+    void ComputeRminmax( std::vector<int> & ref );
+    void Init( int dim );
+    void Init( std::vector<int> & dimList );
+    void SetNewDimension( int axis, int newStart, int newWidth );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+};
+
+class SplitZone;
+class SplitBcPatch;
+
+class RangeRegion
+{
+public:
+    RangeRegion( int nSize = 1 );
+    ~RangeRegion();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    void Init( int nSize );
+    RangeRegion & operator = ( const RangeRegion & rhs );
+    bool operator == ( const RangeRegion & rhs ) const;
+    bool InRegion( const RangeRegion & region );
+    void SetRegion( std::vector<int> &pnts );
+    void Normalize();
+    void Localize( std::vector<int> & oriPoint );
+    void AddShift( std::vector<int> & oriPoint );
+    void PrintGlobal( std::vector<int> & oriPoint );
+    void Print();
+};
+
+class PhysicalSplitBc
+{
+public:
+    PhysicalSplitBc();
+    ~PhysicalSplitBc();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class BasicSplitBc
+{
+public:
+    BasicSplitBc();
+    ~BasicSplitBc();
+public:
+    RangeRegion region;
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> & pnts );
+    void SetRegion( RangeRegion & region );
+};
+
+class trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class InterfaceSplitBc;
+class SplitZone;
+
+class InterfaceInfo
+{
+public:
+    InterfaceInfo();
+    ~InterfaceInfo();
+public:
+    InterfaceSplitBc * donor_interface = nullptr;
+    SplitZone * donor_zone = nullptr;
+    RangeRegion donor_region;
+};
+
+class InterfaceSplitBc
+{
+public:
+    InterfaceSplitBc();
+    ~InterfaceSplitBc();
+public:
+    std::vector<int> transform;
+    int Mt[ 3 ][ 3 ];
+    RangeRegion region;
+    SplitZone * zone = nullptr;
+    RangeRegion donor_region;
+    SplitZone * donor_zone = nullptr;
+    InterfaceSplitBc * donor_bc = nullptr;
+public:
+    std::vector<InterfaceSplitBc *> child;
+public:
+    void CopyMatrix( InterfaceSplitBc * interfaceSplitBc );
+    void CalcTransformMatrix();
+    void CalcSubDonorRegion( RangeRegion & subRegion, RangeRegion & subDonorRegion );
+    void mapindex( std::vector<int> & begin1, std::vector<int> & begin2, std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( int Mt[][ 3 ], std::vector<int> & a, std::vector<int> & b );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class SplitZone
+{
+public:
+    SplitZone();
+    ~SplitZone();
+public:
+    DimInfo dimInfo;
+    int zoneIndex, iProc;
+    int newIndex;
+protected:
+    SplitZone * parent;
+    std::vector<SplitZone *> child;
+public:
+    std::vector< PhysicalSplitBc * > physicalSplitBcList;
+    std::vector< InterfaceSplitBc * > interfaceSplitBcList;
+public:
+    int GetNCell();
+    void ComputeRminmax();
+    void GetRootInfo( SplitZone *& root, std::vector<int> & ref );
+    void SetZoneIndex( int zoneIndex ) { this->zoneIndex = zoneIndex; }
+    int  GetZoneIndex() { return zoneIndex; }
+    void SetProcId( int iProc ) { this->iProc = iProc; }
+    void SetParent( SplitZone * parent ) { this->parent = parent; };
+    void SetParentAndChild( SplitZone * parent );
+    InterfaceSplitBc * FindDonorInterface( InterfaceSplitBc * interfaceSplitBc, InterfaceInfo & interfaceInfo );
+    void GetChildDonorRegion( RangeRegion & subDonorRegion, InterfaceInfo & interfaceInfo );
+public:
+    void CreateBcFromParent();
+    void CreatePhysicalBcFromParent();
+    void CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc );
+    void CreatePhysicalBc( RangeRegion & overlapRegion, int bcType );
+    void CreateInterfaceBcFromParent();
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc );
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion );
+
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+    SplitZone * GetRootZone();
+public:
+    void Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell );
+    void SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+    void SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+private:
+    int FindAxisNeedSplit();
+    int FindSplitPosition( int axisNeedSplit, double nCell );
+    bool IsPoleBc( int splitDirection );
+    int GetCrossSection( int axis );
+};
+
diff --git a/example/partition/struct/2d/stage1/01i/heat2d2blocks.cgns b/example/partition/struct/2d/stage1/01i/heat2d2blocks.cgns
new file mode 100644
index 00000000..ab4dcea5
Binary files /dev/null and b/example/partition/struct/2d/stage1/01i/heat2d2blocks.cgns differ
diff --git a/example/partition/struct/2d/stage1/01i/main.cpp b/example/partition/struct/2d/stage1/01i/main.cpp
new file mode 100644
index 00000000..5da1de7c
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01i/main.cpp
@@ -0,0 +1,18 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include "Partition.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip>
+
+int main(int argc, char **argv)
+{
+    Partition * partition = new Partition();
+    partition->Solve();
+    delete partition;
+
+    return 0;
+}
diff --git a/example/partition/struct/2d/stage1/01j/CMakeLists.txt b/example/partition/struct/2d/stage1/01j/CMakeLists.txt
new file mode 100644
index 00000000..74ceea7d
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01j/CMakeLists.txt
@@ -0,0 +1,78 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	Partition.h Partition.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	SplitZone.h SplitZone.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/partition/struct/2d/stage1/01j/CgnsGrid.cpp b/example/partition/struct/2d/stage1/01j/CgnsGrid.cpp
new file mode 100644
index 00000000..dfe750bd
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01j/CgnsGrid.cpp
@@ -0,0 +1,349 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include <map>
+
+Grid::Grid()
+{
+    ;
+}
+
+Grid::~Grid()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if( (i+1)%5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+    delete this->patch;
+}
+
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+ZoneBcPatch::ZoneBcPatch()
+{
+    ;
+}
+
+ZoneBcPatch::~ZoneBcPatch()
+{
+}
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+Global::Global()
+{
+    ;
+}
+
+Global::~Global()
+{
+}
+
+void Global::FreeData()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+    zones.resize( 0 );
+}
+
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            //baseZone.baseId = baseId;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin( index_dim );
+            std::vector<cgsize_t> irmax( index_dim );
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                std::vector<char> coord( nNodes * sizeof(double) );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+                coor->DumpCoor();
+            }
+
+            int nbocos = -1;
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+                int kkk = 1;
+            }
+        }
+        int kkk = 1;
+    }
+    int kkk = 1;
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage1/01j/CgnsGrid.h b/example/partition/struct/2d/stage1/01j/CgnsGrid.h
new file mode 100644
index 00000000..053c467b
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01j/CgnsGrid.h
@@ -0,0 +1,140 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <map>
+
+class Grid;
+
+class Zone;
+
+class Grid
+{
+public:
+    Grid();
+    ~Grid();
+public:
+    int nZone;
+    std::vector<double> x;
+    std::vector<Zone *> zones;
+};
+
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+};
+
+class ZoneBc;
+class ZoneBc1To1;
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class ZoneBcPatch;
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+    ZoneBcPatch * patch = nullptr;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+class ZoneBcPatch
+{
+public:
+    ZoneBcPatch();
+    ~ZoneBcPatch();
+public:
+    int donor_zoneid;
+    std::vector<int> transform;
+    std::vector<int> donor_pnts;
+};
+
+class BaseZone
+{
+public:
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Global
+{
+public:
+    Global();
+    ~Global();
+public:
+    static int cell_dim;
+    static int phys_dim;
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+public:
+    static void FreeData();
+};
+
+void ReadCgnsGrid( const std::string & filename );
+void ReadCgnsGridBaseZone( const std::string & filename );
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage1/01j/Partition.cpp b/example/partition/struct/2d/stage1/01j/Partition.cpp
new file mode 100644
index 00000000..86d4c39f
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01j/Partition.cpp
@@ -0,0 +1,618 @@
+#include "Partition.h"
+#include "CgnsGrid.h"
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+bool CmpSplitZone::operator() ( SplitZone * a, SplitZone * b ) const
+{
+    return a->zoneIndex < b->zoneIndex;
+};
+
+
+double CalSumOfProcSpeed( std::vector<double> & procSpeed );
+double CalSumOfProcSpeed( std::vector<double> & procSpeed )
+{
+    int nProc = procSpeed.size();
+    double sumOfProcSpeed = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        sumOfProcSpeed += procSpeed[ iProc ];
+    }
+    return sumOfProcSpeed;
+}
+
+Partition::Partition()
+{
+    this->inputName = "../heat2d2blocks.cgns";
+    this->outName =  "../heat2dpart.cgns";
+}
+
+Partition::~Partition()
+{
+    ;
+}
+
+int Partition::GetMinValueIndex( double * data, int numberOfData )
+{
+    double minValue = data[ 0 ];
+    int minimumValueIndex = 0;
+
+    for ( int iData = 1; iData < numberOfData; ++ iData )
+    {
+        if ( minValue > data[ iData ] )
+        {
+            minValue      = data[ iData ];
+            minimumValueIndex = iData;
+        }
+    }
+    return minimumValueIndex;
+}
+
+int Partition::GetMinLoadProc()
+{
+    return this->GetMinValueIndex( this->timeProc.data(), this->nProc );
+}
+
+SplitZone * Partition::GetLargestZone()
+{
+    SplitZone * largestZone = 0;
+
+    double nMaxCell = 0.0;
+
+    for ( std::set< SplitZone * >::iterator iter = unsignedZoneGroup.begin(); iter != unsignedZoneGroup.end(); ++ iter )
+    {
+        double nSize = ( * iter )->GetNCell();
+        if ( nMaxCell < nSize )
+        {
+            nMaxCell    = nSize;
+            largestZone = * iter;
+        }
+    }
+
+    return largestZone;
+}
+
+void Partition::Solve()
+{
+    std::cout << "Partition::Split()\n";
+    //this->nProc = 2;
+    this->nProc = 4;
+    this->ReadGrid();
+    this->Split();
+    this->DumpPartitionedGridFile();
+    this->FreeAllZones();
+}
+
+void Partition::ReadGrid()
+{
+    ReadCgnsGridBaseZone( this->inputName );
+    ReadCgnsGrid( this->inputName );
+
+    this->nOriZone = ::Global::zones.size();
+    Dim::dim = Global::cell_dim;
+
+    std::cout << "numberOfBlocks = " << nOriZone << "\n";
+
+    this->refZone.resize( nOriZone );
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = new SplitZone();
+        refZone[ iZone ] = splitZone;
+
+        splitZone->SetZoneIndex( iZone );
+        splitZone->SetProcId( 0 );
+        splitZone->SetParentAndChild( 0 );
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        Zone * zone = ::Global::zones[ iZone ];
+
+        splitZone->dimInfo.dimList = zone->nijk;
+
+        int nbccos = zone->bccos.size();
+        std::cout << "nbccos = " << nbccos << "\n";
+
+        for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+        {
+            ZoneBc * zoneBc = zone->bccos[ ibcco ];
+
+            PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+            splitZone->physicalSplitBcList.push_back( physicalSplitBc );
+            physicalSplitBc->bcType = zoneBc->bcType;
+            physicalSplitBc->SetRegion( zoneBc->pnts );
+            physicalSplitBc->splitZone = splitZone;
+        }
+
+        int nbc1to1s = zone->bc1to1s.size();
+
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * zoneBc1To1 = zone->bc1to1s[ ibc1to1 ];
+
+            InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+            splitZone->interfaceSplitBcList.push_back( interfaceSplitBc );
+            interfaceSplitBc->zone = splitZone;
+            interfaceSplitBc->region.SetRegion( zoneBc1To1->pnts );
+
+            interfaceSplitBc->transform = zoneBc1To1->transform;
+            interfaceSplitBc->CalcTransformMatrix();
+
+            interfaceSplitBc->donor_zone = refZone[ zoneBc1To1->donor_zoneid ];
+            interfaceSplitBc->donor_region.SetRegion( zoneBc1To1->donor_pnts );
+        }
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        int nbc1to1s = splitZone->interfaceSplitBcList.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            InterfaceSplitBc * interfaceSplitBc = splitZone->interfaceSplitBcList[ ibc1to1 ];
+            InterfaceInfo interfaceInfo;
+            interfaceSplitBc->donor_zone->FindDonorInterface( interfaceSplitBc, interfaceInfo );
+            interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+            interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+        }
+    }
+}
+
+void Partition::Split()
+{
+    this->InitSplit();
+    this->BinarySplit();
+    this->ModifyZoneIndex();
+    int kkk = 1;
+}
+
+void Partition::InitSplit()
+{
+    //nZone is the number of zones in the original grid
+    //nProc is not the number of blocks in the end, but the number of processes that need to be divided.
+    //This difference occurs because the structure grid can have many blocks per process.
+
+    //this->nProc    = nProc;
+    //this->nPhyBlocks = referenceBlock.size();
+    //this->nZone  = this->nPhyBlocks;
+
+    //tj Computation time on processor j
+    //Nk Number of internal grid-cells for zone j
+    //aveFloatOp:  Number of Real operations per gridcell
+    //Gj The set of blocks allocated to process j
+    //Pj Real operations per second for process j
+
+    //The Greedy Load Balancing Algorithm
+    //1.Compute an "ideal" uniprocessor time, Tuni = sum ( Nk * aveFloatOp )/ sum( Pj ).
+    //2.Set the group of unassigned blocks, Gu, to contain all blocks. The number of blocks in Nu=M, where M is the total number of blocks in the mesh.
+    //3.Start all processors with a very small fictitious zone to get a start tj=delt aveFloatOp/Pj, where delt<<1 is the size of the very small fictious zone.
+    //This is used to find the fastest processor in a heterogeneous system, tj could otherwise be set to 0 in the homogeneous case.
+    this->aveFloatOp = 1.0;
+    this->delta      = 1.0e-5;
+    this->procSpeed.resize( nProc );
+    this->timeProc.resize( nProc );
+
+    this->nTZone = this->nOriZone;
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        procSpeed[ iProc ] = 1.0;
+    }
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        timeProc[ iProc ] = delta * aveFloatOp / procSpeed[ iProc ];
+    }
+
+    double sumProcSpeed = CalSumOfProcSpeed( procSpeed );
+
+    double sumProcOp = 0.0;
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        sumProcOp += refZone[ iZone ]->GetNCell() * aveFloatOp;
+    }
+
+    this->idealUniProcTime = sumProcOp / sumProcSpeed;
+
+    this->eps = 0.05;
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        unsignedZoneGroup.insert( refZone[ iZone ] );
+    }
+
+    //Init zoneStorage
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        zoneStorage.insert( refZone[ iZone ] );
+    }
+
+    //Assign procSplitZone to each process
+    procSplitZone.resize( nProc );
+
+    this->minNumberCell = 1;
+    for ( int m = 0; m < Dim::dim; ++ m )
+    {
+        this->minNumberCell *= 1;
+    }
+
+    int kkk = 1;
+
+}
+
+void Partition::FreeAllZones()
+{
+    int iCount = 0;
+    for ( std::set < SplitZone * >::iterator iter = zoneStorage.begin(); iter != zoneStorage.end(); ++ iter )
+    {
+        //cout << "iCount = " << iCount << "\n";
+        ++ iCount;
+        delete * iter;
+    }
+}
+
+int Partition::GetNZones( int iProc )
+{
+    return this->procSplitZone[ iProc ].size();
+}
+
+SplitZone * Partition::GetSplitZone( int iProc, int zoneId )
+{
+    return this->procSplitZone[ iProc ][ zoneId ];
+}
+
+void Partition::AddZoneToUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.insert( zone );
+}
+
+void Partition::RemoveZoneFromUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.erase( zone );
+}
+
+void Partition::AddZoneToProcess( int iProc, SplitZone * zone )
+{
+    this->procSplitZone[ iProc ].push_back( zone );
+}
+
+void Partition::AddNewZone( SplitZone * zone )
+{
+    zone->SetZoneIndex( nTZone ++ );
+
+    this->AddZoneToUnsignedGroup( zone );
+
+    this->zoneStorage.insert( zone );
+}
+
+SplitZone * Partition::Split( SplitZone * zone, double nCell )
+{
+    SplitZone * zoneL = new SplitZone();
+    zoneL->SetParentAndChild( zone );
+
+    SplitZone * zoneR = new SplitZone();
+    zoneR->SetParentAndChild( zone );
+
+    //Remove the original block from the UnsignedGroup
+    this->RemoveZoneFromUnsignedGroup( zone );
+
+    this->AddNewZone( zoneL );
+    this->AddNewZone( zoneR );
+
+    zone->Split( zoneL, zoneR, nCell );
+
+    return zoneL;
+}
+
+void Partition::BinarySplit()
+{
+    while ( ! unsignedZoneGroup.empty() )
+    {
+        std::cout << "number of unsigned zone = " << unsignedZoneGroup.size() << "\n";
+        int iProc = this->GetMinLoadProc();
+
+        //Get the block with the largest number of grids and its size
+        SplitZone * largestZone = this->GetLargestZone();
+
+        double nMaxCell = largestZone->GetNCell();
+
+        double aveFloatOp = this->aveFloatOp;
+        double tau = timeProc[ iProc ] + nMaxCell * aveFloatOp / procSpeed[ iProc ];
+
+        //It seems that EPS is still necessary
+        //The idea here is as follows. For the candidate blocks which can be divided into blocks, 
+        //if the difference between the target blocks and the candidate blocks is too wide, 
+        //the binarySplit method is adopted. The binarySplit blocks do not directly join the process,
+        //but enter the next round of screening.
+
+        if ( tau > idealUniProcTime * ( 1.0 + eps ) )
+        {
+            double nRest = ( tau - idealUniProcTime ) * procSpeed[ iProc ] / aveFloatOp;
+
+            double nTarget = nMaxCell - nRest;
+            if ( nRest > this->minNumberCell && nTarget > this->minNumberCell )
+            {
+                //It is necessary to divide blocks only when a certain number of points are satisfied.
+                double nHalf = nMaxCell / 2.0;
+                nMaxCell = nTarget;
+                double ratio = nMaxCell / nRest;
+                double oRatio = 1.0 / ratio;
+
+                if ( std::max( ratio, oRatio ) < 3.0 )
+                {
+                    int kkk = 1;
+                    largestZone = this->Split( largestZone, nMaxCell );
+                    timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                    this->RemoveZoneFromUnsignedGroup( largestZone );
+                    this->AddZoneToProcess( iProc, largestZone );
+                }
+                else
+                {
+                    this->Split( largestZone, nHalf );
+                }
+            }
+            else
+            {
+                //If the block is of the right size, join the process directly, and there is no need to split it.
+                timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                this->RemoveZoneFromUnsignedGroup( largestZone );
+                this->AddZoneToProcess( iProc, largestZone );
+            }
+        }
+        else
+        {
+            //If the block is of the right size, join the process directly, and there is no need to split it.
+            timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+            this->RemoveZoneFromUnsignedGroup( largestZone );
+            this->AddZoneToProcess( iProc, largestZone );
+        }
+    }
+}
+
+void Partition::ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord )
+{
+    SplitZone * rootSplitZone = splitZone->GetRootZone();
+    Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+    int nNodes = splitZone->dimInfo.ComputeNumNodes();
+    std::cout << "nNodes = " << nNodes << "\n";
+
+    coord.resize( nNodes * sizeof(double) );
+
+    int index_dim = splitZone->dimInfo.dimList.size();
+    Coor * coor = zone->coors[ icoord ];
+
+    double * xlocal = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    double * xglobal = reinterpret_cast<double *>( const_cast<char *>( coor->coord.data() ) );
+    if ( index_dim == 1 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        for ( int i = imin; i < imax; ++ i )
+        {
+            xlocal[ icount++ ] = xglobal[ i ];
+        }
+    }
+    else if ( index_dim == 2 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        int jmin = splitZone->dimInfo.rmin[ 1 ] - 1;
+        int jmax = splitZone->dimInfo.rmax[ 1 ];
+        int ni = rootSplitZone->dimInfo.dimList[ 0 ];
+        int nj = rootSplitZone->dimInfo.dimList[ 1 ];
+        for ( int j = jmin; j < jmax; ++ j )
+        {
+            int jstride = j * ni;
+            for ( int i = imin; i < imax; ++ i )
+            {
+                xlocal[ icount++ ] = xglobal[ jstride + i ];
+            }
+        }
+    }
+}
+
+void Partition::DumpBc( SplitZone * splitZone )
+{
+}
+
+void Partition::DumpPartitionedGridFile()
+{
+    std::cout << "\n";
+    std::cout << "DumpPartitionedGridFile -------------------------------" << "\n";
+    std::cout << "\n";
+    int fileId = -1;
+    std::string filename = this->outName;
+    int ierr = cg_open( filename.c_str(), CG_MODE_WRITE, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+
+    std::vector<std::string> coordnames;
+    coordnames.push_back( "CoordinateX" );
+    coordnames.push_back( "CoordinateY" );
+    coordnames.push_back( "CoordinateZ" );
+
+    std::string basename = "Base";
+    int baseId = -1;
+    int icelldim = Global::cell_dim;
+    int iphysdim = Global::phys_dim;
+    cg_base_write( fileId, basename.c_str(), icelldim, iphysdim, &baseId );
+
+    std::cout << "baseId = " << baseId << "\n";
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        int nZones = this->GetNZones( iProc );
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            ZoneType_t zoneType = Structured;
+
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+
+            int index_dim = splitZone->dimInfo.dimList.size();
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            splitZone->dimInfo.ComputeISize();
+
+            int isize_dim = index_dim * 3;
+
+            std::vector<cgsize_t> isize( index_dim * 3, 0 );
+            for ( int m = 0; m < isize_dim; ++ m )
+            {
+                isize[ m ] = splitZone->dimInfo.isize[ m ];
+            }
+
+            int zoneId = -1;
+
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+
+            std::string zonename = "Zone" + std::to_string( splitZone->newIndex );
+
+            cg_zone_write( fileId, baseId, zonename.c_str(), isize.data(), zoneType, &zoneId );
+
+            std::cout << "zoneId = " << zoneId << "\n";
+            std::cout << "zonename = " << zonename << "\n";
+                
+            splitZone->ComputeRminmax();
+
+            SplitZone * rootSplitZone = splitZone->GetRootZone();
+
+            Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+            int ncoords = zone->coors.size();
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = -1;
+                DataType_t dataType = RealDouble;
+                std::string coordname = coordnames[ icoord ];
+                Coor * coor = zone->coors[ icoord ];
+
+                int nNodes = splitZone->dimInfo.ComputeNumNodes();
+                std::cout << "nNodes = " << nNodes << "\n";
+
+                std::vector<char> coord;
+                ComputeCoor( splitZone, icoord, coord );
+
+                cg_coord_write( fileId, baseId, zoneId, dataType, coordname.c_str(), coord.data(), &coorId );
+
+                std::cout << "fileId = " << fileId  << " baseId = " << baseId << " zoneId = " << zoneId  << " coorId = " << coorId << "\n";
+            }
+
+            std::vector< PhysicalSplitBc * > &bccoList = splitZone->physicalSplitBcList;
+
+            int nbocos = bccoList.size();
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = -1;
+                GridLocation_t location = Vertex;
+
+                std::string boconame = "BC" + std::to_string( iboco + 1 );
+
+                PhysicalSplitBc * physicalSplitBc = bccoList[ iboco ];
+                BCType_t bocotype = static_cast<BCType_t>( physicalSplitBc->bcType );
+                PointSetType_t ptset_type = PointRange;
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> pnts;
+                int nSize = physicalSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.end[ i ] );
+                }
+
+                cg_boco_write( fileId, baseId, zoneId, boconame.c_str(), bocotype, ptset_type, npnts, pnts.data(), & bccoId );
+            }
+
+            std::vector< InterfaceSplitBc * > & bc1to1List = splitZone->interfaceSplitBcList;
+
+            int n1to1 = bc1to1List.size();
+            std::cout << "n1to1 = " << n1to1 << "\n";
+
+            std::vector<int> itranfrm( index_dim );
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                itranfrm[ m ] = m + 1;
+            }
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int index_conn = -1;
+
+                InterfaceSplitBc * interfaceSplitBc = bc1to1List[ i1to1 ];
+
+                std::vector<cgsize_t> pnts;
+                std::vector<cgsize_t> pntsdonor;
+                int nSize = interfaceSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.end[ i ] );
+                }
+
+                int nPatchSize = interfaceSplitBc->donor_region.start.size();
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.start[ i ] );
+                }
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.end[ i ] );
+                }
+                int id = interfaceSplitBc->donor_zone->newIndex;
+                int oldZoneIndex = interfaceSplitBc->donor_zone->zoneIndex;
+                std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+                std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+                std::cout << "donor zone id = " << id << "\n";
+                std::cout << "donor zone oldZoneIndex = " << oldZoneIndex << "\n";
+                std::string donorname = "Zone" + std::to_string( id );
+                std::string connectname = "Interface" + std::to_string( i1to1 );
+
+                std::cout << "donorname = " << donorname << "\n";
+                std::cout << "connectname = " << connectname << "\n";
+
+                std::vector<int> & itranfrm = interfaceSplitBc->transform;
+
+                cg_1to1_write( fileId, baseId, zoneId, connectname.c_str(), donorname.c_str(), pnts.data(), pntsdonor.data(), itranfrm.data(), &index_conn );
+                std::cout << "index_conn = " << index_conn << "\n";
+            }
+        }
+    }
+    cg_close( fileId );
+}
+
+void Partition::ModifyZoneIndex()
+{
+    std::cout << "ModifyZoneIndex +++++++++++++++++++++++++ " << "\n";
+    int globalZoneId = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        std::cout << "iProc = " << iProc << "\n";
+        int nZones = this->GetNZones( iProc );
+        std::cout << "nZones in Proc " << iProc << "  = " << nZones << "\n";
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+            //splitZone->SetZoneIndex( globalZoneId++ );
+            splitZone->newIndex = ( globalZoneId++ );
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+        }
+    }
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage1/01j/Partition.h b/example/partition/struct/2d/stage1/01j/Partition.h
new file mode 100644
index 00000000..8a4a9731
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01j/Partition.h
@@ -0,0 +1,59 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class SplitZone;
+
+struct CmpSplitZone 
+{
+    bool operator() ( SplitZone * a, SplitZone * b ) const;
+};
+
+class Partition
+{
+public:
+    Partition();
+    ~Partition();
+protected:
+    std::set < SplitZone * > zoneStorage;
+    std::set < SplitZone *, CmpSplitZone > unsignedZoneGroup;
+    std::vector< SplitZone * > refZone;
+    std::vector< std::vector< SplitZone * > > procSplitZone;
+    std::vector<double> procSpeed;
+    std::vector<double> timeProc;
+    double aveFloatOp, delta;
+    double idealUniProcTime, eps;
+    int minNumberCell;
+    int nTZone;
+    int nOriZone;
+    int nProc;
+public:
+    std::string inputName;
+    std::string outName;
+public:
+    void Solve();
+    void ReadGrid();
+    void Split();
+    void InitSplit();
+    void BinarySplit();
+    //void GreedySplit();
+public:
+    void AddNewZone( SplitZone * zone );
+    void AddZoneToUnsignedGroup( SplitZone * zone );
+    void RemoveZoneFromUnsignedGroup( SplitZone * zone );
+    void AddZoneToProcess( int iProc, SplitZone * zone );
+    void DumpPartitionedGridFile();
+    void ModifyZoneIndex();
+    void FreeAllZones();
+    int GetNZones( int iProc );
+    SplitZone * GetSplitZone( int iProc, int zoneId );
+    void ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord );
+    void DumpBc( SplitZone * splitZone );
+private:
+    int GetMinValueIndex( double * data, int numberOfData );
+    int GetMinLoadProc();
+    SplitZone * GetLargestZone();
+    SplitZone * Split( SplitZone * zone, double nCell );
+};
+
diff --git a/example/partition/struct/2d/stage1/01j/README.txt b/example/partition/struct/2d/stage1/01j/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01j/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/partition/struct/2d/stage1/01j/SplitZone.cpp b/example/partition/struct/2d/stage1/01j/SplitZone.cpp
new file mode 100644
index 00000000..633d4cf5
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01j/SplitZone.cpp
@@ -0,0 +1,1046 @@
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+int Dim::dim = -1;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox  )
+{
+    domainBox.start = zoneBox.start;
+    domainBox.end = zoneBox.end;
+
+    int axis = iDomain / 2;
+    int direction = iDomain % 2;
+
+    if ( direction == 0 )
+    {
+        domainBox.end[ axis ] = domainBox.start[ axis ];
+    }
+    else if ( direction == 1 )
+    {
+        domainBox.start[ axis ] = domainBox.end[ axis ];
+    }
+}
+
+DimInfo::DimInfo()
+{
+    this->Init( 1 );
+}
+
+DimInfo::~DimInfo()
+{
+}
+
+void DimInfo::Init( int dim )
+{
+    this->dim = dim;
+    dimList.resize( this->dim, 1 );
+    oriPoint.resize( this->dim, 0 );
+}
+
+DimInfo & DimInfo::operator = ( const DimInfo & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->dim = rhs.dim;
+    this->dimList = rhs.dimList;
+    this->oriPoint = rhs.oriPoint;
+
+    return * this;
+}
+
+int DimInfo::ComputeNumNodes()
+{
+    int nNodes = 1;
+    for ( int m = 0; m < this->dimList.size(); ++ m )
+    {
+        nNodes *= this->dimList[ m ];
+    }
+    return nNodes;
+}
+
+void DimInfo::ComputeISize()
+{
+    int index_dim = this->dimList.size();
+    this->isize.resize( index_dim * 3, 0 );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        isize[ m ] = this->dimList[ m ];
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 1;
+        isize[ start + m ] = this->dimList[ m ] - 1;
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 2;
+        isize[ start + m ] = 0;
+    }
+
+    for ( int i = 0; i < isize.size(); ++ i )
+    {
+        std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+    }
+}
+
+void DimInfo::ComputeRminmax( std::vector<int> & ref )
+{
+    int index_dim = this->dimList.size();
+    this->rmin.resize( index_dim );
+    this->rmax.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        rmin[ m ] = ref[ m ] + 1;
+        rmax[ m ] = ref[ m ] + this->dimList[ m ];
+    }
+
+    std::cout << "rmin, rmax = \n";
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        std::cout << rmin[ m ] << " " << rmax[ m ] << "\n";
+    }
+}
+
+void DimInfo::Init( std::vector<int> & dimList )
+{
+    this->dim = dimList.size();
+    this->dimList = dimList;
+    std::vector<int> zero( dimList.size(), 0 );
+    this->oriPoint = zero;
+}
+
+void DimInfo::SetNewDimension( int axis, int newStart, int newWidth )
+{
+    this->oriPoint[ axis ] = newStart;
+    this->dimList [ axis ] = newWidth;
+}
+
+void DimInfo::GetZoneGlobalBox( RangeRegion &zoneBox )
+{
+    int index_dim = this->dimList.size();
+    zoneBox.start.resize( index_dim );
+    zoneBox.end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        zoneBox.start[ m ] = this->oriPoint[ m ] + 1;
+        zoneBox.end[ m ] = this->oriPoint[ m ] + this->dimList[ m ];
+    }
+}
+
+void DimInfo::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    int index_dim = this->dimList.size();
+    localBox.start.resize( index_dim );
+    localBox.end.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        localBox.start[ m ] = globalBox.start[ m ] - this->oriPoint[ m ];
+        localBox.end[ m ] = globalBox.end[ m ] - this->oriPoint[ m ];
+    }
+}
+
+RangeRegion::RangeRegion( int nSize )
+{
+    this->Init( nSize );
+}
+
+RangeRegion::~RangeRegion()
+{
+}
+
+void RangeRegion::Init( int nSize )
+{
+    this->start.resize( nSize );
+    this->end.resize( nSize );
+}
+
+RangeRegion & RangeRegion::operator = ( const RangeRegion & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+bool RangeRegion::operator == ( const RangeRegion & rhs ) const
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] != rhs.start[ m ] || 
+            this->end  [ m ] != rhs.end  [ m ] )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+bool RangeRegion::InRegion( const RangeRegion & region )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( ( this->start[ m ] < region.start[ m ] ) || ( this->end[ m ] > region.end[ m ] ) )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::Normalize()
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        int minv = std::min( this->start[ m ], this->end[ m ] );
+        int maxv = std::max( this->start[ m ], this->end[ m ] );
+        this->start[ m ] = minv;
+        this->end[ m ] = maxv;
+    }
+}
+
+void RangeRegion::Localize( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] -= oriPoint[ m ];
+        this->end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void RangeRegion::AddShift( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] += oriPoint[ m ];
+        this->end[ m ] += oriPoint[ m ];
+    }
+}
+
+void RangeRegion::PrintGlobal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    std::cout << "global start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ] + oriPoint[m];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "global end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ] + oriPoint[m];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+void RangeRegion::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion );
+
+bool ComputeOverlapRegion( RangeRegion & region1, RangeRegion & region2, RangeRegion & overlapRegion )
+{
+    int index_dim = region1.start.size();
+    overlapRegion.Init( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int ijkmin1 = std::min( region1.start[ m ], region1.end[ m ] );
+        int ijkmax1 = std::max( region1.start[ m ], region1.end[ m ] );
+        int ijkmin2 = std::min( region2.start[ m ], region2.end[ m ] );
+        int ijkmax2 = std::max( region2.start[ m ], region2.end[ m ] );
+        if ( ( ijkmax1 < ijkmin2 ) || ( ijkmin1 > ijkmax2 ) )
+        {
+            return false;
+        }
+
+        int ijkmin = std::max( ijkmin1, ijkmin2 );
+        int ijkmax = std::min( ijkmax1, ijkmax2 );
+
+        overlapRegion.start[ m ] = ijkmin;
+        overlapRegion.end  [ m ] = ijkmax;
+    }
+
+    return CheckOverLapping( overlapRegion );
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion )
+{
+    int index_dim = overlapRegion.start.size();
+    int iCount = 0;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        if ( overlapRegion.start[ m ] == overlapRegion.end[ m ] )
+        {
+            ++ iCount;
+        }
+    }
+
+    return ( iCount == 1 );
+}
+
+bool GetInterfaceRegion( RangeRegion & zoneBoxL, RangeRegion & zoneBoxR, RangeRegion & interfaceRegion )
+{
+    int index_dim = zoneBoxL.start.size();
+    int nDomains = 2 * index_dim;
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegionL;
+        GetDomainRegion( zoneBoxL, iDomain, domainRegionL );
+
+        for ( int jDomain = 0; jDomain < nDomains; ++ jDomain )
+        {
+            RangeRegion domainRegionR;
+            GetDomainRegion( zoneBoxR, jDomain, domainRegionR );
+
+            if ( domainRegionL == domainRegionR )
+            {
+                interfaceRegion = domainRegionL;
+                return true;
+            }
+        }
+    }
+    return false;
+}
+
+void CreateInterfaceBc( SplitZone * zoneL, SplitZone * zoneR )
+{
+    RangeRegion globalBoxL, globalBoxR, globalInterfaceRegion;
+
+    zoneL->GetZoneGlobalBox( globalBoxL );
+    zoneR->GetZoneGlobalBox( globalBoxR );
+
+    if ( ! GetInterfaceRegion( globalBoxL, globalBoxR, globalInterfaceRegion ) )
+    {
+        return;
+    }
+
+    RangeRegion localInterfaceRegionL, localInterfaceRegionR;
+
+    zoneL->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionL );
+    zoneR->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionR );
+
+    int kkk = 1;
+
+    InterfaceSplitBc * interfaceSplitBcL = new InterfaceSplitBc();
+    zoneL->interfaceSplitBcList.push_back( interfaceSplitBcL );
+    interfaceSplitBcL->zone = zoneL;
+    interfaceSplitBcL->region = localInterfaceRegionL;
+
+    int nSize = localInterfaceRegionL.start.size();
+
+    std::vector<int> transform;
+
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        transform.push_back( m + 1 );
+    }
+
+    interfaceSplitBcL->transform = transform;
+    interfaceSplitBcL->CalcTransformMatrix();
+
+    interfaceSplitBcL->donor_zone = zoneR;
+    interfaceSplitBcL->donor_region = localInterfaceRegionR;
+
+    InterfaceSplitBc * interfaceSplitBcR = new InterfaceSplitBc();
+    zoneR->interfaceSplitBcList.push_back( interfaceSplitBcR );
+
+    interfaceSplitBcR->zone = zoneR;
+    interfaceSplitBcR->region = localInterfaceRegionR;
+
+    interfaceSplitBcR->transform = transform;
+    interfaceSplitBcR->CalcTransformMatrix();
+
+    interfaceSplitBcR->donor_zone = zoneL;
+    interfaceSplitBcR->donor_region = localInterfaceRegionL;
+}
+
+
+PhysicalSplitBc::PhysicalSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+PhysicalSplitBc::~PhysicalSplitBc()
+{
+}
+
+void PhysicalSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void PhysicalSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+void PhysicalSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = splitZone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+BasicSplitBc::BasicSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+BasicSplitBc::~BasicSplitBc()
+{
+    ;
+}
+
+void BasicSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void BasicSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+int trans::M[ 3 ][ 3 ];
+std::vector<int> trans::transform;
+
+int trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void trans::CalcTransformMatrix()
+{
+    int dim = trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = trans::transform[ 0 ];
+        int sgna = trans::sgn( a );
+        int a1 = trans::del( a, 1 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int c = trans::transform[ 2 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int sgnc = trans::sgn( c );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int a3 = trans::del( a, 3 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        int b3 = trans::del( b, 3 );
+        int c1 = trans::del( c, 1 );
+        int c2 = trans::del( c, 2 );
+        int c3 = trans::del( c, 3 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 2 ][ 0 ] = sgna * a3;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+        trans::M[ 2 ][ 1 ] = sgnb * b3;
+        trans::M[ 0 ][ 2 ] = sgnc * c1;
+        trans::M[ 1 ][ 2 ] = sgnc * c2;
+        trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+InterfaceInfo::InterfaceInfo()
+{
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceInfo::~InterfaceInfo()
+{
+}
+
+InterfaceSplitBc::InterfaceSplitBc()
+{
+    this->region.Init( Dim::dim );
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceSplitBc::~InterfaceSplitBc()
+{
+}
+
+void InterfaceSplitBc::CopyMatrix( InterfaceSplitBc * interfaceSplitBc )
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = interfaceSplitBc->Mt[ i ][ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::CalcTransformMatrix()
+{
+    trans::ZeroMatrix();
+    trans::transform = this->transform;
+    trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = trans::M[ i ][ j ];
+        }
+    }
+
+}
+
+void InterfaceSplitBc::mapindex( std::vector<int> & begin1, std::vector<int> & begin2,  std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = Dim::dim;
+    std::vector<int> diff( dim );
+    for ( int m = 0; m < dim; ++ m )
+    {
+        diff[ m ] = index1[ m ] - begin1[ m ];
+    }
+
+    std::vector<int> mul( dim );
+
+    Multiply( Mt, diff, mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = mul[ m ] + begin2[ m ];
+    }
+}
+
+void InterfaceSplitBc::Multiply( int Mt[][3], std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = Dim::dim;
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = this->zone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void InterfaceSplitBc::CalcSubDonorRegion( RangeRegion &subRegion, RangeRegion &subDonorRegion )
+{
+    std::vector<int> begin1 = this->region.start;
+    std::vector<int> end1 = this->region.end;
+    std::vector<int> begin2 = this->donor_region.start;
+    std::vector<int> end2 = this->donor_region.end;
+
+    std::vector<int> new_begin1 = subRegion.start;
+    std::vector<int> new_end1 = subRegion.end;
+
+    int dim = Dim::dim;
+    std::vector<int> new_begin2( dim );
+    std::vector<int> new_end2( dim );
+
+    mapindex( begin1, begin2, new_begin1, new_begin2 );
+    mapindex( begin1, begin2, new_end1, new_end2 );
+
+    subDonorRegion.start = new_begin2;
+    subDonorRegion.end = new_end2;
+}
+
+SplitZone::SplitZone()
+{
+    this->parent  = 0;
+    this->zoneIndex = 0;
+    this->iProc = 0;
+    dimInfo.Init( Dim::dim );
+    int kk = 1;
+}
+
+SplitZone::~SplitZone()
+{
+    ;
+}
+
+void SplitZone::GetZoneGlobalBox( RangeRegion & zoneBox )
+{
+    this->dimInfo.GetZoneGlobalBox( zoneBox );
+}
+
+void SplitZone::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    this->dimInfo.GetZoneLocalBox( globalBox, localBox );
+}
+
+
+void SplitZone::ComputeRminmax()
+{
+    int index_dim = this->dimInfo.dimList.size();
+    std::vector<int> ref( index_dim, 0 );
+
+    SplitZone * rootSplitZone = 0;
+    this->GetRootInfo( rootSplitZone, ref );
+
+    this->dimInfo.ComputeRminmax( ref );
+}
+
+SplitZone * SplitZone::GetRootZone()
+{
+    SplitZone * root = this;
+
+    while ( true )
+    {
+        if ( root->parent )
+        {
+            root = root->parent;
+        }
+        else
+        {
+            return root;
+        }
+    };
+}
+
+void SplitZone::GetRootInfo( SplitZone *& root, std::vector<int> & ref )
+{
+    for ( int i = 0; i < this->dimInfo.dimList.size(); ++ i )
+    {
+        ref[ i ] += this->dimInfo.oriPoint[ i ];
+    }
+
+    if ( this->parent )
+    {
+        this->parent->GetRootInfo( root, ref );
+    }
+    else
+    {
+        root = this;
+    }
+}
+
+void SplitZone::SetParentAndChild( SplitZone * parent )
+{
+    this->parent = parent;
+    if ( parent )
+    {
+        parent->child.push_back( this );
+    }
+}
+
+
+int SplitZone::GetNCell()
+{
+    int numberOfCells = 1;
+    for ( int i = 0; i < this->dimInfo.dim; ++ i )
+    {
+        numberOfCells *= std::max( 1, ( this->dimInfo.dimList[ i ] - 1 ) );
+    }
+
+    return numberOfCells; 
+}
+
+void SplitZone::SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int leftStart = 0;
+    int leftWidth = iSplit - 0;
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, leftStart , leftWidth  );
+}
+
+void SplitZone::SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int rightStart = iSplit - 1;
+    int rightWidth = dimList[ axisNeedSplit ] - ( iSplit - 1 );
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, rightStart, rightWidth );
+}
+
+void SplitZone::Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell )
+{
+    //Find the longest axis
+    int axisNeedSplit = this->FindAxisNeedSplit();
+    int iSplit        = this->FindSplitPosition( axisNeedSplit, nCell );
+
+    zoneL->SetLeftDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+    zoneR->SetRightDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+
+    zoneL->CreateBcFromParent();
+    zoneR->CreateBcFromParent();
+    
+    CreateInterfaceBc( zoneL, zoneR );
+}
+
+void SplitZone::CreateBcFromParent()
+{
+    this->CreatePhysicalBcFromParent();
+    this->CreateInterfaceBcFromParent();
+}
+
+void SplitZone::CreatePhysicalBcFromParent()
+{
+    int nParentPhysicalBcs = this->parent->physicalSplitBcList.size();
+
+    for ( int iParentPhysicalBcs = 0; iParentPhysicalBcs < nParentPhysicalBcs; ++ iParentPhysicalBcs )
+    {
+        PhysicalSplitBc * parentPhysicalSplitBc = this->parent->physicalSplitBcList[ iParentPhysicalBcs ];
+
+        this->CreatePhysicalBcFromParent( parentPhysicalSplitBc );
+    }
+}
+
+void SplitZone::CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentPhysicalSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreatePhysicalBc( overlapRegion, parentPhysicalSplitBc->bcType );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent()
+{
+    int nInterfaceSplitBcs = this->parent->interfaceSplitBcList.size();
+
+    for ( int iInterfaceSplitBcs = 0; iInterfaceSplitBcs < nInterfaceSplitBcs; ++ iInterfaceSplitBcs )
+    {
+        InterfaceSplitBc * parentInterfaceSplitBc = this->parent->interfaceSplitBcList[ iInterfaceSplitBcs ];
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc );
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentInterfaceSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc, overlapRegion );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::FindDonorInterface( InterfaceSplitBc * interfaceSplitBc, InterfaceInfo & interfaceInfo )
+{
+    RangeRegion donor_region = interfaceSplitBc->donor_region;
+    donor_region.Normalize();
+    interfaceInfo.donor_zone = this;
+    for ( int iInterface = 0; iInterface < interfaceSplitBcList.size(); ++ iInterface )
+    {
+        InterfaceSplitBc * candidateDonorBc = interfaceSplitBcList[ iInterface ];
+        bool flag = donor_region.InRegion( candidateDonorBc->region );
+        if ( flag )
+        {
+            if ( donor_region == candidateDonorBc->region )
+            {
+                interfaceInfo.donor_interface = candidateDonorBc;
+                return;
+            }
+            else
+            {
+                InterfaceSplitBc * donorBc = new InterfaceSplitBc();
+                candidateDonorBc->child.push_back( donorBc );
+                donorBc->region = donor_region;
+                donorBc->zone = candidateDonorBc->zone;
+                donorBc->donor_zone = interfaceSplitBc->zone;
+                donorBc->transform = candidateDonorBc->transform;
+                donorBc->CopyMatrix( candidateDonorBc );
+                RangeRegion subDonorRegion( Dim::dim );
+                candidateDonorBc->CalcSubDonorRegion( donorBc->region, subDonorRegion );
+                std::vector<int> & oriPoint = interfaceSplitBc->zone->dimInfo.oriPoint;
+                subDonorRegion.Localize( oriPoint );
+                donorBc->donor_region = subDonorRegion;
+                donorBc->donor_bc = interfaceSplitBc;
+                interfaceInfo.donor_interface = donorBc;
+                return;
+            }
+        }
+    }
+    return;
+}
+
+void SplitZone::GetChildDonorRegion( RangeRegion & subDonorRegion, InterfaceInfo & interfaceInfo )
+{
+    std::cout << "subDonorRegion = \n";
+    subDonorRegion.Print();
+    int nChild = this->child.size();
+    for ( int ichild = 0; ichild < nChild; ++ ichild )
+    {
+        std::cout << " iChild = " << ichild << " nChild = " << nChild << "\n";
+        SplitZone * sub_zone = this->child[ ichild ];
+        std::cout << " zoneIndex = " << sub_zone->zoneIndex << "\n";
+        int nInters = sub_zone->interfaceSplitBcList.size();
+        for ( int iInter = 0; iInter < nInters; ++ iInter )
+        {
+            std::cout << " iInter = " << iInter << "\n";
+            InterfaceSplitBc * interfaceSplitBc = sub_zone->interfaceSplitBcList[ iInter ];
+            std::cout << "interfaceSplitBc local = \n";
+            interfaceSplitBc->region.Print();
+            std::cout << "interfaceSplitBc global = \n";
+            interfaceSplitBc->region.PrintGlobal( sub_zone->dimInfo.oriPoint );
+            RangeRegion g_region = interfaceSplitBc->region;
+            g_region.AddShift( sub_zone->dimInfo.oriPoint );
+            if ( g_region == subDonorRegion )
+            {
+                interfaceInfo.donor_zone = sub_zone;
+                interfaceInfo.donor_interface = interfaceSplitBc;
+                interfaceInfo.donor_region = interfaceSplitBc->region;
+                return;
+            }
+        }
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion )
+{
+    InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+    this->interfaceSplitBcList.push_back( interfaceSplitBc );
+
+    interfaceSplitBc->region = overlapRegion;
+    interfaceSplitBc->zone = this;
+    interfaceSplitBc->transform = parentInterfaceSplitBc->transform;
+    interfaceSplitBc->CopyMatrix( parentInterfaceSplitBc );
+    RangeRegion subDonorRegion( Dim::dim );
+    parentInterfaceSplitBc->CalcSubDonorRegion( overlapRegion, subDonorRegion );
+    interfaceSplitBc->ChangeRegionToLocalCoordinate();
+    interfaceSplitBc->donor_region = subDonorRegion;
+    SplitZone * parent_donor_zone = parentInterfaceSplitBc->donor_zone;
+    std::cout << " parentInterfaceSplitBc->zone->zoneIndex " << parentInterfaceSplitBc->zone->zoneIndex << "\n";
+    std::cout << " parentInterfaceSplitBc->donor_zone->zoneIndex " << parent_donor_zone->zoneIndex << "\n";
+    if ( parent_donor_zone->child.size() > 0 )
+    {
+        InterfaceInfo interfaceInfo;
+        parent_donor_zone->GetChildDonorRegion( subDonorRegion, interfaceInfo );
+        interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+        interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+        interfaceSplitBc->donor_region = interfaceInfo.donor_region;
+        //compatibility
+        InterfaceSplitBc * donor_bc = interfaceSplitBc->donor_bc;
+        SplitZone * donor_zone = interfaceSplitBc->donor_zone;
+        //if ( donor_bc->donor_zone->zoneIndex == interfaceSplitBc->zone->zoneIndex )
+        if ( interfaceSplitBc->zone != donor_bc->donor_zone )
+        {
+            donor_bc->donor_zone = interfaceSplitBc->zone;
+            donor_bc->donor_region = interfaceSplitBc->region;
+           
+            int kkk = 1;
+        }
+        int kkk = 1;
+    }
+    else
+    {
+        InterfaceInfo interfaceInfo;
+        parent_donor_zone->FindDonorInterface( interfaceSplitBc, interfaceInfo );
+        interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+        interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+    }
+    
+    int kkk = 1;
+}
+
+void SplitZone::CreatePhysicalBc( RangeRegion & overlapRegion, int bcType )
+{
+    PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+    this->physicalSplitBcList.push_back( physicalSplitBc );
+    physicalSplitBc->SetRegion( overlapRegion );
+    physicalSplitBc->bcType = bcType;
+    physicalSplitBc->splitZone = this;
+    physicalSplitBc->ChangeRegionToLocalCoordinate();
+}
+
+int SplitZone::FindAxisNeedSplit()
+{
+    //Find the longest axis
+    int axisNeedSplit = 0;
+    int maxN = this->dimInfo.dimList[ 0 ];
+
+    for ( int m = 1; m < this->dimInfo.dimList.size(); ++ m )
+    {
+        if ( this->IsPoleBc( m ) )
+        {
+            continue;
+        }
+        int Nm = this->dimInfo.dimList[ m ];
+        if ( maxN < Nm )
+        {
+            maxN = Nm;
+            axisNeedSplit = m;
+        }
+    }
+
+    return axisNeedSplit;
+}
+
+int SplitZone::GetCrossSection( int axis )
+{
+    int nDim = this->dimInfo.dimList.size();
+    int crossSection = 1;
+    int N = nDim - 1;
+    for ( int m = 0; m < N; ++ m )
+    {
+         int mm = ( axis + 1 ) % nDim;
+         int nLineElements = std::max( 1, ( this->dimInfo.dimList[ mm ] - 1 ) );
+         crossSection *= nLineElements;
+    }
+    return crossSection;
+}
+
+int SplitZone::FindSplitPosition( int axisNeedSplit, double nCell )
+{
+    int nDim = this->dimInfo.dimList.size();
+    std::vector<int> crossSections( nDim );
+    for ( int m = 0; m < nDim; ++ m )
+    {
+        crossSections[ m ] = this->GetCrossSection( m );
+    }
+
+    //guess the value
+    double dSplit = nCell / crossSections[ axisNeedSplit ];
+    int  iSplit = 1 + static_cast< int >( std::floor( dSplit + 0.5 ) );
+    return iSplit;
+}
+
+
+bool SplitZone::IsPoleBc( int splitDirection )
+{
+    return false;
+}
+
diff --git a/example/partition/struct/2d/stage1/01j/SplitZone.h b/example/partition/struct/2d/stage1/01j/SplitZone.h
new file mode 100644
index 00000000..8e312dd2
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01j/SplitZone.h
@@ -0,0 +1,193 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class Dim
+{
+public:
+    static int dim;
+};
+
+class SplitZone;
+class RangeRegion;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox );
+
+class DimInfo
+{
+public:
+    DimInfo();
+    ~DimInfo();
+public:
+    int dim;
+    std::vector<int> dimList;
+    std::vector<int> oriPoint;
+    std::vector<int> isize;
+    std::vector<int> rmin;
+    std::vector<int> rmax;
+public:
+    int GetSize() const { return dim; }
+    DimInfo & operator = ( const DimInfo & rhs );
+public:
+    int ComputeNumNodes();
+    void ComputeISize();
+    void ComputeRminmax( std::vector<int> & ref );
+    void Init( int dim );
+    void Init( std::vector<int> & dimList );
+    void SetNewDimension( int axis, int newStart, int newWidth );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+};
+
+class SplitZone;
+class SplitBcPatch;
+
+class RangeRegion
+{
+public:
+    RangeRegion( int nSize = 1 );
+    ~RangeRegion();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    void Init( int nSize );
+    RangeRegion & operator = ( const RangeRegion & rhs );
+    bool operator == ( const RangeRegion & rhs ) const;
+    bool InRegion( const RangeRegion & region );
+    void SetRegion( std::vector<int> &pnts );
+    void Normalize();
+    void Localize( std::vector<int> & oriPoint );
+    void AddShift( std::vector<int> & oriPoint );
+    void PrintGlobal( std::vector<int> & oriPoint );
+    void Print();
+};
+
+class PhysicalSplitBc
+{
+public:
+    PhysicalSplitBc();
+    ~PhysicalSplitBc();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class BasicSplitBc
+{
+public:
+    BasicSplitBc();
+    ~BasicSplitBc();
+public:
+    RangeRegion region;
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> & pnts );
+    void SetRegion( RangeRegion & region );
+};
+
+class trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class InterfaceSplitBc;
+class SplitZone;
+
+class InterfaceInfo
+{
+public:
+    InterfaceInfo();
+    ~InterfaceInfo();
+public:
+    InterfaceSplitBc * donor_interface = nullptr;
+    SplitZone * donor_zone = nullptr;
+    RangeRegion donor_region;
+};
+
+class InterfaceSplitBc
+{
+public:
+    InterfaceSplitBc();
+    ~InterfaceSplitBc();
+public:
+    std::vector<int> transform;
+    int Mt[ 3 ][ 3 ];
+    RangeRegion region;
+    SplitZone * zone = nullptr;
+    RangeRegion donor_region;
+    SplitZone * donor_zone = nullptr;
+    InterfaceSplitBc * donor_bc = nullptr;
+public:
+    std::vector<InterfaceSplitBc *> child;
+public:
+    void CopyMatrix( InterfaceSplitBc * interfaceSplitBc );
+    void CalcTransformMatrix();
+    void CalcSubDonorRegion( RangeRegion & subRegion, RangeRegion & subDonorRegion );
+    void mapindex( std::vector<int> & begin1, std::vector<int> & begin2, std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( int Mt[][ 3 ], std::vector<int> & a, std::vector<int> & b );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class SplitZone
+{
+public:
+    SplitZone();
+    ~SplitZone();
+public:
+    DimInfo dimInfo;
+    int zoneIndex, iProc;
+    int newIndex;
+protected:
+    SplitZone * parent;
+    std::vector<SplitZone *> child;
+public:
+    std::vector< PhysicalSplitBc * > physicalSplitBcList;
+    std::vector< InterfaceSplitBc * > interfaceSplitBcList;
+public:
+    int GetNCell();
+    void ComputeRminmax();
+    void GetRootInfo( SplitZone *& root, std::vector<int> & ref );
+    void SetZoneIndex( int zoneIndex ) { this->zoneIndex = zoneIndex; }
+    int  GetZoneIndex() { return zoneIndex; }
+    void SetProcId( int iProc ) { this->iProc = iProc; }
+    void SetParent( SplitZone * parent ) { this->parent = parent; };
+    void SetParentAndChild( SplitZone * parent );
+    void FindDonorInterface( InterfaceSplitBc * interfaceSplitBc, InterfaceInfo & interfaceInfo );
+    void GetChildDonorRegion( RangeRegion & subDonorRegion, InterfaceInfo & interfaceInfo );
+public:
+    void CreateBcFromParent();
+    void CreatePhysicalBcFromParent();
+    void CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc );
+    void CreatePhysicalBc( RangeRegion & overlapRegion, int bcType );
+    void CreateInterfaceBcFromParent();
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc );
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion );
+
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+    SplitZone * GetRootZone();
+public:
+    void Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell );
+    void SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+    void SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+private:
+    int FindAxisNeedSplit();
+    int FindSplitPosition( int axisNeedSplit, double nCell );
+    bool IsPoleBc( int splitDirection );
+    int GetCrossSection( int axis );
+};
+
diff --git a/example/partition/struct/2d/stage1/01j/heat2d2blocks.cgns b/example/partition/struct/2d/stage1/01j/heat2d2blocks.cgns
new file mode 100644
index 00000000..ab4dcea5
Binary files /dev/null and b/example/partition/struct/2d/stage1/01j/heat2d2blocks.cgns differ
diff --git a/example/partition/struct/2d/stage1/01j/heat2dpart.cgns b/example/partition/struct/2d/stage1/01j/heat2dpart.cgns
new file mode 100644
index 00000000..3e2c9e62
Binary files /dev/null and b/example/partition/struct/2d/stage1/01j/heat2dpart.cgns differ
diff --git a/example/partition/struct/2d/stage1/01j/main.cpp b/example/partition/struct/2d/stage1/01j/main.cpp
new file mode 100644
index 00000000..5da1de7c
--- /dev/null
+++ b/example/partition/struct/2d/stage1/01j/main.cpp
@@ -0,0 +1,18 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include "Partition.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip>
+
+int main(int argc, char **argv)
+{
+    Partition * partition = new Partition();
+    partition->Solve();
+    delete partition;
+
+    return 0;
+}
diff --git a/example/partition/struct/2d/stage2/01/CMakeLists.txt b/example/partition/struct/2d/stage2/01/CMakeLists.txt
new file mode 100644
index 00000000..74ceea7d
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01/CMakeLists.txt
@@ -0,0 +1,78 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	Partition.h Partition.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	SplitZone.h SplitZone.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/partition/struct/2d/stage2/01/CgnsGrid.cpp b/example/partition/struct/2d/stage2/01/CgnsGrid.cpp
new file mode 100644
index 00000000..dfe750bd
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01/CgnsGrid.cpp
@@ -0,0 +1,349 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include <map>
+
+Grid::Grid()
+{
+    ;
+}
+
+Grid::~Grid()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if( (i+1)%5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+    delete this->patch;
+}
+
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+ZoneBcPatch::ZoneBcPatch()
+{
+    ;
+}
+
+ZoneBcPatch::~ZoneBcPatch()
+{
+}
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+Global::Global()
+{
+    ;
+}
+
+Global::~Global()
+{
+}
+
+void Global::FreeData()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+    zones.resize( 0 );
+}
+
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            //baseZone.baseId = baseId;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin( index_dim );
+            std::vector<cgsize_t> irmax( index_dim );
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                std::vector<char> coord( nNodes * sizeof(double) );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+                coor->DumpCoor();
+            }
+
+            int nbocos = -1;
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+                int kkk = 1;
+            }
+        }
+        int kkk = 1;
+    }
+    int kkk = 1;
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage2/01/CgnsGrid.h b/example/partition/struct/2d/stage2/01/CgnsGrid.h
new file mode 100644
index 00000000..053c467b
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01/CgnsGrid.h
@@ -0,0 +1,140 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <map>
+
+class Grid;
+
+class Zone;
+
+class Grid
+{
+public:
+    Grid();
+    ~Grid();
+public:
+    int nZone;
+    std::vector<double> x;
+    std::vector<Zone *> zones;
+};
+
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+};
+
+class ZoneBc;
+class ZoneBc1To1;
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class ZoneBcPatch;
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+    ZoneBcPatch * patch = nullptr;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+class ZoneBcPatch
+{
+public:
+    ZoneBcPatch();
+    ~ZoneBcPatch();
+public:
+    int donor_zoneid;
+    std::vector<int> transform;
+    std::vector<int> donor_pnts;
+};
+
+class BaseZone
+{
+public:
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Global
+{
+public:
+    Global();
+    ~Global();
+public:
+    static int cell_dim;
+    static int phys_dim;
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+public:
+    static void FreeData();
+};
+
+void ReadCgnsGrid( const std::string & filename );
+void ReadCgnsGridBaseZone( const std::string & filename );
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage2/01/Partition.cpp b/example/partition/struct/2d/stage2/01/Partition.cpp
new file mode 100644
index 00000000..70532641
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01/Partition.cpp
@@ -0,0 +1,618 @@
+#include "Partition.h"
+#include "CgnsGrid.h"
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+bool CmpSplitZone::operator() ( SplitZone * a, SplitZone * b ) const
+{
+    return a->zoneIndex < b->zoneIndex;
+};
+
+
+double CalSumOfProcSpeed( std::vector<double> & procSpeed );
+double CalSumOfProcSpeed( std::vector<double> & procSpeed )
+{
+    int nProc = procSpeed.size();
+    double sumOfProcSpeed = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        sumOfProcSpeed += procSpeed[ iProc ];
+    }
+    return sumOfProcSpeed;
+}
+
+Partition::Partition()
+{
+    this->inputName = "../heat2d2blocksv1.cgns";
+    this->outName =  "../heat2dpart.cgns";
+}
+
+Partition::~Partition()
+{
+    ;
+}
+
+int Partition::GetMinValueIndex( double * data, int numberOfData )
+{
+    double minValue = data[ 0 ];
+    int minimumValueIndex = 0;
+
+    for ( int iData = 1; iData < numberOfData; ++ iData )
+    {
+        if ( minValue > data[ iData ] )
+        {
+            minValue      = data[ iData ];
+            minimumValueIndex = iData;
+        }
+    }
+    return minimumValueIndex;
+}
+
+int Partition::GetMinLoadProc()
+{
+    return this->GetMinValueIndex( this->timeProc.data(), this->nProc );
+}
+
+SplitZone * Partition::GetLargestZone()
+{
+    SplitZone * largestZone = 0;
+
+    double nMaxCell = 0.0;
+
+    for ( std::set< SplitZone * >::iterator iter = unsignedZoneGroup.begin(); iter != unsignedZoneGroup.end(); ++ iter )
+    {
+        double nSize = ( * iter )->GetNCell();
+        if ( nMaxCell < nSize )
+        {
+            nMaxCell    = nSize;
+            largestZone = * iter;
+        }
+    }
+
+    return largestZone;
+}
+
+void Partition::Solve()
+{
+    std::cout << "Partition::Split()\n";
+    //this->nProc = 2;
+    this->nProc = 4;
+    this->ReadGrid();
+    this->Split();
+    this->DumpPartitionedGridFile();
+    this->FreeAllZones();
+}
+
+void Partition::ReadGrid()
+{
+    ReadCgnsGridBaseZone( this->inputName );
+    ReadCgnsGrid( this->inputName );
+
+    this->nOriZone = ::Global::zones.size();
+    Dim::dim = Global::cell_dim;
+
+    std::cout << "numberOfBlocks = " << nOriZone << "\n";
+
+    this->refZone.resize( nOriZone );
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = new SplitZone();
+        refZone[ iZone ] = splitZone;
+
+        splitZone->SetZoneIndex( iZone );
+        splitZone->SetProcId( 0 );
+        splitZone->SetParentAndChild( 0 );
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        Zone * zone = ::Global::zones[ iZone ];
+
+        splitZone->dimInfo.dimList = zone->nijk;
+
+        int nbccos = zone->bccos.size();
+        std::cout << "nbccos = " << nbccos << "\n";
+
+        for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+        {
+            ZoneBc * zoneBc = zone->bccos[ ibcco ];
+
+            PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+            splitZone->physicalSplitBcList.push_back( physicalSplitBc );
+            physicalSplitBc->bcType = zoneBc->bcType;
+            physicalSplitBc->SetRegion( zoneBc->pnts );
+            physicalSplitBc->splitZone = splitZone;
+        }
+
+        int nbc1to1s = zone->bc1to1s.size();
+
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * zoneBc1To1 = zone->bc1to1s[ ibc1to1 ];
+
+            InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+            splitZone->interfaceSplitBcList.push_back( interfaceSplitBc );
+            interfaceSplitBc->zone = splitZone;
+            interfaceSplitBc->region.SetRegion( zoneBc1To1->pnts );
+
+            interfaceSplitBc->transform = zoneBc1To1->transform;
+            interfaceSplitBc->CalcTransformMatrix();
+
+            interfaceSplitBc->donor_zone = refZone[ zoneBc1To1->donor_zoneid ];
+            interfaceSplitBc->donor_region.SetRegion( zoneBc1To1->donor_pnts );
+        }
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        int nbc1to1s = splitZone->interfaceSplitBcList.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            InterfaceSplitBc * interfaceSplitBc = splitZone->interfaceSplitBcList[ ibc1to1 ];
+            InterfaceInfo interfaceInfo;
+            interfaceSplitBc->donor_zone->FindDonorInterface( interfaceSplitBc, interfaceInfo );
+            interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+            interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+        }
+    }
+}
+
+void Partition::Split()
+{
+    this->InitSplit();
+    this->BinarySplit();
+    this->ModifyZoneIndex();
+    int kkk = 1;
+}
+
+void Partition::InitSplit()
+{
+    //nZone is the number of zones in the original grid
+    //nProc is not the number of blocks in the end, but the number of processes that need to be divided.
+    //This difference occurs because the structure grid can have many blocks per process.
+
+    //this->nProc    = nProc;
+    //this->nPhyBlocks = referenceBlock.size();
+    //this->nZone  = this->nPhyBlocks;
+
+    //tj Computation time on processor j
+    //Nk Number of internal grid-cells for zone j
+    //aveFloatOp:  Number of Real operations per gridcell
+    //Gj The set of blocks allocated to process j
+    //Pj Real operations per second for process j
+
+    //The Greedy Load Balancing Algorithm
+    //1.Compute an "ideal" uniprocessor time, Tuni = sum ( Nk * aveFloatOp )/ sum( Pj ).
+    //2.Set the group of unassigned blocks, Gu, to contain all blocks. The number of blocks in Nu=M, where M is the total number of blocks in the mesh.
+    //3.Start all processors with a very small fictitious zone to get a start tj=delt aveFloatOp/Pj, where delt<<1 is the size of the very small fictious zone.
+    //This is used to find the fastest processor in a heterogeneous system, tj could otherwise be set to 0 in the homogeneous case.
+    this->aveFloatOp = 1.0;
+    this->delta      = 1.0e-5;
+    this->procSpeed.resize( nProc );
+    this->timeProc.resize( nProc );
+
+    this->nTZone = this->nOriZone;
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        procSpeed[ iProc ] = 1.0;
+    }
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        timeProc[ iProc ] = delta * aveFloatOp / procSpeed[ iProc ];
+    }
+
+    double sumProcSpeed = CalSumOfProcSpeed( procSpeed );
+
+    double sumProcOp = 0.0;
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        sumProcOp += refZone[ iZone ]->GetNCell() * aveFloatOp;
+    }
+
+    this->idealUniProcTime = sumProcOp / sumProcSpeed;
+
+    this->eps = 0.05;
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        unsignedZoneGroup.insert( refZone[ iZone ] );
+    }
+
+    //Init zoneStorage
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        zoneStorage.insert( refZone[ iZone ] );
+    }
+
+    //Assign procSplitZone to each process
+    procSplitZone.resize( nProc );
+
+    this->minNumberCell = 1;
+    for ( int m = 0; m < Dim::dim; ++ m )
+    {
+        this->minNumberCell *= 1;
+    }
+
+    int kkk = 1;
+
+}
+
+void Partition::FreeAllZones()
+{
+    int iCount = 0;
+    for ( std::set < SplitZone * >::iterator iter = zoneStorage.begin(); iter != zoneStorage.end(); ++ iter )
+    {
+        //cout << "iCount = " << iCount << "\n";
+        ++ iCount;
+        delete * iter;
+    }
+}
+
+int Partition::GetNZones( int iProc )
+{
+    return this->procSplitZone[ iProc ].size();
+}
+
+SplitZone * Partition::GetSplitZone( int iProc, int zoneId )
+{
+    return this->procSplitZone[ iProc ][ zoneId ];
+}
+
+void Partition::AddZoneToUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.insert( zone );
+}
+
+void Partition::RemoveZoneFromUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.erase( zone );
+}
+
+void Partition::AddZoneToProcess( int iProc, SplitZone * zone )
+{
+    this->procSplitZone[ iProc ].push_back( zone );
+}
+
+void Partition::AddNewZone( SplitZone * zone )
+{
+    zone->SetZoneIndex( nTZone ++ );
+
+    this->AddZoneToUnsignedGroup( zone );
+
+    this->zoneStorage.insert( zone );
+}
+
+SplitZone * Partition::Split( SplitZone * zone, double nCell )
+{
+    SplitZone * zoneL = new SplitZone();
+    zoneL->SetParentAndChild( zone );
+
+    SplitZone * zoneR = new SplitZone();
+    zoneR->SetParentAndChild( zone );
+
+    //Remove the original block from the UnsignedGroup
+    this->RemoveZoneFromUnsignedGroup( zone );
+
+    this->AddNewZone( zoneL );
+    this->AddNewZone( zoneR );
+
+    zone->Split( zoneL, zoneR, nCell );
+
+    return zoneL;
+}
+
+void Partition::BinarySplit()
+{
+    while ( ! unsignedZoneGroup.empty() )
+    {
+        std::cout << "number of unsigned zone = " << unsignedZoneGroup.size() << "\n";
+        int iProc = this->GetMinLoadProc();
+
+        //Get the block with the largest number of grids and its size
+        SplitZone * largestZone = this->GetLargestZone();
+
+        double nMaxCell = largestZone->GetNCell();
+
+        double aveFloatOp = this->aveFloatOp;
+        double tau = timeProc[ iProc ] + nMaxCell * aveFloatOp / procSpeed[ iProc ];
+
+        //It seems that EPS is still necessary
+        //The idea here is as follows. For the candidate blocks which can be divided into blocks, 
+        //if the difference between the target blocks and the candidate blocks is too wide, 
+        //the binarySplit method is adopted. The binarySplit blocks do not directly join the process,
+        //but enter the next round of screening.
+
+        if ( tau > idealUniProcTime * ( 1.0 + eps ) )
+        {
+            double nRest = ( tau - idealUniProcTime ) * procSpeed[ iProc ] / aveFloatOp;
+
+            double nTarget = nMaxCell - nRest;
+            if ( nRest > this->minNumberCell && nTarget > this->minNumberCell )
+            {
+                //It is necessary to divide blocks only when a certain number of points are satisfied.
+                double nHalf = nMaxCell / 2.0;
+                nMaxCell = nTarget;
+                double ratio = nMaxCell / nRest;
+                double oRatio = 1.0 / ratio;
+
+                if ( std::max( ratio, oRatio ) < 3.0 )
+                {
+                    int kkk = 1;
+                    largestZone = this->Split( largestZone, nMaxCell );
+                    timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                    this->RemoveZoneFromUnsignedGroup( largestZone );
+                    this->AddZoneToProcess( iProc, largestZone );
+                }
+                else
+                {
+                    this->Split( largestZone, nHalf );
+                }
+            }
+            else
+            {
+                //If the block is of the right size, join the process directly, and there is no need to split it.
+                timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                this->RemoveZoneFromUnsignedGroup( largestZone );
+                this->AddZoneToProcess( iProc, largestZone );
+            }
+        }
+        else
+        {
+            //If the block is of the right size, join the process directly, and there is no need to split it.
+            timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+            this->RemoveZoneFromUnsignedGroup( largestZone );
+            this->AddZoneToProcess( iProc, largestZone );
+        }
+    }
+}
+
+void Partition::ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord )
+{
+    SplitZone * rootSplitZone = splitZone->GetRootZone();
+    Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+    int nNodes = splitZone->dimInfo.ComputeNumNodes();
+    std::cout << "nNodes = " << nNodes << "\n";
+
+    coord.resize( nNodes * sizeof(double) );
+
+    int index_dim = splitZone->dimInfo.dimList.size();
+    Coor * coor = zone->coors[ icoord ];
+
+    double * xlocal = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    double * xglobal = reinterpret_cast<double *>( const_cast<char *>( coor->coord.data() ) );
+    if ( index_dim == 1 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        for ( int i = imin; i < imax; ++ i )
+        {
+            xlocal[ icount++ ] = xglobal[ i ];
+        }
+    }
+    else if ( index_dim == 2 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        int jmin = splitZone->dimInfo.rmin[ 1 ] - 1;
+        int jmax = splitZone->dimInfo.rmax[ 1 ];
+        int ni = rootSplitZone->dimInfo.dimList[ 0 ];
+        int nj = rootSplitZone->dimInfo.dimList[ 1 ];
+        for ( int j = jmin; j < jmax; ++ j )
+        {
+            int jstride = j * ni;
+            for ( int i = imin; i < imax; ++ i )
+            {
+                xlocal[ icount++ ] = xglobal[ jstride + i ];
+            }
+        }
+    }
+}
+
+void Partition::DumpBc( SplitZone * splitZone )
+{
+}
+
+void Partition::DumpPartitionedGridFile()
+{
+    std::cout << "\n";
+    std::cout << "DumpPartitionedGridFile -------------------------------" << "\n";
+    std::cout << "\n";
+    int fileId = -1;
+    std::string filename = this->outName;
+    int ierr = cg_open( filename.c_str(), CG_MODE_WRITE, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+
+    std::vector<std::string> coordnames;
+    coordnames.push_back( "CoordinateX" );
+    coordnames.push_back( "CoordinateY" );
+    coordnames.push_back( "CoordinateZ" );
+
+    std::string basename = "Base";
+    int baseId = -1;
+    int icelldim = Global::cell_dim;
+    int iphysdim = Global::phys_dim;
+    cg_base_write( fileId, basename.c_str(), icelldim, iphysdim, &baseId );
+
+    std::cout << "baseId = " << baseId << "\n";
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        int nZones = this->GetNZones( iProc );
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            ZoneType_t zoneType = Structured;
+
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+
+            int index_dim = splitZone->dimInfo.dimList.size();
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            splitZone->dimInfo.ComputeISize();
+
+            int isize_dim = index_dim * 3;
+
+            std::vector<cgsize_t> isize( index_dim * 3, 0 );
+            for ( int m = 0; m < isize_dim; ++ m )
+            {
+                isize[ m ] = splitZone->dimInfo.isize[ m ];
+            }
+
+            int zoneId = -1;
+
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+
+            std::string zonename = "Zone" + std::to_string( splitZone->newIndex );
+
+            cg_zone_write( fileId, baseId, zonename.c_str(), isize.data(), zoneType, &zoneId );
+
+            std::cout << "zoneId = " << zoneId << "\n";
+            std::cout << "zonename = " << zonename << "\n";
+                
+            splitZone->ComputeRminmax();
+
+            SplitZone * rootSplitZone = splitZone->GetRootZone();
+
+            Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+            int ncoords = zone->coors.size();
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = -1;
+                DataType_t dataType = RealDouble;
+                std::string coordname = coordnames[ icoord ];
+                Coor * coor = zone->coors[ icoord ];
+
+                int nNodes = splitZone->dimInfo.ComputeNumNodes();
+                std::cout << "nNodes = " << nNodes << "\n";
+
+                std::vector<char> coord;
+                ComputeCoor( splitZone, icoord, coord );
+
+                cg_coord_write( fileId, baseId, zoneId, dataType, coordname.c_str(), coord.data(), &coorId );
+
+                std::cout << "fileId = " << fileId  << " baseId = " << baseId << " zoneId = " << zoneId  << " coorId = " << coorId << "\n";
+            }
+
+            std::vector< PhysicalSplitBc * > &bccoList = splitZone->physicalSplitBcList;
+
+            int nbocos = bccoList.size();
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = -1;
+                GridLocation_t location = Vertex;
+
+                std::string boconame = "BC" + std::to_string( iboco + 1 );
+
+                PhysicalSplitBc * physicalSplitBc = bccoList[ iboco ];
+                BCType_t bocotype = static_cast<BCType_t>( physicalSplitBc->bcType );
+                PointSetType_t ptset_type = PointRange;
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> pnts;
+                int nSize = physicalSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.end[ i ] );
+                }
+
+                cg_boco_write( fileId, baseId, zoneId, boconame.c_str(), bocotype, ptset_type, npnts, pnts.data(), & bccoId );
+            }
+
+            std::vector< InterfaceSplitBc * > & bc1to1List = splitZone->interfaceSplitBcList;
+
+            int n1to1 = bc1to1List.size();
+            std::cout << "n1to1 = " << n1to1 << "\n";
+
+            std::vector<int> itranfrm( index_dim );
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                itranfrm[ m ] = m + 1;
+            }
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int index_conn = -1;
+
+                InterfaceSplitBc * interfaceSplitBc = bc1to1List[ i1to1 ];
+
+                std::vector<cgsize_t> pnts;
+                std::vector<cgsize_t> pntsdonor;
+                int nSize = interfaceSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.end[ i ] );
+                }
+
+                int nPatchSize = interfaceSplitBc->donor_region.start.size();
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.start[ i ] );
+                }
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.end[ i ] );
+                }
+                int id = interfaceSplitBc->donor_zone->newIndex;
+                int oldZoneIndex = interfaceSplitBc->donor_zone->zoneIndex;
+                std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+                std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+                std::cout << "donor zone id = " << id << "\n";
+                std::cout << "donor zone oldZoneIndex = " << oldZoneIndex << "\n";
+                std::string donorname = "Zone" + std::to_string( id );
+                std::string connectname = "Interface" + std::to_string( i1to1 );
+
+                std::cout << "donorname = " << donorname << "\n";
+                std::cout << "connectname = " << connectname << "\n";
+
+                std::vector<int> & itranfrm = interfaceSplitBc->transform;
+
+                cg_1to1_write( fileId, baseId, zoneId, connectname.c_str(), donorname.c_str(), pnts.data(), pntsdonor.data(), itranfrm.data(), &index_conn );
+                std::cout << "index_conn = " << index_conn << "\n";
+            }
+        }
+    }
+    cg_close( fileId );
+}
+
+void Partition::ModifyZoneIndex()
+{
+    std::cout << "ModifyZoneIndex +++++++++++++++++++++++++ " << "\n";
+    int globalZoneId = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        std::cout << "iProc = " << iProc << "\n";
+        int nZones = this->GetNZones( iProc );
+        std::cout << "nZones in Proc " << iProc << "  = " << nZones << "\n";
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+            //splitZone->SetZoneIndex( globalZoneId++ );
+            splitZone->newIndex = ( globalZoneId++ );
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+        }
+    }
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage2/01/Partition.h b/example/partition/struct/2d/stage2/01/Partition.h
new file mode 100644
index 00000000..8a4a9731
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01/Partition.h
@@ -0,0 +1,59 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class SplitZone;
+
+struct CmpSplitZone 
+{
+    bool operator() ( SplitZone * a, SplitZone * b ) const;
+};
+
+class Partition
+{
+public:
+    Partition();
+    ~Partition();
+protected:
+    std::set < SplitZone * > zoneStorage;
+    std::set < SplitZone *, CmpSplitZone > unsignedZoneGroup;
+    std::vector< SplitZone * > refZone;
+    std::vector< std::vector< SplitZone * > > procSplitZone;
+    std::vector<double> procSpeed;
+    std::vector<double> timeProc;
+    double aveFloatOp, delta;
+    double idealUniProcTime, eps;
+    int minNumberCell;
+    int nTZone;
+    int nOriZone;
+    int nProc;
+public:
+    std::string inputName;
+    std::string outName;
+public:
+    void Solve();
+    void ReadGrid();
+    void Split();
+    void InitSplit();
+    void BinarySplit();
+    //void GreedySplit();
+public:
+    void AddNewZone( SplitZone * zone );
+    void AddZoneToUnsignedGroup( SplitZone * zone );
+    void RemoveZoneFromUnsignedGroup( SplitZone * zone );
+    void AddZoneToProcess( int iProc, SplitZone * zone );
+    void DumpPartitionedGridFile();
+    void ModifyZoneIndex();
+    void FreeAllZones();
+    int GetNZones( int iProc );
+    SplitZone * GetSplitZone( int iProc, int zoneId );
+    void ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord );
+    void DumpBc( SplitZone * splitZone );
+private:
+    int GetMinValueIndex( double * data, int numberOfData );
+    int GetMinLoadProc();
+    SplitZone * GetLargestZone();
+    SplitZone * Split( SplitZone * zone, double nCell );
+};
+
diff --git a/example/partition/struct/2d/stage2/01/README.txt b/example/partition/struct/2d/stage2/01/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/partition/struct/2d/stage2/01/SplitZone.cpp b/example/partition/struct/2d/stage2/01/SplitZone.cpp
new file mode 100644
index 00000000..633d4cf5
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01/SplitZone.cpp
@@ -0,0 +1,1046 @@
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+int Dim::dim = -1;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox  )
+{
+    domainBox.start = zoneBox.start;
+    domainBox.end = zoneBox.end;
+
+    int axis = iDomain / 2;
+    int direction = iDomain % 2;
+
+    if ( direction == 0 )
+    {
+        domainBox.end[ axis ] = domainBox.start[ axis ];
+    }
+    else if ( direction == 1 )
+    {
+        domainBox.start[ axis ] = domainBox.end[ axis ];
+    }
+}
+
+DimInfo::DimInfo()
+{
+    this->Init( 1 );
+}
+
+DimInfo::~DimInfo()
+{
+}
+
+void DimInfo::Init( int dim )
+{
+    this->dim = dim;
+    dimList.resize( this->dim, 1 );
+    oriPoint.resize( this->dim, 0 );
+}
+
+DimInfo & DimInfo::operator = ( const DimInfo & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->dim = rhs.dim;
+    this->dimList = rhs.dimList;
+    this->oriPoint = rhs.oriPoint;
+
+    return * this;
+}
+
+int DimInfo::ComputeNumNodes()
+{
+    int nNodes = 1;
+    for ( int m = 0; m < this->dimList.size(); ++ m )
+    {
+        nNodes *= this->dimList[ m ];
+    }
+    return nNodes;
+}
+
+void DimInfo::ComputeISize()
+{
+    int index_dim = this->dimList.size();
+    this->isize.resize( index_dim * 3, 0 );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        isize[ m ] = this->dimList[ m ];
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 1;
+        isize[ start + m ] = this->dimList[ m ] - 1;
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 2;
+        isize[ start + m ] = 0;
+    }
+
+    for ( int i = 0; i < isize.size(); ++ i )
+    {
+        std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+    }
+}
+
+void DimInfo::ComputeRminmax( std::vector<int> & ref )
+{
+    int index_dim = this->dimList.size();
+    this->rmin.resize( index_dim );
+    this->rmax.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        rmin[ m ] = ref[ m ] + 1;
+        rmax[ m ] = ref[ m ] + this->dimList[ m ];
+    }
+
+    std::cout << "rmin, rmax = \n";
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        std::cout << rmin[ m ] << " " << rmax[ m ] << "\n";
+    }
+}
+
+void DimInfo::Init( std::vector<int> & dimList )
+{
+    this->dim = dimList.size();
+    this->dimList = dimList;
+    std::vector<int> zero( dimList.size(), 0 );
+    this->oriPoint = zero;
+}
+
+void DimInfo::SetNewDimension( int axis, int newStart, int newWidth )
+{
+    this->oriPoint[ axis ] = newStart;
+    this->dimList [ axis ] = newWidth;
+}
+
+void DimInfo::GetZoneGlobalBox( RangeRegion &zoneBox )
+{
+    int index_dim = this->dimList.size();
+    zoneBox.start.resize( index_dim );
+    zoneBox.end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        zoneBox.start[ m ] = this->oriPoint[ m ] + 1;
+        zoneBox.end[ m ] = this->oriPoint[ m ] + this->dimList[ m ];
+    }
+}
+
+void DimInfo::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    int index_dim = this->dimList.size();
+    localBox.start.resize( index_dim );
+    localBox.end.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        localBox.start[ m ] = globalBox.start[ m ] - this->oriPoint[ m ];
+        localBox.end[ m ] = globalBox.end[ m ] - this->oriPoint[ m ];
+    }
+}
+
+RangeRegion::RangeRegion( int nSize )
+{
+    this->Init( nSize );
+}
+
+RangeRegion::~RangeRegion()
+{
+}
+
+void RangeRegion::Init( int nSize )
+{
+    this->start.resize( nSize );
+    this->end.resize( nSize );
+}
+
+RangeRegion & RangeRegion::operator = ( const RangeRegion & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+bool RangeRegion::operator == ( const RangeRegion & rhs ) const
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] != rhs.start[ m ] || 
+            this->end  [ m ] != rhs.end  [ m ] )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+bool RangeRegion::InRegion( const RangeRegion & region )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( ( this->start[ m ] < region.start[ m ] ) || ( this->end[ m ] > region.end[ m ] ) )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::Normalize()
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        int minv = std::min( this->start[ m ], this->end[ m ] );
+        int maxv = std::max( this->start[ m ], this->end[ m ] );
+        this->start[ m ] = minv;
+        this->end[ m ] = maxv;
+    }
+}
+
+void RangeRegion::Localize( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] -= oriPoint[ m ];
+        this->end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void RangeRegion::AddShift( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] += oriPoint[ m ];
+        this->end[ m ] += oriPoint[ m ];
+    }
+}
+
+void RangeRegion::PrintGlobal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    std::cout << "global start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ] + oriPoint[m];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "global end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ] + oriPoint[m];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+void RangeRegion::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion );
+
+bool ComputeOverlapRegion( RangeRegion & region1, RangeRegion & region2, RangeRegion & overlapRegion )
+{
+    int index_dim = region1.start.size();
+    overlapRegion.Init( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int ijkmin1 = std::min( region1.start[ m ], region1.end[ m ] );
+        int ijkmax1 = std::max( region1.start[ m ], region1.end[ m ] );
+        int ijkmin2 = std::min( region2.start[ m ], region2.end[ m ] );
+        int ijkmax2 = std::max( region2.start[ m ], region2.end[ m ] );
+        if ( ( ijkmax1 < ijkmin2 ) || ( ijkmin1 > ijkmax2 ) )
+        {
+            return false;
+        }
+
+        int ijkmin = std::max( ijkmin1, ijkmin2 );
+        int ijkmax = std::min( ijkmax1, ijkmax2 );
+
+        overlapRegion.start[ m ] = ijkmin;
+        overlapRegion.end  [ m ] = ijkmax;
+    }
+
+    return CheckOverLapping( overlapRegion );
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion )
+{
+    int index_dim = overlapRegion.start.size();
+    int iCount = 0;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        if ( overlapRegion.start[ m ] == overlapRegion.end[ m ] )
+        {
+            ++ iCount;
+        }
+    }
+
+    return ( iCount == 1 );
+}
+
+bool GetInterfaceRegion( RangeRegion & zoneBoxL, RangeRegion & zoneBoxR, RangeRegion & interfaceRegion )
+{
+    int index_dim = zoneBoxL.start.size();
+    int nDomains = 2 * index_dim;
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegionL;
+        GetDomainRegion( zoneBoxL, iDomain, domainRegionL );
+
+        for ( int jDomain = 0; jDomain < nDomains; ++ jDomain )
+        {
+            RangeRegion domainRegionR;
+            GetDomainRegion( zoneBoxR, jDomain, domainRegionR );
+
+            if ( domainRegionL == domainRegionR )
+            {
+                interfaceRegion = domainRegionL;
+                return true;
+            }
+        }
+    }
+    return false;
+}
+
+void CreateInterfaceBc( SplitZone * zoneL, SplitZone * zoneR )
+{
+    RangeRegion globalBoxL, globalBoxR, globalInterfaceRegion;
+
+    zoneL->GetZoneGlobalBox( globalBoxL );
+    zoneR->GetZoneGlobalBox( globalBoxR );
+
+    if ( ! GetInterfaceRegion( globalBoxL, globalBoxR, globalInterfaceRegion ) )
+    {
+        return;
+    }
+
+    RangeRegion localInterfaceRegionL, localInterfaceRegionR;
+
+    zoneL->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionL );
+    zoneR->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionR );
+
+    int kkk = 1;
+
+    InterfaceSplitBc * interfaceSplitBcL = new InterfaceSplitBc();
+    zoneL->interfaceSplitBcList.push_back( interfaceSplitBcL );
+    interfaceSplitBcL->zone = zoneL;
+    interfaceSplitBcL->region = localInterfaceRegionL;
+
+    int nSize = localInterfaceRegionL.start.size();
+
+    std::vector<int> transform;
+
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        transform.push_back( m + 1 );
+    }
+
+    interfaceSplitBcL->transform = transform;
+    interfaceSplitBcL->CalcTransformMatrix();
+
+    interfaceSplitBcL->donor_zone = zoneR;
+    interfaceSplitBcL->donor_region = localInterfaceRegionR;
+
+    InterfaceSplitBc * interfaceSplitBcR = new InterfaceSplitBc();
+    zoneR->interfaceSplitBcList.push_back( interfaceSplitBcR );
+
+    interfaceSplitBcR->zone = zoneR;
+    interfaceSplitBcR->region = localInterfaceRegionR;
+
+    interfaceSplitBcR->transform = transform;
+    interfaceSplitBcR->CalcTransformMatrix();
+
+    interfaceSplitBcR->donor_zone = zoneL;
+    interfaceSplitBcR->donor_region = localInterfaceRegionL;
+}
+
+
+PhysicalSplitBc::PhysicalSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+PhysicalSplitBc::~PhysicalSplitBc()
+{
+}
+
+void PhysicalSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void PhysicalSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+void PhysicalSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = splitZone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+BasicSplitBc::BasicSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+BasicSplitBc::~BasicSplitBc()
+{
+    ;
+}
+
+void BasicSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void BasicSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+int trans::M[ 3 ][ 3 ];
+std::vector<int> trans::transform;
+
+int trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void trans::CalcTransformMatrix()
+{
+    int dim = trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = trans::transform[ 0 ];
+        int sgna = trans::sgn( a );
+        int a1 = trans::del( a, 1 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int c = trans::transform[ 2 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int sgnc = trans::sgn( c );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int a3 = trans::del( a, 3 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        int b3 = trans::del( b, 3 );
+        int c1 = trans::del( c, 1 );
+        int c2 = trans::del( c, 2 );
+        int c3 = trans::del( c, 3 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 2 ][ 0 ] = sgna * a3;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+        trans::M[ 2 ][ 1 ] = sgnb * b3;
+        trans::M[ 0 ][ 2 ] = sgnc * c1;
+        trans::M[ 1 ][ 2 ] = sgnc * c2;
+        trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+InterfaceInfo::InterfaceInfo()
+{
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceInfo::~InterfaceInfo()
+{
+}
+
+InterfaceSplitBc::InterfaceSplitBc()
+{
+    this->region.Init( Dim::dim );
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceSplitBc::~InterfaceSplitBc()
+{
+}
+
+void InterfaceSplitBc::CopyMatrix( InterfaceSplitBc * interfaceSplitBc )
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = interfaceSplitBc->Mt[ i ][ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::CalcTransformMatrix()
+{
+    trans::ZeroMatrix();
+    trans::transform = this->transform;
+    trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = trans::M[ i ][ j ];
+        }
+    }
+
+}
+
+void InterfaceSplitBc::mapindex( std::vector<int> & begin1, std::vector<int> & begin2,  std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = Dim::dim;
+    std::vector<int> diff( dim );
+    for ( int m = 0; m < dim; ++ m )
+    {
+        diff[ m ] = index1[ m ] - begin1[ m ];
+    }
+
+    std::vector<int> mul( dim );
+
+    Multiply( Mt, diff, mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = mul[ m ] + begin2[ m ];
+    }
+}
+
+void InterfaceSplitBc::Multiply( int Mt[][3], std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = Dim::dim;
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = this->zone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void InterfaceSplitBc::CalcSubDonorRegion( RangeRegion &subRegion, RangeRegion &subDonorRegion )
+{
+    std::vector<int> begin1 = this->region.start;
+    std::vector<int> end1 = this->region.end;
+    std::vector<int> begin2 = this->donor_region.start;
+    std::vector<int> end2 = this->donor_region.end;
+
+    std::vector<int> new_begin1 = subRegion.start;
+    std::vector<int> new_end1 = subRegion.end;
+
+    int dim = Dim::dim;
+    std::vector<int> new_begin2( dim );
+    std::vector<int> new_end2( dim );
+
+    mapindex( begin1, begin2, new_begin1, new_begin2 );
+    mapindex( begin1, begin2, new_end1, new_end2 );
+
+    subDonorRegion.start = new_begin2;
+    subDonorRegion.end = new_end2;
+}
+
+SplitZone::SplitZone()
+{
+    this->parent  = 0;
+    this->zoneIndex = 0;
+    this->iProc = 0;
+    dimInfo.Init( Dim::dim );
+    int kk = 1;
+}
+
+SplitZone::~SplitZone()
+{
+    ;
+}
+
+void SplitZone::GetZoneGlobalBox( RangeRegion & zoneBox )
+{
+    this->dimInfo.GetZoneGlobalBox( zoneBox );
+}
+
+void SplitZone::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    this->dimInfo.GetZoneLocalBox( globalBox, localBox );
+}
+
+
+void SplitZone::ComputeRminmax()
+{
+    int index_dim = this->dimInfo.dimList.size();
+    std::vector<int> ref( index_dim, 0 );
+
+    SplitZone * rootSplitZone = 0;
+    this->GetRootInfo( rootSplitZone, ref );
+
+    this->dimInfo.ComputeRminmax( ref );
+}
+
+SplitZone * SplitZone::GetRootZone()
+{
+    SplitZone * root = this;
+
+    while ( true )
+    {
+        if ( root->parent )
+        {
+            root = root->parent;
+        }
+        else
+        {
+            return root;
+        }
+    };
+}
+
+void SplitZone::GetRootInfo( SplitZone *& root, std::vector<int> & ref )
+{
+    for ( int i = 0; i < this->dimInfo.dimList.size(); ++ i )
+    {
+        ref[ i ] += this->dimInfo.oriPoint[ i ];
+    }
+
+    if ( this->parent )
+    {
+        this->parent->GetRootInfo( root, ref );
+    }
+    else
+    {
+        root = this;
+    }
+}
+
+void SplitZone::SetParentAndChild( SplitZone * parent )
+{
+    this->parent = parent;
+    if ( parent )
+    {
+        parent->child.push_back( this );
+    }
+}
+
+
+int SplitZone::GetNCell()
+{
+    int numberOfCells = 1;
+    for ( int i = 0; i < this->dimInfo.dim; ++ i )
+    {
+        numberOfCells *= std::max( 1, ( this->dimInfo.dimList[ i ] - 1 ) );
+    }
+
+    return numberOfCells; 
+}
+
+void SplitZone::SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int leftStart = 0;
+    int leftWidth = iSplit - 0;
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, leftStart , leftWidth  );
+}
+
+void SplitZone::SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int rightStart = iSplit - 1;
+    int rightWidth = dimList[ axisNeedSplit ] - ( iSplit - 1 );
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, rightStart, rightWidth );
+}
+
+void SplitZone::Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell )
+{
+    //Find the longest axis
+    int axisNeedSplit = this->FindAxisNeedSplit();
+    int iSplit        = this->FindSplitPosition( axisNeedSplit, nCell );
+
+    zoneL->SetLeftDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+    zoneR->SetRightDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+
+    zoneL->CreateBcFromParent();
+    zoneR->CreateBcFromParent();
+    
+    CreateInterfaceBc( zoneL, zoneR );
+}
+
+void SplitZone::CreateBcFromParent()
+{
+    this->CreatePhysicalBcFromParent();
+    this->CreateInterfaceBcFromParent();
+}
+
+void SplitZone::CreatePhysicalBcFromParent()
+{
+    int nParentPhysicalBcs = this->parent->physicalSplitBcList.size();
+
+    for ( int iParentPhysicalBcs = 0; iParentPhysicalBcs < nParentPhysicalBcs; ++ iParentPhysicalBcs )
+    {
+        PhysicalSplitBc * parentPhysicalSplitBc = this->parent->physicalSplitBcList[ iParentPhysicalBcs ];
+
+        this->CreatePhysicalBcFromParent( parentPhysicalSplitBc );
+    }
+}
+
+void SplitZone::CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentPhysicalSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreatePhysicalBc( overlapRegion, parentPhysicalSplitBc->bcType );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent()
+{
+    int nInterfaceSplitBcs = this->parent->interfaceSplitBcList.size();
+
+    for ( int iInterfaceSplitBcs = 0; iInterfaceSplitBcs < nInterfaceSplitBcs; ++ iInterfaceSplitBcs )
+    {
+        InterfaceSplitBc * parentInterfaceSplitBc = this->parent->interfaceSplitBcList[ iInterfaceSplitBcs ];
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc );
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentInterfaceSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc, overlapRegion );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::FindDonorInterface( InterfaceSplitBc * interfaceSplitBc, InterfaceInfo & interfaceInfo )
+{
+    RangeRegion donor_region = interfaceSplitBc->donor_region;
+    donor_region.Normalize();
+    interfaceInfo.donor_zone = this;
+    for ( int iInterface = 0; iInterface < interfaceSplitBcList.size(); ++ iInterface )
+    {
+        InterfaceSplitBc * candidateDonorBc = interfaceSplitBcList[ iInterface ];
+        bool flag = donor_region.InRegion( candidateDonorBc->region );
+        if ( flag )
+        {
+            if ( donor_region == candidateDonorBc->region )
+            {
+                interfaceInfo.donor_interface = candidateDonorBc;
+                return;
+            }
+            else
+            {
+                InterfaceSplitBc * donorBc = new InterfaceSplitBc();
+                candidateDonorBc->child.push_back( donorBc );
+                donorBc->region = donor_region;
+                donorBc->zone = candidateDonorBc->zone;
+                donorBc->donor_zone = interfaceSplitBc->zone;
+                donorBc->transform = candidateDonorBc->transform;
+                donorBc->CopyMatrix( candidateDonorBc );
+                RangeRegion subDonorRegion( Dim::dim );
+                candidateDonorBc->CalcSubDonorRegion( donorBc->region, subDonorRegion );
+                std::vector<int> & oriPoint = interfaceSplitBc->zone->dimInfo.oriPoint;
+                subDonorRegion.Localize( oriPoint );
+                donorBc->donor_region = subDonorRegion;
+                donorBc->donor_bc = interfaceSplitBc;
+                interfaceInfo.donor_interface = donorBc;
+                return;
+            }
+        }
+    }
+    return;
+}
+
+void SplitZone::GetChildDonorRegion( RangeRegion & subDonorRegion, InterfaceInfo & interfaceInfo )
+{
+    std::cout << "subDonorRegion = \n";
+    subDonorRegion.Print();
+    int nChild = this->child.size();
+    for ( int ichild = 0; ichild < nChild; ++ ichild )
+    {
+        std::cout << " iChild = " << ichild << " nChild = " << nChild << "\n";
+        SplitZone * sub_zone = this->child[ ichild ];
+        std::cout << " zoneIndex = " << sub_zone->zoneIndex << "\n";
+        int nInters = sub_zone->interfaceSplitBcList.size();
+        for ( int iInter = 0; iInter < nInters; ++ iInter )
+        {
+            std::cout << " iInter = " << iInter << "\n";
+            InterfaceSplitBc * interfaceSplitBc = sub_zone->interfaceSplitBcList[ iInter ];
+            std::cout << "interfaceSplitBc local = \n";
+            interfaceSplitBc->region.Print();
+            std::cout << "interfaceSplitBc global = \n";
+            interfaceSplitBc->region.PrintGlobal( sub_zone->dimInfo.oriPoint );
+            RangeRegion g_region = interfaceSplitBc->region;
+            g_region.AddShift( sub_zone->dimInfo.oriPoint );
+            if ( g_region == subDonorRegion )
+            {
+                interfaceInfo.donor_zone = sub_zone;
+                interfaceInfo.donor_interface = interfaceSplitBc;
+                interfaceInfo.donor_region = interfaceSplitBc->region;
+                return;
+            }
+        }
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion )
+{
+    InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+    this->interfaceSplitBcList.push_back( interfaceSplitBc );
+
+    interfaceSplitBc->region = overlapRegion;
+    interfaceSplitBc->zone = this;
+    interfaceSplitBc->transform = parentInterfaceSplitBc->transform;
+    interfaceSplitBc->CopyMatrix( parentInterfaceSplitBc );
+    RangeRegion subDonorRegion( Dim::dim );
+    parentInterfaceSplitBc->CalcSubDonorRegion( overlapRegion, subDonorRegion );
+    interfaceSplitBc->ChangeRegionToLocalCoordinate();
+    interfaceSplitBc->donor_region = subDonorRegion;
+    SplitZone * parent_donor_zone = parentInterfaceSplitBc->donor_zone;
+    std::cout << " parentInterfaceSplitBc->zone->zoneIndex " << parentInterfaceSplitBc->zone->zoneIndex << "\n";
+    std::cout << " parentInterfaceSplitBc->donor_zone->zoneIndex " << parent_donor_zone->zoneIndex << "\n";
+    if ( parent_donor_zone->child.size() > 0 )
+    {
+        InterfaceInfo interfaceInfo;
+        parent_donor_zone->GetChildDonorRegion( subDonorRegion, interfaceInfo );
+        interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+        interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+        interfaceSplitBc->donor_region = interfaceInfo.donor_region;
+        //compatibility
+        InterfaceSplitBc * donor_bc = interfaceSplitBc->donor_bc;
+        SplitZone * donor_zone = interfaceSplitBc->donor_zone;
+        //if ( donor_bc->donor_zone->zoneIndex == interfaceSplitBc->zone->zoneIndex )
+        if ( interfaceSplitBc->zone != donor_bc->donor_zone )
+        {
+            donor_bc->donor_zone = interfaceSplitBc->zone;
+            donor_bc->donor_region = interfaceSplitBc->region;
+           
+            int kkk = 1;
+        }
+        int kkk = 1;
+    }
+    else
+    {
+        InterfaceInfo interfaceInfo;
+        parent_donor_zone->FindDonorInterface( interfaceSplitBc, interfaceInfo );
+        interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+        interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+    }
+    
+    int kkk = 1;
+}
+
+void SplitZone::CreatePhysicalBc( RangeRegion & overlapRegion, int bcType )
+{
+    PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+    this->physicalSplitBcList.push_back( physicalSplitBc );
+    physicalSplitBc->SetRegion( overlapRegion );
+    physicalSplitBc->bcType = bcType;
+    physicalSplitBc->splitZone = this;
+    physicalSplitBc->ChangeRegionToLocalCoordinate();
+}
+
+int SplitZone::FindAxisNeedSplit()
+{
+    //Find the longest axis
+    int axisNeedSplit = 0;
+    int maxN = this->dimInfo.dimList[ 0 ];
+
+    for ( int m = 1; m < this->dimInfo.dimList.size(); ++ m )
+    {
+        if ( this->IsPoleBc( m ) )
+        {
+            continue;
+        }
+        int Nm = this->dimInfo.dimList[ m ];
+        if ( maxN < Nm )
+        {
+            maxN = Nm;
+            axisNeedSplit = m;
+        }
+    }
+
+    return axisNeedSplit;
+}
+
+int SplitZone::GetCrossSection( int axis )
+{
+    int nDim = this->dimInfo.dimList.size();
+    int crossSection = 1;
+    int N = nDim - 1;
+    for ( int m = 0; m < N; ++ m )
+    {
+         int mm = ( axis + 1 ) % nDim;
+         int nLineElements = std::max( 1, ( this->dimInfo.dimList[ mm ] - 1 ) );
+         crossSection *= nLineElements;
+    }
+    return crossSection;
+}
+
+int SplitZone::FindSplitPosition( int axisNeedSplit, double nCell )
+{
+    int nDim = this->dimInfo.dimList.size();
+    std::vector<int> crossSections( nDim );
+    for ( int m = 0; m < nDim; ++ m )
+    {
+        crossSections[ m ] = this->GetCrossSection( m );
+    }
+
+    //guess the value
+    double dSplit = nCell / crossSections[ axisNeedSplit ];
+    int  iSplit = 1 + static_cast< int >( std::floor( dSplit + 0.5 ) );
+    return iSplit;
+}
+
+
+bool SplitZone::IsPoleBc( int splitDirection )
+{
+    return false;
+}
+
diff --git a/example/partition/struct/2d/stage2/01/SplitZone.h b/example/partition/struct/2d/stage2/01/SplitZone.h
new file mode 100644
index 00000000..8e312dd2
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01/SplitZone.h
@@ -0,0 +1,193 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class Dim
+{
+public:
+    static int dim;
+};
+
+class SplitZone;
+class RangeRegion;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox );
+
+class DimInfo
+{
+public:
+    DimInfo();
+    ~DimInfo();
+public:
+    int dim;
+    std::vector<int> dimList;
+    std::vector<int> oriPoint;
+    std::vector<int> isize;
+    std::vector<int> rmin;
+    std::vector<int> rmax;
+public:
+    int GetSize() const { return dim; }
+    DimInfo & operator = ( const DimInfo & rhs );
+public:
+    int ComputeNumNodes();
+    void ComputeISize();
+    void ComputeRminmax( std::vector<int> & ref );
+    void Init( int dim );
+    void Init( std::vector<int> & dimList );
+    void SetNewDimension( int axis, int newStart, int newWidth );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+};
+
+class SplitZone;
+class SplitBcPatch;
+
+class RangeRegion
+{
+public:
+    RangeRegion( int nSize = 1 );
+    ~RangeRegion();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    void Init( int nSize );
+    RangeRegion & operator = ( const RangeRegion & rhs );
+    bool operator == ( const RangeRegion & rhs ) const;
+    bool InRegion( const RangeRegion & region );
+    void SetRegion( std::vector<int> &pnts );
+    void Normalize();
+    void Localize( std::vector<int> & oriPoint );
+    void AddShift( std::vector<int> & oriPoint );
+    void PrintGlobal( std::vector<int> & oriPoint );
+    void Print();
+};
+
+class PhysicalSplitBc
+{
+public:
+    PhysicalSplitBc();
+    ~PhysicalSplitBc();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class BasicSplitBc
+{
+public:
+    BasicSplitBc();
+    ~BasicSplitBc();
+public:
+    RangeRegion region;
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> & pnts );
+    void SetRegion( RangeRegion & region );
+};
+
+class trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class InterfaceSplitBc;
+class SplitZone;
+
+class InterfaceInfo
+{
+public:
+    InterfaceInfo();
+    ~InterfaceInfo();
+public:
+    InterfaceSplitBc * donor_interface = nullptr;
+    SplitZone * donor_zone = nullptr;
+    RangeRegion donor_region;
+};
+
+class InterfaceSplitBc
+{
+public:
+    InterfaceSplitBc();
+    ~InterfaceSplitBc();
+public:
+    std::vector<int> transform;
+    int Mt[ 3 ][ 3 ];
+    RangeRegion region;
+    SplitZone * zone = nullptr;
+    RangeRegion donor_region;
+    SplitZone * donor_zone = nullptr;
+    InterfaceSplitBc * donor_bc = nullptr;
+public:
+    std::vector<InterfaceSplitBc *> child;
+public:
+    void CopyMatrix( InterfaceSplitBc * interfaceSplitBc );
+    void CalcTransformMatrix();
+    void CalcSubDonorRegion( RangeRegion & subRegion, RangeRegion & subDonorRegion );
+    void mapindex( std::vector<int> & begin1, std::vector<int> & begin2, std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( int Mt[][ 3 ], std::vector<int> & a, std::vector<int> & b );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class SplitZone
+{
+public:
+    SplitZone();
+    ~SplitZone();
+public:
+    DimInfo dimInfo;
+    int zoneIndex, iProc;
+    int newIndex;
+protected:
+    SplitZone * parent;
+    std::vector<SplitZone *> child;
+public:
+    std::vector< PhysicalSplitBc * > physicalSplitBcList;
+    std::vector< InterfaceSplitBc * > interfaceSplitBcList;
+public:
+    int GetNCell();
+    void ComputeRminmax();
+    void GetRootInfo( SplitZone *& root, std::vector<int> & ref );
+    void SetZoneIndex( int zoneIndex ) { this->zoneIndex = zoneIndex; }
+    int  GetZoneIndex() { return zoneIndex; }
+    void SetProcId( int iProc ) { this->iProc = iProc; }
+    void SetParent( SplitZone * parent ) { this->parent = parent; };
+    void SetParentAndChild( SplitZone * parent );
+    void FindDonorInterface( InterfaceSplitBc * interfaceSplitBc, InterfaceInfo & interfaceInfo );
+    void GetChildDonorRegion( RangeRegion & subDonorRegion, InterfaceInfo & interfaceInfo );
+public:
+    void CreateBcFromParent();
+    void CreatePhysicalBcFromParent();
+    void CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc );
+    void CreatePhysicalBc( RangeRegion & overlapRegion, int bcType );
+    void CreateInterfaceBcFromParent();
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc );
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion );
+
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+    SplitZone * GetRootZone();
+public:
+    void Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell );
+    void SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+    void SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+private:
+    int FindAxisNeedSplit();
+    int FindSplitPosition( int axisNeedSplit, double nCell );
+    bool IsPoleBc( int splitDirection );
+    int GetCrossSection( int axis );
+};
+
diff --git a/example/partition/struct/2d/stage2/01/heat2d2blocksv1.cgns b/example/partition/struct/2d/stage2/01/heat2d2blocksv1.cgns
new file mode 100644
index 00000000..2e1e69ca
Binary files /dev/null and b/example/partition/struct/2d/stage2/01/heat2d2blocksv1.cgns differ
diff --git a/example/partition/struct/2d/stage2/01/heat2dpart.cgns b/example/partition/struct/2d/stage2/01/heat2dpart.cgns
new file mode 100644
index 00000000..f61ec4a2
Binary files /dev/null and b/example/partition/struct/2d/stage2/01/heat2dpart.cgns differ
diff --git a/example/partition/struct/2d/stage2/01/main.cpp b/example/partition/struct/2d/stage2/01/main.cpp
new file mode 100644
index 00000000..5da1de7c
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01/main.cpp
@@ -0,0 +1,18 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include "Partition.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip>
+
+int main(int argc, char **argv)
+{
+    Partition * partition = new Partition();
+    partition->Solve();
+    delete partition;
+
+    return 0;
+}
diff --git a/example/partition/struct/2d/stage2/01a/CMakeLists.txt b/example/partition/struct/2d/stage2/01a/CMakeLists.txt
new file mode 100644
index 00000000..74ceea7d
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01a/CMakeLists.txt
@@ -0,0 +1,78 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	Partition.h Partition.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	SplitZone.h SplitZone.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/partition/struct/2d/stage2/01a/CgnsGrid.cpp b/example/partition/struct/2d/stage2/01a/CgnsGrid.cpp
new file mode 100644
index 00000000..dfe750bd
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01a/CgnsGrid.cpp
@@ -0,0 +1,349 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include <map>
+
+Grid::Grid()
+{
+    ;
+}
+
+Grid::~Grid()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if( (i+1)%5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+    delete this->patch;
+}
+
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+ZoneBcPatch::ZoneBcPatch()
+{
+    ;
+}
+
+ZoneBcPatch::~ZoneBcPatch()
+{
+}
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+Global::Global()
+{
+    ;
+}
+
+Global::~Global()
+{
+}
+
+void Global::FreeData()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+    zones.resize( 0 );
+}
+
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            //baseZone.baseId = baseId;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin( index_dim );
+            std::vector<cgsize_t> irmax( index_dim );
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                std::vector<char> coord( nNodes * sizeof(double) );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+                coor->DumpCoor();
+            }
+
+            int nbocos = -1;
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+                int kkk = 1;
+            }
+        }
+        int kkk = 1;
+    }
+    int kkk = 1;
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage2/01a/CgnsGrid.h b/example/partition/struct/2d/stage2/01a/CgnsGrid.h
new file mode 100644
index 00000000..053c467b
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01a/CgnsGrid.h
@@ -0,0 +1,140 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <map>
+
+class Grid;
+
+class Zone;
+
+class Grid
+{
+public:
+    Grid();
+    ~Grid();
+public:
+    int nZone;
+    std::vector<double> x;
+    std::vector<Zone *> zones;
+};
+
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+};
+
+class ZoneBc;
+class ZoneBc1To1;
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class ZoneBcPatch;
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+    ZoneBcPatch * patch = nullptr;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+class ZoneBcPatch
+{
+public:
+    ZoneBcPatch();
+    ~ZoneBcPatch();
+public:
+    int donor_zoneid;
+    std::vector<int> transform;
+    std::vector<int> donor_pnts;
+};
+
+class BaseZone
+{
+public:
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Global
+{
+public:
+    Global();
+    ~Global();
+public:
+    static int cell_dim;
+    static int phys_dim;
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+public:
+    static void FreeData();
+};
+
+void ReadCgnsGrid( const std::string & filename );
+void ReadCgnsGridBaseZone( const std::string & filename );
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage2/01a/Partition.cpp b/example/partition/struct/2d/stage2/01a/Partition.cpp
new file mode 100644
index 00000000..913d4f9c
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01a/Partition.cpp
@@ -0,0 +1,618 @@
+#include "Partition.h"
+#include "CgnsGrid.h"
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+bool CmpSplitZone::operator() ( SplitZone * a, SplitZone * b ) const
+{
+    return a->zoneIndex < b->zoneIndex;
+};
+
+
+double CalSumOfProcSpeed( std::vector<double> & procSpeed );
+double CalSumOfProcSpeed( std::vector<double> & procSpeed )
+{
+    int nProc = procSpeed.size();
+    double sumOfProcSpeed = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        sumOfProcSpeed += procSpeed[ iProc ];
+    }
+    return sumOfProcSpeed;
+}
+
+Partition::Partition()
+{
+    this->inputName = "../heat2d2blocksv2.cgns";
+    this->outName =  "../heat2dpart.cgns";
+}
+
+Partition::~Partition()
+{
+    ;
+}
+
+int Partition::GetMinValueIndex( double * data, int numberOfData )
+{
+    double minValue = data[ 0 ];
+    int minimumValueIndex = 0;
+
+    for ( int iData = 1; iData < numberOfData; ++ iData )
+    {
+        if ( minValue > data[ iData ] )
+        {
+            minValue      = data[ iData ];
+            minimumValueIndex = iData;
+        }
+    }
+    return minimumValueIndex;
+}
+
+int Partition::GetMinLoadProc()
+{
+    return this->GetMinValueIndex( this->timeProc.data(), this->nProc );
+}
+
+SplitZone * Partition::GetLargestZone()
+{
+    SplitZone * largestZone = 0;
+
+    double nMaxCell = 0.0;
+
+    for ( std::set< SplitZone * >::iterator iter = unsignedZoneGroup.begin(); iter != unsignedZoneGroup.end(); ++ iter )
+    {
+        double nSize = ( * iter )->GetNCell();
+        if ( nMaxCell < nSize )
+        {
+            nMaxCell    = nSize;
+            largestZone = * iter;
+        }
+    }
+
+    return largestZone;
+}
+
+void Partition::Solve()
+{
+    std::cout << "Partition::Split()\n";
+    //this->nProc = 2;
+    this->nProc = 4;
+    this->ReadGrid();
+    this->Split();
+    this->DumpPartitionedGridFile();
+    this->FreeAllZones();
+}
+
+void Partition::ReadGrid()
+{
+    ReadCgnsGridBaseZone( this->inputName );
+    ReadCgnsGrid( this->inputName );
+
+    this->nOriZone = ::Global::zones.size();
+    Dim::dim = Global::cell_dim;
+
+    std::cout << "numberOfBlocks = " << nOriZone << "\n";
+
+    this->refZone.resize( nOriZone );
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = new SplitZone();
+        refZone[ iZone ] = splitZone;
+
+        splitZone->SetZoneIndex( iZone );
+        splitZone->SetProcId( 0 );
+        splitZone->SetParentAndChild( 0 );
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        Zone * zone = ::Global::zones[ iZone ];
+
+        splitZone->dimInfo.dimList = zone->nijk;
+
+        int nbccos = zone->bccos.size();
+        std::cout << "nbccos = " << nbccos << "\n";
+
+        for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+        {
+            ZoneBc * zoneBc = zone->bccos[ ibcco ];
+
+            PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+            splitZone->physicalSplitBcList.push_back( physicalSplitBc );
+            physicalSplitBc->bcType = zoneBc->bcType;
+            physicalSplitBc->SetRegion( zoneBc->pnts );
+            physicalSplitBc->splitZone = splitZone;
+        }
+
+        int nbc1to1s = zone->bc1to1s.size();
+
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * zoneBc1To1 = zone->bc1to1s[ ibc1to1 ];
+
+            InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+            splitZone->interfaceSplitBcList.push_back( interfaceSplitBc );
+            interfaceSplitBc->zone = splitZone;
+            interfaceSplitBc->region.SetRegion( zoneBc1To1->pnts );
+
+            interfaceSplitBc->transform = zoneBc1To1->transform;
+            interfaceSplitBc->CalcTransformMatrix();
+
+            interfaceSplitBc->donor_zone = refZone[ zoneBc1To1->donor_zoneid ];
+            interfaceSplitBc->donor_region.SetRegion( zoneBc1To1->donor_pnts );
+        }
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        int nbc1to1s = splitZone->interfaceSplitBcList.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            InterfaceSplitBc * interfaceSplitBc = splitZone->interfaceSplitBcList[ ibc1to1 ];
+            InterfaceInfo interfaceInfo;
+            interfaceSplitBc->donor_zone->FindDonorInterface( interfaceSplitBc, interfaceInfo );
+            interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+            interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+        }
+    }
+}
+
+void Partition::Split()
+{
+    this->InitSplit();
+    this->BinarySplit();
+    this->ModifyZoneIndex();
+    int kkk = 1;
+}
+
+void Partition::InitSplit()
+{
+    //nZone is the number of zones in the original grid
+    //nProc is not the number of blocks in the end, but the number of processes that need to be divided.
+    //This difference occurs because the structure grid can have many blocks per process.
+
+    //this->nProc    = nProc;
+    //this->nPhyBlocks = referenceBlock.size();
+    //this->nZone  = this->nPhyBlocks;
+
+    //tj Computation time on processor j
+    //Nk Number of internal grid-cells for zone j
+    //aveFloatOp:  Number of Real operations per gridcell
+    //Gj The set of blocks allocated to process j
+    //Pj Real operations per second for process j
+
+    //The Greedy Load Balancing Algorithm
+    //1.Compute an "ideal" uniprocessor time, Tuni = sum ( Nk * aveFloatOp )/ sum( Pj ).
+    //2.Set the group of unassigned blocks, Gu, to contain all blocks. The number of blocks in Nu=M, where M is the total number of blocks in the mesh.
+    //3.Start all processors with a very small fictitious zone to get a start tj=delt aveFloatOp/Pj, where delt<<1 is the size of the very small fictious zone.
+    //This is used to find the fastest processor in a heterogeneous system, tj could otherwise be set to 0 in the homogeneous case.
+    this->aveFloatOp = 1.0;
+    this->delta      = 1.0e-5;
+    this->procSpeed.resize( nProc );
+    this->timeProc.resize( nProc );
+
+    this->nTZone = this->nOriZone;
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        procSpeed[ iProc ] = 1.0;
+    }
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        timeProc[ iProc ] = delta * aveFloatOp / procSpeed[ iProc ];
+    }
+
+    double sumProcSpeed = CalSumOfProcSpeed( procSpeed );
+
+    double sumProcOp = 0.0;
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        sumProcOp += refZone[ iZone ]->GetNCell() * aveFloatOp;
+    }
+
+    this->idealUniProcTime = sumProcOp / sumProcSpeed;
+
+    this->eps = 0.05;
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        unsignedZoneGroup.insert( refZone[ iZone ] );
+    }
+
+    //Init zoneStorage
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        zoneStorage.insert( refZone[ iZone ] );
+    }
+
+    //Assign procSplitZone to each process
+    procSplitZone.resize( nProc );
+
+    this->minNumberCell = 1;
+    for ( int m = 0; m < Dim::dim; ++ m )
+    {
+        this->minNumberCell *= 1;
+    }
+
+    int kkk = 1;
+
+}
+
+void Partition::FreeAllZones()
+{
+    int iCount = 0;
+    for ( std::set < SplitZone * >::iterator iter = zoneStorage.begin(); iter != zoneStorage.end(); ++ iter )
+    {
+        //cout << "iCount = " << iCount << "\n";
+        ++ iCount;
+        delete * iter;
+    }
+}
+
+int Partition::GetNZones( int iProc )
+{
+    return this->procSplitZone[ iProc ].size();
+}
+
+SplitZone * Partition::GetSplitZone( int iProc, int zoneId )
+{
+    return this->procSplitZone[ iProc ][ zoneId ];
+}
+
+void Partition::AddZoneToUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.insert( zone );
+}
+
+void Partition::RemoveZoneFromUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.erase( zone );
+}
+
+void Partition::AddZoneToProcess( int iProc, SplitZone * zone )
+{
+    this->procSplitZone[ iProc ].push_back( zone );
+}
+
+void Partition::AddNewZone( SplitZone * zone )
+{
+    zone->SetZoneIndex( nTZone ++ );
+
+    this->AddZoneToUnsignedGroup( zone );
+
+    this->zoneStorage.insert( zone );
+}
+
+SplitZone * Partition::Split( SplitZone * zone, double nCell )
+{
+    SplitZone * zoneL = new SplitZone();
+    zoneL->SetParentAndChild( zone );
+
+    SplitZone * zoneR = new SplitZone();
+    zoneR->SetParentAndChild( zone );
+
+    //Remove the original block from the UnsignedGroup
+    this->RemoveZoneFromUnsignedGroup( zone );
+
+    this->AddNewZone( zoneL );
+    this->AddNewZone( zoneR );
+
+    zone->Split( zoneL, zoneR, nCell );
+
+    return zoneL;
+}
+
+void Partition::BinarySplit()
+{
+    while ( ! unsignedZoneGroup.empty() )
+    {
+        std::cout << "number of unsigned zone = " << unsignedZoneGroup.size() << "\n";
+        int iProc = this->GetMinLoadProc();
+
+        //Get the block with the largest number of grids and its size
+        SplitZone * largestZone = this->GetLargestZone();
+
+        double nMaxCell = largestZone->GetNCell();
+
+        double aveFloatOp = this->aveFloatOp;
+        double tau = timeProc[ iProc ] + nMaxCell * aveFloatOp / procSpeed[ iProc ];
+
+        //It seems that EPS is still necessary
+        //The idea here is as follows. For the candidate blocks which can be divided into blocks, 
+        //if the difference between the target blocks and the candidate blocks is too wide, 
+        //the binarySplit method is adopted. The binarySplit blocks do not directly join the process,
+        //but enter the next round of screening.
+
+        if ( tau > idealUniProcTime * ( 1.0 + eps ) )
+        {
+            double nRest = ( tau - idealUniProcTime ) * procSpeed[ iProc ] / aveFloatOp;
+
+            double nTarget = nMaxCell - nRest;
+            if ( nRest > this->minNumberCell && nTarget > this->minNumberCell )
+            {
+                //It is necessary to divide blocks only when a certain number of points are satisfied.
+                double nHalf = nMaxCell / 2.0;
+                nMaxCell = nTarget;
+                double ratio = nMaxCell / nRest;
+                double oRatio = 1.0 / ratio;
+
+                if ( std::max( ratio, oRatio ) < 3.0 )
+                {
+                    int kkk = 1;
+                    largestZone = this->Split( largestZone, nMaxCell );
+                    timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                    this->RemoveZoneFromUnsignedGroup( largestZone );
+                    this->AddZoneToProcess( iProc, largestZone );
+                }
+                else
+                {
+                    this->Split( largestZone, nHalf );
+                }
+            }
+            else
+            {
+                //If the block is of the right size, join the process directly, and there is no need to split it.
+                timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                this->RemoveZoneFromUnsignedGroup( largestZone );
+                this->AddZoneToProcess( iProc, largestZone );
+            }
+        }
+        else
+        {
+            //If the block is of the right size, join the process directly, and there is no need to split it.
+            timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+            this->RemoveZoneFromUnsignedGroup( largestZone );
+            this->AddZoneToProcess( iProc, largestZone );
+        }
+    }
+}
+
+void Partition::ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord )
+{
+    SplitZone * rootSplitZone = splitZone->GetRootZone();
+    Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+    int nNodes = splitZone->dimInfo.ComputeNumNodes();
+    std::cout << "nNodes = " << nNodes << "\n";
+
+    coord.resize( nNodes * sizeof(double) );
+
+    int index_dim = splitZone->dimInfo.dimList.size();
+    Coor * coor = zone->coors[ icoord ];
+
+    double * xlocal = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    double * xglobal = reinterpret_cast<double *>( const_cast<char *>( coor->coord.data() ) );
+    if ( index_dim == 1 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        for ( int i = imin; i < imax; ++ i )
+        {
+            xlocal[ icount++ ] = xglobal[ i ];
+        }
+    }
+    else if ( index_dim == 2 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        int jmin = splitZone->dimInfo.rmin[ 1 ] - 1;
+        int jmax = splitZone->dimInfo.rmax[ 1 ];
+        int ni = rootSplitZone->dimInfo.dimList[ 0 ];
+        int nj = rootSplitZone->dimInfo.dimList[ 1 ];
+        for ( int j = jmin; j < jmax; ++ j )
+        {
+            int jstride = j * ni;
+            for ( int i = imin; i < imax; ++ i )
+            {
+                xlocal[ icount++ ] = xglobal[ jstride + i ];
+            }
+        }
+    }
+}
+
+void Partition::DumpBc( SplitZone * splitZone )
+{
+}
+
+void Partition::DumpPartitionedGridFile()
+{
+    std::cout << "\n";
+    std::cout << "DumpPartitionedGridFile -------------------------------" << "\n";
+    std::cout << "\n";
+    int fileId = -1;
+    std::string filename = this->outName;
+    int ierr = cg_open( filename.c_str(), CG_MODE_WRITE, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+
+    std::vector<std::string> coordnames;
+    coordnames.push_back( "CoordinateX" );
+    coordnames.push_back( "CoordinateY" );
+    coordnames.push_back( "CoordinateZ" );
+
+    std::string basename = "Base";
+    int baseId = -1;
+    int icelldim = Global::cell_dim;
+    int iphysdim = Global::phys_dim;
+    cg_base_write( fileId, basename.c_str(), icelldim, iphysdim, &baseId );
+
+    std::cout << "baseId = " << baseId << "\n";
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        int nZones = this->GetNZones( iProc );
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            ZoneType_t zoneType = Structured;
+
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+
+            int index_dim = splitZone->dimInfo.dimList.size();
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            splitZone->dimInfo.ComputeISize();
+
+            int isize_dim = index_dim * 3;
+
+            std::vector<cgsize_t> isize( index_dim * 3, 0 );
+            for ( int m = 0; m < isize_dim; ++ m )
+            {
+                isize[ m ] = splitZone->dimInfo.isize[ m ];
+            }
+
+            int zoneId = -1;
+
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+
+            std::string zonename = "Zone" + std::to_string( splitZone->newIndex );
+
+            cg_zone_write( fileId, baseId, zonename.c_str(), isize.data(), zoneType, &zoneId );
+
+            std::cout << "zoneId = " << zoneId << "\n";
+            std::cout << "zonename = " << zonename << "\n";
+                
+            splitZone->ComputeRminmax();
+
+            SplitZone * rootSplitZone = splitZone->GetRootZone();
+
+            Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+            int ncoords = zone->coors.size();
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = -1;
+                DataType_t dataType = RealDouble;
+                std::string coordname = coordnames[ icoord ];
+                Coor * coor = zone->coors[ icoord ];
+
+                int nNodes = splitZone->dimInfo.ComputeNumNodes();
+                std::cout << "nNodes = " << nNodes << "\n";
+
+                std::vector<char> coord;
+                ComputeCoor( splitZone, icoord, coord );
+
+                cg_coord_write( fileId, baseId, zoneId, dataType, coordname.c_str(), coord.data(), &coorId );
+
+                std::cout << "fileId = " << fileId  << " baseId = " << baseId << " zoneId = " << zoneId  << " coorId = " << coorId << "\n";
+            }
+
+            std::vector< PhysicalSplitBc * > &bccoList = splitZone->physicalSplitBcList;
+
+            int nbocos = bccoList.size();
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = -1;
+                GridLocation_t location = Vertex;
+
+                std::string boconame = "BC" + std::to_string( iboco + 1 );
+
+                PhysicalSplitBc * physicalSplitBc = bccoList[ iboco ];
+                BCType_t bocotype = static_cast<BCType_t>( physicalSplitBc->bcType );
+                PointSetType_t ptset_type = PointRange;
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> pnts;
+                int nSize = physicalSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.end[ i ] );
+                }
+
+                cg_boco_write( fileId, baseId, zoneId, boconame.c_str(), bocotype, ptset_type, npnts, pnts.data(), & bccoId );
+            }
+
+            std::vector< InterfaceSplitBc * > & bc1to1List = splitZone->interfaceSplitBcList;
+
+            int n1to1 = bc1to1List.size();
+            std::cout << "n1to1 = " << n1to1 << "\n";
+
+            std::vector<int> itranfrm( index_dim );
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                itranfrm[ m ] = m + 1;
+            }
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int index_conn = -1;
+
+                InterfaceSplitBc * interfaceSplitBc = bc1to1List[ i1to1 ];
+
+                std::vector<cgsize_t> pnts;
+                std::vector<cgsize_t> pntsdonor;
+                int nSize = interfaceSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.end[ i ] );
+                }
+
+                int nPatchSize = interfaceSplitBc->donor_region.start.size();
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.start[ i ] );
+                }
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.end[ i ] );
+                }
+                int id = interfaceSplitBc->donor_zone->newIndex;
+                int oldZoneIndex = interfaceSplitBc->donor_zone->zoneIndex;
+                std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+                std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+                std::cout << "donor zone id = " << id << "\n";
+                std::cout << "donor zone oldZoneIndex = " << oldZoneIndex << "\n";
+                std::string donorname = "Zone" + std::to_string( id );
+                std::string connectname = "Interface" + std::to_string( i1to1 );
+
+                std::cout << "donorname = " << donorname << "\n";
+                std::cout << "connectname = " << connectname << "\n";
+
+                std::vector<int> & itranfrm = interfaceSplitBc->transform;
+
+                cg_1to1_write( fileId, baseId, zoneId, connectname.c_str(), donorname.c_str(), pnts.data(), pntsdonor.data(), itranfrm.data(), &index_conn );
+                std::cout << "index_conn = " << index_conn << "\n";
+            }
+        }
+    }
+    cg_close( fileId );
+}
+
+void Partition::ModifyZoneIndex()
+{
+    std::cout << "ModifyZoneIndex +++++++++++++++++++++++++ " << "\n";
+    int globalZoneId = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        std::cout << "iProc = " << iProc << "\n";
+        int nZones = this->GetNZones( iProc );
+        std::cout << "nZones in Proc " << iProc << "  = " << nZones << "\n";
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+            //splitZone->SetZoneIndex( globalZoneId++ );
+            splitZone->newIndex = ( globalZoneId++ );
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+        }
+    }
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage2/01a/Partition.h b/example/partition/struct/2d/stage2/01a/Partition.h
new file mode 100644
index 00000000..8a4a9731
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01a/Partition.h
@@ -0,0 +1,59 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class SplitZone;
+
+struct CmpSplitZone 
+{
+    bool operator() ( SplitZone * a, SplitZone * b ) const;
+};
+
+class Partition
+{
+public:
+    Partition();
+    ~Partition();
+protected:
+    std::set < SplitZone * > zoneStorage;
+    std::set < SplitZone *, CmpSplitZone > unsignedZoneGroup;
+    std::vector< SplitZone * > refZone;
+    std::vector< std::vector< SplitZone * > > procSplitZone;
+    std::vector<double> procSpeed;
+    std::vector<double> timeProc;
+    double aveFloatOp, delta;
+    double idealUniProcTime, eps;
+    int minNumberCell;
+    int nTZone;
+    int nOriZone;
+    int nProc;
+public:
+    std::string inputName;
+    std::string outName;
+public:
+    void Solve();
+    void ReadGrid();
+    void Split();
+    void InitSplit();
+    void BinarySplit();
+    //void GreedySplit();
+public:
+    void AddNewZone( SplitZone * zone );
+    void AddZoneToUnsignedGroup( SplitZone * zone );
+    void RemoveZoneFromUnsignedGroup( SplitZone * zone );
+    void AddZoneToProcess( int iProc, SplitZone * zone );
+    void DumpPartitionedGridFile();
+    void ModifyZoneIndex();
+    void FreeAllZones();
+    int GetNZones( int iProc );
+    SplitZone * GetSplitZone( int iProc, int zoneId );
+    void ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord );
+    void DumpBc( SplitZone * splitZone );
+private:
+    int GetMinValueIndex( double * data, int numberOfData );
+    int GetMinLoadProc();
+    SplitZone * GetLargestZone();
+    SplitZone * Split( SplitZone * zone, double nCell );
+};
+
diff --git a/example/partition/struct/2d/stage2/01a/README.txt b/example/partition/struct/2d/stage2/01a/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01a/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/partition/struct/2d/stage2/01a/SplitZone.cpp b/example/partition/struct/2d/stage2/01a/SplitZone.cpp
new file mode 100644
index 00000000..e7ffa1b3
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01a/SplitZone.cpp
@@ -0,0 +1,1065 @@
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+int Dim::dim = -1;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox  )
+{
+    domainBox.start = zoneBox.start;
+    domainBox.end = zoneBox.end;
+
+    int axis = iDomain / 2;
+    int direction = iDomain % 2;
+
+    if ( direction == 0 )
+    {
+        domainBox.end[ axis ] = domainBox.start[ axis ];
+    }
+    else if ( direction == 1 )
+    {
+        domainBox.start[ axis ] = domainBox.end[ axis ];
+    }
+}
+
+DimInfo::DimInfo()
+{
+    this->Init( 1 );
+}
+
+DimInfo::~DimInfo()
+{
+}
+
+void DimInfo::Init( int dim )
+{
+    this->dim = dim;
+    dimList.resize( this->dim, 1 );
+    oriPoint.resize( this->dim, 0 );
+}
+
+DimInfo & DimInfo::operator = ( const DimInfo & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->dim = rhs.dim;
+    this->dimList = rhs.dimList;
+    this->oriPoint = rhs.oriPoint;
+
+    return * this;
+}
+
+int DimInfo::ComputeNumNodes()
+{
+    int nNodes = 1;
+    for ( int m = 0; m < this->dimList.size(); ++ m )
+    {
+        nNodes *= this->dimList[ m ];
+    }
+    return nNodes;
+}
+
+void DimInfo::ComputeISize()
+{
+    int index_dim = this->dimList.size();
+    this->isize.resize( index_dim * 3, 0 );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        isize[ m ] = this->dimList[ m ];
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 1;
+        isize[ start + m ] = this->dimList[ m ] - 1;
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 2;
+        isize[ start + m ] = 0;
+    }
+
+    for ( int i = 0; i < isize.size(); ++ i )
+    {
+        std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+    }
+}
+
+void DimInfo::ComputeRminmax( std::vector<int> & ref )
+{
+    int index_dim = this->dimList.size();
+    this->rmin.resize( index_dim );
+    this->rmax.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        rmin[ m ] = ref[ m ] + 1;
+        rmax[ m ] = ref[ m ] + this->dimList[ m ];
+    }
+
+    std::cout << "rmin, rmax = \n";
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        std::cout << rmin[ m ] << " " << rmax[ m ] << "\n";
+    }
+}
+
+void DimInfo::Init( std::vector<int> & dimList )
+{
+    this->dim = dimList.size();
+    this->dimList = dimList;
+    std::vector<int> zero( dimList.size(), 0 );
+    this->oriPoint = zero;
+}
+
+void DimInfo::SetNewDimension( int axis, int newStart, int newWidth )
+{
+    this->oriPoint[ axis ] = newStart;
+    this->dimList [ axis ] = newWidth;
+}
+
+void DimInfo::GetZoneGlobalBox( RangeRegion &zoneBox )
+{
+    int index_dim = this->dimList.size();
+    zoneBox.start.resize( index_dim );
+    zoneBox.end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        zoneBox.start[ m ] = this->oriPoint[ m ] + 1;
+        zoneBox.end[ m ] = this->oriPoint[ m ] + this->dimList[ m ];
+    }
+}
+
+void DimInfo::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    int index_dim = this->dimList.size();
+    localBox.start.resize( index_dim );
+    localBox.end.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        localBox.start[ m ] = globalBox.start[ m ] - this->oriPoint[ m ];
+        localBox.end[ m ] = globalBox.end[ m ] - this->oriPoint[ m ];
+    }
+}
+
+RangeRegion::RangeRegion( int nSize )
+{
+    this->Init( nSize );
+}
+
+RangeRegion::~RangeRegion()
+{
+}
+
+void RangeRegion::Init( int nSize )
+{
+    this->start.resize( nSize );
+    this->end.resize( nSize );
+}
+
+RangeRegion & RangeRegion::operator = ( const RangeRegion & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+bool RangeRegion::operator == ( const RangeRegion & rhs ) const
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] != rhs.start[ m ] || 
+            this->end  [ m ] != rhs.end  [ m ] )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+bool RangeRegion::InRegion( const RangeRegion & region )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( ( this->start[ m ] < region.start[ m ] ) || ( this->end[ m ] > region.end[ m ] ) )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::Normalize()
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        int minv = std::min( this->start[ m ], this->end[ m ] );
+        int maxv = std::max( this->start[ m ], this->end[ m ] );
+        this->start[ m ] = minv;
+        this->end[ m ] = maxv;
+    }
+}
+
+void RangeRegion::Localize( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] -= oriPoint[ m ];
+        this->end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void RangeRegion::ToGlobal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] += oriPoint[ m ];
+        this->end[ m ] += oriPoint[ m ];
+    }
+}
+
+void RangeRegion::ToLocal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] -= oriPoint[ m ];
+        this->end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void RangeRegion::PrintGlobal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    std::cout << "global start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ] + oriPoint[m];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "global end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ] + oriPoint[m];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+void RangeRegion::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion );
+
+bool ComputeOverlapRegion( RangeRegion & region1, RangeRegion & region2, RangeRegion & overlapRegion )
+{
+    int index_dim = region1.start.size();
+    overlapRegion.Init( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int ijkmin1 = std::min( region1.start[ m ], region1.end[ m ] );
+        int ijkmax1 = std::max( region1.start[ m ], region1.end[ m ] );
+        int ijkmin2 = std::min( region2.start[ m ], region2.end[ m ] );
+        int ijkmax2 = std::max( region2.start[ m ], region2.end[ m ] );
+        if ( ( ijkmax1 < ijkmin2 ) || ( ijkmin1 > ijkmax2 ) )
+        {
+            return false;
+        }
+
+        int ijkmin = std::max( ijkmin1, ijkmin2 );
+        int ijkmax = std::min( ijkmax1, ijkmax2 );
+
+        overlapRegion.start[ m ] = ijkmin;
+        overlapRegion.end  [ m ] = ijkmax;
+    }
+
+    return CheckOverLapping( overlapRegion );
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion )
+{
+    int index_dim = overlapRegion.start.size();
+    int iCount = 0;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        if ( overlapRegion.start[ m ] == overlapRegion.end[ m ] )
+        {
+            ++ iCount;
+        }
+    }
+
+    return ( iCount == 1 );
+}
+
+bool GetInterfaceRegion( RangeRegion & zoneBoxL, RangeRegion & zoneBoxR, RangeRegion & interfaceRegion )
+{
+    int index_dim = zoneBoxL.start.size();
+    int nDomains = 2 * index_dim;
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegionL;
+        GetDomainRegion( zoneBoxL, iDomain, domainRegionL );
+
+        for ( int jDomain = 0; jDomain < nDomains; ++ jDomain )
+        {
+            RangeRegion domainRegionR;
+            GetDomainRegion( zoneBoxR, jDomain, domainRegionR );
+
+            if ( domainRegionL == domainRegionR )
+            {
+                interfaceRegion = domainRegionL;
+                return true;
+            }
+        }
+    }
+    return false;
+}
+
+void CreateInterfaceBc( SplitZone * zoneL, SplitZone * zoneR )
+{
+    RangeRegion globalBoxL, globalBoxR, globalInterfaceRegion;
+
+    zoneL->GetZoneGlobalBox( globalBoxL );
+    zoneR->GetZoneGlobalBox( globalBoxR );
+
+    if ( ! GetInterfaceRegion( globalBoxL, globalBoxR, globalInterfaceRegion ) )
+    {
+        return;
+    }
+
+    RangeRegion localInterfaceRegionL, localInterfaceRegionR;
+
+    zoneL->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionL );
+    zoneR->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionR );
+
+    int kkk = 1;
+
+    InterfaceSplitBc * interfaceSplitBcL = new InterfaceSplitBc();
+    zoneL->interfaceSplitBcList.push_back( interfaceSplitBcL );
+    interfaceSplitBcL->zone = zoneL;
+    interfaceSplitBcL->region = localInterfaceRegionL;
+
+    int nSize = localInterfaceRegionL.start.size();
+
+    std::vector<int> transform;
+
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        transform.push_back( m + 1 );
+    }
+
+    interfaceSplitBcL->transform = transform;
+    interfaceSplitBcL->CalcTransformMatrix();
+
+    interfaceSplitBcL->donor_zone = zoneR;
+    interfaceSplitBcL->donor_region = localInterfaceRegionR;
+
+    InterfaceSplitBc * interfaceSplitBcR = new InterfaceSplitBc();
+    zoneR->interfaceSplitBcList.push_back( interfaceSplitBcR );
+
+    interfaceSplitBcR->zone = zoneR;
+    interfaceSplitBcR->region = localInterfaceRegionR;
+
+    interfaceSplitBcR->transform = transform;
+    interfaceSplitBcR->CalcTransformMatrix();
+
+    interfaceSplitBcR->donor_zone = zoneL;
+    interfaceSplitBcR->donor_region = localInterfaceRegionL;
+}
+
+
+PhysicalSplitBc::PhysicalSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+PhysicalSplitBc::~PhysicalSplitBc()
+{
+}
+
+void PhysicalSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void PhysicalSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+void PhysicalSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = splitZone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+BasicSplitBc::BasicSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+BasicSplitBc::~BasicSplitBc()
+{
+    ;
+}
+
+void BasicSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void BasicSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+int trans::M[ 3 ][ 3 ];
+std::vector<int> trans::transform;
+
+int trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void trans::CalcTransformMatrix()
+{
+    int dim = trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = trans::transform[ 0 ];
+        int sgna = trans::sgn( a );
+        int a1 = trans::del( a, 1 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int c = trans::transform[ 2 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int sgnc = trans::sgn( c );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int a3 = trans::del( a, 3 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        int b3 = trans::del( b, 3 );
+        int c1 = trans::del( c, 1 );
+        int c2 = trans::del( c, 2 );
+        int c3 = trans::del( c, 3 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 2 ][ 0 ] = sgna * a3;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+        trans::M[ 2 ][ 1 ] = sgnb * b3;
+        trans::M[ 0 ][ 2 ] = sgnc * c1;
+        trans::M[ 1 ][ 2 ] = sgnc * c2;
+        trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+InterfaceInfo::InterfaceInfo()
+{
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceInfo::~InterfaceInfo()
+{
+}
+
+InterfaceSplitBc::InterfaceSplitBc()
+{
+    this->region.Init( Dim::dim );
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceSplitBc::~InterfaceSplitBc()
+{
+}
+
+void InterfaceSplitBc::CopyMatrix( InterfaceSplitBc * interfaceSplitBc )
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = interfaceSplitBc->Mt[ i ][ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::CalcTransformMatrix()
+{
+    trans::ZeroMatrix();
+    trans::transform = this->transform;
+    trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = trans::M[ i ][ j ];
+        }
+    }
+
+}
+
+void InterfaceSplitBc::mapindex( std::vector<int> & begin1, std::vector<int> & begin2,  std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = Dim::dim;
+    std::vector<int> diff( dim );
+    for ( int m = 0; m < dim; ++ m )
+    {
+        diff[ m ] = index1[ m ] - begin1[ m ];
+    }
+
+    std::vector<int> mul( dim );
+
+    Multiply( Mt, diff, mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = mul[ m ] + begin2[ m ];
+    }
+}
+
+void InterfaceSplitBc::Multiply( int Mt[][3], std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = Dim::dim;
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = this->zone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void InterfaceSplitBc::CalcSubDonorRegion( RangeRegion &subRegion, RangeRegion &subDonorRegion )
+{
+    std::vector<int> begin1 = this->region.start;
+    std::vector<int> end1 = this->region.end;
+    std::vector<int> begin2 = this->donor_region.start;
+    std::vector<int> end2 = this->donor_region.end;
+
+    std::vector<int> new_begin1 = subRegion.start;
+    std::vector<int> new_end1 = subRegion.end;
+
+    int dim = Dim::dim;
+    std::vector<int> new_begin2( dim );
+    std::vector<int> new_end2( dim );
+
+    mapindex( begin1, begin2, new_begin1, new_begin2 );
+    mapindex( begin1, begin2, new_end1, new_end2 );
+
+    subDonorRegion.start = new_begin2;
+    subDonorRegion.end = new_end2;
+}
+
+SplitZone::SplitZone()
+{
+    this->parent  = 0;
+    this->zoneIndex = 0;
+    this->iProc = 0;
+    dimInfo.Init( Dim::dim );
+    int kk = 1;
+}
+
+SplitZone::~SplitZone()
+{
+    ;
+}
+
+void SplitZone::GetZoneGlobalBox( RangeRegion & zoneBox )
+{
+    this->dimInfo.GetZoneGlobalBox( zoneBox );
+}
+
+void SplitZone::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    this->dimInfo.GetZoneLocalBox( globalBox, localBox );
+}
+
+
+void SplitZone::ComputeRminmax()
+{
+    int index_dim = this->dimInfo.dimList.size();
+    std::vector<int> ref( index_dim, 0 );
+
+    SplitZone * rootSplitZone = 0;
+    this->GetRootInfo( rootSplitZone, ref );
+
+    this->dimInfo.ComputeRminmax( ref );
+}
+
+SplitZone * SplitZone::GetRootZone()
+{
+    SplitZone * root = this;
+
+    while ( true )
+    {
+        if ( root->parent )
+        {
+            root = root->parent;
+        }
+        else
+        {
+            return root;
+        }
+    };
+}
+
+void SplitZone::GetRootInfo( SplitZone *& root, std::vector<int> & ref )
+{
+    for ( int i = 0; i < this->dimInfo.dimList.size(); ++ i )
+    {
+        ref[ i ] += this->dimInfo.oriPoint[ i ];
+    }
+
+    if ( this->parent )
+    {
+        this->parent->GetRootInfo( root, ref );
+    }
+    else
+    {
+        root = this;
+    }
+}
+
+void SplitZone::SetParentAndChild( SplitZone * parent )
+{
+    this->parent = parent;
+    if ( parent )
+    {
+        parent->child.push_back( this );
+    }
+}
+
+
+int SplitZone::GetNCell()
+{
+    int numberOfCells = 1;
+    for ( int i = 0; i < this->dimInfo.dim; ++ i )
+    {
+        numberOfCells *= std::max( 1, ( this->dimInfo.dimList[ i ] - 1 ) );
+    }
+
+    return numberOfCells; 
+}
+
+void SplitZone::SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int leftStart = 0;
+    int leftWidth = iSplit - 0;
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, leftStart , leftWidth  );
+}
+
+void SplitZone::SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int rightStart = iSplit - 1;
+    int rightWidth = dimList[ axisNeedSplit ] - ( iSplit - 1 );
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, rightStart, rightWidth );
+}
+
+void SplitZone::Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell )
+{
+    //Find the longest axis
+    int axisNeedSplit = this->FindAxisNeedSplit();
+    int iSplit        = this->FindSplitPosition( axisNeedSplit, nCell );
+
+    zoneL->SetLeftDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+    zoneR->SetRightDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+
+    zoneL->CreateBcFromParent();
+    zoneR->CreateBcFromParent();
+    
+    CreateInterfaceBc( zoneL, zoneR );
+}
+
+void SplitZone::CreateBcFromParent()
+{
+    this->CreatePhysicalBcFromParent();
+    this->CreateInterfaceBcFromParent();
+}
+
+void SplitZone::CreatePhysicalBcFromParent()
+{
+    int nParentPhysicalBcs = this->parent->physicalSplitBcList.size();
+
+    for ( int iParentPhysicalBcs = 0; iParentPhysicalBcs < nParentPhysicalBcs; ++ iParentPhysicalBcs )
+    {
+        PhysicalSplitBc * parentPhysicalSplitBc = this->parent->physicalSplitBcList[ iParentPhysicalBcs ];
+
+        this->CreatePhysicalBcFromParent( parentPhysicalSplitBc );
+    }
+}
+
+void SplitZone::CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentPhysicalSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreatePhysicalBc( overlapRegion, parentPhysicalSplitBc->bcType );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent()
+{
+    int nInterfaceSplitBcs = this->parent->interfaceSplitBcList.size();
+
+    for ( int iInterfaceSplitBcs = 0; iInterfaceSplitBcs < nInterfaceSplitBcs; ++ iInterfaceSplitBcs )
+    {
+        InterfaceSplitBc * parentInterfaceSplitBc = this->parent->interfaceSplitBcList[ iInterfaceSplitBcs ];
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc );
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentInterfaceSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc, overlapRegion );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::FindDonorInterface( InterfaceSplitBc * interfaceSplitBc, InterfaceInfo & interfaceInfo )
+{
+    RangeRegion donor_region = interfaceSplitBc->donor_region;
+    donor_region.Normalize();
+    interfaceInfo.donor_zone = this;
+    for ( int iInterface = 0; iInterface < interfaceSplitBcList.size(); ++ iInterface )
+    {
+        InterfaceSplitBc * candidateDonorBc = interfaceSplitBcList[ iInterface ];
+        bool flag = donor_region.InRegion( candidateDonorBc->region );
+        if ( flag )
+        {
+            if ( donor_region == candidateDonorBc->region )
+            {
+                interfaceInfo.donor_interface = candidateDonorBc;
+                return;
+            }
+            else
+            {
+                InterfaceSplitBc * donorBc = new InterfaceSplitBc();
+                candidateDonorBc->child.push_back( donorBc );
+                donorBc->region = donor_region;
+                donorBc->zone = candidateDonorBc->zone;
+                donorBc->donor_zone = interfaceSplitBc->zone;
+                donorBc->transform = candidateDonorBc->transform;
+                donorBc->CopyMatrix( candidateDonorBc );
+                RangeRegion subDonorRegion( Dim::dim );
+                candidateDonorBc->CalcSubDonorRegion( donorBc->region, subDonorRegion );
+                std::vector<int> & oriPoint = interfaceSplitBc->zone->dimInfo.oriPoint;
+                subDonorRegion.Localize( oriPoint );
+                donorBc->donor_region = subDonorRegion;
+                donorBc->donor_bc = interfaceSplitBc;
+                interfaceInfo.donor_interface = donorBc;
+                return;
+            }
+        }
+    }
+    return;
+}
+
+void SplitZone::GetChildDonorRegion( RangeRegion & subDonorRegion, InterfaceInfo & interfaceInfo )
+{
+    std::cout << "subDonorRegion = \n";
+    //subDonorRegion.Print();
+    RangeRegion normalizedDonorRegion = subDonorRegion;
+    normalizedDonorRegion.Normalize();
+    int nChild = this->child.size();
+    for ( int ichild = 0; ichild < nChild; ++ ichild )
+    {
+        std::cout << " iChild = " << ichild << " nChild = " << nChild << "\n";
+        SplitZone * sub_zone = this->child[ ichild ];
+        std::cout << " zoneIndex = " << sub_zone->zoneIndex << "\n";
+        int nInters = sub_zone->interfaceSplitBcList.size();
+        for ( int iInter = 0; iInter < nInters; ++ iInter )
+        {
+            std::cout << " iInter = " << iInter << "\n";
+            InterfaceSplitBc * interfaceSplitBc = sub_zone->interfaceSplitBcList[ iInter ];
+            std::cout << "interfaceSplitBc local = \n";
+            interfaceSplitBc->region.Print();
+            std::cout << "interfaceSplitBc global = \n";
+            interfaceSplitBc->region.PrintGlobal( sub_zone->dimInfo.oriPoint );
+            RangeRegion g_region = interfaceSplitBc->region;
+            g_region.ToGlobal( sub_zone->dimInfo.oriPoint );
+            if ( g_region == normalizedDonorRegion )
+            {
+                RangeRegion donorRegion = subDonorRegion;
+                donorRegion.ToLocal( sub_zone->dimInfo.oriPoint );
+
+                interfaceInfo.donor_zone = sub_zone;
+                interfaceInfo.donor_interface = interfaceSplitBc;
+                interfaceInfo.donor_region = donorRegion;
+                return;
+            }
+        }
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion )
+{
+    InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+    this->interfaceSplitBcList.push_back( interfaceSplitBc );
+
+    interfaceSplitBc->region = overlapRegion;
+    interfaceSplitBc->zone = this;
+    interfaceSplitBc->transform = parentInterfaceSplitBc->transform;
+    interfaceSplitBc->CopyMatrix( parentInterfaceSplitBc );
+    RangeRegion subDonorRegion( Dim::dim );
+    parentInterfaceSplitBc->CalcSubDonorRegion( overlapRegion, subDonorRegion );
+    interfaceSplitBc->ChangeRegionToLocalCoordinate();
+    interfaceSplitBc->donor_region = subDonorRegion;
+    SplitZone * parent_donor_zone = parentInterfaceSplitBc->donor_zone;
+    std::cout << " parentInterfaceSplitBc->zone->zoneIndex " << parentInterfaceSplitBc->zone->zoneIndex << "\n";
+    std::cout << " parentInterfaceSplitBc->donor_zone->zoneIndex " << parent_donor_zone->zoneIndex << "\n";
+    if ( parent_donor_zone->child.size() > 0 )
+    {
+        InterfaceInfo interfaceInfo;
+        parent_donor_zone->GetChildDonorRegion( subDonorRegion, interfaceInfo );
+        interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+        interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+        interfaceSplitBc->donor_region = interfaceInfo.donor_region;
+        //compatibility
+        InterfaceSplitBc * donor_bc = interfaceSplitBc->donor_bc;
+        SplitZone * donor_zone = interfaceSplitBc->donor_zone;
+        if ( interfaceSplitBc->zone != donor_bc->donor_zone )
+        {
+            if ( interfaceSplitBc->zone->parent == donor_bc->donor_zone )
+            {
+                RangeRegion d_region = donor_bc->donor_region;
+                d_region.ToLocal( interfaceSplitBc->zone->dimInfo.oriPoint );
+                donor_bc->donor_region = d_region;
+            }
+            donor_bc->donor_zone = interfaceSplitBc->zone;
+         
+            int kkk = 1;
+        }
+        int kkk = 1;
+    }
+    else
+    {
+        InterfaceInfo interfaceInfo;
+        parent_donor_zone->FindDonorInterface( interfaceSplitBc, interfaceInfo );
+        interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+        interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+    }
+    
+    int kkk = 1;
+}
+
+void SplitZone::CreatePhysicalBc( RangeRegion & overlapRegion, int bcType )
+{
+    PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+    this->physicalSplitBcList.push_back( physicalSplitBc );
+    physicalSplitBc->SetRegion( overlapRegion );
+    physicalSplitBc->bcType = bcType;
+    physicalSplitBc->splitZone = this;
+    physicalSplitBc->ChangeRegionToLocalCoordinate();
+}
+
+int SplitZone::FindAxisNeedSplit()
+{
+    //Find the longest axis
+    int axisNeedSplit = 0;
+    int maxN = this->dimInfo.dimList[ 0 ];
+
+    for ( int m = 1; m < this->dimInfo.dimList.size(); ++ m )
+    {
+        if ( this->IsPoleBc( m ) )
+        {
+            continue;
+        }
+        int Nm = this->dimInfo.dimList[ m ];
+        if ( maxN < Nm )
+        {
+            maxN = Nm;
+            axisNeedSplit = m;
+        }
+    }
+
+    return axisNeedSplit;
+}
+
+int SplitZone::GetCrossSection( int axis )
+{
+    int nDim = this->dimInfo.dimList.size();
+    int crossSection = 1;
+    int N = nDim - 1;
+    for ( int m = 0; m < N; ++ m )
+    {
+         int mm = ( axis + 1 ) % nDim;
+         int nLineElements = std::max( 1, ( this->dimInfo.dimList[ mm ] - 1 ) );
+         crossSection *= nLineElements;
+    }
+    return crossSection;
+}
+
+int SplitZone::FindSplitPosition( int axisNeedSplit, double nCell )
+{
+    int nDim = this->dimInfo.dimList.size();
+    std::vector<int> crossSections( nDim );
+    for ( int m = 0; m < nDim; ++ m )
+    {
+        crossSections[ m ] = this->GetCrossSection( m );
+    }
+
+    //guess the value
+    double dSplit = nCell / crossSections[ axisNeedSplit ];
+    int  iSplit = 1 + static_cast< int >( std::floor( dSplit + 0.5 ) );
+    return iSplit;
+}
+
+
+bool SplitZone::IsPoleBc( int splitDirection )
+{
+    return false;
+}
+
diff --git a/example/partition/struct/2d/stage2/01a/SplitZone.h b/example/partition/struct/2d/stage2/01a/SplitZone.h
new file mode 100644
index 00000000..6ba99614
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01a/SplitZone.h
@@ -0,0 +1,194 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class Dim
+{
+public:
+    static int dim;
+};
+
+class SplitZone;
+class RangeRegion;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox );
+
+class DimInfo
+{
+public:
+    DimInfo();
+    ~DimInfo();
+public:
+    int dim;
+    std::vector<int> dimList;
+    std::vector<int> oriPoint;
+    std::vector<int> isize;
+    std::vector<int> rmin;
+    std::vector<int> rmax;
+public:
+    int GetSize() const { return dim; }
+    DimInfo & operator = ( const DimInfo & rhs );
+public:
+    int ComputeNumNodes();
+    void ComputeISize();
+    void ComputeRminmax( std::vector<int> & ref );
+    void Init( int dim );
+    void Init( std::vector<int> & dimList );
+    void SetNewDimension( int axis, int newStart, int newWidth );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+};
+
+class SplitZone;
+class SplitBcPatch;
+
+class RangeRegion
+{
+public:
+    RangeRegion( int nSize = 1 );
+    ~RangeRegion();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    void Init( int nSize );
+    RangeRegion & operator = ( const RangeRegion & rhs );
+    bool operator == ( const RangeRegion & rhs ) const;
+    bool InRegion( const RangeRegion & region );
+    void SetRegion( std::vector<int> &pnts );
+    void Normalize();
+    void Localize( std::vector<int> & oriPoint );
+    void ToGlobal( std::vector<int> & oriPoint );
+    void ToLocal( std::vector<int> & oriPoint );
+    void PrintGlobal( std::vector<int> & oriPoint );
+    void Print();
+};
+
+class PhysicalSplitBc
+{
+public:
+    PhysicalSplitBc();
+    ~PhysicalSplitBc();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class BasicSplitBc
+{
+public:
+    BasicSplitBc();
+    ~BasicSplitBc();
+public:
+    RangeRegion region;
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> & pnts );
+    void SetRegion( RangeRegion & region );
+};
+
+class trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class InterfaceSplitBc;
+class SplitZone;
+
+class InterfaceInfo
+{
+public:
+    InterfaceInfo();
+    ~InterfaceInfo();
+public:
+    InterfaceSplitBc * donor_interface = nullptr;
+    SplitZone * donor_zone = nullptr;
+    RangeRegion donor_region;
+};
+
+class InterfaceSplitBc
+{
+public:
+    InterfaceSplitBc();
+    ~InterfaceSplitBc();
+public:
+    std::vector<int> transform;
+    int Mt[ 3 ][ 3 ];
+    RangeRegion region;
+    SplitZone * zone = nullptr;
+    RangeRegion donor_region;
+    SplitZone * donor_zone = nullptr;
+    InterfaceSplitBc * donor_bc = nullptr;
+public:
+    std::vector<InterfaceSplitBc *> child;
+public:
+    void CopyMatrix( InterfaceSplitBc * interfaceSplitBc );
+    void CalcTransformMatrix();
+    void CalcSubDonorRegion( RangeRegion & subRegion, RangeRegion & subDonorRegion );
+    void mapindex( std::vector<int> & begin1, std::vector<int> & begin2, std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( int Mt[][ 3 ], std::vector<int> & a, std::vector<int> & b );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class SplitZone
+{
+public:
+    SplitZone();
+    ~SplitZone();
+public:
+    DimInfo dimInfo;
+    int zoneIndex, iProc;
+    int newIndex;
+protected:
+    SplitZone * parent;
+    std::vector<SplitZone *> child;
+public:
+    std::vector< PhysicalSplitBc * > physicalSplitBcList;
+    std::vector< InterfaceSplitBc * > interfaceSplitBcList;
+public:
+    int GetNCell();
+    void ComputeRminmax();
+    void GetRootInfo( SplitZone *& root, std::vector<int> & ref );
+    void SetZoneIndex( int zoneIndex ) { this->zoneIndex = zoneIndex; }
+    int  GetZoneIndex() { return zoneIndex; }
+    void SetProcId( int iProc ) { this->iProc = iProc; }
+    void SetParent( SplitZone * parent ) { this->parent = parent; };
+    void SetParentAndChild( SplitZone * parent );
+    void FindDonorInterface( InterfaceSplitBc * interfaceSplitBc, InterfaceInfo & interfaceInfo );
+    void GetChildDonorRegion( RangeRegion & subDonorRegion, InterfaceInfo & interfaceInfo );
+public:
+    void CreateBcFromParent();
+    void CreatePhysicalBcFromParent();
+    void CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc );
+    void CreatePhysicalBc( RangeRegion & overlapRegion, int bcType );
+    void CreateInterfaceBcFromParent();
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc );
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion );
+
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+    SplitZone * GetRootZone();
+public:
+    void Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell );
+    void SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+    void SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+private:
+    int FindAxisNeedSplit();
+    int FindSplitPosition( int axisNeedSplit, double nCell );
+    bool IsPoleBc( int splitDirection );
+    int GetCrossSection( int axis );
+};
+
diff --git a/example/partition/struct/2d/stage2/01a/heat2d2blocksv2.cgns b/example/partition/struct/2d/stage2/01a/heat2d2blocksv2.cgns
new file mode 100644
index 00000000..c4af0d29
Binary files /dev/null and b/example/partition/struct/2d/stage2/01a/heat2d2blocksv2.cgns differ
diff --git a/example/partition/struct/2d/stage2/01a/main.cpp b/example/partition/struct/2d/stage2/01a/main.cpp
new file mode 100644
index 00000000..5da1de7c
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01a/main.cpp
@@ -0,0 +1,18 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include "Partition.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip>
+
+int main(int argc, char **argv)
+{
+    Partition * partition = new Partition();
+    partition->Solve();
+    delete partition;
+
+    return 0;
+}
diff --git a/example/partition/struct/2d/stage2/01b/CMakeLists.txt b/example/partition/struct/2d/stage2/01b/CMakeLists.txt
new file mode 100644
index 00000000..74ceea7d
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01b/CMakeLists.txt
@@ -0,0 +1,78 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	Partition.h Partition.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	SplitZone.h SplitZone.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/partition/struct/2d/stage2/01b/CgnsGrid.cpp b/example/partition/struct/2d/stage2/01b/CgnsGrid.cpp
new file mode 100644
index 00000000..dfe750bd
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01b/CgnsGrid.cpp
@@ -0,0 +1,349 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include <map>
+
+Grid::Grid()
+{
+    ;
+}
+
+Grid::~Grid()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if( (i+1)%5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+    delete this->patch;
+}
+
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+ZoneBcPatch::ZoneBcPatch()
+{
+    ;
+}
+
+ZoneBcPatch::~ZoneBcPatch()
+{
+}
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+Global::Global()
+{
+    ;
+}
+
+Global::~Global()
+{
+}
+
+void Global::FreeData()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+    zones.resize( 0 );
+}
+
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            //baseZone.baseId = baseId;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin( index_dim );
+            std::vector<cgsize_t> irmax( index_dim );
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                std::vector<char> coord( nNodes * sizeof(double) );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+                coor->DumpCoor();
+            }
+
+            int nbocos = -1;
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+                int kkk = 1;
+            }
+        }
+        int kkk = 1;
+    }
+    int kkk = 1;
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage2/01b/CgnsGrid.h b/example/partition/struct/2d/stage2/01b/CgnsGrid.h
new file mode 100644
index 00000000..053c467b
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01b/CgnsGrid.h
@@ -0,0 +1,140 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <map>
+
+class Grid;
+
+class Zone;
+
+class Grid
+{
+public:
+    Grid();
+    ~Grid();
+public:
+    int nZone;
+    std::vector<double> x;
+    std::vector<Zone *> zones;
+};
+
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+};
+
+class ZoneBc;
+class ZoneBc1To1;
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class ZoneBcPatch;
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+    ZoneBcPatch * patch = nullptr;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+class ZoneBcPatch
+{
+public:
+    ZoneBcPatch();
+    ~ZoneBcPatch();
+public:
+    int donor_zoneid;
+    std::vector<int> transform;
+    std::vector<int> donor_pnts;
+};
+
+class BaseZone
+{
+public:
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Global
+{
+public:
+    Global();
+    ~Global();
+public:
+    static int cell_dim;
+    static int phys_dim;
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+public:
+    static void FreeData();
+};
+
+void ReadCgnsGrid( const std::string & filename );
+void ReadCgnsGridBaseZone( const std::string & filename );
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage2/01b/Partition.cpp b/example/partition/struct/2d/stage2/01b/Partition.cpp
new file mode 100644
index 00000000..320fe4e5
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01b/Partition.cpp
@@ -0,0 +1,618 @@
+#include "Partition.h"
+#include "CgnsGrid.h"
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+bool CmpSplitZone::operator() ( SplitZone * a, SplitZone * b ) const
+{
+    return a->zoneIndex < b->zoneIndex;
+};
+
+
+double CalSumOfProcSpeed( std::vector<double> & procSpeed );
+double CalSumOfProcSpeed( std::vector<double> & procSpeed )
+{
+    int nProc = procSpeed.size();
+    double sumOfProcSpeed = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        sumOfProcSpeed += procSpeed[ iProc ];
+    }
+    return sumOfProcSpeed;
+}
+
+Partition::Partition()
+{
+    this->inputName = "../heat2d2blocksv3.cgns";
+    this->outName =  "../heat2dpart.cgns";
+}
+
+Partition::~Partition()
+{
+    ;
+}
+
+int Partition::GetMinValueIndex( double * data, int numberOfData )
+{
+    double minValue = data[ 0 ];
+    int minimumValueIndex = 0;
+
+    for ( int iData = 1; iData < numberOfData; ++ iData )
+    {
+        if ( minValue > data[ iData ] )
+        {
+            minValue      = data[ iData ];
+            minimumValueIndex = iData;
+        }
+    }
+    return minimumValueIndex;
+}
+
+int Partition::GetMinLoadProc()
+{
+    return this->GetMinValueIndex( this->timeProc.data(), this->nProc );
+}
+
+SplitZone * Partition::GetLargestZone()
+{
+    SplitZone * largestZone = 0;
+
+    double nMaxCell = 0.0;
+
+    for ( std::set< SplitZone * >::iterator iter = unsignedZoneGroup.begin(); iter != unsignedZoneGroup.end(); ++ iter )
+    {
+        double nSize = ( * iter )->GetNCell();
+        if ( nMaxCell < nSize )
+        {
+            nMaxCell    = nSize;
+            largestZone = * iter;
+        }
+    }
+
+    return largestZone;
+}
+
+void Partition::Solve()
+{
+    std::cout << "Partition::Split()\n";
+    //this->nProc = 2;
+    this->nProc = 4;
+    this->ReadGrid();
+    this->Split();
+    this->DumpPartitionedGridFile();
+    this->FreeAllZones();
+}
+
+void Partition::ReadGrid()
+{
+    ReadCgnsGridBaseZone( this->inputName );
+    ReadCgnsGrid( this->inputName );
+
+    this->nOriZone = ::Global::zones.size();
+    Dim::dim = Global::cell_dim;
+
+    std::cout << "numberOfBlocks = " << nOriZone << "\n";
+
+    this->refZone.resize( nOriZone );
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = new SplitZone();
+        refZone[ iZone ] = splitZone;
+
+        splitZone->SetZoneIndex( iZone );
+        splitZone->SetProcId( 0 );
+        splitZone->SetParentAndChild( 0 );
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        Zone * zone = ::Global::zones[ iZone ];
+
+        splitZone->dimInfo.dimList = zone->nijk;
+
+        int nbccos = zone->bccos.size();
+        std::cout << "nbccos = " << nbccos << "\n";
+
+        for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+        {
+            ZoneBc * zoneBc = zone->bccos[ ibcco ];
+
+            PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+            splitZone->physicalSplitBcList.push_back( physicalSplitBc );
+            physicalSplitBc->bcType = zoneBc->bcType;
+            physicalSplitBc->SetRegion( zoneBc->pnts );
+            physicalSplitBc->splitZone = splitZone;
+        }
+
+        int nbc1to1s = zone->bc1to1s.size();
+
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * zoneBc1To1 = zone->bc1to1s[ ibc1to1 ];
+
+            InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+            splitZone->interfaceSplitBcList.push_back( interfaceSplitBc );
+            interfaceSplitBc->zone = splitZone;
+            interfaceSplitBc->region.SetRegion( zoneBc1To1->pnts );
+
+            interfaceSplitBc->transform = zoneBc1To1->transform;
+            interfaceSplitBc->CalcTransformMatrix();
+
+            interfaceSplitBc->donor_zone = refZone[ zoneBc1To1->donor_zoneid ];
+            interfaceSplitBc->donor_region.SetRegion( zoneBc1To1->donor_pnts );
+        }
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        int nbc1to1s = splitZone->interfaceSplitBcList.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            InterfaceSplitBc * interfaceSplitBc = splitZone->interfaceSplitBcList[ ibc1to1 ];
+            InterfaceInfo interfaceInfo;
+            interfaceSplitBc->donor_zone->FindDonorInterface( interfaceSplitBc, interfaceInfo );
+            interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+            interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+        }
+    }
+}
+
+void Partition::Split()
+{
+    this->InitSplit();
+    this->BinarySplit();
+    this->ModifyZoneIndex();
+    int kkk = 1;
+}
+
+void Partition::InitSplit()
+{
+    //nZone is the number of zones in the original grid
+    //nProc is not the number of blocks in the end, but the number of processes that need to be divided.
+    //This difference occurs because the structure grid can have many blocks per process.
+
+    //this->nProc    = nProc;
+    //this->nPhyBlocks = referenceBlock.size();
+    //this->nZone  = this->nPhyBlocks;
+
+    //tj Computation time on processor j
+    //Nk Number of internal grid-cells for zone j
+    //aveFloatOp:  Number of Real operations per gridcell
+    //Gj The set of blocks allocated to process j
+    //Pj Real operations per second for process j
+
+    //The Greedy Load Balancing Algorithm
+    //1.Compute an "ideal" uniprocessor time, Tuni = sum ( Nk * aveFloatOp )/ sum( Pj ).
+    //2.Set the group of unassigned blocks, Gu, to contain all blocks. The number of blocks in Nu=M, where M is the total number of blocks in the mesh.
+    //3.Start all processors with a very small fictitious zone to get a start tj=delt aveFloatOp/Pj, where delt<<1 is the size of the very small fictious zone.
+    //This is used to find the fastest processor in a heterogeneous system, tj could otherwise be set to 0 in the homogeneous case.
+    this->aveFloatOp = 1.0;
+    this->delta      = 1.0e-5;
+    this->procSpeed.resize( nProc );
+    this->timeProc.resize( nProc );
+
+    this->nTZone = this->nOriZone;
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        procSpeed[ iProc ] = 1.0;
+    }
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        timeProc[ iProc ] = delta * aveFloatOp / procSpeed[ iProc ];
+    }
+
+    double sumProcSpeed = CalSumOfProcSpeed( procSpeed );
+
+    double sumProcOp = 0.0;
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        sumProcOp += refZone[ iZone ]->GetNCell() * aveFloatOp;
+    }
+
+    this->idealUniProcTime = sumProcOp / sumProcSpeed;
+
+    this->eps = 0.05;
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        unsignedZoneGroup.insert( refZone[ iZone ] );
+    }
+
+    //Init zoneStorage
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        zoneStorage.insert( refZone[ iZone ] );
+    }
+
+    //Assign procSplitZone to each process
+    procSplitZone.resize( nProc );
+
+    this->minNumberCell = 1;
+    for ( int m = 0; m < Dim::dim; ++ m )
+    {
+        this->minNumberCell *= 1;
+    }
+
+    int kkk = 1;
+
+}
+
+void Partition::FreeAllZones()
+{
+    int iCount = 0;
+    for ( std::set < SplitZone * >::iterator iter = zoneStorage.begin(); iter != zoneStorage.end(); ++ iter )
+    {
+        //cout << "iCount = " << iCount << "\n";
+        ++ iCount;
+        delete * iter;
+    }
+}
+
+int Partition::GetNZones( int iProc )
+{
+    return this->procSplitZone[ iProc ].size();
+}
+
+SplitZone * Partition::GetSplitZone( int iProc, int zoneId )
+{
+    return this->procSplitZone[ iProc ][ zoneId ];
+}
+
+void Partition::AddZoneToUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.insert( zone );
+}
+
+void Partition::RemoveZoneFromUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.erase( zone );
+}
+
+void Partition::AddZoneToProcess( int iProc, SplitZone * zone )
+{
+    this->procSplitZone[ iProc ].push_back( zone );
+}
+
+void Partition::AddNewZone( SplitZone * zone )
+{
+    zone->SetZoneIndex( nTZone ++ );
+
+    this->AddZoneToUnsignedGroup( zone );
+
+    this->zoneStorage.insert( zone );
+}
+
+SplitZone * Partition::Split( SplitZone * zone, double nCell )
+{
+    SplitZone * zoneL = new SplitZone();
+    zoneL->SetParentAndChild( zone );
+
+    SplitZone * zoneR = new SplitZone();
+    zoneR->SetParentAndChild( zone );
+
+    //Remove the original block from the UnsignedGroup
+    this->RemoveZoneFromUnsignedGroup( zone );
+
+    this->AddNewZone( zoneL );
+    this->AddNewZone( zoneR );
+
+    zone->Split( zoneL, zoneR, nCell );
+
+    return zoneL;
+}
+
+void Partition::BinarySplit()
+{
+    while ( ! unsignedZoneGroup.empty() )
+    {
+        std::cout << "number of unsigned zone = " << unsignedZoneGroup.size() << "\n";
+        int iProc = this->GetMinLoadProc();
+
+        //Get the block with the largest number of grids and its size
+        SplitZone * largestZone = this->GetLargestZone();
+
+        double nMaxCell = largestZone->GetNCell();
+
+        double aveFloatOp = this->aveFloatOp;
+        double tau = timeProc[ iProc ] + nMaxCell * aveFloatOp / procSpeed[ iProc ];
+
+        //It seems that EPS is still necessary
+        //The idea here is as follows. For the candidate blocks which can be divided into blocks, 
+        //if the difference between the target blocks and the candidate blocks is too wide, 
+        //the binarySplit method is adopted. The binarySplit blocks do not directly join the process,
+        //but enter the next round of screening.
+
+        if ( tau > idealUniProcTime * ( 1.0 + eps ) )
+        {
+            double nRest = ( tau - idealUniProcTime ) * procSpeed[ iProc ] / aveFloatOp;
+
+            double nTarget = nMaxCell - nRest;
+            if ( nRest > this->minNumberCell && nTarget > this->minNumberCell )
+            {
+                //It is necessary to divide blocks only when a certain number of points are satisfied.
+                double nHalf = nMaxCell / 2.0;
+                nMaxCell = nTarget;
+                double ratio = nMaxCell / nRest;
+                double oRatio = 1.0 / ratio;
+
+                if ( std::max( ratio, oRatio ) < 3.0 )
+                {
+                    int kkk = 1;
+                    largestZone = this->Split( largestZone, nMaxCell );
+                    timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                    this->RemoveZoneFromUnsignedGroup( largestZone );
+                    this->AddZoneToProcess( iProc, largestZone );
+                }
+                else
+                {
+                    this->Split( largestZone, nHalf );
+                }
+            }
+            else
+            {
+                //If the block is of the right size, join the process directly, and there is no need to split it.
+                timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                this->RemoveZoneFromUnsignedGroup( largestZone );
+                this->AddZoneToProcess( iProc, largestZone );
+            }
+        }
+        else
+        {
+            //If the block is of the right size, join the process directly, and there is no need to split it.
+            timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+            this->RemoveZoneFromUnsignedGroup( largestZone );
+            this->AddZoneToProcess( iProc, largestZone );
+        }
+    }
+}
+
+void Partition::ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord )
+{
+    SplitZone * rootSplitZone = splitZone->GetRootZone();
+    Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+    int nNodes = splitZone->dimInfo.ComputeNumNodes();
+    std::cout << "nNodes = " << nNodes << "\n";
+
+    coord.resize( nNodes * sizeof(double) );
+
+    int index_dim = splitZone->dimInfo.dimList.size();
+    Coor * coor = zone->coors[ icoord ];
+
+    double * xlocal = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    double * xglobal = reinterpret_cast<double *>( const_cast<char *>( coor->coord.data() ) );
+    if ( index_dim == 1 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        for ( int i = imin; i < imax; ++ i )
+        {
+            xlocal[ icount++ ] = xglobal[ i ];
+        }
+    }
+    else if ( index_dim == 2 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        int jmin = splitZone->dimInfo.rmin[ 1 ] - 1;
+        int jmax = splitZone->dimInfo.rmax[ 1 ];
+        int ni = rootSplitZone->dimInfo.dimList[ 0 ];
+        int nj = rootSplitZone->dimInfo.dimList[ 1 ];
+        for ( int j = jmin; j < jmax; ++ j )
+        {
+            int jstride = j * ni;
+            for ( int i = imin; i < imax; ++ i )
+            {
+                xlocal[ icount++ ] = xglobal[ jstride + i ];
+            }
+        }
+    }
+}
+
+void Partition::DumpBc( SplitZone * splitZone )
+{
+}
+
+void Partition::DumpPartitionedGridFile()
+{
+    std::cout << "\n";
+    std::cout << "DumpPartitionedGridFile -------------------------------" << "\n";
+    std::cout << "\n";
+    int fileId = -1;
+    std::string filename = this->outName;
+    int ierr = cg_open( filename.c_str(), CG_MODE_WRITE, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+
+    std::vector<std::string> coordnames;
+    coordnames.push_back( "CoordinateX" );
+    coordnames.push_back( "CoordinateY" );
+    coordnames.push_back( "CoordinateZ" );
+
+    std::string basename = "Base";
+    int baseId = -1;
+    int icelldim = Global::cell_dim;
+    int iphysdim = Global::phys_dim;
+    cg_base_write( fileId, basename.c_str(), icelldim, iphysdim, &baseId );
+
+    std::cout << "baseId = " << baseId << "\n";
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        int nZones = this->GetNZones( iProc );
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            ZoneType_t zoneType = Structured;
+
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+
+            int index_dim = splitZone->dimInfo.dimList.size();
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            splitZone->dimInfo.ComputeISize();
+
+            int isize_dim = index_dim * 3;
+
+            std::vector<cgsize_t> isize( index_dim * 3, 0 );
+            for ( int m = 0; m < isize_dim; ++ m )
+            {
+                isize[ m ] = splitZone->dimInfo.isize[ m ];
+            }
+
+            int zoneId = -1;
+
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+
+            std::string zonename = "Zone" + std::to_string( splitZone->newIndex );
+
+            cg_zone_write( fileId, baseId, zonename.c_str(), isize.data(), zoneType, &zoneId );
+
+            std::cout << "zoneId = " << zoneId << "\n";
+            std::cout << "zonename = " << zonename << "\n";
+                
+            splitZone->ComputeRminmax();
+
+            SplitZone * rootSplitZone = splitZone->GetRootZone();
+
+            Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+            int ncoords = zone->coors.size();
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = -1;
+                DataType_t dataType = RealDouble;
+                std::string coordname = coordnames[ icoord ];
+                Coor * coor = zone->coors[ icoord ];
+
+                int nNodes = splitZone->dimInfo.ComputeNumNodes();
+                std::cout << "nNodes = " << nNodes << "\n";
+
+                std::vector<char> coord;
+                ComputeCoor( splitZone, icoord, coord );
+
+                cg_coord_write( fileId, baseId, zoneId, dataType, coordname.c_str(), coord.data(), &coorId );
+
+                std::cout << "fileId = " << fileId  << " baseId = " << baseId << " zoneId = " << zoneId  << " coorId = " << coorId << "\n";
+            }
+
+            std::vector< PhysicalSplitBc * > &bccoList = splitZone->physicalSplitBcList;
+
+            int nbocos = bccoList.size();
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = -1;
+                GridLocation_t location = Vertex;
+
+                std::string boconame = "BC" + std::to_string( iboco + 1 );
+
+                PhysicalSplitBc * physicalSplitBc = bccoList[ iboco ];
+                BCType_t bocotype = static_cast<BCType_t>( physicalSplitBc->bcType );
+                PointSetType_t ptset_type = PointRange;
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> pnts;
+                int nSize = physicalSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.end[ i ] );
+                }
+
+                cg_boco_write( fileId, baseId, zoneId, boconame.c_str(), bocotype, ptset_type, npnts, pnts.data(), & bccoId );
+            }
+
+            std::vector< InterfaceSplitBc * > & bc1to1List = splitZone->interfaceSplitBcList;
+
+            int n1to1 = bc1to1List.size();
+            std::cout << "n1to1 = " << n1to1 << "\n";
+
+            std::vector<int> itranfrm( index_dim );
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                itranfrm[ m ] = m + 1;
+            }
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int index_conn = -1;
+
+                InterfaceSplitBc * interfaceSplitBc = bc1to1List[ i1to1 ];
+
+                std::vector<cgsize_t> pnts;
+                std::vector<cgsize_t> pntsdonor;
+                int nSize = interfaceSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.end[ i ] );
+                }
+
+                int nPatchSize = interfaceSplitBc->donor_region.start.size();
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.start[ i ] );
+                }
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.end[ i ] );
+                }
+                int id = interfaceSplitBc->donor_zone->newIndex;
+                int oldZoneIndex = interfaceSplitBc->donor_zone->zoneIndex;
+                std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+                std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+                std::cout << "donor zone id = " << id << "\n";
+                std::cout << "donor zone oldZoneIndex = " << oldZoneIndex << "\n";
+                std::string donorname = "Zone" + std::to_string( id );
+                std::string connectname = "Interface" + std::to_string( i1to1 );
+
+                std::cout << "donorname = " << donorname << "\n";
+                std::cout << "connectname = " << connectname << "\n";
+
+                std::vector<int> & itranfrm = interfaceSplitBc->transform;
+
+                cg_1to1_write( fileId, baseId, zoneId, connectname.c_str(), donorname.c_str(), pnts.data(), pntsdonor.data(), itranfrm.data(), &index_conn );
+                std::cout << "index_conn = " << index_conn << "\n";
+            }
+        }
+    }
+    cg_close( fileId );
+}
+
+void Partition::ModifyZoneIndex()
+{
+    std::cout << "ModifyZoneIndex +++++++++++++++++++++++++ " << "\n";
+    int globalZoneId = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        std::cout << "iProc = " << iProc << "\n";
+        int nZones = this->GetNZones( iProc );
+        std::cout << "nZones in Proc " << iProc << "  = " << nZones << "\n";
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+            //splitZone->SetZoneIndex( globalZoneId++ );
+            splitZone->newIndex = ( globalZoneId++ );
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+        }
+    }
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage2/01b/Partition.h b/example/partition/struct/2d/stage2/01b/Partition.h
new file mode 100644
index 00000000..8a4a9731
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01b/Partition.h
@@ -0,0 +1,59 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class SplitZone;
+
+struct CmpSplitZone 
+{
+    bool operator() ( SplitZone * a, SplitZone * b ) const;
+};
+
+class Partition
+{
+public:
+    Partition();
+    ~Partition();
+protected:
+    std::set < SplitZone * > zoneStorage;
+    std::set < SplitZone *, CmpSplitZone > unsignedZoneGroup;
+    std::vector< SplitZone * > refZone;
+    std::vector< std::vector< SplitZone * > > procSplitZone;
+    std::vector<double> procSpeed;
+    std::vector<double> timeProc;
+    double aveFloatOp, delta;
+    double idealUniProcTime, eps;
+    int minNumberCell;
+    int nTZone;
+    int nOriZone;
+    int nProc;
+public:
+    std::string inputName;
+    std::string outName;
+public:
+    void Solve();
+    void ReadGrid();
+    void Split();
+    void InitSplit();
+    void BinarySplit();
+    //void GreedySplit();
+public:
+    void AddNewZone( SplitZone * zone );
+    void AddZoneToUnsignedGroup( SplitZone * zone );
+    void RemoveZoneFromUnsignedGroup( SplitZone * zone );
+    void AddZoneToProcess( int iProc, SplitZone * zone );
+    void DumpPartitionedGridFile();
+    void ModifyZoneIndex();
+    void FreeAllZones();
+    int GetNZones( int iProc );
+    SplitZone * GetSplitZone( int iProc, int zoneId );
+    void ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord );
+    void DumpBc( SplitZone * splitZone );
+private:
+    int GetMinValueIndex( double * data, int numberOfData );
+    int GetMinLoadProc();
+    SplitZone * GetLargestZone();
+    SplitZone * Split( SplitZone * zone, double nCell );
+};
+
diff --git a/example/partition/struct/2d/stage2/01b/README.txt b/example/partition/struct/2d/stage2/01b/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01b/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/partition/struct/2d/stage2/01b/SplitZone.cpp b/example/partition/struct/2d/stage2/01b/SplitZone.cpp
new file mode 100644
index 00000000..e7ffa1b3
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01b/SplitZone.cpp
@@ -0,0 +1,1065 @@
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+int Dim::dim = -1;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox  )
+{
+    domainBox.start = zoneBox.start;
+    domainBox.end = zoneBox.end;
+
+    int axis = iDomain / 2;
+    int direction = iDomain % 2;
+
+    if ( direction == 0 )
+    {
+        domainBox.end[ axis ] = domainBox.start[ axis ];
+    }
+    else if ( direction == 1 )
+    {
+        domainBox.start[ axis ] = domainBox.end[ axis ];
+    }
+}
+
+DimInfo::DimInfo()
+{
+    this->Init( 1 );
+}
+
+DimInfo::~DimInfo()
+{
+}
+
+void DimInfo::Init( int dim )
+{
+    this->dim = dim;
+    dimList.resize( this->dim, 1 );
+    oriPoint.resize( this->dim, 0 );
+}
+
+DimInfo & DimInfo::operator = ( const DimInfo & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->dim = rhs.dim;
+    this->dimList = rhs.dimList;
+    this->oriPoint = rhs.oriPoint;
+
+    return * this;
+}
+
+int DimInfo::ComputeNumNodes()
+{
+    int nNodes = 1;
+    for ( int m = 0; m < this->dimList.size(); ++ m )
+    {
+        nNodes *= this->dimList[ m ];
+    }
+    return nNodes;
+}
+
+void DimInfo::ComputeISize()
+{
+    int index_dim = this->dimList.size();
+    this->isize.resize( index_dim * 3, 0 );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        isize[ m ] = this->dimList[ m ];
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 1;
+        isize[ start + m ] = this->dimList[ m ] - 1;
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 2;
+        isize[ start + m ] = 0;
+    }
+
+    for ( int i = 0; i < isize.size(); ++ i )
+    {
+        std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+    }
+}
+
+void DimInfo::ComputeRminmax( std::vector<int> & ref )
+{
+    int index_dim = this->dimList.size();
+    this->rmin.resize( index_dim );
+    this->rmax.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        rmin[ m ] = ref[ m ] + 1;
+        rmax[ m ] = ref[ m ] + this->dimList[ m ];
+    }
+
+    std::cout << "rmin, rmax = \n";
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        std::cout << rmin[ m ] << " " << rmax[ m ] << "\n";
+    }
+}
+
+void DimInfo::Init( std::vector<int> & dimList )
+{
+    this->dim = dimList.size();
+    this->dimList = dimList;
+    std::vector<int> zero( dimList.size(), 0 );
+    this->oriPoint = zero;
+}
+
+void DimInfo::SetNewDimension( int axis, int newStart, int newWidth )
+{
+    this->oriPoint[ axis ] = newStart;
+    this->dimList [ axis ] = newWidth;
+}
+
+void DimInfo::GetZoneGlobalBox( RangeRegion &zoneBox )
+{
+    int index_dim = this->dimList.size();
+    zoneBox.start.resize( index_dim );
+    zoneBox.end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        zoneBox.start[ m ] = this->oriPoint[ m ] + 1;
+        zoneBox.end[ m ] = this->oriPoint[ m ] + this->dimList[ m ];
+    }
+}
+
+void DimInfo::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    int index_dim = this->dimList.size();
+    localBox.start.resize( index_dim );
+    localBox.end.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        localBox.start[ m ] = globalBox.start[ m ] - this->oriPoint[ m ];
+        localBox.end[ m ] = globalBox.end[ m ] - this->oriPoint[ m ];
+    }
+}
+
+RangeRegion::RangeRegion( int nSize )
+{
+    this->Init( nSize );
+}
+
+RangeRegion::~RangeRegion()
+{
+}
+
+void RangeRegion::Init( int nSize )
+{
+    this->start.resize( nSize );
+    this->end.resize( nSize );
+}
+
+RangeRegion & RangeRegion::operator = ( const RangeRegion & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+bool RangeRegion::operator == ( const RangeRegion & rhs ) const
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] != rhs.start[ m ] || 
+            this->end  [ m ] != rhs.end  [ m ] )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+bool RangeRegion::InRegion( const RangeRegion & region )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( ( this->start[ m ] < region.start[ m ] ) || ( this->end[ m ] > region.end[ m ] ) )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::Normalize()
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        int minv = std::min( this->start[ m ], this->end[ m ] );
+        int maxv = std::max( this->start[ m ], this->end[ m ] );
+        this->start[ m ] = minv;
+        this->end[ m ] = maxv;
+    }
+}
+
+void RangeRegion::Localize( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] -= oriPoint[ m ];
+        this->end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void RangeRegion::ToGlobal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] += oriPoint[ m ];
+        this->end[ m ] += oriPoint[ m ];
+    }
+}
+
+void RangeRegion::ToLocal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] -= oriPoint[ m ];
+        this->end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void RangeRegion::PrintGlobal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    std::cout << "global start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ] + oriPoint[m];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "global end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ] + oriPoint[m];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+void RangeRegion::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion );
+
+bool ComputeOverlapRegion( RangeRegion & region1, RangeRegion & region2, RangeRegion & overlapRegion )
+{
+    int index_dim = region1.start.size();
+    overlapRegion.Init( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int ijkmin1 = std::min( region1.start[ m ], region1.end[ m ] );
+        int ijkmax1 = std::max( region1.start[ m ], region1.end[ m ] );
+        int ijkmin2 = std::min( region2.start[ m ], region2.end[ m ] );
+        int ijkmax2 = std::max( region2.start[ m ], region2.end[ m ] );
+        if ( ( ijkmax1 < ijkmin2 ) || ( ijkmin1 > ijkmax2 ) )
+        {
+            return false;
+        }
+
+        int ijkmin = std::max( ijkmin1, ijkmin2 );
+        int ijkmax = std::min( ijkmax1, ijkmax2 );
+
+        overlapRegion.start[ m ] = ijkmin;
+        overlapRegion.end  [ m ] = ijkmax;
+    }
+
+    return CheckOverLapping( overlapRegion );
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion )
+{
+    int index_dim = overlapRegion.start.size();
+    int iCount = 0;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        if ( overlapRegion.start[ m ] == overlapRegion.end[ m ] )
+        {
+            ++ iCount;
+        }
+    }
+
+    return ( iCount == 1 );
+}
+
+bool GetInterfaceRegion( RangeRegion & zoneBoxL, RangeRegion & zoneBoxR, RangeRegion & interfaceRegion )
+{
+    int index_dim = zoneBoxL.start.size();
+    int nDomains = 2 * index_dim;
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegionL;
+        GetDomainRegion( zoneBoxL, iDomain, domainRegionL );
+
+        for ( int jDomain = 0; jDomain < nDomains; ++ jDomain )
+        {
+            RangeRegion domainRegionR;
+            GetDomainRegion( zoneBoxR, jDomain, domainRegionR );
+
+            if ( domainRegionL == domainRegionR )
+            {
+                interfaceRegion = domainRegionL;
+                return true;
+            }
+        }
+    }
+    return false;
+}
+
+void CreateInterfaceBc( SplitZone * zoneL, SplitZone * zoneR )
+{
+    RangeRegion globalBoxL, globalBoxR, globalInterfaceRegion;
+
+    zoneL->GetZoneGlobalBox( globalBoxL );
+    zoneR->GetZoneGlobalBox( globalBoxR );
+
+    if ( ! GetInterfaceRegion( globalBoxL, globalBoxR, globalInterfaceRegion ) )
+    {
+        return;
+    }
+
+    RangeRegion localInterfaceRegionL, localInterfaceRegionR;
+
+    zoneL->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionL );
+    zoneR->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionR );
+
+    int kkk = 1;
+
+    InterfaceSplitBc * interfaceSplitBcL = new InterfaceSplitBc();
+    zoneL->interfaceSplitBcList.push_back( interfaceSplitBcL );
+    interfaceSplitBcL->zone = zoneL;
+    interfaceSplitBcL->region = localInterfaceRegionL;
+
+    int nSize = localInterfaceRegionL.start.size();
+
+    std::vector<int> transform;
+
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        transform.push_back( m + 1 );
+    }
+
+    interfaceSplitBcL->transform = transform;
+    interfaceSplitBcL->CalcTransformMatrix();
+
+    interfaceSplitBcL->donor_zone = zoneR;
+    interfaceSplitBcL->donor_region = localInterfaceRegionR;
+
+    InterfaceSplitBc * interfaceSplitBcR = new InterfaceSplitBc();
+    zoneR->interfaceSplitBcList.push_back( interfaceSplitBcR );
+
+    interfaceSplitBcR->zone = zoneR;
+    interfaceSplitBcR->region = localInterfaceRegionR;
+
+    interfaceSplitBcR->transform = transform;
+    interfaceSplitBcR->CalcTransformMatrix();
+
+    interfaceSplitBcR->donor_zone = zoneL;
+    interfaceSplitBcR->donor_region = localInterfaceRegionL;
+}
+
+
+PhysicalSplitBc::PhysicalSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+PhysicalSplitBc::~PhysicalSplitBc()
+{
+}
+
+void PhysicalSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void PhysicalSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+void PhysicalSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = splitZone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+BasicSplitBc::BasicSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+BasicSplitBc::~BasicSplitBc()
+{
+    ;
+}
+
+void BasicSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void BasicSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+int trans::M[ 3 ][ 3 ];
+std::vector<int> trans::transform;
+
+int trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void trans::CalcTransformMatrix()
+{
+    int dim = trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = trans::transform[ 0 ];
+        int sgna = trans::sgn( a );
+        int a1 = trans::del( a, 1 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int c = trans::transform[ 2 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int sgnc = trans::sgn( c );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int a3 = trans::del( a, 3 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        int b3 = trans::del( b, 3 );
+        int c1 = trans::del( c, 1 );
+        int c2 = trans::del( c, 2 );
+        int c3 = trans::del( c, 3 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 2 ][ 0 ] = sgna * a3;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+        trans::M[ 2 ][ 1 ] = sgnb * b3;
+        trans::M[ 0 ][ 2 ] = sgnc * c1;
+        trans::M[ 1 ][ 2 ] = sgnc * c2;
+        trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+InterfaceInfo::InterfaceInfo()
+{
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceInfo::~InterfaceInfo()
+{
+}
+
+InterfaceSplitBc::InterfaceSplitBc()
+{
+    this->region.Init( Dim::dim );
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceSplitBc::~InterfaceSplitBc()
+{
+}
+
+void InterfaceSplitBc::CopyMatrix( InterfaceSplitBc * interfaceSplitBc )
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = interfaceSplitBc->Mt[ i ][ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::CalcTransformMatrix()
+{
+    trans::ZeroMatrix();
+    trans::transform = this->transform;
+    trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = trans::M[ i ][ j ];
+        }
+    }
+
+}
+
+void InterfaceSplitBc::mapindex( std::vector<int> & begin1, std::vector<int> & begin2,  std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = Dim::dim;
+    std::vector<int> diff( dim );
+    for ( int m = 0; m < dim; ++ m )
+    {
+        diff[ m ] = index1[ m ] - begin1[ m ];
+    }
+
+    std::vector<int> mul( dim );
+
+    Multiply( Mt, diff, mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = mul[ m ] + begin2[ m ];
+    }
+}
+
+void InterfaceSplitBc::Multiply( int Mt[][3], std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = Dim::dim;
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = this->zone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void InterfaceSplitBc::CalcSubDonorRegion( RangeRegion &subRegion, RangeRegion &subDonorRegion )
+{
+    std::vector<int> begin1 = this->region.start;
+    std::vector<int> end1 = this->region.end;
+    std::vector<int> begin2 = this->donor_region.start;
+    std::vector<int> end2 = this->donor_region.end;
+
+    std::vector<int> new_begin1 = subRegion.start;
+    std::vector<int> new_end1 = subRegion.end;
+
+    int dim = Dim::dim;
+    std::vector<int> new_begin2( dim );
+    std::vector<int> new_end2( dim );
+
+    mapindex( begin1, begin2, new_begin1, new_begin2 );
+    mapindex( begin1, begin2, new_end1, new_end2 );
+
+    subDonorRegion.start = new_begin2;
+    subDonorRegion.end = new_end2;
+}
+
+SplitZone::SplitZone()
+{
+    this->parent  = 0;
+    this->zoneIndex = 0;
+    this->iProc = 0;
+    dimInfo.Init( Dim::dim );
+    int kk = 1;
+}
+
+SplitZone::~SplitZone()
+{
+    ;
+}
+
+void SplitZone::GetZoneGlobalBox( RangeRegion & zoneBox )
+{
+    this->dimInfo.GetZoneGlobalBox( zoneBox );
+}
+
+void SplitZone::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    this->dimInfo.GetZoneLocalBox( globalBox, localBox );
+}
+
+
+void SplitZone::ComputeRminmax()
+{
+    int index_dim = this->dimInfo.dimList.size();
+    std::vector<int> ref( index_dim, 0 );
+
+    SplitZone * rootSplitZone = 0;
+    this->GetRootInfo( rootSplitZone, ref );
+
+    this->dimInfo.ComputeRminmax( ref );
+}
+
+SplitZone * SplitZone::GetRootZone()
+{
+    SplitZone * root = this;
+
+    while ( true )
+    {
+        if ( root->parent )
+        {
+            root = root->parent;
+        }
+        else
+        {
+            return root;
+        }
+    };
+}
+
+void SplitZone::GetRootInfo( SplitZone *& root, std::vector<int> & ref )
+{
+    for ( int i = 0; i < this->dimInfo.dimList.size(); ++ i )
+    {
+        ref[ i ] += this->dimInfo.oriPoint[ i ];
+    }
+
+    if ( this->parent )
+    {
+        this->parent->GetRootInfo( root, ref );
+    }
+    else
+    {
+        root = this;
+    }
+}
+
+void SplitZone::SetParentAndChild( SplitZone * parent )
+{
+    this->parent = parent;
+    if ( parent )
+    {
+        parent->child.push_back( this );
+    }
+}
+
+
+int SplitZone::GetNCell()
+{
+    int numberOfCells = 1;
+    for ( int i = 0; i < this->dimInfo.dim; ++ i )
+    {
+        numberOfCells *= std::max( 1, ( this->dimInfo.dimList[ i ] - 1 ) );
+    }
+
+    return numberOfCells; 
+}
+
+void SplitZone::SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int leftStart = 0;
+    int leftWidth = iSplit - 0;
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, leftStart , leftWidth  );
+}
+
+void SplitZone::SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int rightStart = iSplit - 1;
+    int rightWidth = dimList[ axisNeedSplit ] - ( iSplit - 1 );
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, rightStart, rightWidth );
+}
+
+void SplitZone::Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell )
+{
+    //Find the longest axis
+    int axisNeedSplit = this->FindAxisNeedSplit();
+    int iSplit        = this->FindSplitPosition( axisNeedSplit, nCell );
+
+    zoneL->SetLeftDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+    zoneR->SetRightDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+
+    zoneL->CreateBcFromParent();
+    zoneR->CreateBcFromParent();
+    
+    CreateInterfaceBc( zoneL, zoneR );
+}
+
+void SplitZone::CreateBcFromParent()
+{
+    this->CreatePhysicalBcFromParent();
+    this->CreateInterfaceBcFromParent();
+}
+
+void SplitZone::CreatePhysicalBcFromParent()
+{
+    int nParentPhysicalBcs = this->parent->physicalSplitBcList.size();
+
+    for ( int iParentPhysicalBcs = 0; iParentPhysicalBcs < nParentPhysicalBcs; ++ iParentPhysicalBcs )
+    {
+        PhysicalSplitBc * parentPhysicalSplitBc = this->parent->physicalSplitBcList[ iParentPhysicalBcs ];
+
+        this->CreatePhysicalBcFromParent( parentPhysicalSplitBc );
+    }
+}
+
+void SplitZone::CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentPhysicalSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreatePhysicalBc( overlapRegion, parentPhysicalSplitBc->bcType );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent()
+{
+    int nInterfaceSplitBcs = this->parent->interfaceSplitBcList.size();
+
+    for ( int iInterfaceSplitBcs = 0; iInterfaceSplitBcs < nInterfaceSplitBcs; ++ iInterfaceSplitBcs )
+    {
+        InterfaceSplitBc * parentInterfaceSplitBc = this->parent->interfaceSplitBcList[ iInterfaceSplitBcs ];
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc );
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentInterfaceSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc, overlapRegion );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::FindDonorInterface( InterfaceSplitBc * interfaceSplitBc, InterfaceInfo & interfaceInfo )
+{
+    RangeRegion donor_region = interfaceSplitBc->donor_region;
+    donor_region.Normalize();
+    interfaceInfo.donor_zone = this;
+    for ( int iInterface = 0; iInterface < interfaceSplitBcList.size(); ++ iInterface )
+    {
+        InterfaceSplitBc * candidateDonorBc = interfaceSplitBcList[ iInterface ];
+        bool flag = donor_region.InRegion( candidateDonorBc->region );
+        if ( flag )
+        {
+            if ( donor_region == candidateDonorBc->region )
+            {
+                interfaceInfo.donor_interface = candidateDonorBc;
+                return;
+            }
+            else
+            {
+                InterfaceSplitBc * donorBc = new InterfaceSplitBc();
+                candidateDonorBc->child.push_back( donorBc );
+                donorBc->region = donor_region;
+                donorBc->zone = candidateDonorBc->zone;
+                donorBc->donor_zone = interfaceSplitBc->zone;
+                donorBc->transform = candidateDonorBc->transform;
+                donorBc->CopyMatrix( candidateDonorBc );
+                RangeRegion subDonorRegion( Dim::dim );
+                candidateDonorBc->CalcSubDonorRegion( donorBc->region, subDonorRegion );
+                std::vector<int> & oriPoint = interfaceSplitBc->zone->dimInfo.oriPoint;
+                subDonorRegion.Localize( oriPoint );
+                donorBc->donor_region = subDonorRegion;
+                donorBc->donor_bc = interfaceSplitBc;
+                interfaceInfo.donor_interface = donorBc;
+                return;
+            }
+        }
+    }
+    return;
+}
+
+void SplitZone::GetChildDonorRegion( RangeRegion & subDonorRegion, InterfaceInfo & interfaceInfo )
+{
+    std::cout << "subDonorRegion = \n";
+    //subDonorRegion.Print();
+    RangeRegion normalizedDonorRegion = subDonorRegion;
+    normalizedDonorRegion.Normalize();
+    int nChild = this->child.size();
+    for ( int ichild = 0; ichild < nChild; ++ ichild )
+    {
+        std::cout << " iChild = " << ichild << " nChild = " << nChild << "\n";
+        SplitZone * sub_zone = this->child[ ichild ];
+        std::cout << " zoneIndex = " << sub_zone->zoneIndex << "\n";
+        int nInters = sub_zone->interfaceSplitBcList.size();
+        for ( int iInter = 0; iInter < nInters; ++ iInter )
+        {
+            std::cout << " iInter = " << iInter << "\n";
+            InterfaceSplitBc * interfaceSplitBc = sub_zone->interfaceSplitBcList[ iInter ];
+            std::cout << "interfaceSplitBc local = \n";
+            interfaceSplitBc->region.Print();
+            std::cout << "interfaceSplitBc global = \n";
+            interfaceSplitBc->region.PrintGlobal( sub_zone->dimInfo.oriPoint );
+            RangeRegion g_region = interfaceSplitBc->region;
+            g_region.ToGlobal( sub_zone->dimInfo.oriPoint );
+            if ( g_region == normalizedDonorRegion )
+            {
+                RangeRegion donorRegion = subDonorRegion;
+                donorRegion.ToLocal( sub_zone->dimInfo.oriPoint );
+
+                interfaceInfo.donor_zone = sub_zone;
+                interfaceInfo.donor_interface = interfaceSplitBc;
+                interfaceInfo.donor_region = donorRegion;
+                return;
+            }
+        }
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion )
+{
+    InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+    this->interfaceSplitBcList.push_back( interfaceSplitBc );
+
+    interfaceSplitBc->region = overlapRegion;
+    interfaceSplitBc->zone = this;
+    interfaceSplitBc->transform = parentInterfaceSplitBc->transform;
+    interfaceSplitBc->CopyMatrix( parentInterfaceSplitBc );
+    RangeRegion subDonorRegion( Dim::dim );
+    parentInterfaceSplitBc->CalcSubDonorRegion( overlapRegion, subDonorRegion );
+    interfaceSplitBc->ChangeRegionToLocalCoordinate();
+    interfaceSplitBc->donor_region = subDonorRegion;
+    SplitZone * parent_donor_zone = parentInterfaceSplitBc->donor_zone;
+    std::cout << " parentInterfaceSplitBc->zone->zoneIndex " << parentInterfaceSplitBc->zone->zoneIndex << "\n";
+    std::cout << " parentInterfaceSplitBc->donor_zone->zoneIndex " << parent_donor_zone->zoneIndex << "\n";
+    if ( parent_donor_zone->child.size() > 0 )
+    {
+        InterfaceInfo interfaceInfo;
+        parent_donor_zone->GetChildDonorRegion( subDonorRegion, interfaceInfo );
+        interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+        interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+        interfaceSplitBc->donor_region = interfaceInfo.donor_region;
+        //compatibility
+        InterfaceSplitBc * donor_bc = interfaceSplitBc->donor_bc;
+        SplitZone * donor_zone = interfaceSplitBc->donor_zone;
+        if ( interfaceSplitBc->zone != donor_bc->donor_zone )
+        {
+            if ( interfaceSplitBc->zone->parent == donor_bc->donor_zone )
+            {
+                RangeRegion d_region = donor_bc->donor_region;
+                d_region.ToLocal( interfaceSplitBc->zone->dimInfo.oriPoint );
+                donor_bc->donor_region = d_region;
+            }
+            donor_bc->donor_zone = interfaceSplitBc->zone;
+         
+            int kkk = 1;
+        }
+        int kkk = 1;
+    }
+    else
+    {
+        InterfaceInfo interfaceInfo;
+        parent_donor_zone->FindDonorInterface( interfaceSplitBc, interfaceInfo );
+        interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+        interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+    }
+    
+    int kkk = 1;
+}
+
+void SplitZone::CreatePhysicalBc( RangeRegion & overlapRegion, int bcType )
+{
+    PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+    this->physicalSplitBcList.push_back( physicalSplitBc );
+    physicalSplitBc->SetRegion( overlapRegion );
+    physicalSplitBc->bcType = bcType;
+    physicalSplitBc->splitZone = this;
+    physicalSplitBc->ChangeRegionToLocalCoordinate();
+}
+
+int SplitZone::FindAxisNeedSplit()
+{
+    //Find the longest axis
+    int axisNeedSplit = 0;
+    int maxN = this->dimInfo.dimList[ 0 ];
+
+    for ( int m = 1; m < this->dimInfo.dimList.size(); ++ m )
+    {
+        if ( this->IsPoleBc( m ) )
+        {
+            continue;
+        }
+        int Nm = this->dimInfo.dimList[ m ];
+        if ( maxN < Nm )
+        {
+            maxN = Nm;
+            axisNeedSplit = m;
+        }
+    }
+
+    return axisNeedSplit;
+}
+
+int SplitZone::GetCrossSection( int axis )
+{
+    int nDim = this->dimInfo.dimList.size();
+    int crossSection = 1;
+    int N = nDim - 1;
+    for ( int m = 0; m < N; ++ m )
+    {
+         int mm = ( axis + 1 ) % nDim;
+         int nLineElements = std::max( 1, ( this->dimInfo.dimList[ mm ] - 1 ) );
+         crossSection *= nLineElements;
+    }
+    return crossSection;
+}
+
+int SplitZone::FindSplitPosition( int axisNeedSplit, double nCell )
+{
+    int nDim = this->dimInfo.dimList.size();
+    std::vector<int> crossSections( nDim );
+    for ( int m = 0; m < nDim; ++ m )
+    {
+        crossSections[ m ] = this->GetCrossSection( m );
+    }
+
+    //guess the value
+    double dSplit = nCell / crossSections[ axisNeedSplit ];
+    int  iSplit = 1 + static_cast< int >( std::floor( dSplit + 0.5 ) );
+    return iSplit;
+}
+
+
+bool SplitZone::IsPoleBc( int splitDirection )
+{
+    return false;
+}
+
diff --git a/example/partition/struct/2d/stage2/01b/SplitZone.h b/example/partition/struct/2d/stage2/01b/SplitZone.h
new file mode 100644
index 00000000..6ba99614
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01b/SplitZone.h
@@ -0,0 +1,194 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class Dim
+{
+public:
+    static int dim;
+};
+
+class SplitZone;
+class RangeRegion;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox );
+
+class DimInfo
+{
+public:
+    DimInfo();
+    ~DimInfo();
+public:
+    int dim;
+    std::vector<int> dimList;
+    std::vector<int> oriPoint;
+    std::vector<int> isize;
+    std::vector<int> rmin;
+    std::vector<int> rmax;
+public:
+    int GetSize() const { return dim; }
+    DimInfo & operator = ( const DimInfo & rhs );
+public:
+    int ComputeNumNodes();
+    void ComputeISize();
+    void ComputeRminmax( std::vector<int> & ref );
+    void Init( int dim );
+    void Init( std::vector<int> & dimList );
+    void SetNewDimension( int axis, int newStart, int newWidth );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+};
+
+class SplitZone;
+class SplitBcPatch;
+
+class RangeRegion
+{
+public:
+    RangeRegion( int nSize = 1 );
+    ~RangeRegion();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    void Init( int nSize );
+    RangeRegion & operator = ( const RangeRegion & rhs );
+    bool operator == ( const RangeRegion & rhs ) const;
+    bool InRegion( const RangeRegion & region );
+    void SetRegion( std::vector<int> &pnts );
+    void Normalize();
+    void Localize( std::vector<int> & oriPoint );
+    void ToGlobal( std::vector<int> & oriPoint );
+    void ToLocal( std::vector<int> & oriPoint );
+    void PrintGlobal( std::vector<int> & oriPoint );
+    void Print();
+};
+
+class PhysicalSplitBc
+{
+public:
+    PhysicalSplitBc();
+    ~PhysicalSplitBc();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class BasicSplitBc
+{
+public:
+    BasicSplitBc();
+    ~BasicSplitBc();
+public:
+    RangeRegion region;
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> & pnts );
+    void SetRegion( RangeRegion & region );
+};
+
+class trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class InterfaceSplitBc;
+class SplitZone;
+
+class InterfaceInfo
+{
+public:
+    InterfaceInfo();
+    ~InterfaceInfo();
+public:
+    InterfaceSplitBc * donor_interface = nullptr;
+    SplitZone * donor_zone = nullptr;
+    RangeRegion donor_region;
+};
+
+class InterfaceSplitBc
+{
+public:
+    InterfaceSplitBc();
+    ~InterfaceSplitBc();
+public:
+    std::vector<int> transform;
+    int Mt[ 3 ][ 3 ];
+    RangeRegion region;
+    SplitZone * zone = nullptr;
+    RangeRegion donor_region;
+    SplitZone * donor_zone = nullptr;
+    InterfaceSplitBc * donor_bc = nullptr;
+public:
+    std::vector<InterfaceSplitBc *> child;
+public:
+    void CopyMatrix( InterfaceSplitBc * interfaceSplitBc );
+    void CalcTransformMatrix();
+    void CalcSubDonorRegion( RangeRegion & subRegion, RangeRegion & subDonorRegion );
+    void mapindex( std::vector<int> & begin1, std::vector<int> & begin2, std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( int Mt[][ 3 ], std::vector<int> & a, std::vector<int> & b );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class SplitZone
+{
+public:
+    SplitZone();
+    ~SplitZone();
+public:
+    DimInfo dimInfo;
+    int zoneIndex, iProc;
+    int newIndex;
+protected:
+    SplitZone * parent;
+    std::vector<SplitZone *> child;
+public:
+    std::vector< PhysicalSplitBc * > physicalSplitBcList;
+    std::vector< InterfaceSplitBc * > interfaceSplitBcList;
+public:
+    int GetNCell();
+    void ComputeRminmax();
+    void GetRootInfo( SplitZone *& root, std::vector<int> & ref );
+    void SetZoneIndex( int zoneIndex ) { this->zoneIndex = zoneIndex; }
+    int  GetZoneIndex() { return zoneIndex; }
+    void SetProcId( int iProc ) { this->iProc = iProc; }
+    void SetParent( SplitZone * parent ) { this->parent = parent; };
+    void SetParentAndChild( SplitZone * parent );
+    void FindDonorInterface( InterfaceSplitBc * interfaceSplitBc, InterfaceInfo & interfaceInfo );
+    void GetChildDonorRegion( RangeRegion & subDonorRegion, InterfaceInfo & interfaceInfo );
+public:
+    void CreateBcFromParent();
+    void CreatePhysicalBcFromParent();
+    void CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc );
+    void CreatePhysicalBc( RangeRegion & overlapRegion, int bcType );
+    void CreateInterfaceBcFromParent();
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc );
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion );
+
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+    SplitZone * GetRootZone();
+public:
+    void Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell );
+    void SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+    void SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+private:
+    int FindAxisNeedSplit();
+    int FindSplitPosition( int axisNeedSplit, double nCell );
+    bool IsPoleBc( int splitDirection );
+    int GetCrossSection( int axis );
+};
+
diff --git a/example/partition/struct/2d/stage2/01b/heat2d2blocksv3.cgns b/example/partition/struct/2d/stage2/01b/heat2d2blocksv3.cgns
new file mode 100644
index 00000000..d5c1096e
Binary files /dev/null and b/example/partition/struct/2d/stage2/01b/heat2d2blocksv3.cgns differ
diff --git a/example/partition/struct/2d/stage2/01b/main.cpp b/example/partition/struct/2d/stage2/01b/main.cpp
new file mode 100644
index 00000000..5da1de7c
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01b/main.cpp
@@ -0,0 +1,18 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include "Partition.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip>
+
+int main(int argc, char **argv)
+{
+    Partition * partition = new Partition();
+    partition->Solve();
+    delete partition;
+
+    return 0;
+}
diff --git a/example/partition/struct/2d/stage2/01c/CMakeLists.txt b/example/partition/struct/2d/stage2/01c/CMakeLists.txt
new file mode 100644
index 00000000..74ceea7d
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01c/CMakeLists.txt
@@ -0,0 +1,78 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	Partition.h Partition.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	SplitZone.h SplitZone.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/partition/struct/2d/stage2/01c/CgnsGrid.cpp b/example/partition/struct/2d/stage2/01c/CgnsGrid.cpp
new file mode 100644
index 00000000..dfe750bd
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01c/CgnsGrid.cpp
@@ -0,0 +1,349 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include <map>
+
+Grid::Grid()
+{
+    ;
+}
+
+Grid::~Grid()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if( (i+1)%5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+    delete this->patch;
+}
+
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+ZoneBcPatch::ZoneBcPatch()
+{
+    ;
+}
+
+ZoneBcPatch::~ZoneBcPatch()
+{
+}
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+Global::Global()
+{
+    ;
+}
+
+Global::~Global()
+{
+}
+
+void Global::FreeData()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+    zones.resize( 0 );
+}
+
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            //baseZone.baseId = baseId;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin( index_dim );
+            std::vector<cgsize_t> irmax( index_dim );
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                std::vector<char> coord( nNodes * sizeof(double) );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+                coor->DumpCoor();
+            }
+
+            int nbocos = -1;
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+                int kkk = 1;
+            }
+        }
+        int kkk = 1;
+    }
+    int kkk = 1;
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage2/01c/CgnsGrid.h b/example/partition/struct/2d/stage2/01c/CgnsGrid.h
new file mode 100644
index 00000000..053c467b
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01c/CgnsGrid.h
@@ -0,0 +1,140 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <map>
+
+class Grid;
+
+class Zone;
+
+class Grid
+{
+public:
+    Grid();
+    ~Grid();
+public:
+    int nZone;
+    std::vector<double> x;
+    std::vector<Zone *> zones;
+};
+
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+};
+
+class ZoneBc;
+class ZoneBc1To1;
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class ZoneBcPatch;
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+    ZoneBcPatch * patch = nullptr;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+class ZoneBcPatch
+{
+public:
+    ZoneBcPatch();
+    ~ZoneBcPatch();
+public:
+    int donor_zoneid;
+    std::vector<int> transform;
+    std::vector<int> donor_pnts;
+};
+
+class BaseZone
+{
+public:
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Global
+{
+public:
+    Global();
+    ~Global();
+public:
+    static int cell_dim;
+    static int phys_dim;
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+public:
+    static void FreeData();
+};
+
+void ReadCgnsGrid( const std::string & filename );
+void ReadCgnsGridBaseZone( const std::string & filename );
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage2/01c/Partition.cpp b/example/partition/struct/2d/stage2/01c/Partition.cpp
new file mode 100644
index 00000000..f8d26e33
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01c/Partition.cpp
@@ -0,0 +1,618 @@
+#include "Partition.h"
+#include "CgnsGrid.h"
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+bool CmpSplitZone::operator() ( SplitZone * a, SplitZone * b ) const
+{
+    return a->zoneIndex < b->zoneIndex;
+};
+
+
+double CalSumOfProcSpeed( std::vector<double> & procSpeed );
+double CalSumOfProcSpeed( std::vector<double> & procSpeed )
+{
+    int nProc = procSpeed.size();
+    double sumOfProcSpeed = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        sumOfProcSpeed += procSpeed[ iProc ];
+    }
+    return sumOfProcSpeed;
+}
+
+Partition::Partition()
+{
+    this->inputName = "../heat2d2blocksv4.cgns";
+    this->outName =  "../heat2dpart.cgns";
+}
+
+Partition::~Partition()
+{
+    ;
+}
+
+int Partition::GetMinValueIndex( double * data, int numberOfData )
+{
+    double minValue = data[ 0 ];
+    int minimumValueIndex = 0;
+
+    for ( int iData = 1; iData < numberOfData; ++ iData )
+    {
+        if ( minValue > data[ iData ] )
+        {
+            minValue      = data[ iData ];
+            minimumValueIndex = iData;
+        }
+    }
+    return minimumValueIndex;
+}
+
+int Partition::GetMinLoadProc()
+{
+    return this->GetMinValueIndex( this->timeProc.data(), this->nProc );
+}
+
+SplitZone * Partition::GetLargestZone()
+{
+    SplitZone * largestZone = 0;
+
+    double nMaxCell = 0.0;
+
+    for ( std::set< SplitZone * >::iterator iter = unsignedZoneGroup.begin(); iter != unsignedZoneGroup.end(); ++ iter )
+    {
+        double nSize = ( * iter )->GetNCell();
+        if ( nMaxCell < nSize )
+        {
+            nMaxCell    = nSize;
+            largestZone = * iter;
+        }
+    }
+
+    return largestZone;
+}
+
+void Partition::Solve()
+{
+    std::cout << "Partition::Split()\n";
+    //this->nProc = 2;
+    this->nProc = 4;
+    this->ReadGrid();
+    this->Split();
+    this->DumpPartitionedGridFile();
+    this->FreeAllZones();
+}
+
+void Partition::ReadGrid()
+{
+    ReadCgnsGridBaseZone( this->inputName );
+    ReadCgnsGrid( this->inputName );
+
+    this->nOriZone = ::Global::zones.size();
+    Dim::dim = Global::cell_dim;
+
+    std::cout << "numberOfBlocks = " << nOriZone << "\n";
+
+    this->refZone.resize( nOriZone );
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = new SplitZone();
+        refZone[ iZone ] = splitZone;
+
+        splitZone->SetZoneIndex( iZone );
+        splitZone->SetProcId( 0 );
+        splitZone->SetParentAndChild( 0 );
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        Zone * zone = ::Global::zones[ iZone ];
+
+        splitZone->dimInfo.dimList = zone->nijk;
+
+        int nbccos = zone->bccos.size();
+        std::cout << "nbccos = " << nbccos << "\n";
+
+        for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+        {
+            ZoneBc * zoneBc = zone->bccos[ ibcco ];
+
+            PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+            splitZone->physicalSplitBcList.push_back( physicalSplitBc );
+            physicalSplitBc->bcType = zoneBc->bcType;
+            physicalSplitBc->SetRegion( zoneBc->pnts );
+            physicalSplitBc->splitZone = splitZone;
+        }
+
+        int nbc1to1s = zone->bc1to1s.size();
+
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * zoneBc1To1 = zone->bc1to1s[ ibc1to1 ];
+
+            InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+            splitZone->interfaceSplitBcList.push_back( interfaceSplitBc );
+            interfaceSplitBc->zone = splitZone;
+            interfaceSplitBc->region.SetRegion( zoneBc1To1->pnts );
+
+            interfaceSplitBc->transform = zoneBc1To1->transform;
+            interfaceSplitBc->CalcTransformMatrix();
+
+            interfaceSplitBc->donor_zone = refZone[ zoneBc1To1->donor_zoneid ];
+            interfaceSplitBc->donor_region.SetRegion( zoneBc1To1->donor_pnts );
+        }
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        int nbc1to1s = splitZone->interfaceSplitBcList.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            InterfaceSplitBc * interfaceSplitBc = splitZone->interfaceSplitBcList[ ibc1to1 ];
+            InterfaceInfo interfaceInfo;
+            interfaceSplitBc->donor_zone->FindDonorInterface( interfaceSplitBc, interfaceInfo );
+            interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+            interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+        }
+    }
+}
+
+void Partition::Split()
+{
+    this->InitSplit();
+    this->BinarySplit();
+    this->ModifyZoneIndex();
+    int kkk = 1;
+}
+
+void Partition::InitSplit()
+{
+    //nZone is the number of zones in the original grid
+    //nProc is not the number of blocks in the end, but the number of processes that need to be divided.
+    //This difference occurs because the structure grid can have many blocks per process.
+
+    //this->nProc    = nProc;
+    //this->nPhyBlocks = referenceBlock.size();
+    //this->nZone  = this->nPhyBlocks;
+
+    //tj Computation time on processor j
+    //Nk Number of internal grid-cells for zone j
+    //aveFloatOp:  Number of Real operations per gridcell
+    //Gj The set of blocks allocated to process j
+    //Pj Real operations per second for process j
+
+    //The Greedy Load Balancing Algorithm
+    //1.Compute an "ideal" uniprocessor time, Tuni = sum ( Nk * aveFloatOp )/ sum( Pj ).
+    //2.Set the group of unassigned blocks, Gu, to contain all blocks. The number of blocks in Nu=M, where M is the total number of blocks in the mesh.
+    //3.Start all processors with a very small fictitious zone to get a start tj=delt aveFloatOp/Pj, where delt<<1 is the size of the very small fictious zone.
+    //This is used to find the fastest processor in a heterogeneous system, tj could otherwise be set to 0 in the homogeneous case.
+    this->aveFloatOp = 1.0;
+    this->delta      = 1.0e-5;
+    this->procSpeed.resize( nProc );
+    this->timeProc.resize( nProc );
+
+    this->nTZone = this->nOriZone;
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        procSpeed[ iProc ] = 1.0;
+    }
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        timeProc[ iProc ] = delta * aveFloatOp / procSpeed[ iProc ];
+    }
+
+    double sumProcSpeed = CalSumOfProcSpeed( procSpeed );
+
+    double sumProcOp = 0.0;
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        sumProcOp += refZone[ iZone ]->GetNCell() * aveFloatOp;
+    }
+
+    this->idealUniProcTime = sumProcOp / sumProcSpeed;
+
+    this->eps = 0.05;
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        unsignedZoneGroup.insert( refZone[ iZone ] );
+    }
+
+    //Init zoneStorage
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        zoneStorage.insert( refZone[ iZone ] );
+    }
+
+    //Assign procSplitZone to each process
+    procSplitZone.resize( nProc );
+
+    this->minNumberCell = 1;
+    for ( int m = 0; m < Dim::dim; ++ m )
+    {
+        this->minNumberCell *= 1;
+    }
+
+    int kkk = 1;
+
+}
+
+void Partition::FreeAllZones()
+{
+    int iCount = 0;
+    for ( std::set < SplitZone * >::iterator iter = zoneStorage.begin(); iter != zoneStorage.end(); ++ iter )
+    {
+        //cout << "iCount = " << iCount << "\n";
+        ++ iCount;
+        delete * iter;
+    }
+}
+
+int Partition::GetNZones( int iProc )
+{
+    return this->procSplitZone[ iProc ].size();
+}
+
+SplitZone * Partition::GetSplitZone( int iProc, int zoneId )
+{
+    return this->procSplitZone[ iProc ][ zoneId ];
+}
+
+void Partition::AddZoneToUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.insert( zone );
+}
+
+void Partition::RemoveZoneFromUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.erase( zone );
+}
+
+void Partition::AddZoneToProcess( int iProc, SplitZone * zone )
+{
+    this->procSplitZone[ iProc ].push_back( zone );
+}
+
+void Partition::AddNewZone( SplitZone * zone )
+{
+    zone->SetZoneIndex( nTZone ++ );
+
+    this->AddZoneToUnsignedGroup( zone );
+
+    this->zoneStorage.insert( zone );
+}
+
+SplitZone * Partition::Split( SplitZone * zone, double nCell )
+{
+    SplitZone * zoneL = new SplitZone();
+    zoneL->SetParentAndChild( zone );
+
+    SplitZone * zoneR = new SplitZone();
+    zoneR->SetParentAndChild( zone );
+
+    //Remove the original block from the UnsignedGroup
+    this->RemoveZoneFromUnsignedGroup( zone );
+
+    this->AddNewZone( zoneL );
+    this->AddNewZone( zoneR );
+
+    zone->Split( zoneL, zoneR, nCell );
+
+    return zoneL;
+}
+
+void Partition::BinarySplit()
+{
+    while ( ! unsignedZoneGroup.empty() )
+    {
+        std::cout << "number of unsigned zone = " << unsignedZoneGroup.size() << "\n";
+        int iProc = this->GetMinLoadProc();
+
+        //Get the block with the largest number of grids and its size
+        SplitZone * largestZone = this->GetLargestZone();
+
+        double nMaxCell = largestZone->GetNCell();
+
+        double aveFloatOp = this->aveFloatOp;
+        double tau = timeProc[ iProc ] + nMaxCell * aveFloatOp / procSpeed[ iProc ];
+
+        //It seems that EPS is still necessary
+        //The idea here is as follows. For the candidate blocks which can be divided into blocks, 
+        //if the difference between the target blocks and the candidate blocks is too wide, 
+        //the binarySplit method is adopted. The binarySplit blocks do not directly join the process,
+        //but enter the next round of screening.
+
+        if ( tau > idealUniProcTime * ( 1.0 + eps ) )
+        {
+            double nRest = ( tau - idealUniProcTime ) * procSpeed[ iProc ] / aveFloatOp;
+
+            double nTarget = nMaxCell - nRest;
+            if ( nRest > this->minNumberCell && nTarget > this->minNumberCell )
+            {
+                //It is necessary to divide blocks only when a certain number of points are satisfied.
+                double nHalf = nMaxCell / 2.0;
+                nMaxCell = nTarget;
+                double ratio = nMaxCell / nRest;
+                double oRatio = 1.0 / ratio;
+
+                if ( std::max( ratio, oRatio ) < 3.0 )
+                {
+                    int kkk = 1;
+                    largestZone = this->Split( largestZone, nMaxCell );
+                    timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                    this->RemoveZoneFromUnsignedGroup( largestZone );
+                    this->AddZoneToProcess( iProc, largestZone );
+                }
+                else
+                {
+                    this->Split( largestZone, nHalf );
+                }
+            }
+            else
+            {
+                //If the block is of the right size, join the process directly, and there is no need to split it.
+                timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                this->RemoveZoneFromUnsignedGroup( largestZone );
+                this->AddZoneToProcess( iProc, largestZone );
+            }
+        }
+        else
+        {
+            //If the block is of the right size, join the process directly, and there is no need to split it.
+            timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+            this->RemoveZoneFromUnsignedGroup( largestZone );
+            this->AddZoneToProcess( iProc, largestZone );
+        }
+    }
+}
+
+void Partition::ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord )
+{
+    SplitZone * rootSplitZone = splitZone->GetRootZone();
+    Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+    int nNodes = splitZone->dimInfo.ComputeNumNodes();
+    std::cout << "nNodes = " << nNodes << "\n";
+
+    coord.resize( nNodes * sizeof(double) );
+
+    int index_dim = splitZone->dimInfo.dimList.size();
+    Coor * coor = zone->coors[ icoord ];
+
+    double * xlocal = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    double * xglobal = reinterpret_cast<double *>( const_cast<char *>( coor->coord.data() ) );
+    if ( index_dim == 1 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        for ( int i = imin; i < imax; ++ i )
+        {
+            xlocal[ icount++ ] = xglobal[ i ];
+        }
+    }
+    else if ( index_dim == 2 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        int jmin = splitZone->dimInfo.rmin[ 1 ] - 1;
+        int jmax = splitZone->dimInfo.rmax[ 1 ];
+        int ni = rootSplitZone->dimInfo.dimList[ 0 ];
+        int nj = rootSplitZone->dimInfo.dimList[ 1 ];
+        for ( int j = jmin; j < jmax; ++ j )
+        {
+            int jstride = j * ni;
+            for ( int i = imin; i < imax; ++ i )
+            {
+                xlocal[ icount++ ] = xglobal[ jstride + i ];
+            }
+        }
+    }
+}
+
+void Partition::DumpBc( SplitZone * splitZone )
+{
+}
+
+void Partition::DumpPartitionedGridFile()
+{
+    std::cout << "\n";
+    std::cout << "DumpPartitionedGridFile -------------------------------" << "\n";
+    std::cout << "\n";
+    int fileId = -1;
+    std::string filename = this->outName;
+    int ierr = cg_open( filename.c_str(), CG_MODE_WRITE, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+
+    std::vector<std::string> coordnames;
+    coordnames.push_back( "CoordinateX" );
+    coordnames.push_back( "CoordinateY" );
+    coordnames.push_back( "CoordinateZ" );
+
+    std::string basename = "Base";
+    int baseId = -1;
+    int icelldim = Global::cell_dim;
+    int iphysdim = Global::phys_dim;
+    cg_base_write( fileId, basename.c_str(), icelldim, iphysdim, &baseId );
+
+    std::cout << "baseId = " << baseId << "\n";
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        int nZones = this->GetNZones( iProc );
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            ZoneType_t zoneType = Structured;
+
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+
+            int index_dim = splitZone->dimInfo.dimList.size();
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            splitZone->dimInfo.ComputeISize();
+
+            int isize_dim = index_dim * 3;
+
+            std::vector<cgsize_t> isize( index_dim * 3, 0 );
+            for ( int m = 0; m < isize_dim; ++ m )
+            {
+                isize[ m ] = splitZone->dimInfo.isize[ m ];
+            }
+
+            int zoneId = -1;
+
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+
+            std::string zonename = "Zone" + std::to_string( splitZone->newIndex );
+
+            cg_zone_write( fileId, baseId, zonename.c_str(), isize.data(), zoneType, &zoneId );
+
+            std::cout << "zoneId = " << zoneId << "\n";
+            std::cout << "zonename = " << zonename << "\n";
+                
+            splitZone->ComputeRminmax();
+
+            SplitZone * rootSplitZone = splitZone->GetRootZone();
+
+            Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+            int ncoords = zone->coors.size();
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = -1;
+                DataType_t dataType = RealDouble;
+                std::string coordname = coordnames[ icoord ];
+                Coor * coor = zone->coors[ icoord ];
+
+                int nNodes = splitZone->dimInfo.ComputeNumNodes();
+                std::cout << "nNodes = " << nNodes << "\n";
+
+                std::vector<char> coord;
+                ComputeCoor( splitZone, icoord, coord );
+
+                cg_coord_write( fileId, baseId, zoneId, dataType, coordname.c_str(), coord.data(), &coorId );
+
+                std::cout << "fileId = " << fileId  << " baseId = " << baseId << " zoneId = " << zoneId  << " coorId = " << coorId << "\n";
+            }
+
+            std::vector< PhysicalSplitBc * > &bccoList = splitZone->physicalSplitBcList;
+
+            int nbocos = bccoList.size();
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = -1;
+                GridLocation_t location = Vertex;
+
+                std::string boconame = "BC" + std::to_string( iboco + 1 );
+
+                PhysicalSplitBc * physicalSplitBc = bccoList[ iboco ];
+                BCType_t bocotype = static_cast<BCType_t>( physicalSplitBc->bcType );
+                PointSetType_t ptset_type = PointRange;
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> pnts;
+                int nSize = physicalSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.end[ i ] );
+                }
+
+                cg_boco_write( fileId, baseId, zoneId, boconame.c_str(), bocotype, ptset_type, npnts, pnts.data(), & bccoId );
+            }
+
+            std::vector< InterfaceSplitBc * > & bc1to1List = splitZone->interfaceSplitBcList;
+
+            int n1to1 = bc1to1List.size();
+            std::cout << "n1to1 = " << n1to1 << "\n";
+
+            std::vector<int> itranfrm( index_dim );
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                itranfrm[ m ] = m + 1;
+            }
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int index_conn = -1;
+
+                InterfaceSplitBc * interfaceSplitBc = bc1to1List[ i1to1 ];
+
+                std::vector<cgsize_t> pnts;
+                std::vector<cgsize_t> pntsdonor;
+                int nSize = interfaceSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.end[ i ] );
+                }
+
+                int nPatchSize = interfaceSplitBc->donor_region.start.size();
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.start[ i ] );
+                }
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.end[ i ] );
+                }
+                int id = interfaceSplitBc->donor_zone->newIndex;
+                int oldZoneIndex = interfaceSplitBc->donor_zone->zoneIndex;
+                std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+                std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+                std::cout << "donor zone id = " << id << "\n";
+                std::cout << "donor zone oldZoneIndex = " << oldZoneIndex << "\n";
+                std::string donorname = "Zone" + std::to_string( id );
+                std::string connectname = "Interface" + std::to_string( i1to1 );
+
+                std::cout << "donorname = " << donorname << "\n";
+                std::cout << "connectname = " << connectname << "\n";
+
+                std::vector<int> & itranfrm = interfaceSplitBc->transform;
+
+                cg_1to1_write( fileId, baseId, zoneId, connectname.c_str(), donorname.c_str(), pnts.data(), pntsdonor.data(), itranfrm.data(), &index_conn );
+                std::cout << "index_conn = " << index_conn << "\n";
+            }
+        }
+    }
+    cg_close( fileId );
+}
+
+void Partition::ModifyZoneIndex()
+{
+    std::cout << "ModifyZoneIndex +++++++++++++++++++++++++ " << "\n";
+    int globalZoneId = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        std::cout << "iProc = " << iProc << "\n";
+        int nZones = this->GetNZones( iProc );
+        std::cout << "nZones in Proc " << iProc << "  = " << nZones << "\n";
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+            //splitZone->SetZoneIndex( globalZoneId++ );
+            splitZone->newIndex = ( globalZoneId++ );
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+        }
+    }
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage2/01c/Partition.h b/example/partition/struct/2d/stage2/01c/Partition.h
new file mode 100644
index 00000000..8a4a9731
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01c/Partition.h
@@ -0,0 +1,59 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class SplitZone;
+
+struct CmpSplitZone 
+{
+    bool operator() ( SplitZone * a, SplitZone * b ) const;
+};
+
+class Partition
+{
+public:
+    Partition();
+    ~Partition();
+protected:
+    std::set < SplitZone * > zoneStorage;
+    std::set < SplitZone *, CmpSplitZone > unsignedZoneGroup;
+    std::vector< SplitZone * > refZone;
+    std::vector< std::vector< SplitZone * > > procSplitZone;
+    std::vector<double> procSpeed;
+    std::vector<double> timeProc;
+    double aveFloatOp, delta;
+    double idealUniProcTime, eps;
+    int minNumberCell;
+    int nTZone;
+    int nOriZone;
+    int nProc;
+public:
+    std::string inputName;
+    std::string outName;
+public:
+    void Solve();
+    void ReadGrid();
+    void Split();
+    void InitSplit();
+    void BinarySplit();
+    //void GreedySplit();
+public:
+    void AddNewZone( SplitZone * zone );
+    void AddZoneToUnsignedGroup( SplitZone * zone );
+    void RemoveZoneFromUnsignedGroup( SplitZone * zone );
+    void AddZoneToProcess( int iProc, SplitZone * zone );
+    void DumpPartitionedGridFile();
+    void ModifyZoneIndex();
+    void FreeAllZones();
+    int GetNZones( int iProc );
+    SplitZone * GetSplitZone( int iProc, int zoneId );
+    void ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord );
+    void DumpBc( SplitZone * splitZone );
+private:
+    int GetMinValueIndex( double * data, int numberOfData );
+    int GetMinLoadProc();
+    SplitZone * GetLargestZone();
+    SplitZone * Split( SplitZone * zone, double nCell );
+};
+
diff --git a/example/partition/struct/2d/stage2/01c/README.txt b/example/partition/struct/2d/stage2/01c/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01c/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/partition/struct/2d/stage2/01c/SplitZone.cpp b/example/partition/struct/2d/stage2/01c/SplitZone.cpp
new file mode 100644
index 00000000..e7ffa1b3
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01c/SplitZone.cpp
@@ -0,0 +1,1065 @@
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+int Dim::dim = -1;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox  )
+{
+    domainBox.start = zoneBox.start;
+    domainBox.end = zoneBox.end;
+
+    int axis = iDomain / 2;
+    int direction = iDomain % 2;
+
+    if ( direction == 0 )
+    {
+        domainBox.end[ axis ] = domainBox.start[ axis ];
+    }
+    else if ( direction == 1 )
+    {
+        domainBox.start[ axis ] = domainBox.end[ axis ];
+    }
+}
+
+DimInfo::DimInfo()
+{
+    this->Init( 1 );
+}
+
+DimInfo::~DimInfo()
+{
+}
+
+void DimInfo::Init( int dim )
+{
+    this->dim = dim;
+    dimList.resize( this->dim, 1 );
+    oriPoint.resize( this->dim, 0 );
+}
+
+DimInfo & DimInfo::operator = ( const DimInfo & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->dim = rhs.dim;
+    this->dimList = rhs.dimList;
+    this->oriPoint = rhs.oriPoint;
+
+    return * this;
+}
+
+int DimInfo::ComputeNumNodes()
+{
+    int nNodes = 1;
+    for ( int m = 0; m < this->dimList.size(); ++ m )
+    {
+        nNodes *= this->dimList[ m ];
+    }
+    return nNodes;
+}
+
+void DimInfo::ComputeISize()
+{
+    int index_dim = this->dimList.size();
+    this->isize.resize( index_dim * 3, 0 );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        isize[ m ] = this->dimList[ m ];
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 1;
+        isize[ start + m ] = this->dimList[ m ] - 1;
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 2;
+        isize[ start + m ] = 0;
+    }
+
+    for ( int i = 0; i < isize.size(); ++ i )
+    {
+        std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+    }
+}
+
+void DimInfo::ComputeRminmax( std::vector<int> & ref )
+{
+    int index_dim = this->dimList.size();
+    this->rmin.resize( index_dim );
+    this->rmax.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        rmin[ m ] = ref[ m ] + 1;
+        rmax[ m ] = ref[ m ] + this->dimList[ m ];
+    }
+
+    std::cout << "rmin, rmax = \n";
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        std::cout << rmin[ m ] << " " << rmax[ m ] << "\n";
+    }
+}
+
+void DimInfo::Init( std::vector<int> & dimList )
+{
+    this->dim = dimList.size();
+    this->dimList = dimList;
+    std::vector<int> zero( dimList.size(), 0 );
+    this->oriPoint = zero;
+}
+
+void DimInfo::SetNewDimension( int axis, int newStart, int newWidth )
+{
+    this->oriPoint[ axis ] = newStart;
+    this->dimList [ axis ] = newWidth;
+}
+
+void DimInfo::GetZoneGlobalBox( RangeRegion &zoneBox )
+{
+    int index_dim = this->dimList.size();
+    zoneBox.start.resize( index_dim );
+    zoneBox.end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        zoneBox.start[ m ] = this->oriPoint[ m ] + 1;
+        zoneBox.end[ m ] = this->oriPoint[ m ] + this->dimList[ m ];
+    }
+}
+
+void DimInfo::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    int index_dim = this->dimList.size();
+    localBox.start.resize( index_dim );
+    localBox.end.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        localBox.start[ m ] = globalBox.start[ m ] - this->oriPoint[ m ];
+        localBox.end[ m ] = globalBox.end[ m ] - this->oriPoint[ m ];
+    }
+}
+
+RangeRegion::RangeRegion( int nSize )
+{
+    this->Init( nSize );
+}
+
+RangeRegion::~RangeRegion()
+{
+}
+
+void RangeRegion::Init( int nSize )
+{
+    this->start.resize( nSize );
+    this->end.resize( nSize );
+}
+
+RangeRegion & RangeRegion::operator = ( const RangeRegion & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+bool RangeRegion::operator == ( const RangeRegion & rhs ) const
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] != rhs.start[ m ] || 
+            this->end  [ m ] != rhs.end  [ m ] )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+bool RangeRegion::InRegion( const RangeRegion & region )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( ( this->start[ m ] < region.start[ m ] ) || ( this->end[ m ] > region.end[ m ] ) )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::Normalize()
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        int minv = std::min( this->start[ m ], this->end[ m ] );
+        int maxv = std::max( this->start[ m ], this->end[ m ] );
+        this->start[ m ] = minv;
+        this->end[ m ] = maxv;
+    }
+}
+
+void RangeRegion::Localize( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] -= oriPoint[ m ];
+        this->end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void RangeRegion::ToGlobal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] += oriPoint[ m ];
+        this->end[ m ] += oriPoint[ m ];
+    }
+}
+
+void RangeRegion::ToLocal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] -= oriPoint[ m ];
+        this->end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void RangeRegion::PrintGlobal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    std::cout << "global start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ] + oriPoint[m];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "global end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ] + oriPoint[m];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+void RangeRegion::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion );
+
+bool ComputeOverlapRegion( RangeRegion & region1, RangeRegion & region2, RangeRegion & overlapRegion )
+{
+    int index_dim = region1.start.size();
+    overlapRegion.Init( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int ijkmin1 = std::min( region1.start[ m ], region1.end[ m ] );
+        int ijkmax1 = std::max( region1.start[ m ], region1.end[ m ] );
+        int ijkmin2 = std::min( region2.start[ m ], region2.end[ m ] );
+        int ijkmax2 = std::max( region2.start[ m ], region2.end[ m ] );
+        if ( ( ijkmax1 < ijkmin2 ) || ( ijkmin1 > ijkmax2 ) )
+        {
+            return false;
+        }
+
+        int ijkmin = std::max( ijkmin1, ijkmin2 );
+        int ijkmax = std::min( ijkmax1, ijkmax2 );
+
+        overlapRegion.start[ m ] = ijkmin;
+        overlapRegion.end  [ m ] = ijkmax;
+    }
+
+    return CheckOverLapping( overlapRegion );
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion )
+{
+    int index_dim = overlapRegion.start.size();
+    int iCount = 0;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        if ( overlapRegion.start[ m ] == overlapRegion.end[ m ] )
+        {
+            ++ iCount;
+        }
+    }
+
+    return ( iCount == 1 );
+}
+
+bool GetInterfaceRegion( RangeRegion & zoneBoxL, RangeRegion & zoneBoxR, RangeRegion & interfaceRegion )
+{
+    int index_dim = zoneBoxL.start.size();
+    int nDomains = 2 * index_dim;
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegionL;
+        GetDomainRegion( zoneBoxL, iDomain, domainRegionL );
+
+        for ( int jDomain = 0; jDomain < nDomains; ++ jDomain )
+        {
+            RangeRegion domainRegionR;
+            GetDomainRegion( zoneBoxR, jDomain, domainRegionR );
+
+            if ( domainRegionL == domainRegionR )
+            {
+                interfaceRegion = domainRegionL;
+                return true;
+            }
+        }
+    }
+    return false;
+}
+
+void CreateInterfaceBc( SplitZone * zoneL, SplitZone * zoneR )
+{
+    RangeRegion globalBoxL, globalBoxR, globalInterfaceRegion;
+
+    zoneL->GetZoneGlobalBox( globalBoxL );
+    zoneR->GetZoneGlobalBox( globalBoxR );
+
+    if ( ! GetInterfaceRegion( globalBoxL, globalBoxR, globalInterfaceRegion ) )
+    {
+        return;
+    }
+
+    RangeRegion localInterfaceRegionL, localInterfaceRegionR;
+
+    zoneL->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionL );
+    zoneR->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionR );
+
+    int kkk = 1;
+
+    InterfaceSplitBc * interfaceSplitBcL = new InterfaceSplitBc();
+    zoneL->interfaceSplitBcList.push_back( interfaceSplitBcL );
+    interfaceSplitBcL->zone = zoneL;
+    interfaceSplitBcL->region = localInterfaceRegionL;
+
+    int nSize = localInterfaceRegionL.start.size();
+
+    std::vector<int> transform;
+
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        transform.push_back( m + 1 );
+    }
+
+    interfaceSplitBcL->transform = transform;
+    interfaceSplitBcL->CalcTransformMatrix();
+
+    interfaceSplitBcL->donor_zone = zoneR;
+    interfaceSplitBcL->donor_region = localInterfaceRegionR;
+
+    InterfaceSplitBc * interfaceSplitBcR = new InterfaceSplitBc();
+    zoneR->interfaceSplitBcList.push_back( interfaceSplitBcR );
+
+    interfaceSplitBcR->zone = zoneR;
+    interfaceSplitBcR->region = localInterfaceRegionR;
+
+    interfaceSplitBcR->transform = transform;
+    interfaceSplitBcR->CalcTransformMatrix();
+
+    interfaceSplitBcR->donor_zone = zoneL;
+    interfaceSplitBcR->donor_region = localInterfaceRegionL;
+}
+
+
+PhysicalSplitBc::PhysicalSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+PhysicalSplitBc::~PhysicalSplitBc()
+{
+}
+
+void PhysicalSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void PhysicalSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+void PhysicalSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = splitZone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+BasicSplitBc::BasicSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+BasicSplitBc::~BasicSplitBc()
+{
+    ;
+}
+
+void BasicSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void BasicSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+int trans::M[ 3 ][ 3 ];
+std::vector<int> trans::transform;
+
+int trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void trans::CalcTransformMatrix()
+{
+    int dim = trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = trans::transform[ 0 ];
+        int sgna = trans::sgn( a );
+        int a1 = trans::del( a, 1 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int c = trans::transform[ 2 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int sgnc = trans::sgn( c );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int a3 = trans::del( a, 3 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        int b3 = trans::del( b, 3 );
+        int c1 = trans::del( c, 1 );
+        int c2 = trans::del( c, 2 );
+        int c3 = trans::del( c, 3 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 2 ][ 0 ] = sgna * a3;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+        trans::M[ 2 ][ 1 ] = sgnb * b3;
+        trans::M[ 0 ][ 2 ] = sgnc * c1;
+        trans::M[ 1 ][ 2 ] = sgnc * c2;
+        trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+InterfaceInfo::InterfaceInfo()
+{
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceInfo::~InterfaceInfo()
+{
+}
+
+InterfaceSplitBc::InterfaceSplitBc()
+{
+    this->region.Init( Dim::dim );
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceSplitBc::~InterfaceSplitBc()
+{
+}
+
+void InterfaceSplitBc::CopyMatrix( InterfaceSplitBc * interfaceSplitBc )
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = interfaceSplitBc->Mt[ i ][ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::CalcTransformMatrix()
+{
+    trans::ZeroMatrix();
+    trans::transform = this->transform;
+    trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = trans::M[ i ][ j ];
+        }
+    }
+
+}
+
+void InterfaceSplitBc::mapindex( std::vector<int> & begin1, std::vector<int> & begin2,  std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = Dim::dim;
+    std::vector<int> diff( dim );
+    for ( int m = 0; m < dim; ++ m )
+    {
+        diff[ m ] = index1[ m ] - begin1[ m ];
+    }
+
+    std::vector<int> mul( dim );
+
+    Multiply( Mt, diff, mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = mul[ m ] + begin2[ m ];
+    }
+}
+
+void InterfaceSplitBc::Multiply( int Mt[][3], std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = Dim::dim;
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = this->zone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void InterfaceSplitBc::CalcSubDonorRegion( RangeRegion &subRegion, RangeRegion &subDonorRegion )
+{
+    std::vector<int> begin1 = this->region.start;
+    std::vector<int> end1 = this->region.end;
+    std::vector<int> begin2 = this->donor_region.start;
+    std::vector<int> end2 = this->donor_region.end;
+
+    std::vector<int> new_begin1 = subRegion.start;
+    std::vector<int> new_end1 = subRegion.end;
+
+    int dim = Dim::dim;
+    std::vector<int> new_begin2( dim );
+    std::vector<int> new_end2( dim );
+
+    mapindex( begin1, begin2, new_begin1, new_begin2 );
+    mapindex( begin1, begin2, new_end1, new_end2 );
+
+    subDonorRegion.start = new_begin2;
+    subDonorRegion.end = new_end2;
+}
+
+SplitZone::SplitZone()
+{
+    this->parent  = 0;
+    this->zoneIndex = 0;
+    this->iProc = 0;
+    dimInfo.Init( Dim::dim );
+    int kk = 1;
+}
+
+SplitZone::~SplitZone()
+{
+    ;
+}
+
+void SplitZone::GetZoneGlobalBox( RangeRegion & zoneBox )
+{
+    this->dimInfo.GetZoneGlobalBox( zoneBox );
+}
+
+void SplitZone::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    this->dimInfo.GetZoneLocalBox( globalBox, localBox );
+}
+
+
+void SplitZone::ComputeRminmax()
+{
+    int index_dim = this->dimInfo.dimList.size();
+    std::vector<int> ref( index_dim, 0 );
+
+    SplitZone * rootSplitZone = 0;
+    this->GetRootInfo( rootSplitZone, ref );
+
+    this->dimInfo.ComputeRminmax( ref );
+}
+
+SplitZone * SplitZone::GetRootZone()
+{
+    SplitZone * root = this;
+
+    while ( true )
+    {
+        if ( root->parent )
+        {
+            root = root->parent;
+        }
+        else
+        {
+            return root;
+        }
+    };
+}
+
+void SplitZone::GetRootInfo( SplitZone *& root, std::vector<int> & ref )
+{
+    for ( int i = 0; i < this->dimInfo.dimList.size(); ++ i )
+    {
+        ref[ i ] += this->dimInfo.oriPoint[ i ];
+    }
+
+    if ( this->parent )
+    {
+        this->parent->GetRootInfo( root, ref );
+    }
+    else
+    {
+        root = this;
+    }
+}
+
+void SplitZone::SetParentAndChild( SplitZone * parent )
+{
+    this->parent = parent;
+    if ( parent )
+    {
+        parent->child.push_back( this );
+    }
+}
+
+
+int SplitZone::GetNCell()
+{
+    int numberOfCells = 1;
+    for ( int i = 0; i < this->dimInfo.dim; ++ i )
+    {
+        numberOfCells *= std::max( 1, ( this->dimInfo.dimList[ i ] - 1 ) );
+    }
+
+    return numberOfCells; 
+}
+
+void SplitZone::SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int leftStart = 0;
+    int leftWidth = iSplit - 0;
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, leftStart , leftWidth  );
+}
+
+void SplitZone::SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int rightStart = iSplit - 1;
+    int rightWidth = dimList[ axisNeedSplit ] - ( iSplit - 1 );
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, rightStart, rightWidth );
+}
+
+void SplitZone::Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell )
+{
+    //Find the longest axis
+    int axisNeedSplit = this->FindAxisNeedSplit();
+    int iSplit        = this->FindSplitPosition( axisNeedSplit, nCell );
+
+    zoneL->SetLeftDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+    zoneR->SetRightDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+
+    zoneL->CreateBcFromParent();
+    zoneR->CreateBcFromParent();
+    
+    CreateInterfaceBc( zoneL, zoneR );
+}
+
+void SplitZone::CreateBcFromParent()
+{
+    this->CreatePhysicalBcFromParent();
+    this->CreateInterfaceBcFromParent();
+}
+
+void SplitZone::CreatePhysicalBcFromParent()
+{
+    int nParentPhysicalBcs = this->parent->physicalSplitBcList.size();
+
+    for ( int iParentPhysicalBcs = 0; iParentPhysicalBcs < nParentPhysicalBcs; ++ iParentPhysicalBcs )
+    {
+        PhysicalSplitBc * parentPhysicalSplitBc = this->parent->physicalSplitBcList[ iParentPhysicalBcs ];
+
+        this->CreatePhysicalBcFromParent( parentPhysicalSplitBc );
+    }
+}
+
+void SplitZone::CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentPhysicalSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreatePhysicalBc( overlapRegion, parentPhysicalSplitBc->bcType );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent()
+{
+    int nInterfaceSplitBcs = this->parent->interfaceSplitBcList.size();
+
+    for ( int iInterfaceSplitBcs = 0; iInterfaceSplitBcs < nInterfaceSplitBcs; ++ iInterfaceSplitBcs )
+    {
+        InterfaceSplitBc * parentInterfaceSplitBc = this->parent->interfaceSplitBcList[ iInterfaceSplitBcs ];
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc );
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentInterfaceSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc, overlapRegion );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::FindDonorInterface( InterfaceSplitBc * interfaceSplitBc, InterfaceInfo & interfaceInfo )
+{
+    RangeRegion donor_region = interfaceSplitBc->donor_region;
+    donor_region.Normalize();
+    interfaceInfo.donor_zone = this;
+    for ( int iInterface = 0; iInterface < interfaceSplitBcList.size(); ++ iInterface )
+    {
+        InterfaceSplitBc * candidateDonorBc = interfaceSplitBcList[ iInterface ];
+        bool flag = donor_region.InRegion( candidateDonorBc->region );
+        if ( flag )
+        {
+            if ( donor_region == candidateDonorBc->region )
+            {
+                interfaceInfo.donor_interface = candidateDonorBc;
+                return;
+            }
+            else
+            {
+                InterfaceSplitBc * donorBc = new InterfaceSplitBc();
+                candidateDonorBc->child.push_back( donorBc );
+                donorBc->region = donor_region;
+                donorBc->zone = candidateDonorBc->zone;
+                donorBc->donor_zone = interfaceSplitBc->zone;
+                donorBc->transform = candidateDonorBc->transform;
+                donorBc->CopyMatrix( candidateDonorBc );
+                RangeRegion subDonorRegion( Dim::dim );
+                candidateDonorBc->CalcSubDonorRegion( donorBc->region, subDonorRegion );
+                std::vector<int> & oriPoint = interfaceSplitBc->zone->dimInfo.oriPoint;
+                subDonorRegion.Localize( oriPoint );
+                donorBc->donor_region = subDonorRegion;
+                donorBc->donor_bc = interfaceSplitBc;
+                interfaceInfo.donor_interface = donorBc;
+                return;
+            }
+        }
+    }
+    return;
+}
+
+void SplitZone::GetChildDonorRegion( RangeRegion & subDonorRegion, InterfaceInfo & interfaceInfo )
+{
+    std::cout << "subDonorRegion = \n";
+    //subDonorRegion.Print();
+    RangeRegion normalizedDonorRegion = subDonorRegion;
+    normalizedDonorRegion.Normalize();
+    int nChild = this->child.size();
+    for ( int ichild = 0; ichild < nChild; ++ ichild )
+    {
+        std::cout << " iChild = " << ichild << " nChild = " << nChild << "\n";
+        SplitZone * sub_zone = this->child[ ichild ];
+        std::cout << " zoneIndex = " << sub_zone->zoneIndex << "\n";
+        int nInters = sub_zone->interfaceSplitBcList.size();
+        for ( int iInter = 0; iInter < nInters; ++ iInter )
+        {
+            std::cout << " iInter = " << iInter << "\n";
+            InterfaceSplitBc * interfaceSplitBc = sub_zone->interfaceSplitBcList[ iInter ];
+            std::cout << "interfaceSplitBc local = \n";
+            interfaceSplitBc->region.Print();
+            std::cout << "interfaceSplitBc global = \n";
+            interfaceSplitBc->region.PrintGlobal( sub_zone->dimInfo.oriPoint );
+            RangeRegion g_region = interfaceSplitBc->region;
+            g_region.ToGlobal( sub_zone->dimInfo.oriPoint );
+            if ( g_region == normalizedDonorRegion )
+            {
+                RangeRegion donorRegion = subDonorRegion;
+                donorRegion.ToLocal( sub_zone->dimInfo.oriPoint );
+
+                interfaceInfo.donor_zone = sub_zone;
+                interfaceInfo.donor_interface = interfaceSplitBc;
+                interfaceInfo.donor_region = donorRegion;
+                return;
+            }
+        }
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion )
+{
+    InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+    this->interfaceSplitBcList.push_back( interfaceSplitBc );
+
+    interfaceSplitBc->region = overlapRegion;
+    interfaceSplitBc->zone = this;
+    interfaceSplitBc->transform = parentInterfaceSplitBc->transform;
+    interfaceSplitBc->CopyMatrix( parentInterfaceSplitBc );
+    RangeRegion subDonorRegion( Dim::dim );
+    parentInterfaceSplitBc->CalcSubDonorRegion( overlapRegion, subDonorRegion );
+    interfaceSplitBc->ChangeRegionToLocalCoordinate();
+    interfaceSplitBc->donor_region = subDonorRegion;
+    SplitZone * parent_donor_zone = parentInterfaceSplitBc->donor_zone;
+    std::cout << " parentInterfaceSplitBc->zone->zoneIndex " << parentInterfaceSplitBc->zone->zoneIndex << "\n";
+    std::cout << " parentInterfaceSplitBc->donor_zone->zoneIndex " << parent_donor_zone->zoneIndex << "\n";
+    if ( parent_donor_zone->child.size() > 0 )
+    {
+        InterfaceInfo interfaceInfo;
+        parent_donor_zone->GetChildDonorRegion( subDonorRegion, interfaceInfo );
+        interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+        interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+        interfaceSplitBc->donor_region = interfaceInfo.donor_region;
+        //compatibility
+        InterfaceSplitBc * donor_bc = interfaceSplitBc->donor_bc;
+        SplitZone * donor_zone = interfaceSplitBc->donor_zone;
+        if ( interfaceSplitBc->zone != donor_bc->donor_zone )
+        {
+            if ( interfaceSplitBc->zone->parent == donor_bc->donor_zone )
+            {
+                RangeRegion d_region = donor_bc->donor_region;
+                d_region.ToLocal( interfaceSplitBc->zone->dimInfo.oriPoint );
+                donor_bc->donor_region = d_region;
+            }
+            donor_bc->donor_zone = interfaceSplitBc->zone;
+         
+            int kkk = 1;
+        }
+        int kkk = 1;
+    }
+    else
+    {
+        InterfaceInfo interfaceInfo;
+        parent_donor_zone->FindDonorInterface( interfaceSplitBc, interfaceInfo );
+        interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+        interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+    }
+    
+    int kkk = 1;
+}
+
+void SplitZone::CreatePhysicalBc( RangeRegion & overlapRegion, int bcType )
+{
+    PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+    this->physicalSplitBcList.push_back( physicalSplitBc );
+    physicalSplitBc->SetRegion( overlapRegion );
+    physicalSplitBc->bcType = bcType;
+    physicalSplitBc->splitZone = this;
+    physicalSplitBc->ChangeRegionToLocalCoordinate();
+}
+
+int SplitZone::FindAxisNeedSplit()
+{
+    //Find the longest axis
+    int axisNeedSplit = 0;
+    int maxN = this->dimInfo.dimList[ 0 ];
+
+    for ( int m = 1; m < this->dimInfo.dimList.size(); ++ m )
+    {
+        if ( this->IsPoleBc( m ) )
+        {
+            continue;
+        }
+        int Nm = this->dimInfo.dimList[ m ];
+        if ( maxN < Nm )
+        {
+            maxN = Nm;
+            axisNeedSplit = m;
+        }
+    }
+
+    return axisNeedSplit;
+}
+
+int SplitZone::GetCrossSection( int axis )
+{
+    int nDim = this->dimInfo.dimList.size();
+    int crossSection = 1;
+    int N = nDim - 1;
+    for ( int m = 0; m < N; ++ m )
+    {
+         int mm = ( axis + 1 ) % nDim;
+         int nLineElements = std::max( 1, ( this->dimInfo.dimList[ mm ] - 1 ) );
+         crossSection *= nLineElements;
+    }
+    return crossSection;
+}
+
+int SplitZone::FindSplitPosition( int axisNeedSplit, double nCell )
+{
+    int nDim = this->dimInfo.dimList.size();
+    std::vector<int> crossSections( nDim );
+    for ( int m = 0; m < nDim; ++ m )
+    {
+        crossSections[ m ] = this->GetCrossSection( m );
+    }
+
+    //guess the value
+    double dSplit = nCell / crossSections[ axisNeedSplit ];
+    int  iSplit = 1 + static_cast< int >( std::floor( dSplit + 0.5 ) );
+    return iSplit;
+}
+
+
+bool SplitZone::IsPoleBc( int splitDirection )
+{
+    return false;
+}
+
diff --git a/example/partition/struct/2d/stage2/01c/SplitZone.h b/example/partition/struct/2d/stage2/01c/SplitZone.h
new file mode 100644
index 00000000..6ba99614
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01c/SplitZone.h
@@ -0,0 +1,194 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class Dim
+{
+public:
+    static int dim;
+};
+
+class SplitZone;
+class RangeRegion;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox );
+
+class DimInfo
+{
+public:
+    DimInfo();
+    ~DimInfo();
+public:
+    int dim;
+    std::vector<int> dimList;
+    std::vector<int> oriPoint;
+    std::vector<int> isize;
+    std::vector<int> rmin;
+    std::vector<int> rmax;
+public:
+    int GetSize() const { return dim; }
+    DimInfo & operator = ( const DimInfo & rhs );
+public:
+    int ComputeNumNodes();
+    void ComputeISize();
+    void ComputeRminmax( std::vector<int> & ref );
+    void Init( int dim );
+    void Init( std::vector<int> & dimList );
+    void SetNewDimension( int axis, int newStart, int newWidth );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+};
+
+class SplitZone;
+class SplitBcPatch;
+
+class RangeRegion
+{
+public:
+    RangeRegion( int nSize = 1 );
+    ~RangeRegion();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    void Init( int nSize );
+    RangeRegion & operator = ( const RangeRegion & rhs );
+    bool operator == ( const RangeRegion & rhs ) const;
+    bool InRegion( const RangeRegion & region );
+    void SetRegion( std::vector<int> &pnts );
+    void Normalize();
+    void Localize( std::vector<int> & oriPoint );
+    void ToGlobal( std::vector<int> & oriPoint );
+    void ToLocal( std::vector<int> & oriPoint );
+    void PrintGlobal( std::vector<int> & oriPoint );
+    void Print();
+};
+
+class PhysicalSplitBc
+{
+public:
+    PhysicalSplitBc();
+    ~PhysicalSplitBc();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class BasicSplitBc
+{
+public:
+    BasicSplitBc();
+    ~BasicSplitBc();
+public:
+    RangeRegion region;
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> & pnts );
+    void SetRegion( RangeRegion & region );
+};
+
+class trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class InterfaceSplitBc;
+class SplitZone;
+
+class InterfaceInfo
+{
+public:
+    InterfaceInfo();
+    ~InterfaceInfo();
+public:
+    InterfaceSplitBc * donor_interface = nullptr;
+    SplitZone * donor_zone = nullptr;
+    RangeRegion donor_region;
+};
+
+class InterfaceSplitBc
+{
+public:
+    InterfaceSplitBc();
+    ~InterfaceSplitBc();
+public:
+    std::vector<int> transform;
+    int Mt[ 3 ][ 3 ];
+    RangeRegion region;
+    SplitZone * zone = nullptr;
+    RangeRegion donor_region;
+    SplitZone * donor_zone = nullptr;
+    InterfaceSplitBc * donor_bc = nullptr;
+public:
+    std::vector<InterfaceSplitBc *> child;
+public:
+    void CopyMatrix( InterfaceSplitBc * interfaceSplitBc );
+    void CalcTransformMatrix();
+    void CalcSubDonorRegion( RangeRegion & subRegion, RangeRegion & subDonorRegion );
+    void mapindex( std::vector<int> & begin1, std::vector<int> & begin2, std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( int Mt[][ 3 ], std::vector<int> & a, std::vector<int> & b );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class SplitZone
+{
+public:
+    SplitZone();
+    ~SplitZone();
+public:
+    DimInfo dimInfo;
+    int zoneIndex, iProc;
+    int newIndex;
+protected:
+    SplitZone * parent;
+    std::vector<SplitZone *> child;
+public:
+    std::vector< PhysicalSplitBc * > physicalSplitBcList;
+    std::vector< InterfaceSplitBc * > interfaceSplitBcList;
+public:
+    int GetNCell();
+    void ComputeRminmax();
+    void GetRootInfo( SplitZone *& root, std::vector<int> & ref );
+    void SetZoneIndex( int zoneIndex ) { this->zoneIndex = zoneIndex; }
+    int  GetZoneIndex() { return zoneIndex; }
+    void SetProcId( int iProc ) { this->iProc = iProc; }
+    void SetParent( SplitZone * parent ) { this->parent = parent; };
+    void SetParentAndChild( SplitZone * parent );
+    void FindDonorInterface( InterfaceSplitBc * interfaceSplitBc, InterfaceInfo & interfaceInfo );
+    void GetChildDonorRegion( RangeRegion & subDonorRegion, InterfaceInfo & interfaceInfo );
+public:
+    void CreateBcFromParent();
+    void CreatePhysicalBcFromParent();
+    void CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc );
+    void CreatePhysicalBc( RangeRegion & overlapRegion, int bcType );
+    void CreateInterfaceBcFromParent();
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc );
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion );
+
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+    SplitZone * GetRootZone();
+public:
+    void Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell );
+    void SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+    void SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+private:
+    int FindAxisNeedSplit();
+    int FindSplitPosition( int axisNeedSplit, double nCell );
+    bool IsPoleBc( int splitDirection );
+    int GetCrossSection( int axis );
+};
+
diff --git a/example/partition/struct/2d/stage2/01c/heat2d2blocksv4.cgns b/example/partition/struct/2d/stage2/01c/heat2d2blocksv4.cgns
new file mode 100644
index 00000000..199a53cf
Binary files /dev/null and b/example/partition/struct/2d/stage2/01c/heat2d2blocksv4.cgns differ
diff --git a/example/partition/struct/2d/stage2/01c/heat2dpart.cgns b/example/partition/struct/2d/stage2/01c/heat2dpart.cgns
new file mode 100644
index 00000000..6c5ee464
Binary files /dev/null and b/example/partition/struct/2d/stage2/01c/heat2dpart.cgns differ
diff --git a/example/partition/struct/2d/stage2/01c/main.cpp b/example/partition/struct/2d/stage2/01c/main.cpp
new file mode 100644
index 00000000..5da1de7c
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01c/main.cpp
@@ -0,0 +1,18 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include "Partition.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip>
+
+int main(int argc, char **argv)
+{
+    Partition * partition = new Partition();
+    partition->Solve();
+    delete partition;
+
+    return 0;
+}
diff --git a/example/partition/struct/2d/stage2/01d/CMakeLists.txt b/example/partition/struct/2d/stage2/01d/CMakeLists.txt
new file mode 100644
index 00000000..74ceea7d
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01d/CMakeLists.txt
@@ -0,0 +1,78 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	Partition.h Partition.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	SplitZone.h SplitZone.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/partition/struct/2d/stage2/01d/CgnsGrid.cpp b/example/partition/struct/2d/stage2/01d/CgnsGrid.cpp
new file mode 100644
index 00000000..dfe750bd
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01d/CgnsGrid.cpp
@@ -0,0 +1,349 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include <map>
+
+Grid::Grid()
+{
+    ;
+}
+
+Grid::~Grid()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if( (i+1)%5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+    delete this->patch;
+}
+
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+ZoneBcPatch::ZoneBcPatch()
+{
+    ;
+}
+
+ZoneBcPatch::~ZoneBcPatch()
+{
+}
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+Global::Global()
+{
+    ;
+}
+
+Global::~Global()
+{
+}
+
+void Global::FreeData()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+    zones.resize( 0 );
+}
+
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            //baseZone.baseId = baseId;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin( index_dim );
+            std::vector<cgsize_t> irmax( index_dim );
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                std::vector<char> coord( nNodes * sizeof(double) );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+                coor->DumpCoor();
+            }
+
+            int nbocos = -1;
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+                int kkk = 1;
+            }
+        }
+        int kkk = 1;
+    }
+    int kkk = 1;
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage2/01d/CgnsGrid.h b/example/partition/struct/2d/stage2/01d/CgnsGrid.h
new file mode 100644
index 00000000..053c467b
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01d/CgnsGrid.h
@@ -0,0 +1,140 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <map>
+
+class Grid;
+
+class Zone;
+
+class Grid
+{
+public:
+    Grid();
+    ~Grid();
+public:
+    int nZone;
+    std::vector<double> x;
+    std::vector<Zone *> zones;
+};
+
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+};
+
+class ZoneBc;
+class ZoneBc1To1;
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class ZoneBcPatch;
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+    ZoneBcPatch * patch = nullptr;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+class ZoneBcPatch
+{
+public:
+    ZoneBcPatch();
+    ~ZoneBcPatch();
+public:
+    int donor_zoneid;
+    std::vector<int> transform;
+    std::vector<int> donor_pnts;
+};
+
+class BaseZone
+{
+public:
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Global
+{
+public:
+    Global();
+    ~Global();
+public:
+    static int cell_dim;
+    static int phys_dim;
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+public:
+    static void FreeData();
+};
+
+void ReadCgnsGrid( const std::string & filename );
+void ReadCgnsGridBaseZone( const std::string & filename );
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage2/01d/Partition.cpp b/example/partition/struct/2d/stage2/01d/Partition.cpp
new file mode 100644
index 00000000..6b0e6ccb
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01d/Partition.cpp
@@ -0,0 +1,618 @@
+#include "Partition.h"
+#include "CgnsGrid.h"
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+bool CmpSplitZone::operator() ( SplitZone * a, SplitZone * b ) const
+{
+    return a->zoneIndex < b->zoneIndex;
+};
+
+
+double CalSumOfProcSpeed( std::vector<double> & procSpeed );
+double CalSumOfProcSpeed( std::vector<double> & procSpeed )
+{
+    int nProc = procSpeed.size();
+    double sumOfProcSpeed = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        sumOfProcSpeed += procSpeed[ iProc ];
+    }
+    return sumOfProcSpeed;
+}
+
+Partition::Partition()
+{
+    this->inputName = "../heat2d2blocksv5.cgns";
+    this->outName =  "../heat2dpart.cgns";
+}
+
+Partition::~Partition()
+{
+    ;
+}
+
+int Partition::GetMinValueIndex( double * data, int numberOfData )
+{
+    double minValue = data[ 0 ];
+    int minimumValueIndex = 0;
+
+    for ( int iData = 1; iData < numberOfData; ++ iData )
+    {
+        if ( minValue > data[ iData ] )
+        {
+            minValue      = data[ iData ];
+            minimumValueIndex = iData;
+        }
+    }
+    return minimumValueIndex;
+}
+
+int Partition::GetMinLoadProc()
+{
+    return this->GetMinValueIndex( this->timeProc.data(), this->nProc );
+}
+
+SplitZone * Partition::GetLargestZone()
+{
+    SplitZone * largestZone = 0;
+
+    double nMaxCell = 0.0;
+
+    for ( std::set< SplitZone * >::iterator iter = unsignedZoneGroup.begin(); iter != unsignedZoneGroup.end(); ++ iter )
+    {
+        double nSize = ( * iter )->GetNCell();
+        if ( nMaxCell < nSize )
+        {
+            nMaxCell    = nSize;
+            largestZone = * iter;
+        }
+    }
+
+    return largestZone;
+}
+
+void Partition::Solve()
+{
+    std::cout << "Partition::Split()\n";
+    //this->nProc = 2;
+    this->nProc = 4;
+    this->ReadGrid();
+    this->Split();
+    this->DumpPartitionedGridFile();
+    this->FreeAllZones();
+}
+
+void Partition::ReadGrid()
+{
+    ReadCgnsGridBaseZone( this->inputName );
+    ReadCgnsGrid( this->inputName );
+
+    this->nOriZone = ::Global::zones.size();
+    Dim::dim = Global::cell_dim;
+
+    std::cout << "numberOfBlocks = " << nOriZone << "\n";
+
+    this->refZone.resize( nOriZone );
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = new SplitZone();
+        refZone[ iZone ] = splitZone;
+
+        splitZone->SetZoneIndex( iZone );
+        splitZone->SetProcId( 0 );
+        splitZone->SetParentAndChild( 0 );
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        Zone * zone = ::Global::zones[ iZone ];
+
+        splitZone->dimInfo.dimList = zone->nijk;
+
+        int nbccos = zone->bccos.size();
+        std::cout << "nbccos = " << nbccos << "\n";
+
+        for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+        {
+            ZoneBc * zoneBc = zone->bccos[ ibcco ];
+
+            PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+            splitZone->physicalSplitBcList.push_back( physicalSplitBc );
+            physicalSplitBc->bcType = zoneBc->bcType;
+            physicalSplitBc->SetRegion( zoneBc->pnts );
+            physicalSplitBc->splitZone = splitZone;
+        }
+
+        int nbc1to1s = zone->bc1to1s.size();
+
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * zoneBc1To1 = zone->bc1to1s[ ibc1to1 ];
+
+            InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+            splitZone->interfaceSplitBcList.push_back( interfaceSplitBc );
+            interfaceSplitBc->zone = splitZone;
+            interfaceSplitBc->region.SetRegion( zoneBc1To1->pnts );
+
+            interfaceSplitBc->transform = zoneBc1To1->transform;
+            interfaceSplitBc->CalcTransformMatrix();
+
+            interfaceSplitBc->donor_zone = refZone[ zoneBc1To1->donor_zoneid ];
+            interfaceSplitBc->donor_region.SetRegion( zoneBc1To1->donor_pnts );
+        }
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        int nbc1to1s = splitZone->interfaceSplitBcList.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            InterfaceSplitBc * interfaceSplitBc = splitZone->interfaceSplitBcList[ ibc1to1 ];
+            InterfaceInfo interfaceInfo;
+            interfaceSplitBc->donor_zone->FindDonorInterface( interfaceSplitBc, interfaceInfo );
+            interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+            interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+        }
+    }
+}
+
+void Partition::Split()
+{
+    this->InitSplit();
+    this->BinarySplit();
+    this->ModifyZoneIndex();
+    int kkk = 1;
+}
+
+void Partition::InitSplit()
+{
+    //nZone is the number of zones in the original grid
+    //nProc is not the number of blocks in the end, but the number of processes that need to be divided.
+    //This difference occurs because the structure grid can have many blocks per process.
+
+    //this->nProc    = nProc;
+    //this->nPhyBlocks = referenceBlock.size();
+    //this->nZone  = this->nPhyBlocks;
+
+    //tj Computation time on processor j
+    //Nk Number of internal grid-cells for zone j
+    //aveFloatOp:  Number of Real operations per gridcell
+    //Gj The set of blocks allocated to process j
+    //Pj Real operations per second for process j
+
+    //The Greedy Load Balancing Algorithm
+    //1.Compute an "ideal" uniprocessor time, Tuni = sum ( Nk * aveFloatOp )/ sum( Pj ).
+    //2.Set the group of unassigned blocks, Gu, to contain all blocks. The number of blocks in Nu=M, where M is the total number of blocks in the mesh.
+    //3.Start all processors with a very small fictitious zone to get a start tj=delt aveFloatOp/Pj, where delt<<1 is the size of the very small fictious zone.
+    //This is used to find the fastest processor in a heterogeneous system, tj could otherwise be set to 0 in the homogeneous case.
+    this->aveFloatOp = 1.0;
+    this->delta      = 1.0e-5;
+    this->procSpeed.resize( nProc );
+    this->timeProc.resize( nProc );
+
+    this->nTZone = this->nOriZone;
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        procSpeed[ iProc ] = 1.0;
+    }
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        timeProc[ iProc ] = delta * aveFloatOp / procSpeed[ iProc ];
+    }
+
+    double sumProcSpeed = CalSumOfProcSpeed( procSpeed );
+
+    double sumProcOp = 0.0;
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        sumProcOp += refZone[ iZone ]->GetNCell() * aveFloatOp;
+    }
+
+    this->idealUniProcTime = sumProcOp / sumProcSpeed;
+
+    this->eps = 0.05;
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        unsignedZoneGroup.insert( refZone[ iZone ] );
+    }
+
+    //Init zoneStorage
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        zoneStorage.insert( refZone[ iZone ] );
+    }
+
+    //Assign procSplitZone to each process
+    procSplitZone.resize( nProc );
+
+    this->minNumberCell = 1;
+    for ( int m = 0; m < Dim::dim; ++ m )
+    {
+        this->minNumberCell *= 1;
+    }
+
+    int kkk = 1;
+
+}
+
+void Partition::FreeAllZones()
+{
+    int iCount = 0;
+    for ( std::set < SplitZone * >::iterator iter = zoneStorage.begin(); iter != zoneStorage.end(); ++ iter )
+    {
+        //cout << "iCount = " << iCount << "\n";
+        ++ iCount;
+        delete * iter;
+    }
+}
+
+int Partition::GetNZones( int iProc )
+{
+    return this->procSplitZone[ iProc ].size();
+}
+
+SplitZone * Partition::GetSplitZone( int iProc, int zoneId )
+{
+    return this->procSplitZone[ iProc ][ zoneId ];
+}
+
+void Partition::AddZoneToUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.insert( zone );
+}
+
+void Partition::RemoveZoneFromUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.erase( zone );
+}
+
+void Partition::AddZoneToProcess( int iProc, SplitZone * zone )
+{
+    this->procSplitZone[ iProc ].push_back( zone );
+}
+
+void Partition::AddNewZone( SplitZone * zone )
+{
+    zone->SetZoneIndex( nTZone ++ );
+
+    this->AddZoneToUnsignedGroup( zone );
+
+    this->zoneStorage.insert( zone );
+}
+
+SplitZone * Partition::Split( SplitZone * zone, double nCell )
+{
+    SplitZone * zoneL = new SplitZone();
+    zoneL->SetParentAndChild( zone );
+
+    SplitZone * zoneR = new SplitZone();
+    zoneR->SetParentAndChild( zone );
+
+    //Remove the original block from the UnsignedGroup
+    this->RemoveZoneFromUnsignedGroup( zone );
+
+    this->AddNewZone( zoneL );
+    this->AddNewZone( zoneR );
+
+    zone->Split( zoneL, zoneR, nCell );
+
+    return zoneL;
+}
+
+void Partition::BinarySplit()
+{
+    while ( ! unsignedZoneGroup.empty() )
+    {
+        std::cout << "number of unsigned zone = " << unsignedZoneGroup.size() << "\n";
+        int iProc = this->GetMinLoadProc();
+
+        //Get the block with the largest number of grids and its size
+        SplitZone * largestZone = this->GetLargestZone();
+
+        double nMaxCell = largestZone->GetNCell();
+
+        double aveFloatOp = this->aveFloatOp;
+        double tau = timeProc[ iProc ] + nMaxCell * aveFloatOp / procSpeed[ iProc ];
+
+        //It seems that EPS is still necessary
+        //The idea here is as follows. For the candidate blocks which can be divided into blocks, 
+        //if the difference between the target blocks and the candidate blocks is too wide, 
+        //the binarySplit method is adopted. The binarySplit blocks do not directly join the process,
+        //but enter the next round of screening.
+
+        if ( tau > idealUniProcTime * ( 1.0 + eps ) )
+        {
+            double nRest = ( tau - idealUniProcTime ) * procSpeed[ iProc ] / aveFloatOp;
+
+            double nTarget = nMaxCell - nRest;
+            if ( nRest > this->minNumberCell && nTarget > this->minNumberCell )
+            {
+                //It is necessary to divide blocks only when a certain number of points are satisfied.
+                double nHalf = nMaxCell / 2.0;
+                nMaxCell = nTarget;
+                double ratio = nMaxCell / nRest;
+                double oRatio = 1.0 / ratio;
+
+                if ( std::max( ratio, oRatio ) < 3.0 )
+                {
+                    int kkk = 1;
+                    largestZone = this->Split( largestZone, nMaxCell );
+                    timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                    this->RemoveZoneFromUnsignedGroup( largestZone );
+                    this->AddZoneToProcess( iProc, largestZone );
+                }
+                else
+                {
+                    this->Split( largestZone, nHalf );
+                }
+            }
+            else
+            {
+                //If the block is of the right size, join the process directly, and there is no need to split it.
+                timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                this->RemoveZoneFromUnsignedGroup( largestZone );
+                this->AddZoneToProcess( iProc, largestZone );
+            }
+        }
+        else
+        {
+            //If the block is of the right size, join the process directly, and there is no need to split it.
+            timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+            this->RemoveZoneFromUnsignedGroup( largestZone );
+            this->AddZoneToProcess( iProc, largestZone );
+        }
+    }
+}
+
+void Partition::ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord )
+{
+    SplitZone * rootSplitZone = splitZone->GetRootZone();
+    Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+    int nNodes = splitZone->dimInfo.ComputeNumNodes();
+    std::cout << "nNodes = " << nNodes << "\n";
+
+    coord.resize( nNodes * sizeof(double) );
+
+    int index_dim = splitZone->dimInfo.dimList.size();
+    Coor * coor = zone->coors[ icoord ];
+
+    double * xlocal = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    double * xglobal = reinterpret_cast<double *>( const_cast<char *>( coor->coord.data() ) );
+    if ( index_dim == 1 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        for ( int i = imin; i < imax; ++ i )
+        {
+            xlocal[ icount++ ] = xglobal[ i ];
+        }
+    }
+    else if ( index_dim == 2 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        int jmin = splitZone->dimInfo.rmin[ 1 ] - 1;
+        int jmax = splitZone->dimInfo.rmax[ 1 ];
+        int ni = rootSplitZone->dimInfo.dimList[ 0 ];
+        int nj = rootSplitZone->dimInfo.dimList[ 1 ];
+        for ( int j = jmin; j < jmax; ++ j )
+        {
+            int jstride = j * ni;
+            for ( int i = imin; i < imax; ++ i )
+            {
+                xlocal[ icount++ ] = xglobal[ jstride + i ];
+            }
+        }
+    }
+}
+
+void Partition::DumpBc( SplitZone * splitZone )
+{
+}
+
+void Partition::DumpPartitionedGridFile()
+{
+    std::cout << "\n";
+    std::cout << "DumpPartitionedGridFile -------------------------------" << "\n";
+    std::cout << "\n";
+    int fileId = -1;
+    std::string filename = this->outName;
+    int ierr = cg_open( filename.c_str(), CG_MODE_WRITE, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+
+    std::vector<std::string> coordnames;
+    coordnames.push_back( "CoordinateX" );
+    coordnames.push_back( "CoordinateY" );
+    coordnames.push_back( "CoordinateZ" );
+
+    std::string basename = "Base";
+    int baseId = -1;
+    int icelldim = Global::cell_dim;
+    int iphysdim = Global::phys_dim;
+    cg_base_write( fileId, basename.c_str(), icelldim, iphysdim, &baseId );
+
+    std::cout << "baseId = " << baseId << "\n";
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        int nZones = this->GetNZones( iProc );
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            ZoneType_t zoneType = Structured;
+
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+
+            int index_dim = splitZone->dimInfo.dimList.size();
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            splitZone->dimInfo.ComputeISize();
+
+            int isize_dim = index_dim * 3;
+
+            std::vector<cgsize_t> isize( index_dim * 3, 0 );
+            for ( int m = 0; m < isize_dim; ++ m )
+            {
+                isize[ m ] = splitZone->dimInfo.isize[ m ];
+            }
+
+            int zoneId = -1;
+
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+
+            std::string zonename = "Zone" + std::to_string( splitZone->newIndex );
+
+            cg_zone_write( fileId, baseId, zonename.c_str(), isize.data(), zoneType, &zoneId );
+
+            std::cout << "zoneId = " << zoneId << "\n";
+            std::cout << "zonename = " << zonename << "\n";
+                
+            splitZone->ComputeRminmax();
+
+            SplitZone * rootSplitZone = splitZone->GetRootZone();
+
+            Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+            int ncoords = zone->coors.size();
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = -1;
+                DataType_t dataType = RealDouble;
+                std::string coordname = coordnames[ icoord ];
+                Coor * coor = zone->coors[ icoord ];
+
+                int nNodes = splitZone->dimInfo.ComputeNumNodes();
+                std::cout << "nNodes = " << nNodes << "\n";
+
+                std::vector<char> coord;
+                ComputeCoor( splitZone, icoord, coord );
+
+                cg_coord_write( fileId, baseId, zoneId, dataType, coordname.c_str(), coord.data(), &coorId );
+
+                std::cout << "fileId = " << fileId  << " baseId = " << baseId << " zoneId = " << zoneId  << " coorId = " << coorId << "\n";
+            }
+
+            std::vector< PhysicalSplitBc * > &bccoList = splitZone->physicalSplitBcList;
+
+            int nbocos = bccoList.size();
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = -1;
+                GridLocation_t location = Vertex;
+
+                std::string boconame = "BC" + std::to_string( iboco + 1 );
+
+                PhysicalSplitBc * physicalSplitBc = bccoList[ iboco ];
+                BCType_t bocotype = static_cast<BCType_t>( physicalSplitBc->bcType );
+                PointSetType_t ptset_type = PointRange;
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> pnts;
+                int nSize = physicalSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.end[ i ] );
+                }
+
+                cg_boco_write( fileId, baseId, zoneId, boconame.c_str(), bocotype, ptset_type, npnts, pnts.data(), & bccoId );
+            }
+
+            std::vector< InterfaceSplitBc * > & bc1to1List = splitZone->interfaceSplitBcList;
+
+            int n1to1 = bc1to1List.size();
+            std::cout << "n1to1 = " << n1to1 << "\n";
+
+            std::vector<int> itranfrm( index_dim );
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                itranfrm[ m ] = m + 1;
+            }
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int index_conn = -1;
+
+                InterfaceSplitBc * interfaceSplitBc = bc1to1List[ i1to1 ];
+
+                std::vector<cgsize_t> pnts;
+                std::vector<cgsize_t> pntsdonor;
+                int nSize = interfaceSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.end[ i ] );
+                }
+
+                int nPatchSize = interfaceSplitBc->donor_region.start.size();
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.start[ i ] );
+                }
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.end[ i ] );
+                }
+                int id = interfaceSplitBc->donor_zone->newIndex;
+                int oldZoneIndex = interfaceSplitBc->donor_zone->zoneIndex;
+                std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+                std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+                std::cout << "donor zone id = " << id << "\n";
+                std::cout << "donor zone oldZoneIndex = " << oldZoneIndex << "\n";
+                std::string donorname = "Zone" + std::to_string( id );
+                std::string connectname = "Interface" + std::to_string( i1to1 );
+
+                std::cout << "donorname = " << donorname << "\n";
+                std::cout << "connectname = " << connectname << "\n";
+
+                std::vector<int> & itranfrm = interfaceSplitBc->transform;
+
+                cg_1to1_write( fileId, baseId, zoneId, connectname.c_str(), donorname.c_str(), pnts.data(), pntsdonor.data(), itranfrm.data(), &index_conn );
+                std::cout << "index_conn = " << index_conn << "\n";
+            }
+        }
+    }
+    cg_close( fileId );
+}
+
+void Partition::ModifyZoneIndex()
+{
+    std::cout << "ModifyZoneIndex +++++++++++++++++++++++++ " << "\n";
+    int globalZoneId = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        std::cout << "iProc = " << iProc << "\n";
+        int nZones = this->GetNZones( iProc );
+        std::cout << "nZones in Proc " << iProc << "  = " << nZones << "\n";
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+            //splitZone->SetZoneIndex( globalZoneId++ );
+            splitZone->newIndex = ( globalZoneId++ );
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+        }
+    }
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage2/01d/Partition.h b/example/partition/struct/2d/stage2/01d/Partition.h
new file mode 100644
index 00000000..8a4a9731
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01d/Partition.h
@@ -0,0 +1,59 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class SplitZone;
+
+struct CmpSplitZone 
+{
+    bool operator() ( SplitZone * a, SplitZone * b ) const;
+};
+
+class Partition
+{
+public:
+    Partition();
+    ~Partition();
+protected:
+    std::set < SplitZone * > zoneStorage;
+    std::set < SplitZone *, CmpSplitZone > unsignedZoneGroup;
+    std::vector< SplitZone * > refZone;
+    std::vector< std::vector< SplitZone * > > procSplitZone;
+    std::vector<double> procSpeed;
+    std::vector<double> timeProc;
+    double aveFloatOp, delta;
+    double idealUniProcTime, eps;
+    int minNumberCell;
+    int nTZone;
+    int nOriZone;
+    int nProc;
+public:
+    std::string inputName;
+    std::string outName;
+public:
+    void Solve();
+    void ReadGrid();
+    void Split();
+    void InitSplit();
+    void BinarySplit();
+    //void GreedySplit();
+public:
+    void AddNewZone( SplitZone * zone );
+    void AddZoneToUnsignedGroup( SplitZone * zone );
+    void RemoveZoneFromUnsignedGroup( SplitZone * zone );
+    void AddZoneToProcess( int iProc, SplitZone * zone );
+    void DumpPartitionedGridFile();
+    void ModifyZoneIndex();
+    void FreeAllZones();
+    int GetNZones( int iProc );
+    SplitZone * GetSplitZone( int iProc, int zoneId );
+    void ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord );
+    void DumpBc( SplitZone * splitZone );
+private:
+    int GetMinValueIndex( double * data, int numberOfData );
+    int GetMinLoadProc();
+    SplitZone * GetLargestZone();
+    SplitZone * Split( SplitZone * zone, double nCell );
+};
+
diff --git a/example/partition/struct/2d/stage2/01d/README.txt b/example/partition/struct/2d/stage2/01d/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01d/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/partition/struct/2d/stage2/01d/SplitZone.cpp b/example/partition/struct/2d/stage2/01d/SplitZone.cpp
new file mode 100644
index 00000000..e7ffa1b3
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01d/SplitZone.cpp
@@ -0,0 +1,1065 @@
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+int Dim::dim = -1;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox  )
+{
+    domainBox.start = zoneBox.start;
+    domainBox.end = zoneBox.end;
+
+    int axis = iDomain / 2;
+    int direction = iDomain % 2;
+
+    if ( direction == 0 )
+    {
+        domainBox.end[ axis ] = domainBox.start[ axis ];
+    }
+    else if ( direction == 1 )
+    {
+        domainBox.start[ axis ] = domainBox.end[ axis ];
+    }
+}
+
+DimInfo::DimInfo()
+{
+    this->Init( 1 );
+}
+
+DimInfo::~DimInfo()
+{
+}
+
+void DimInfo::Init( int dim )
+{
+    this->dim = dim;
+    dimList.resize( this->dim, 1 );
+    oriPoint.resize( this->dim, 0 );
+}
+
+DimInfo & DimInfo::operator = ( const DimInfo & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->dim = rhs.dim;
+    this->dimList = rhs.dimList;
+    this->oriPoint = rhs.oriPoint;
+
+    return * this;
+}
+
+int DimInfo::ComputeNumNodes()
+{
+    int nNodes = 1;
+    for ( int m = 0; m < this->dimList.size(); ++ m )
+    {
+        nNodes *= this->dimList[ m ];
+    }
+    return nNodes;
+}
+
+void DimInfo::ComputeISize()
+{
+    int index_dim = this->dimList.size();
+    this->isize.resize( index_dim * 3, 0 );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        isize[ m ] = this->dimList[ m ];
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 1;
+        isize[ start + m ] = this->dimList[ m ] - 1;
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 2;
+        isize[ start + m ] = 0;
+    }
+
+    for ( int i = 0; i < isize.size(); ++ i )
+    {
+        std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+    }
+}
+
+void DimInfo::ComputeRminmax( std::vector<int> & ref )
+{
+    int index_dim = this->dimList.size();
+    this->rmin.resize( index_dim );
+    this->rmax.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        rmin[ m ] = ref[ m ] + 1;
+        rmax[ m ] = ref[ m ] + this->dimList[ m ];
+    }
+
+    std::cout << "rmin, rmax = \n";
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        std::cout << rmin[ m ] << " " << rmax[ m ] << "\n";
+    }
+}
+
+void DimInfo::Init( std::vector<int> & dimList )
+{
+    this->dim = dimList.size();
+    this->dimList = dimList;
+    std::vector<int> zero( dimList.size(), 0 );
+    this->oriPoint = zero;
+}
+
+void DimInfo::SetNewDimension( int axis, int newStart, int newWidth )
+{
+    this->oriPoint[ axis ] = newStart;
+    this->dimList [ axis ] = newWidth;
+}
+
+void DimInfo::GetZoneGlobalBox( RangeRegion &zoneBox )
+{
+    int index_dim = this->dimList.size();
+    zoneBox.start.resize( index_dim );
+    zoneBox.end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        zoneBox.start[ m ] = this->oriPoint[ m ] + 1;
+        zoneBox.end[ m ] = this->oriPoint[ m ] + this->dimList[ m ];
+    }
+}
+
+void DimInfo::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    int index_dim = this->dimList.size();
+    localBox.start.resize( index_dim );
+    localBox.end.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        localBox.start[ m ] = globalBox.start[ m ] - this->oriPoint[ m ];
+        localBox.end[ m ] = globalBox.end[ m ] - this->oriPoint[ m ];
+    }
+}
+
+RangeRegion::RangeRegion( int nSize )
+{
+    this->Init( nSize );
+}
+
+RangeRegion::~RangeRegion()
+{
+}
+
+void RangeRegion::Init( int nSize )
+{
+    this->start.resize( nSize );
+    this->end.resize( nSize );
+}
+
+RangeRegion & RangeRegion::operator = ( const RangeRegion & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+bool RangeRegion::operator == ( const RangeRegion & rhs ) const
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] != rhs.start[ m ] || 
+            this->end  [ m ] != rhs.end  [ m ] )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+bool RangeRegion::InRegion( const RangeRegion & region )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( ( this->start[ m ] < region.start[ m ] ) || ( this->end[ m ] > region.end[ m ] ) )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::Normalize()
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        int minv = std::min( this->start[ m ], this->end[ m ] );
+        int maxv = std::max( this->start[ m ], this->end[ m ] );
+        this->start[ m ] = minv;
+        this->end[ m ] = maxv;
+    }
+}
+
+void RangeRegion::Localize( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] -= oriPoint[ m ];
+        this->end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void RangeRegion::ToGlobal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] += oriPoint[ m ];
+        this->end[ m ] += oriPoint[ m ];
+    }
+}
+
+void RangeRegion::ToLocal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] -= oriPoint[ m ];
+        this->end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void RangeRegion::PrintGlobal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    std::cout << "global start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ] + oriPoint[m];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "global end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ] + oriPoint[m];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+void RangeRegion::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion );
+
+bool ComputeOverlapRegion( RangeRegion & region1, RangeRegion & region2, RangeRegion & overlapRegion )
+{
+    int index_dim = region1.start.size();
+    overlapRegion.Init( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int ijkmin1 = std::min( region1.start[ m ], region1.end[ m ] );
+        int ijkmax1 = std::max( region1.start[ m ], region1.end[ m ] );
+        int ijkmin2 = std::min( region2.start[ m ], region2.end[ m ] );
+        int ijkmax2 = std::max( region2.start[ m ], region2.end[ m ] );
+        if ( ( ijkmax1 < ijkmin2 ) || ( ijkmin1 > ijkmax2 ) )
+        {
+            return false;
+        }
+
+        int ijkmin = std::max( ijkmin1, ijkmin2 );
+        int ijkmax = std::min( ijkmax1, ijkmax2 );
+
+        overlapRegion.start[ m ] = ijkmin;
+        overlapRegion.end  [ m ] = ijkmax;
+    }
+
+    return CheckOverLapping( overlapRegion );
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion )
+{
+    int index_dim = overlapRegion.start.size();
+    int iCount = 0;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        if ( overlapRegion.start[ m ] == overlapRegion.end[ m ] )
+        {
+            ++ iCount;
+        }
+    }
+
+    return ( iCount == 1 );
+}
+
+bool GetInterfaceRegion( RangeRegion & zoneBoxL, RangeRegion & zoneBoxR, RangeRegion & interfaceRegion )
+{
+    int index_dim = zoneBoxL.start.size();
+    int nDomains = 2 * index_dim;
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegionL;
+        GetDomainRegion( zoneBoxL, iDomain, domainRegionL );
+
+        for ( int jDomain = 0; jDomain < nDomains; ++ jDomain )
+        {
+            RangeRegion domainRegionR;
+            GetDomainRegion( zoneBoxR, jDomain, domainRegionR );
+
+            if ( domainRegionL == domainRegionR )
+            {
+                interfaceRegion = domainRegionL;
+                return true;
+            }
+        }
+    }
+    return false;
+}
+
+void CreateInterfaceBc( SplitZone * zoneL, SplitZone * zoneR )
+{
+    RangeRegion globalBoxL, globalBoxR, globalInterfaceRegion;
+
+    zoneL->GetZoneGlobalBox( globalBoxL );
+    zoneR->GetZoneGlobalBox( globalBoxR );
+
+    if ( ! GetInterfaceRegion( globalBoxL, globalBoxR, globalInterfaceRegion ) )
+    {
+        return;
+    }
+
+    RangeRegion localInterfaceRegionL, localInterfaceRegionR;
+
+    zoneL->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionL );
+    zoneR->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionR );
+
+    int kkk = 1;
+
+    InterfaceSplitBc * interfaceSplitBcL = new InterfaceSplitBc();
+    zoneL->interfaceSplitBcList.push_back( interfaceSplitBcL );
+    interfaceSplitBcL->zone = zoneL;
+    interfaceSplitBcL->region = localInterfaceRegionL;
+
+    int nSize = localInterfaceRegionL.start.size();
+
+    std::vector<int> transform;
+
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        transform.push_back( m + 1 );
+    }
+
+    interfaceSplitBcL->transform = transform;
+    interfaceSplitBcL->CalcTransformMatrix();
+
+    interfaceSplitBcL->donor_zone = zoneR;
+    interfaceSplitBcL->donor_region = localInterfaceRegionR;
+
+    InterfaceSplitBc * interfaceSplitBcR = new InterfaceSplitBc();
+    zoneR->interfaceSplitBcList.push_back( interfaceSplitBcR );
+
+    interfaceSplitBcR->zone = zoneR;
+    interfaceSplitBcR->region = localInterfaceRegionR;
+
+    interfaceSplitBcR->transform = transform;
+    interfaceSplitBcR->CalcTransformMatrix();
+
+    interfaceSplitBcR->donor_zone = zoneL;
+    interfaceSplitBcR->donor_region = localInterfaceRegionL;
+}
+
+
+PhysicalSplitBc::PhysicalSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+PhysicalSplitBc::~PhysicalSplitBc()
+{
+}
+
+void PhysicalSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void PhysicalSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+void PhysicalSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = splitZone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+BasicSplitBc::BasicSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+BasicSplitBc::~BasicSplitBc()
+{
+    ;
+}
+
+void BasicSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void BasicSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+int trans::M[ 3 ][ 3 ];
+std::vector<int> trans::transform;
+
+int trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void trans::CalcTransformMatrix()
+{
+    int dim = trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = trans::transform[ 0 ];
+        int sgna = trans::sgn( a );
+        int a1 = trans::del( a, 1 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int c = trans::transform[ 2 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int sgnc = trans::sgn( c );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int a3 = trans::del( a, 3 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        int b3 = trans::del( b, 3 );
+        int c1 = trans::del( c, 1 );
+        int c2 = trans::del( c, 2 );
+        int c3 = trans::del( c, 3 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 2 ][ 0 ] = sgna * a3;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+        trans::M[ 2 ][ 1 ] = sgnb * b3;
+        trans::M[ 0 ][ 2 ] = sgnc * c1;
+        trans::M[ 1 ][ 2 ] = sgnc * c2;
+        trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+InterfaceInfo::InterfaceInfo()
+{
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceInfo::~InterfaceInfo()
+{
+}
+
+InterfaceSplitBc::InterfaceSplitBc()
+{
+    this->region.Init( Dim::dim );
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceSplitBc::~InterfaceSplitBc()
+{
+}
+
+void InterfaceSplitBc::CopyMatrix( InterfaceSplitBc * interfaceSplitBc )
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = interfaceSplitBc->Mt[ i ][ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::CalcTransformMatrix()
+{
+    trans::ZeroMatrix();
+    trans::transform = this->transform;
+    trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = trans::M[ i ][ j ];
+        }
+    }
+
+}
+
+void InterfaceSplitBc::mapindex( std::vector<int> & begin1, std::vector<int> & begin2,  std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = Dim::dim;
+    std::vector<int> diff( dim );
+    for ( int m = 0; m < dim; ++ m )
+    {
+        diff[ m ] = index1[ m ] - begin1[ m ];
+    }
+
+    std::vector<int> mul( dim );
+
+    Multiply( Mt, diff, mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = mul[ m ] + begin2[ m ];
+    }
+}
+
+void InterfaceSplitBc::Multiply( int Mt[][3], std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = Dim::dim;
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = this->zone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void InterfaceSplitBc::CalcSubDonorRegion( RangeRegion &subRegion, RangeRegion &subDonorRegion )
+{
+    std::vector<int> begin1 = this->region.start;
+    std::vector<int> end1 = this->region.end;
+    std::vector<int> begin2 = this->donor_region.start;
+    std::vector<int> end2 = this->donor_region.end;
+
+    std::vector<int> new_begin1 = subRegion.start;
+    std::vector<int> new_end1 = subRegion.end;
+
+    int dim = Dim::dim;
+    std::vector<int> new_begin2( dim );
+    std::vector<int> new_end2( dim );
+
+    mapindex( begin1, begin2, new_begin1, new_begin2 );
+    mapindex( begin1, begin2, new_end1, new_end2 );
+
+    subDonorRegion.start = new_begin2;
+    subDonorRegion.end = new_end2;
+}
+
+SplitZone::SplitZone()
+{
+    this->parent  = 0;
+    this->zoneIndex = 0;
+    this->iProc = 0;
+    dimInfo.Init( Dim::dim );
+    int kk = 1;
+}
+
+SplitZone::~SplitZone()
+{
+    ;
+}
+
+void SplitZone::GetZoneGlobalBox( RangeRegion & zoneBox )
+{
+    this->dimInfo.GetZoneGlobalBox( zoneBox );
+}
+
+void SplitZone::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    this->dimInfo.GetZoneLocalBox( globalBox, localBox );
+}
+
+
+void SplitZone::ComputeRminmax()
+{
+    int index_dim = this->dimInfo.dimList.size();
+    std::vector<int> ref( index_dim, 0 );
+
+    SplitZone * rootSplitZone = 0;
+    this->GetRootInfo( rootSplitZone, ref );
+
+    this->dimInfo.ComputeRminmax( ref );
+}
+
+SplitZone * SplitZone::GetRootZone()
+{
+    SplitZone * root = this;
+
+    while ( true )
+    {
+        if ( root->parent )
+        {
+            root = root->parent;
+        }
+        else
+        {
+            return root;
+        }
+    };
+}
+
+void SplitZone::GetRootInfo( SplitZone *& root, std::vector<int> & ref )
+{
+    for ( int i = 0; i < this->dimInfo.dimList.size(); ++ i )
+    {
+        ref[ i ] += this->dimInfo.oriPoint[ i ];
+    }
+
+    if ( this->parent )
+    {
+        this->parent->GetRootInfo( root, ref );
+    }
+    else
+    {
+        root = this;
+    }
+}
+
+void SplitZone::SetParentAndChild( SplitZone * parent )
+{
+    this->parent = parent;
+    if ( parent )
+    {
+        parent->child.push_back( this );
+    }
+}
+
+
+int SplitZone::GetNCell()
+{
+    int numberOfCells = 1;
+    for ( int i = 0; i < this->dimInfo.dim; ++ i )
+    {
+        numberOfCells *= std::max( 1, ( this->dimInfo.dimList[ i ] - 1 ) );
+    }
+
+    return numberOfCells; 
+}
+
+void SplitZone::SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int leftStart = 0;
+    int leftWidth = iSplit - 0;
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, leftStart , leftWidth  );
+}
+
+void SplitZone::SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int rightStart = iSplit - 1;
+    int rightWidth = dimList[ axisNeedSplit ] - ( iSplit - 1 );
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, rightStart, rightWidth );
+}
+
+void SplitZone::Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell )
+{
+    //Find the longest axis
+    int axisNeedSplit = this->FindAxisNeedSplit();
+    int iSplit        = this->FindSplitPosition( axisNeedSplit, nCell );
+
+    zoneL->SetLeftDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+    zoneR->SetRightDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+
+    zoneL->CreateBcFromParent();
+    zoneR->CreateBcFromParent();
+    
+    CreateInterfaceBc( zoneL, zoneR );
+}
+
+void SplitZone::CreateBcFromParent()
+{
+    this->CreatePhysicalBcFromParent();
+    this->CreateInterfaceBcFromParent();
+}
+
+void SplitZone::CreatePhysicalBcFromParent()
+{
+    int nParentPhysicalBcs = this->parent->physicalSplitBcList.size();
+
+    for ( int iParentPhysicalBcs = 0; iParentPhysicalBcs < nParentPhysicalBcs; ++ iParentPhysicalBcs )
+    {
+        PhysicalSplitBc * parentPhysicalSplitBc = this->parent->physicalSplitBcList[ iParentPhysicalBcs ];
+
+        this->CreatePhysicalBcFromParent( parentPhysicalSplitBc );
+    }
+}
+
+void SplitZone::CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentPhysicalSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreatePhysicalBc( overlapRegion, parentPhysicalSplitBc->bcType );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent()
+{
+    int nInterfaceSplitBcs = this->parent->interfaceSplitBcList.size();
+
+    for ( int iInterfaceSplitBcs = 0; iInterfaceSplitBcs < nInterfaceSplitBcs; ++ iInterfaceSplitBcs )
+    {
+        InterfaceSplitBc * parentInterfaceSplitBc = this->parent->interfaceSplitBcList[ iInterfaceSplitBcs ];
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc );
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentInterfaceSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc, overlapRegion );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::FindDonorInterface( InterfaceSplitBc * interfaceSplitBc, InterfaceInfo & interfaceInfo )
+{
+    RangeRegion donor_region = interfaceSplitBc->donor_region;
+    donor_region.Normalize();
+    interfaceInfo.donor_zone = this;
+    for ( int iInterface = 0; iInterface < interfaceSplitBcList.size(); ++ iInterface )
+    {
+        InterfaceSplitBc * candidateDonorBc = interfaceSplitBcList[ iInterface ];
+        bool flag = donor_region.InRegion( candidateDonorBc->region );
+        if ( flag )
+        {
+            if ( donor_region == candidateDonorBc->region )
+            {
+                interfaceInfo.donor_interface = candidateDonorBc;
+                return;
+            }
+            else
+            {
+                InterfaceSplitBc * donorBc = new InterfaceSplitBc();
+                candidateDonorBc->child.push_back( donorBc );
+                donorBc->region = donor_region;
+                donorBc->zone = candidateDonorBc->zone;
+                donorBc->donor_zone = interfaceSplitBc->zone;
+                donorBc->transform = candidateDonorBc->transform;
+                donorBc->CopyMatrix( candidateDonorBc );
+                RangeRegion subDonorRegion( Dim::dim );
+                candidateDonorBc->CalcSubDonorRegion( donorBc->region, subDonorRegion );
+                std::vector<int> & oriPoint = interfaceSplitBc->zone->dimInfo.oriPoint;
+                subDonorRegion.Localize( oriPoint );
+                donorBc->donor_region = subDonorRegion;
+                donorBc->donor_bc = interfaceSplitBc;
+                interfaceInfo.donor_interface = donorBc;
+                return;
+            }
+        }
+    }
+    return;
+}
+
+void SplitZone::GetChildDonorRegion( RangeRegion & subDonorRegion, InterfaceInfo & interfaceInfo )
+{
+    std::cout << "subDonorRegion = \n";
+    //subDonorRegion.Print();
+    RangeRegion normalizedDonorRegion = subDonorRegion;
+    normalizedDonorRegion.Normalize();
+    int nChild = this->child.size();
+    for ( int ichild = 0; ichild < nChild; ++ ichild )
+    {
+        std::cout << " iChild = " << ichild << " nChild = " << nChild << "\n";
+        SplitZone * sub_zone = this->child[ ichild ];
+        std::cout << " zoneIndex = " << sub_zone->zoneIndex << "\n";
+        int nInters = sub_zone->interfaceSplitBcList.size();
+        for ( int iInter = 0; iInter < nInters; ++ iInter )
+        {
+            std::cout << " iInter = " << iInter << "\n";
+            InterfaceSplitBc * interfaceSplitBc = sub_zone->interfaceSplitBcList[ iInter ];
+            std::cout << "interfaceSplitBc local = \n";
+            interfaceSplitBc->region.Print();
+            std::cout << "interfaceSplitBc global = \n";
+            interfaceSplitBc->region.PrintGlobal( sub_zone->dimInfo.oriPoint );
+            RangeRegion g_region = interfaceSplitBc->region;
+            g_region.ToGlobal( sub_zone->dimInfo.oriPoint );
+            if ( g_region == normalizedDonorRegion )
+            {
+                RangeRegion donorRegion = subDonorRegion;
+                donorRegion.ToLocal( sub_zone->dimInfo.oriPoint );
+
+                interfaceInfo.donor_zone = sub_zone;
+                interfaceInfo.donor_interface = interfaceSplitBc;
+                interfaceInfo.donor_region = donorRegion;
+                return;
+            }
+        }
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion )
+{
+    InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+    this->interfaceSplitBcList.push_back( interfaceSplitBc );
+
+    interfaceSplitBc->region = overlapRegion;
+    interfaceSplitBc->zone = this;
+    interfaceSplitBc->transform = parentInterfaceSplitBc->transform;
+    interfaceSplitBc->CopyMatrix( parentInterfaceSplitBc );
+    RangeRegion subDonorRegion( Dim::dim );
+    parentInterfaceSplitBc->CalcSubDonorRegion( overlapRegion, subDonorRegion );
+    interfaceSplitBc->ChangeRegionToLocalCoordinate();
+    interfaceSplitBc->donor_region = subDonorRegion;
+    SplitZone * parent_donor_zone = parentInterfaceSplitBc->donor_zone;
+    std::cout << " parentInterfaceSplitBc->zone->zoneIndex " << parentInterfaceSplitBc->zone->zoneIndex << "\n";
+    std::cout << " parentInterfaceSplitBc->donor_zone->zoneIndex " << parent_donor_zone->zoneIndex << "\n";
+    if ( parent_donor_zone->child.size() > 0 )
+    {
+        InterfaceInfo interfaceInfo;
+        parent_donor_zone->GetChildDonorRegion( subDonorRegion, interfaceInfo );
+        interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+        interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+        interfaceSplitBc->donor_region = interfaceInfo.donor_region;
+        //compatibility
+        InterfaceSplitBc * donor_bc = interfaceSplitBc->donor_bc;
+        SplitZone * donor_zone = interfaceSplitBc->donor_zone;
+        if ( interfaceSplitBc->zone != donor_bc->donor_zone )
+        {
+            if ( interfaceSplitBc->zone->parent == donor_bc->donor_zone )
+            {
+                RangeRegion d_region = donor_bc->donor_region;
+                d_region.ToLocal( interfaceSplitBc->zone->dimInfo.oriPoint );
+                donor_bc->donor_region = d_region;
+            }
+            donor_bc->donor_zone = interfaceSplitBc->zone;
+         
+            int kkk = 1;
+        }
+        int kkk = 1;
+    }
+    else
+    {
+        InterfaceInfo interfaceInfo;
+        parent_donor_zone->FindDonorInterface( interfaceSplitBc, interfaceInfo );
+        interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+        interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+    }
+    
+    int kkk = 1;
+}
+
+void SplitZone::CreatePhysicalBc( RangeRegion & overlapRegion, int bcType )
+{
+    PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+    this->physicalSplitBcList.push_back( physicalSplitBc );
+    physicalSplitBc->SetRegion( overlapRegion );
+    physicalSplitBc->bcType = bcType;
+    physicalSplitBc->splitZone = this;
+    physicalSplitBc->ChangeRegionToLocalCoordinate();
+}
+
+int SplitZone::FindAxisNeedSplit()
+{
+    //Find the longest axis
+    int axisNeedSplit = 0;
+    int maxN = this->dimInfo.dimList[ 0 ];
+
+    for ( int m = 1; m < this->dimInfo.dimList.size(); ++ m )
+    {
+        if ( this->IsPoleBc( m ) )
+        {
+            continue;
+        }
+        int Nm = this->dimInfo.dimList[ m ];
+        if ( maxN < Nm )
+        {
+            maxN = Nm;
+            axisNeedSplit = m;
+        }
+    }
+
+    return axisNeedSplit;
+}
+
+int SplitZone::GetCrossSection( int axis )
+{
+    int nDim = this->dimInfo.dimList.size();
+    int crossSection = 1;
+    int N = nDim - 1;
+    for ( int m = 0; m < N; ++ m )
+    {
+         int mm = ( axis + 1 ) % nDim;
+         int nLineElements = std::max( 1, ( this->dimInfo.dimList[ mm ] - 1 ) );
+         crossSection *= nLineElements;
+    }
+    return crossSection;
+}
+
+int SplitZone::FindSplitPosition( int axisNeedSplit, double nCell )
+{
+    int nDim = this->dimInfo.dimList.size();
+    std::vector<int> crossSections( nDim );
+    for ( int m = 0; m < nDim; ++ m )
+    {
+        crossSections[ m ] = this->GetCrossSection( m );
+    }
+
+    //guess the value
+    double dSplit = nCell / crossSections[ axisNeedSplit ];
+    int  iSplit = 1 + static_cast< int >( std::floor( dSplit + 0.5 ) );
+    return iSplit;
+}
+
+
+bool SplitZone::IsPoleBc( int splitDirection )
+{
+    return false;
+}
+
diff --git a/example/partition/struct/2d/stage2/01d/SplitZone.h b/example/partition/struct/2d/stage2/01d/SplitZone.h
new file mode 100644
index 00000000..6ba99614
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01d/SplitZone.h
@@ -0,0 +1,194 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class Dim
+{
+public:
+    static int dim;
+};
+
+class SplitZone;
+class RangeRegion;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox );
+
+class DimInfo
+{
+public:
+    DimInfo();
+    ~DimInfo();
+public:
+    int dim;
+    std::vector<int> dimList;
+    std::vector<int> oriPoint;
+    std::vector<int> isize;
+    std::vector<int> rmin;
+    std::vector<int> rmax;
+public:
+    int GetSize() const { return dim; }
+    DimInfo & operator = ( const DimInfo & rhs );
+public:
+    int ComputeNumNodes();
+    void ComputeISize();
+    void ComputeRminmax( std::vector<int> & ref );
+    void Init( int dim );
+    void Init( std::vector<int> & dimList );
+    void SetNewDimension( int axis, int newStart, int newWidth );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+};
+
+class SplitZone;
+class SplitBcPatch;
+
+class RangeRegion
+{
+public:
+    RangeRegion( int nSize = 1 );
+    ~RangeRegion();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    void Init( int nSize );
+    RangeRegion & operator = ( const RangeRegion & rhs );
+    bool operator == ( const RangeRegion & rhs ) const;
+    bool InRegion( const RangeRegion & region );
+    void SetRegion( std::vector<int> &pnts );
+    void Normalize();
+    void Localize( std::vector<int> & oriPoint );
+    void ToGlobal( std::vector<int> & oriPoint );
+    void ToLocal( std::vector<int> & oriPoint );
+    void PrintGlobal( std::vector<int> & oriPoint );
+    void Print();
+};
+
+class PhysicalSplitBc
+{
+public:
+    PhysicalSplitBc();
+    ~PhysicalSplitBc();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class BasicSplitBc
+{
+public:
+    BasicSplitBc();
+    ~BasicSplitBc();
+public:
+    RangeRegion region;
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> & pnts );
+    void SetRegion( RangeRegion & region );
+};
+
+class trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class InterfaceSplitBc;
+class SplitZone;
+
+class InterfaceInfo
+{
+public:
+    InterfaceInfo();
+    ~InterfaceInfo();
+public:
+    InterfaceSplitBc * donor_interface = nullptr;
+    SplitZone * donor_zone = nullptr;
+    RangeRegion donor_region;
+};
+
+class InterfaceSplitBc
+{
+public:
+    InterfaceSplitBc();
+    ~InterfaceSplitBc();
+public:
+    std::vector<int> transform;
+    int Mt[ 3 ][ 3 ];
+    RangeRegion region;
+    SplitZone * zone = nullptr;
+    RangeRegion donor_region;
+    SplitZone * donor_zone = nullptr;
+    InterfaceSplitBc * donor_bc = nullptr;
+public:
+    std::vector<InterfaceSplitBc *> child;
+public:
+    void CopyMatrix( InterfaceSplitBc * interfaceSplitBc );
+    void CalcTransformMatrix();
+    void CalcSubDonorRegion( RangeRegion & subRegion, RangeRegion & subDonorRegion );
+    void mapindex( std::vector<int> & begin1, std::vector<int> & begin2, std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( int Mt[][ 3 ], std::vector<int> & a, std::vector<int> & b );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class SplitZone
+{
+public:
+    SplitZone();
+    ~SplitZone();
+public:
+    DimInfo dimInfo;
+    int zoneIndex, iProc;
+    int newIndex;
+protected:
+    SplitZone * parent;
+    std::vector<SplitZone *> child;
+public:
+    std::vector< PhysicalSplitBc * > physicalSplitBcList;
+    std::vector< InterfaceSplitBc * > interfaceSplitBcList;
+public:
+    int GetNCell();
+    void ComputeRminmax();
+    void GetRootInfo( SplitZone *& root, std::vector<int> & ref );
+    void SetZoneIndex( int zoneIndex ) { this->zoneIndex = zoneIndex; }
+    int  GetZoneIndex() { return zoneIndex; }
+    void SetProcId( int iProc ) { this->iProc = iProc; }
+    void SetParent( SplitZone * parent ) { this->parent = parent; };
+    void SetParentAndChild( SplitZone * parent );
+    void FindDonorInterface( InterfaceSplitBc * interfaceSplitBc, InterfaceInfo & interfaceInfo );
+    void GetChildDonorRegion( RangeRegion & subDonorRegion, InterfaceInfo & interfaceInfo );
+public:
+    void CreateBcFromParent();
+    void CreatePhysicalBcFromParent();
+    void CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc );
+    void CreatePhysicalBc( RangeRegion & overlapRegion, int bcType );
+    void CreateInterfaceBcFromParent();
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc );
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion );
+
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+    SplitZone * GetRootZone();
+public:
+    void Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell );
+    void SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+    void SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+private:
+    int FindAxisNeedSplit();
+    int FindSplitPosition( int axisNeedSplit, double nCell );
+    bool IsPoleBc( int splitDirection );
+    int GetCrossSection( int axis );
+};
+
diff --git a/example/partition/struct/2d/stage2/01d/heat2d2blocksv5.cgns b/example/partition/struct/2d/stage2/01d/heat2d2blocksv5.cgns
new file mode 100644
index 00000000..4295b7b0
Binary files /dev/null and b/example/partition/struct/2d/stage2/01d/heat2d2blocksv5.cgns differ
diff --git a/example/partition/struct/2d/stage2/01d/heat2dpart.cgns b/example/partition/struct/2d/stage2/01d/heat2dpart.cgns
new file mode 100644
index 00000000..284f2e2c
Binary files /dev/null and b/example/partition/struct/2d/stage2/01d/heat2dpart.cgns differ
diff --git a/example/partition/struct/2d/stage2/01d/main.cpp b/example/partition/struct/2d/stage2/01d/main.cpp
new file mode 100644
index 00000000..5da1de7c
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01d/main.cpp
@@ -0,0 +1,18 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include "Partition.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip>
+
+int main(int argc, char **argv)
+{
+    Partition * partition = new Partition();
+    partition->Solve();
+    delete partition;
+
+    return 0;
+}
diff --git a/example/partition/struct/2d/stage2/01e/CMakeLists.txt b/example/partition/struct/2d/stage2/01e/CMakeLists.txt
new file mode 100644
index 00000000..74ceea7d
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01e/CMakeLists.txt
@@ -0,0 +1,78 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	Partition.h Partition.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	SplitZone.h SplitZone.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/partition/struct/2d/stage2/01e/CgnsGrid.cpp b/example/partition/struct/2d/stage2/01e/CgnsGrid.cpp
new file mode 100644
index 00000000..dfe750bd
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01e/CgnsGrid.cpp
@@ -0,0 +1,349 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include <map>
+
+Grid::Grid()
+{
+    ;
+}
+
+Grid::~Grid()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if( (i+1)%5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+    delete this->patch;
+}
+
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+ZoneBcPatch::ZoneBcPatch()
+{
+    ;
+}
+
+ZoneBcPatch::~ZoneBcPatch()
+{
+}
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+Global::Global()
+{
+    ;
+}
+
+Global::~Global()
+{
+}
+
+void Global::FreeData()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+    zones.resize( 0 );
+}
+
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            //baseZone.baseId = baseId;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin( index_dim );
+            std::vector<cgsize_t> irmax( index_dim );
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                std::vector<char> coord( nNodes * sizeof(double) );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+                coor->DumpCoor();
+            }
+
+            int nbocos = -1;
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+                int kkk = 1;
+            }
+        }
+        int kkk = 1;
+    }
+    int kkk = 1;
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage2/01e/CgnsGrid.h b/example/partition/struct/2d/stage2/01e/CgnsGrid.h
new file mode 100644
index 00000000..053c467b
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01e/CgnsGrid.h
@@ -0,0 +1,140 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <map>
+
+class Grid;
+
+class Zone;
+
+class Grid
+{
+public:
+    Grid();
+    ~Grid();
+public:
+    int nZone;
+    std::vector<double> x;
+    std::vector<Zone *> zones;
+};
+
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+};
+
+class ZoneBc;
+class ZoneBc1To1;
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class ZoneBcPatch;
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+    ZoneBcPatch * patch = nullptr;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+class ZoneBcPatch
+{
+public:
+    ZoneBcPatch();
+    ~ZoneBcPatch();
+public:
+    int donor_zoneid;
+    std::vector<int> transform;
+    std::vector<int> donor_pnts;
+};
+
+class BaseZone
+{
+public:
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Global
+{
+public:
+    Global();
+    ~Global();
+public:
+    static int cell_dim;
+    static int phys_dim;
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+public:
+    static void FreeData();
+};
+
+void ReadCgnsGrid( const std::string & filename );
+void ReadCgnsGridBaseZone( const std::string & filename );
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage2/01e/Partition.cpp b/example/partition/struct/2d/stage2/01e/Partition.cpp
new file mode 100644
index 00000000..ab857e0c
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01e/Partition.cpp
@@ -0,0 +1,618 @@
+#include "Partition.h"
+#include "CgnsGrid.h"
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+bool CmpSplitZone::operator() ( SplitZone * a, SplitZone * b ) const
+{
+    return a->zoneIndex < b->zoneIndex;
+};
+
+
+double CalSumOfProcSpeed( std::vector<double> & procSpeed );
+double CalSumOfProcSpeed( std::vector<double> & procSpeed )
+{
+    int nProc = procSpeed.size();
+    double sumOfProcSpeed = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        sumOfProcSpeed += procSpeed[ iProc ];
+    }
+    return sumOfProcSpeed;
+}
+
+Partition::Partition()
+{
+    this->inputName = "../heat2d2blocksv6.cgns";
+    this->outName =  "../heat2dpart.cgns";
+}
+
+Partition::~Partition()
+{
+    ;
+}
+
+int Partition::GetMinValueIndex( double * data, int numberOfData )
+{
+    double minValue = data[ 0 ];
+    int minimumValueIndex = 0;
+
+    for ( int iData = 1; iData < numberOfData; ++ iData )
+    {
+        if ( minValue > data[ iData ] )
+        {
+            minValue      = data[ iData ];
+            minimumValueIndex = iData;
+        }
+    }
+    return minimumValueIndex;
+}
+
+int Partition::GetMinLoadProc()
+{
+    return this->GetMinValueIndex( this->timeProc.data(), this->nProc );
+}
+
+SplitZone * Partition::GetLargestZone()
+{
+    SplitZone * largestZone = 0;
+
+    double nMaxCell = 0.0;
+
+    for ( std::set< SplitZone * >::iterator iter = unsignedZoneGroup.begin(); iter != unsignedZoneGroup.end(); ++ iter )
+    {
+        double nSize = ( * iter )->GetNCell();
+        if ( nMaxCell < nSize )
+        {
+            nMaxCell    = nSize;
+            largestZone = * iter;
+        }
+    }
+
+    return largestZone;
+}
+
+void Partition::Solve()
+{
+    std::cout << "Partition::Split()\n";
+    //this->nProc = 4;
+    this->nProc = 16;
+    this->ReadGrid();
+    this->Split();
+    this->DumpPartitionedGridFile();
+    this->FreeAllZones();
+}
+
+void Partition::ReadGrid()
+{
+    ReadCgnsGridBaseZone( this->inputName );
+    ReadCgnsGrid( this->inputName );
+
+    this->nOriZone = ::Global::zones.size();
+    Dim::dim = Global::cell_dim;
+
+    std::cout << "numberOfBlocks = " << nOriZone << "\n";
+
+    this->refZone.resize( nOriZone );
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = new SplitZone();
+        refZone[ iZone ] = splitZone;
+
+        splitZone->SetZoneIndex( iZone );
+        splitZone->SetProcId( 0 );
+        splitZone->SetParentAndChild( 0 );
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        Zone * zone = ::Global::zones[ iZone ];
+
+        splitZone->dimInfo.dimList = zone->nijk;
+
+        int nbccos = zone->bccos.size();
+        std::cout << "nbccos = " << nbccos << "\n";
+
+        for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+        {
+            ZoneBc * zoneBc = zone->bccos[ ibcco ];
+
+            PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+            splitZone->physicalSplitBcList.push_back( physicalSplitBc );
+            physicalSplitBc->bcType = zoneBc->bcType;
+            physicalSplitBc->SetRegion( zoneBc->pnts );
+            physicalSplitBc->splitZone = splitZone;
+        }
+
+        int nbc1to1s = zone->bc1to1s.size();
+
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * zoneBc1To1 = zone->bc1to1s[ ibc1to1 ];
+
+            InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+            splitZone->interfaceSplitBcList.push_back( interfaceSplitBc );
+            interfaceSplitBc->zone = splitZone;
+            interfaceSplitBc->region.SetRegion( zoneBc1To1->pnts );
+
+            interfaceSplitBc->transform = zoneBc1To1->transform;
+            interfaceSplitBc->CalcTransformMatrix();
+
+            interfaceSplitBc->donor_zone = refZone[ zoneBc1To1->donor_zoneid ];
+            interfaceSplitBc->donor_region.SetRegion( zoneBc1To1->donor_pnts );
+        }
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        int nbc1to1s = splitZone->interfaceSplitBcList.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            InterfaceSplitBc * interfaceSplitBc = splitZone->interfaceSplitBcList[ ibc1to1 ];
+            InterfaceInfo interfaceInfo;
+            interfaceSplitBc->donor_zone->FindDonorInterface( interfaceSplitBc, interfaceInfo );
+            interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+            interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+        }
+    }
+}
+
+void Partition::Split()
+{
+    this->InitSplit();
+    this->BinarySplit();
+    this->ModifyZoneIndex();
+    int kkk = 1;
+}
+
+void Partition::InitSplit()
+{
+    //nZone is the number of zones in the original grid
+    //nProc is not the number of blocks in the end, but the number of processes that need to be divided.
+    //This difference occurs because the structure grid can have many blocks per process.
+
+    //this->nProc    = nProc;
+    //this->nPhyBlocks = referenceBlock.size();
+    //this->nZone  = this->nPhyBlocks;
+
+    //tj Computation time on processor j
+    //Nk Number of internal grid-cells for zone j
+    //aveFloatOp:  Number of Real operations per gridcell
+    //Gj The set of blocks allocated to process j
+    //Pj Real operations per second for process j
+
+    //The Greedy Load Balancing Algorithm
+    //1.Compute an "ideal" uniprocessor time, Tuni = sum ( Nk * aveFloatOp )/ sum( Pj ).
+    //2.Set the group of unassigned blocks, Gu, to contain all blocks. The number of blocks in Nu=M, where M is the total number of blocks in the mesh.
+    //3.Start all processors with a very small fictitious zone to get a start tj=delt aveFloatOp/Pj, where delt<<1 is the size of the very small fictious zone.
+    //This is used to find the fastest processor in a heterogeneous system, tj could otherwise be set to 0 in the homogeneous case.
+    this->aveFloatOp = 1.0;
+    this->delta      = 1.0e-5;
+    this->procSpeed.resize( nProc );
+    this->timeProc.resize( nProc );
+
+    this->nTZone = this->nOriZone;
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        procSpeed[ iProc ] = 1.0;
+    }
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        timeProc[ iProc ] = delta * aveFloatOp / procSpeed[ iProc ];
+    }
+
+    double sumProcSpeed = CalSumOfProcSpeed( procSpeed );
+
+    double sumProcOp = 0.0;
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        sumProcOp += refZone[ iZone ]->GetNCell() * aveFloatOp;
+    }
+
+    this->idealUniProcTime = sumProcOp / sumProcSpeed;
+
+    this->eps = 0.05;
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        unsignedZoneGroup.insert( refZone[ iZone ] );
+    }
+
+    //Init zoneStorage
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        zoneStorage.insert( refZone[ iZone ] );
+    }
+
+    //Assign procSplitZone to each process
+    procSplitZone.resize( nProc );
+
+    this->minNumberCell = 1;
+    for ( int m = 0; m < Dim::dim; ++ m )
+    {
+        this->minNumberCell *= 1;
+    }
+
+    int kkk = 1;
+
+}
+
+void Partition::FreeAllZones()
+{
+    int iCount = 0;
+    for ( std::set < SplitZone * >::iterator iter = zoneStorage.begin(); iter != zoneStorage.end(); ++ iter )
+    {
+        //cout << "iCount = " << iCount << "\n";
+        ++ iCount;
+        delete * iter;
+    }
+}
+
+int Partition::GetNZones( int iProc )
+{
+    return this->procSplitZone[ iProc ].size();
+}
+
+SplitZone * Partition::GetSplitZone( int iProc, int zoneId )
+{
+    return this->procSplitZone[ iProc ][ zoneId ];
+}
+
+void Partition::AddZoneToUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.insert( zone );
+}
+
+void Partition::RemoveZoneFromUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.erase( zone );
+}
+
+void Partition::AddZoneToProcess( int iProc, SplitZone * zone )
+{
+    this->procSplitZone[ iProc ].push_back( zone );
+}
+
+void Partition::AddNewZone( SplitZone * zone )
+{
+    zone->SetZoneIndex( nTZone ++ );
+
+    this->AddZoneToUnsignedGroup( zone );
+
+    this->zoneStorage.insert( zone );
+}
+
+SplitZone * Partition::Split( SplitZone * zone, double nCell )
+{
+    SplitZone * zoneL = new SplitZone();
+    zoneL->SetParentAndChild( zone );
+
+    SplitZone * zoneR = new SplitZone();
+    zoneR->SetParentAndChild( zone );
+
+    //Remove the original block from the UnsignedGroup
+    this->RemoveZoneFromUnsignedGroup( zone );
+
+    this->AddNewZone( zoneL );
+    this->AddNewZone( zoneR );
+
+    zone->Split( zoneL, zoneR, nCell );
+
+    return zoneL;
+}
+
+void Partition::BinarySplit()
+{
+    while ( ! unsignedZoneGroup.empty() )
+    {
+        std::cout << "number of unsigned zone = " << unsignedZoneGroup.size() << "\n";
+        int iProc = this->GetMinLoadProc();
+
+        //Get the block with the largest number of grids and its size
+        SplitZone * largestZone = this->GetLargestZone();
+
+        double nMaxCell = largestZone->GetNCell();
+
+        double aveFloatOp = this->aveFloatOp;
+        double tau = timeProc[ iProc ] + nMaxCell * aveFloatOp / procSpeed[ iProc ];
+
+        //It seems that EPS is still necessary
+        //The idea here is as follows. For the candidate blocks which can be divided into blocks, 
+        //if the difference between the target blocks and the candidate blocks is too wide, 
+        //the binarySplit method is adopted. The binarySplit blocks do not directly join the process,
+        //but enter the next round of screening.
+
+        if ( tau > idealUniProcTime * ( 1.0 + eps ) )
+        {
+            double nRest = ( tau - idealUniProcTime ) * procSpeed[ iProc ] / aveFloatOp;
+
+            double nTarget = nMaxCell - nRest;
+            if ( nRest > this->minNumberCell && nTarget > this->minNumberCell )
+            {
+                //It is necessary to divide blocks only when a certain number of points are satisfied.
+                double nHalf = nMaxCell / 2.0;
+                nMaxCell = nTarget;
+                double ratio = nMaxCell / nRest;
+                double oRatio = 1.0 / ratio;
+
+                if ( std::max( ratio, oRatio ) < 3.0 )
+                {
+                    int kkk = 1;
+                    largestZone = this->Split( largestZone, nMaxCell );
+                    timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                    this->RemoveZoneFromUnsignedGroup( largestZone );
+                    this->AddZoneToProcess( iProc, largestZone );
+                }
+                else
+                {
+                    this->Split( largestZone, nHalf );
+                }
+            }
+            else
+            {
+                //If the block is of the right size, join the process directly, and there is no need to split it.
+                timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                this->RemoveZoneFromUnsignedGroup( largestZone );
+                this->AddZoneToProcess( iProc, largestZone );
+            }
+        }
+        else
+        {
+            //If the block is of the right size, join the process directly, and there is no need to split it.
+            timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+            this->RemoveZoneFromUnsignedGroup( largestZone );
+            this->AddZoneToProcess( iProc, largestZone );
+        }
+    }
+}
+
+void Partition::ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord )
+{
+    SplitZone * rootSplitZone = splitZone->GetRootZone();
+    Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+    int nNodes = splitZone->dimInfo.ComputeNumNodes();
+    std::cout << "nNodes = " << nNodes << "\n";
+
+    coord.resize( nNodes * sizeof(double) );
+
+    int index_dim = splitZone->dimInfo.dimList.size();
+    Coor * coor = zone->coors[ icoord ];
+
+    double * xlocal = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    double * xglobal = reinterpret_cast<double *>( const_cast<char *>( coor->coord.data() ) );
+    if ( index_dim == 1 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        for ( int i = imin; i < imax; ++ i )
+        {
+            xlocal[ icount++ ] = xglobal[ i ];
+        }
+    }
+    else if ( index_dim == 2 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        int jmin = splitZone->dimInfo.rmin[ 1 ] - 1;
+        int jmax = splitZone->dimInfo.rmax[ 1 ];
+        int ni = rootSplitZone->dimInfo.dimList[ 0 ];
+        int nj = rootSplitZone->dimInfo.dimList[ 1 ];
+        for ( int j = jmin; j < jmax; ++ j )
+        {
+            int jstride = j * ni;
+            for ( int i = imin; i < imax; ++ i )
+            {
+                xlocal[ icount++ ] = xglobal[ jstride + i ];
+            }
+        }
+    }
+}
+
+void Partition::DumpBc( SplitZone * splitZone )
+{
+}
+
+void Partition::DumpPartitionedGridFile()
+{
+    std::cout << "\n";
+    std::cout << "DumpPartitionedGridFile -------------------------------" << "\n";
+    std::cout << "\n";
+    int fileId = -1;
+    std::string filename = this->outName;
+    int ierr = cg_open( filename.c_str(), CG_MODE_WRITE, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+
+    std::vector<std::string> coordnames;
+    coordnames.push_back( "CoordinateX" );
+    coordnames.push_back( "CoordinateY" );
+    coordnames.push_back( "CoordinateZ" );
+
+    std::string basename = "Base";
+    int baseId = -1;
+    int icelldim = Global::cell_dim;
+    int iphysdim = Global::phys_dim;
+    cg_base_write( fileId, basename.c_str(), icelldim, iphysdim, &baseId );
+
+    std::cout << "baseId = " << baseId << "\n";
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        int nZones = this->GetNZones( iProc );
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            ZoneType_t zoneType = Structured;
+
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+
+            int index_dim = splitZone->dimInfo.dimList.size();
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            splitZone->dimInfo.ComputeISize();
+
+            int isize_dim = index_dim * 3;
+
+            std::vector<cgsize_t> isize( index_dim * 3, 0 );
+            for ( int m = 0; m < isize_dim; ++ m )
+            {
+                isize[ m ] = splitZone->dimInfo.isize[ m ];
+            }
+
+            int zoneId = -1;
+
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+
+            std::string zonename = "Zone" + std::to_string( splitZone->newIndex );
+
+            cg_zone_write( fileId, baseId, zonename.c_str(), isize.data(), zoneType, &zoneId );
+
+            std::cout << "zoneId = " << zoneId << "\n";
+            std::cout << "zonename = " << zonename << "\n";
+                
+            splitZone->ComputeRminmax();
+
+            SplitZone * rootSplitZone = splitZone->GetRootZone();
+
+            Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+            int ncoords = zone->coors.size();
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = -1;
+                DataType_t dataType = RealDouble;
+                std::string coordname = coordnames[ icoord ];
+                Coor * coor = zone->coors[ icoord ];
+
+                int nNodes = splitZone->dimInfo.ComputeNumNodes();
+                std::cout << "nNodes = " << nNodes << "\n";
+
+                std::vector<char> coord;
+                ComputeCoor( splitZone, icoord, coord );
+
+                cg_coord_write( fileId, baseId, zoneId, dataType, coordname.c_str(), coord.data(), &coorId );
+
+                std::cout << "fileId = " << fileId  << " baseId = " << baseId << " zoneId = " << zoneId  << " coorId = " << coorId << "\n";
+            }
+
+            std::vector< PhysicalSplitBc * > &bccoList = splitZone->physicalSplitBcList;
+
+            int nbocos = bccoList.size();
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = -1;
+                GridLocation_t location = Vertex;
+
+                std::string boconame = "BC" + std::to_string( iboco + 1 );
+
+                PhysicalSplitBc * physicalSplitBc = bccoList[ iboco ];
+                BCType_t bocotype = static_cast<BCType_t>( physicalSplitBc->bcType );
+                PointSetType_t ptset_type = PointRange;
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> pnts;
+                int nSize = physicalSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.end[ i ] );
+                }
+
+                cg_boco_write( fileId, baseId, zoneId, boconame.c_str(), bocotype, ptset_type, npnts, pnts.data(), & bccoId );
+            }
+
+            std::vector< InterfaceSplitBc * > & bc1to1List = splitZone->interfaceSplitBcList;
+
+            int n1to1 = bc1to1List.size();
+            std::cout << "n1to1 = " << n1to1 << "\n";
+
+            std::vector<int> itranfrm( index_dim );
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                itranfrm[ m ] = m + 1;
+            }
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int index_conn = -1;
+
+                InterfaceSplitBc * interfaceSplitBc = bc1to1List[ i1to1 ];
+
+                std::vector<cgsize_t> pnts;
+                std::vector<cgsize_t> pntsdonor;
+                int nSize = interfaceSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.end[ i ] );
+                }
+
+                int nPatchSize = interfaceSplitBc->donor_region.start.size();
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.start[ i ] );
+                }
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.end[ i ] );
+                }
+                int id = interfaceSplitBc->donor_zone->newIndex;
+                int oldZoneIndex = interfaceSplitBc->donor_zone->zoneIndex;
+                std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+                std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+                std::cout << "donor zone id = " << id << "\n";
+                std::cout << "donor zone oldZoneIndex = " << oldZoneIndex << "\n";
+                std::string donorname = "Zone" + std::to_string( id );
+                std::string connectname = "Interface" + std::to_string( i1to1 );
+
+                std::cout << "donorname = " << donorname << "\n";
+                std::cout << "connectname = " << connectname << "\n";
+
+                std::vector<int> & itranfrm = interfaceSplitBc->transform;
+
+                cg_1to1_write( fileId, baseId, zoneId, connectname.c_str(), donorname.c_str(), pnts.data(), pntsdonor.data(), itranfrm.data(), &index_conn );
+                std::cout << "index_conn = " << index_conn << "\n";
+            }
+        }
+    }
+    cg_close( fileId );
+}
+
+void Partition::ModifyZoneIndex()
+{
+    std::cout << "ModifyZoneIndex +++++++++++++++++++++++++ " << "\n";
+    int globalZoneId = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        std::cout << "iProc = " << iProc << "\n";
+        int nZones = this->GetNZones( iProc );
+        std::cout << "nZones in Proc " << iProc << "  = " << nZones << "\n";
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+            //splitZone->SetZoneIndex( globalZoneId++ );
+            splitZone->newIndex = ( globalZoneId++ );
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+        }
+    }
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage2/01e/Partition.h b/example/partition/struct/2d/stage2/01e/Partition.h
new file mode 100644
index 00000000..8a4a9731
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01e/Partition.h
@@ -0,0 +1,59 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class SplitZone;
+
+struct CmpSplitZone 
+{
+    bool operator() ( SplitZone * a, SplitZone * b ) const;
+};
+
+class Partition
+{
+public:
+    Partition();
+    ~Partition();
+protected:
+    std::set < SplitZone * > zoneStorage;
+    std::set < SplitZone *, CmpSplitZone > unsignedZoneGroup;
+    std::vector< SplitZone * > refZone;
+    std::vector< std::vector< SplitZone * > > procSplitZone;
+    std::vector<double> procSpeed;
+    std::vector<double> timeProc;
+    double aveFloatOp, delta;
+    double idealUniProcTime, eps;
+    int minNumberCell;
+    int nTZone;
+    int nOriZone;
+    int nProc;
+public:
+    std::string inputName;
+    std::string outName;
+public:
+    void Solve();
+    void ReadGrid();
+    void Split();
+    void InitSplit();
+    void BinarySplit();
+    //void GreedySplit();
+public:
+    void AddNewZone( SplitZone * zone );
+    void AddZoneToUnsignedGroup( SplitZone * zone );
+    void RemoveZoneFromUnsignedGroup( SplitZone * zone );
+    void AddZoneToProcess( int iProc, SplitZone * zone );
+    void DumpPartitionedGridFile();
+    void ModifyZoneIndex();
+    void FreeAllZones();
+    int GetNZones( int iProc );
+    SplitZone * GetSplitZone( int iProc, int zoneId );
+    void ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord );
+    void DumpBc( SplitZone * splitZone );
+private:
+    int GetMinValueIndex( double * data, int numberOfData );
+    int GetMinLoadProc();
+    SplitZone * GetLargestZone();
+    SplitZone * Split( SplitZone * zone, double nCell );
+};
+
diff --git a/example/partition/struct/2d/stage2/01e/README.txt b/example/partition/struct/2d/stage2/01e/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01e/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/partition/struct/2d/stage2/01e/SplitZone.cpp b/example/partition/struct/2d/stage2/01e/SplitZone.cpp
new file mode 100644
index 00000000..e7ffa1b3
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01e/SplitZone.cpp
@@ -0,0 +1,1065 @@
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+int Dim::dim = -1;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox  )
+{
+    domainBox.start = zoneBox.start;
+    domainBox.end = zoneBox.end;
+
+    int axis = iDomain / 2;
+    int direction = iDomain % 2;
+
+    if ( direction == 0 )
+    {
+        domainBox.end[ axis ] = domainBox.start[ axis ];
+    }
+    else if ( direction == 1 )
+    {
+        domainBox.start[ axis ] = domainBox.end[ axis ];
+    }
+}
+
+DimInfo::DimInfo()
+{
+    this->Init( 1 );
+}
+
+DimInfo::~DimInfo()
+{
+}
+
+void DimInfo::Init( int dim )
+{
+    this->dim = dim;
+    dimList.resize( this->dim, 1 );
+    oriPoint.resize( this->dim, 0 );
+}
+
+DimInfo & DimInfo::operator = ( const DimInfo & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->dim = rhs.dim;
+    this->dimList = rhs.dimList;
+    this->oriPoint = rhs.oriPoint;
+
+    return * this;
+}
+
+int DimInfo::ComputeNumNodes()
+{
+    int nNodes = 1;
+    for ( int m = 0; m < this->dimList.size(); ++ m )
+    {
+        nNodes *= this->dimList[ m ];
+    }
+    return nNodes;
+}
+
+void DimInfo::ComputeISize()
+{
+    int index_dim = this->dimList.size();
+    this->isize.resize( index_dim * 3, 0 );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        isize[ m ] = this->dimList[ m ];
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 1;
+        isize[ start + m ] = this->dimList[ m ] - 1;
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 2;
+        isize[ start + m ] = 0;
+    }
+
+    for ( int i = 0; i < isize.size(); ++ i )
+    {
+        std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+    }
+}
+
+void DimInfo::ComputeRminmax( std::vector<int> & ref )
+{
+    int index_dim = this->dimList.size();
+    this->rmin.resize( index_dim );
+    this->rmax.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        rmin[ m ] = ref[ m ] + 1;
+        rmax[ m ] = ref[ m ] + this->dimList[ m ];
+    }
+
+    std::cout << "rmin, rmax = \n";
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        std::cout << rmin[ m ] << " " << rmax[ m ] << "\n";
+    }
+}
+
+void DimInfo::Init( std::vector<int> & dimList )
+{
+    this->dim = dimList.size();
+    this->dimList = dimList;
+    std::vector<int> zero( dimList.size(), 0 );
+    this->oriPoint = zero;
+}
+
+void DimInfo::SetNewDimension( int axis, int newStart, int newWidth )
+{
+    this->oriPoint[ axis ] = newStart;
+    this->dimList [ axis ] = newWidth;
+}
+
+void DimInfo::GetZoneGlobalBox( RangeRegion &zoneBox )
+{
+    int index_dim = this->dimList.size();
+    zoneBox.start.resize( index_dim );
+    zoneBox.end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        zoneBox.start[ m ] = this->oriPoint[ m ] + 1;
+        zoneBox.end[ m ] = this->oriPoint[ m ] + this->dimList[ m ];
+    }
+}
+
+void DimInfo::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    int index_dim = this->dimList.size();
+    localBox.start.resize( index_dim );
+    localBox.end.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        localBox.start[ m ] = globalBox.start[ m ] - this->oriPoint[ m ];
+        localBox.end[ m ] = globalBox.end[ m ] - this->oriPoint[ m ];
+    }
+}
+
+RangeRegion::RangeRegion( int nSize )
+{
+    this->Init( nSize );
+}
+
+RangeRegion::~RangeRegion()
+{
+}
+
+void RangeRegion::Init( int nSize )
+{
+    this->start.resize( nSize );
+    this->end.resize( nSize );
+}
+
+RangeRegion & RangeRegion::operator = ( const RangeRegion & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+bool RangeRegion::operator == ( const RangeRegion & rhs ) const
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] != rhs.start[ m ] || 
+            this->end  [ m ] != rhs.end  [ m ] )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+bool RangeRegion::InRegion( const RangeRegion & region )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( ( this->start[ m ] < region.start[ m ] ) || ( this->end[ m ] > region.end[ m ] ) )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::Normalize()
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        int minv = std::min( this->start[ m ], this->end[ m ] );
+        int maxv = std::max( this->start[ m ], this->end[ m ] );
+        this->start[ m ] = minv;
+        this->end[ m ] = maxv;
+    }
+}
+
+void RangeRegion::Localize( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] -= oriPoint[ m ];
+        this->end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void RangeRegion::ToGlobal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] += oriPoint[ m ];
+        this->end[ m ] += oriPoint[ m ];
+    }
+}
+
+void RangeRegion::ToLocal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] -= oriPoint[ m ];
+        this->end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void RangeRegion::PrintGlobal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    std::cout << "global start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ] + oriPoint[m];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "global end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ] + oriPoint[m];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+void RangeRegion::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion );
+
+bool ComputeOverlapRegion( RangeRegion & region1, RangeRegion & region2, RangeRegion & overlapRegion )
+{
+    int index_dim = region1.start.size();
+    overlapRegion.Init( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int ijkmin1 = std::min( region1.start[ m ], region1.end[ m ] );
+        int ijkmax1 = std::max( region1.start[ m ], region1.end[ m ] );
+        int ijkmin2 = std::min( region2.start[ m ], region2.end[ m ] );
+        int ijkmax2 = std::max( region2.start[ m ], region2.end[ m ] );
+        if ( ( ijkmax1 < ijkmin2 ) || ( ijkmin1 > ijkmax2 ) )
+        {
+            return false;
+        }
+
+        int ijkmin = std::max( ijkmin1, ijkmin2 );
+        int ijkmax = std::min( ijkmax1, ijkmax2 );
+
+        overlapRegion.start[ m ] = ijkmin;
+        overlapRegion.end  [ m ] = ijkmax;
+    }
+
+    return CheckOverLapping( overlapRegion );
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion )
+{
+    int index_dim = overlapRegion.start.size();
+    int iCount = 0;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        if ( overlapRegion.start[ m ] == overlapRegion.end[ m ] )
+        {
+            ++ iCount;
+        }
+    }
+
+    return ( iCount == 1 );
+}
+
+bool GetInterfaceRegion( RangeRegion & zoneBoxL, RangeRegion & zoneBoxR, RangeRegion & interfaceRegion )
+{
+    int index_dim = zoneBoxL.start.size();
+    int nDomains = 2 * index_dim;
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegionL;
+        GetDomainRegion( zoneBoxL, iDomain, domainRegionL );
+
+        for ( int jDomain = 0; jDomain < nDomains; ++ jDomain )
+        {
+            RangeRegion domainRegionR;
+            GetDomainRegion( zoneBoxR, jDomain, domainRegionR );
+
+            if ( domainRegionL == domainRegionR )
+            {
+                interfaceRegion = domainRegionL;
+                return true;
+            }
+        }
+    }
+    return false;
+}
+
+void CreateInterfaceBc( SplitZone * zoneL, SplitZone * zoneR )
+{
+    RangeRegion globalBoxL, globalBoxR, globalInterfaceRegion;
+
+    zoneL->GetZoneGlobalBox( globalBoxL );
+    zoneR->GetZoneGlobalBox( globalBoxR );
+
+    if ( ! GetInterfaceRegion( globalBoxL, globalBoxR, globalInterfaceRegion ) )
+    {
+        return;
+    }
+
+    RangeRegion localInterfaceRegionL, localInterfaceRegionR;
+
+    zoneL->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionL );
+    zoneR->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionR );
+
+    int kkk = 1;
+
+    InterfaceSplitBc * interfaceSplitBcL = new InterfaceSplitBc();
+    zoneL->interfaceSplitBcList.push_back( interfaceSplitBcL );
+    interfaceSplitBcL->zone = zoneL;
+    interfaceSplitBcL->region = localInterfaceRegionL;
+
+    int nSize = localInterfaceRegionL.start.size();
+
+    std::vector<int> transform;
+
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        transform.push_back( m + 1 );
+    }
+
+    interfaceSplitBcL->transform = transform;
+    interfaceSplitBcL->CalcTransformMatrix();
+
+    interfaceSplitBcL->donor_zone = zoneR;
+    interfaceSplitBcL->donor_region = localInterfaceRegionR;
+
+    InterfaceSplitBc * interfaceSplitBcR = new InterfaceSplitBc();
+    zoneR->interfaceSplitBcList.push_back( interfaceSplitBcR );
+
+    interfaceSplitBcR->zone = zoneR;
+    interfaceSplitBcR->region = localInterfaceRegionR;
+
+    interfaceSplitBcR->transform = transform;
+    interfaceSplitBcR->CalcTransformMatrix();
+
+    interfaceSplitBcR->donor_zone = zoneL;
+    interfaceSplitBcR->donor_region = localInterfaceRegionL;
+}
+
+
+PhysicalSplitBc::PhysicalSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+PhysicalSplitBc::~PhysicalSplitBc()
+{
+}
+
+void PhysicalSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void PhysicalSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+void PhysicalSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = splitZone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+BasicSplitBc::BasicSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+BasicSplitBc::~BasicSplitBc()
+{
+    ;
+}
+
+void BasicSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void BasicSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+int trans::M[ 3 ][ 3 ];
+std::vector<int> trans::transform;
+
+int trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void trans::CalcTransformMatrix()
+{
+    int dim = trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = trans::transform[ 0 ];
+        int sgna = trans::sgn( a );
+        int a1 = trans::del( a, 1 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int c = trans::transform[ 2 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int sgnc = trans::sgn( c );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int a3 = trans::del( a, 3 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        int b3 = trans::del( b, 3 );
+        int c1 = trans::del( c, 1 );
+        int c2 = trans::del( c, 2 );
+        int c3 = trans::del( c, 3 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 2 ][ 0 ] = sgna * a3;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+        trans::M[ 2 ][ 1 ] = sgnb * b3;
+        trans::M[ 0 ][ 2 ] = sgnc * c1;
+        trans::M[ 1 ][ 2 ] = sgnc * c2;
+        trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+InterfaceInfo::InterfaceInfo()
+{
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceInfo::~InterfaceInfo()
+{
+}
+
+InterfaceSplitBc::InterfaceSplitBc()
+{
+    this->region.Init( Dim::dim );
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceSplitBc::~InterfaceSplitBc()
+{
+}
+
+void InterfaceSplitBc::CopyMatrix( InterfaceSplitBc * interfaceSplitBc )
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = interfaceSplitBc->Mt[ i ][ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::CalcTransformMatrix()
+{
+    trans::ZeroMatrix();
+    trans::transform = this->transform;
+    trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = trans::M[ i ][ j ];
+        }
+    }
+
+}
+
+void InterfaceSplitBc::mapindex( std::vector<int> & begin1, std::vector<int> & begin2,  std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = Dim::dim;
+    std::vector<int> diff( dim );
+    for ( int m = 0; m < dim; ++ m )
+    {
+        diff[ m ] = index1[ m ] - begin1[ m ];
+    }
+
+    std::vector<int> mul( dim );
+
+    Multiply( Mt, diff, mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = mul[ m ] + begin2[ m ];
+    }
+}
+
+void InterfaceSplitBc::Multiply( int Mt[][3], std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = Dim::dim;
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = this->zone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void InterfaceSplitBc::CalcSubDonorRegion( RangeRegion &subRegion, RangeRegion &subDonorRegion )
+{
+    std::vector<int> begin1 = this->region.start;
+    std::vector<int> end1 = this->region.end;
+    std::vector<int> begin2 = this->donor_region.start;
+    std::vector<int> end2 = this->donor_region.end;
+
+    std::vector<int> new_begin1 = subRegion.start;
+    std::vector<int> new_end1 = subRegion.end;
+
+    int dim = Dim::dim;
+    std::vector<int> new_begin2( dim );
+    std::vector<int> new_end2( dim );
+
+    mapindex( begin1, begin2, new_begin1, new_begin2 );
+    mapindex( begin1, begin2, new_end1, new_end2 );
+
+    subDonorRegion.start = new_begin2;
+    subDonorRegion.end = new_end2;
+}
+
+SplitZone::SplitZone()
+{
+    this->parent  = 0;
+    this->zoneIndex = 0;
+    this->iProc = 0;
+    dimInfo.Init( Dim::dim );
+    int kk = 1;
+}
+
+SplitZone::~SplitZone()
+{
+    ;
+}
+
+void SplitZone::GetZoneGlobalBox( RangeRegion & zoneBox )
+{
+    this->dimInfo.GetZoneGlobalBox( zoneBox );
+}
+
+void SplitZone::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    this->dimInfo.GetZoneLocalBox( globalBox, localBox );
+}
+
+
+void SplitZone::ComputeRminmax()
+{
+    int index_dim = this->dimInfo.dimList.size();
+    std::vector<int> ref( index_dim, 0 );
+
+    SplitZone * rootSplitZone = 0;
+    this->GetRootInfo( rootSplitZone, ref );
+
+    this->dimInfo.ComputeRminmax( ref );
+}
+
+SplitZone * SplitZone::GetRootZone()
+{
+    SplitZone * root = this;
+
+    while ( true )
+    {
+        if ( root->parent )
+        {
+            root = root->parent;
+        }
+        else
+        {
+            return root;
+        }
+    };
+}
+
+void SplitZone::GetRootInfo( SplitZone *& root, std::vector<int> & ref )
+{
+    for ( int i = 0; i < this->dimInfo.dimList.size(); ++ i )
+    {
+        ref[ i ] += this->dimInfo.oriPoint[ i ];
+    }
+
+    if ( this->parent )
+    {
+        this->parent->GetRootInfo( root, ref );
+    }
+    else
+    {
+        root = this;
+    }
+}
+
+void SplitZone::SetParentAndChild( SplitZone * parent )
+{
+    this->parent = parent;
+    if ( parent )
+    {
+        parent->child.push_back( this );
+    }
+}
+
+
+int SplitZone::GetNCell()
+{
+    int numberOfCells = 1;
+    for ( int i = 0; i < this->dimInfo.dim; ++ i )
+    {
+        numberOfCells *= std::max( 1, ( this->dimInfo.dimList[ i ] - 1 ) );
+    }
+
+    return numberOfCells; 
+}
+
+void SplitZone::SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int leftStart = 0;
+    int leftWidth = iSplit - 0;
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, leftStart , leftWidth  );
+}
+
+void SplitZone::SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int rightStart = iSplit - 1;
+    int rightWidth = dimList[ axisNeedSplit ] - ( iSplit - 1 );
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, rightStart, rightWidth );
+}
+
+void SplitZone::Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell )
+{
+    //Find the longest axis
+    int axisNeedSplit = this->FindAxisNeedSplit();
+    int iSplit        = this->FindSplitPosition( axisNeedSplit, nCell );
+
+    zoneL->SetLeftDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+    zoneR->SetRightDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+
+    zoneL->CreateBcFromParent();
+    zoneR->CreateBcFromParent();
+    
+    CreateInterfaceBc( zoneL, zoneR );
+}
+
+void SplitZone::CreateBcFromParent()
+{
+    this->CreatePhysicalBcFromParent();
+    this->CreateInterfaceBcFromParent();
+}
+
+void SplitZone::CreatePhysicalBcFromParent()
+{
+    int nParentPhysicalBcs = this->parent->physicalSplitBcList.size();
+
+    for ( int iParentPhysicalBcs = 0; iParentPhysicalBcs < nParentPhysicalBcs; ++ iParentPhysicalBcs )
+    {
+        PhysicalSplitBc * parentPhysicalSplitBc = this->parent->physicalSplitBcList[ iParentPhysicalBcs ];
+
+        this->CreatePhysicalBcFromParent( parentPhysicalSplitBc );
+    }
+}
+
+void SplitZone::CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentPhysicalSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreatePhysicalBc( overlapRegion, parentPhysicalSplitBc->bcType );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent()
+{
+    int nInterfaceSplitBcs = this->parent->interfaceSplitBcList.size();
+
+    for ( int iInterfaceSplitBcs = 0; iInterfaceSplitBcs < nInterfaceSplitBcs; ++ iInterfaceSplitBcs )
+    {
+        InterfaceSplitBc * parentInterfaceSplitBc = this->parent->interfaceSplitBcList[ iInterfaceSplitBcs ];
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc );
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentInterfaceSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc, overlapRegion );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::FindDonorInterface( InterfaceSplitBc * interfaceSplitBc, InterfaceInfo & interfaceInfo )
+{
+    RangeRegion donor_region = interfaceSplitBc->donor_region;
+    donor_region.Normalize();
+    interfaceInfo.donor_zone = this;
+    for ( int iInterface = 0; iInterface < interfaceSplitBcList.size(); ++ iInterface )
+    {
+        InterfaceSplitBc * candidateDonorBc = interfaceSplitBcList[ iInterface ];
+        bool flag = donor_region.InRegion( candidateDonorBc->region );
+        if ( flag )
+        {
+            if ( donor_region == candidateDonorBc->region )
+            {
+                interfaceInfo.donor_interface = candidateDonorBc;
+                return;
+            }
+            else
+            {
+                InterfaceSplitBc * donorBc = new InterfaceSplitBc();
+                candidateDonorBc->child.push_back( donorBc );
+                donorBc->region = donor_region;
+                donorBc->zone = candidateDonorBc->zone;
+                donorBc->donor_zone = interfaceSplitBc->zone;
+                donorBc->transform = candidateDonorBc->transform;
+                donorBc->CopyMatrix( candidateDonorBc );
+                RangeRegion subDonorRegion( Dim::dim );
+                candidateDonorBc->CalcSubDonorRegion( donorBc->region, subDonorRegion );
+                std::vector<int> & oriPoint = interfaceSplitBc->zone->dimInfo.oriPoint;
+                subDonorRegion.Localize( oriPoint );
+                donorBc->donor_region = subDonorRegion;
+                donorBc->donor_bc = interfaceSplitBc;
+                interfaceInfo.donor_interface = donorBc;
+                return;
+            }
+        }
+    }
+    return;
+}
+
+void SplitZone::GetChildDonorRegion( RangeRegion & subDonorRegion, InterfaceInfo & interfaceInfo )
+{
+    std::cout << "subDonorRegion = \n";
+    //subDonorRegion.Print();
+    RangeRegion normalizedDonorRegion = subDonorRegion;
+    normalizedDonorRegion.Normalize();
+    int nChild = this->child.size();
+    for ( int ichild = 0; ichild < nChild; ++ ichild )
+    {
+        std::cout << " iChild = " << ichild << " nChild = " << nChild << "\n";
+        SplitZone * sub_zone = this->child[ ichild ];
+        std::cout << " zoneIndex = " << sub_zone->zoneIndex << "\n";
+        int nInters = sub_zone->interfaceSplitBcList.size();
+        for ( int iInter = 0; iInter < nInters; ++ iInter )
+        {
+            std::cout << " iInter = " << iInter << "\n";
+            InterfaceSplitBc * interfaceSplitBc = sub_zone->interfaceSplitBcList[ iInter ];
+            std::cout << "interfaceSplitBc local = \n";
+            interfaceSplitBc->region.Print();
+            std::cout << "interfaceSplitBc global = \n";
+            interfaceSplitBc->region.PrintGlobal( sub_zone->dimInfo.oriPoint );
+            RangeRegion g_region = interfaceSplitBc->region;
+            g_region.ToGlobal( sub_zone->dimInfo.oriPoint );
+            if ( g_region == normalizedDonorRegion )
+            {
+                RangeRegion donorRegion = subDonorRegion;
+                donorRegion.ToLocal( sub_zone->dimInfo.oriPoint );
+
+                interfaceInfo.donor_zone = sub_zone;
+                interfaceInfo.donor_interface = interfaceSplitBc;
+                interfaceInfo.donor_region = donorRegion;
+                return;
+            }
+        }
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion )
+{
+    InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+    this->interfaceSplitBcList.push_back( interfaceSplitBc );
+
+    interfaceSplitBc->region = overlapRegion;
+    interfaceSplitBc->zone = this;
+    interfaceSplitBc->transform = parentInterfaceSplitBc->transform;
+    interfaceSplitBc->CopyMatrix( parentInterfaceSplitBc );
+    RangeRegion subDonorRegion( Dim::dim );
+    parentInterfaceSplitBc->CalcSubDonorRegion( overlapRegion, subDonorRegion );
+    interfaceSplitBc->ChangeRegionToLocalCoordinate();
+    interfaceSplitBc->donor_region = subDonorRegion;
+    SplitZone * parent_donor_zone = parentInterfaceSplitBc->donor_zone;
+    std::cout << " parentInterfaceSplitBc->zone->zoneIndex " << parentInterfaceSplitBc->zone->zoneIndex << "\n";
+    std::cout << " parentInterfaceSplitBc->donor_zone->zoneIndex " << parent_donor_zone->zoneIndex << "\n";
+    if ( parent_donor_zone->child.size() > 0 )
+    {
+        InterfaceInfo interfaceInfo;
+        parent_donor_zone->GetChildDonorRegion( subDonorRegion, interfaceInfo );
+        interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+        interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+        interfaceSplitBc->donor_region = interfaceInfo.donor_region;
+        //compatibility
+        InterfaceSplitBc * donor_bc = interfaceSplitBc->donor_bc;
+        SplitZone * donor_zone = interfaceSplitBc->donor_zone;
+        if ( interfaceSplitBc->zone != donor_bc->donor_zone )
+        {
+            if ( interfaceSplitBc->zone->parent == donor_bc->donor_zone )
+            {
+                RangeRegion d_region = donor_bc->donor_region;
+                d_region.ToLocal( interfaceSplitBc->zone->dimInfo.oriPoint );
+                donor_bc->donor_region = d_region;
+            }
+            donor_bc->donor_zone = interfaceSplitBc->zone;
+         
+            int kkk = 1;
+        }
+        int kkk = 1;
+    }
+    else
+    {
+        InterfaceInfo interfaceInfo;
+        parent_donor_zone->FindDonorInterface( interfaceSplitBc, interfaceInfo );
+        interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+        interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+    }
+    
+    int kkk = 1;
+}
+
+void SplitZone::CreatePhysicalBc( RangeRegion & overlapRegion, int bcType )
+{
+    PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+    this->physicalSplitBcList.push_back( physicalSplitBc );
+    physicalSplitBc->SetRegion( overlapRegion );
+    physicalSplitBc->bcType = bcType;
+    physicalSplitBc->splitZone = this;
+    physicalSplitBc->ChangeRegionToLocalCoordinate();
+}
+
+int SplitZone::FindAxisNeedSplit()
+{
+    //Find the longest axis
+    int axisNeedSplit = 0;
+    int maxN = this->dimInfo.dimList[ 0 ];
+
+    for ( int m = 1; m < this->dimInfo.dimList.size(); ++ m )
+    {
+        if ( this->IsPoleBc( m ) )
+        {
+            continue;
+        }
+        int Nm = this->dimInfo.dimList[ m ];
+        if ( maxN < Nm )
+        {
+            maxN = Nm;
+            axisNeedSplit = m;
+        }
+    }
+
+    return axisNeedSplit;
+}
+
+int SplitZone::GetCrossSection( int axis )
+{
+    int nDim = this->dimInfo.dimList.size();
+    int crossSection = 1;
+    int N = nDim - 1;
+    for ( int m = 0; m < N; ++ m )
+    {
+         int mm = ( axis + 1 ) % nDim;
+         int nLineElements = std::max( 1, ( this->dimInfo.dimList[ mm ] - 1 ) );
+         crossSection *= nLineElements;
+    }
+    return crossSection;
+}
+
+int SplitZone::FindSplitPosition( int axisNeedSplit, double nCell )
+{
+    int nDim = this->dimInfo.dimList.size();
+    std::vector<int> crossSections( nDim );
+    for ( int m = 0; m < nDim; ++ m )
+    {
+        crossSections[ m ] = this->GetCrossSection( m );
+    }
+
+    //guess the value
+    double dSplit = nCell / crossSections[ axisNeedSplit ];
+    int  iSplit = 1 + static_cast< int >( std::floor( dSplit + 0.5 ) );
+    return iSplit;
+}
+
+
+bool SplitZone::IsPoleBc( int splitDirection )
+{
+    return false;
+}
+
diff --git a/example/partition/struct/2d/stage2/01e/SplitZone.h b/example/partition/struct/2d/stage2/01e/SplitZone.h
new file mode 100644
index 00000000..6ba99614
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01e/SplitZone.h
@@ -0,0 +1,194 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class Dim
+{
+public:
+    static int dim;
+};
+
+class SplitZone;
+class RangeRegion;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox );
+
+class DimInfo
+{
+public:
+    DimInfo();
+    ~DimInfo();
+public:
+    int dim;
+    std::vector<int> dimList;
+    std::vector<int> oriPoint;
+    std::vector<int> isize;
+    std::vector<int> rmin;
+    std::vector<int> rmax;
+public:
+    int GetSize() const { return dim; }
+    DimInfo & operator = ( const DimInfo & rhs );
+public:
+    int ComputeNumNodes();
+    void ComputeISize();
+    void ComputeRminmax( std::vector<int> & ref );
+    void Init( int dim );
+    void Init( std::vector<int> & dimList );
+    void SetNewDimension( int axis, int newStart, int newWidth );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+};
+
+class SplitZone;
+class SplitBcPatch;
+
+class RangeRegion
+{
+public:
+    RangeRegion( int nSize = 1 );
+    ~RangeRegion();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    void Init( int nSize );
+    RangeRegion & operator = ( const RangeRegion & rhs );
+    bool operator == ( const RangeRegion & rhs ) const;
+    bool InRegion( const RangeRegion & region );
+    void SetRegion( std::vector<int> &pnts );
+    void Normalize();
+    void Localize( std::vector<int> & oriPoint );
+    void ToGlobal( std::vector<int> & oriPoint );
+    void ToLocal( std::vector<int> & oriPoint );
+    void PrintGlobal( std::vector<int> & oriPoint );
+    void Print();
+};
+
+class PhysicalSplitBc
+{
+public:
+    PhysicalSplitBc();
+    ~PhysicalSplitBc();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class BasicSplitBc
+{
+public:
+    BasicSplitBc();
+    ~BasicSplitBc();
+public:
+    RangeRegion region;
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> & pnts );
+    void SetRegion( RangeRegion & region );
+};
+
+class trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class InterfaceSplitBc;
+class SplitZone;
+
+class InterfaceInfo
+{
+public:
+    InterfaceInfo();
+    ~InterfaceInfo();
+public:
+    InterfaceSplitBc * donor_interface = nullptr;
+    SplitZone * donor_zone = nullptr;
+    RangeRegion donor_region;
+};
+
+class InterfaceSplitBc
+{
+public:
+    InterfaceSplitBc();
+    ~InterfaceSplitBc();
+public:
+    std::vector<int> transform;
+    int Mt[ 3 ][ 3 ];
+    RangeRegion region;
+    SplitZone * zone = nullptr;
+    RangeRegion donor_region;
+    SplitZone * donor_zone = nullptr;
+    InterfaceSplitBc * donor_bc = nullptr;
+public:
+    std::vector<InterfaceSplitBc *> child;
+public:
+    void CopyMatrix( InterfaceSplitBc * interfaceSplitBc );
+    void CalcTransformMatrix();
+    void CalcSubDonorRegion( RangeRegion & subRegion, RangeRegion & subDonorRegion );
+    void mapindex( std::vector<int> & begin1, std::vector<int> & begin2, std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( int Mt[][ 3 ], std::vector<int> & a, std::vector<int> & b );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class SplitZone
+{
+public:
+    SplitZone();
+    ~SplitZone();
+public:
+    DimInfo dimInfo;
+    int zoneIndex, iProc;
+    int newIndex;
+protected:
+    SplitZone * parent;
+    std::vector<SplitZone *> child;
+public:
+    std::vector< PhysicalSplitBc * > physicalSplitBcList;
+    std::vector< InterfaceSplitBc * > interfaceSplitBcList;
+public:
+    int GetNCell();
+    void ComputeRminmax();
+    void GetRootInfo( SplitZone *& root, std::vector<int> & ref );
+    void SetZoneIndex( int zoneIndex ) { this->zoneIndex = zoneIndex; }
+    int  GetZoneIndex() { return zoneIndex; }
+    void SetProcId( int iProc ) { this->iProc = iProc; }
+    void SetParent( SplitZone * parent ) { this->parent = parent; };
+    void SetParentAndChild( SplitZone * parent );
+    void FindDonorInterface( InterfaceSplitBc * interfaceSplitBc, InterfaceInfo & interfaceInfo );
+    void GetChildDonorRegion( RangeRegion & subDonorRegion, InterfaceInfo & interfaceInfo );
+public:
+    void CreateBcFromParent();
+    void CreatePhysicalBcFromParent();
+    void CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc );
+    void CreatePhysicalBc( RangeRegion & overlapRegion, int bcType );
+    void CreateInterfaceBcFromParent();
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc );
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion );
+
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+    SplitZone * GetRootZone();
+public:
+    void Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell );
+    void SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+    void SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+private:
+    int FindAxisNeedSplit();
+    int FindSplitPosition( int axisNeedSplit, double nCell );
+    bool IsPoleBc( int splitDirection );
+    int GetCrossSection( int axis );
+};
+
diff --git a/example/partition/struct/2d/stage2/01e/heat2d2blocksv6.cgns b/example/partition/struct/2d/stage2/01e/heat2d2blocksv6.cgns
new file mode 100644
index 00000000..3c06915e
Binary files /dev/null and b/example/partition/struct/2d/stage2/01e/heat2d2blocksv6.cgns differ
diff --git a/example/partition/struct/2d/stage2/01e/heat2dpart.cgns b/example/partition/struct/2d/stage2/01e/heat2dpart.cgns
new file mode 100644
index 00000000..f7de0491
Binary files /dev/null and b/example/partition/struct/2d/stage2/01e/heat2dpart.cgns differ
diff --git a/example/partition/struct/2d/stage2/01e/main.cpp b/example/partition/struct/2d/stage2/01e/main.cpp
new file mode 100644
index 00000000..5da1de7c
--- /dev/null
+++ b/example/partition/struct/2d/stage2/01e/main.cpp
@@ -0,0 +1,18 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include "Partition.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip>
+
+int main(int argc, char **argv)
+{
+    Partition * partition = new Partition();
+    partition->Solve();
+    delete partition;
+
+    return 0;
+}
diff --git a/example/partition/struct/2d/stage3/01/CMakeLists.txt b/example/partition/struct/2d/stage3/01/CMakeLists.txt
new file mode 100644
index 00000000..74ceea7d
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01/CMakeLists.txt
@@ -0,0 +1,78 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	Partition.h Partition.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	SplitZone.h SplitZone.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/partition/struct/2d/stage3/01/CgnsGrid.cpp b/example/partition/struct/2d/stage3/01/CgnsGrid.cpp
new file mode 100644
index 00000000..dfe750bd
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01/CgnsGrid.cpp
@@ -0,0 +1,349 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include <map>
+
+Grid::Grid()
+{
+    ;
+}
+
+Grid::~Grid()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if( (i+1)%5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+    delete this->patch;
+}
+
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+ZoneBcPatch::ZoneBcPatch()
+{
+    ;
+}
+
+ZoneBcPatch::~ZoneBcPatch()
+{
+}
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+Global::Global()
+{
+    ;
+}
+
+Global::~Global()
+{
+}
+
+void Global::FreeData()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+    zones.resize( 0 );
+}
+
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            //baseZone.baseId = baseId;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin( index_dim );
+            std::vector<cgsize_t> irmax( index_dim );
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                std::vector<char> coord( nNodes * sizeof(double) );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+                coor->DumpCoor();
+            }
+
+            int nbocos = -1;
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+                int kkk = 1;
+            }
+        }
+        int kkk = 1;
+    }
+    int kkk = 1;
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage3/01/CgnsGrid.h b/example/partition/struct/2d/stage3/01/CgnsGrid.h
new file mode 100644
index 00000000..053c467b
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01/CgnsGrid.h
@@ -0,0 +1,140 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <map>
+
+class Grid;
+
+class Zone;
+
+class Grid
+{
+public:
+    Grid();
+    ~Grid();
+public:
+    int nZone;
+    std::vector<double> x;
+    std::vector<Zone *> zones;
+};
+
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+};
+
+class ZoneBc;
+class ZoneBc1To1;
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class ZoneBcPatch;
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+    ZoneBcPatch * patch = nullptr;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+class ZoneBcPatch
+{
+public:
+    ZoneBcPatch();
+    ~ZoneBcPatch();
+public:
+    int donor_zoneid;
+    std::vector<int> transform;
+    std::vector<int> donor_pnts;
+};
+
+class BaseZone
+{
+public:
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Global
+{
+public:
+    Global();
+    ~Global();
+public:
+    static int cell_dim;
+    static int phys_dim;
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+public:
+    static void FreeData();
+};
+
+void ReadCgnsGrid( const std::string & filename );
+void ReadCgnsGridBaseZone( const std::string & filename );
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage3/01/Partition.cpp b/example/partition/struct/2d/stage3/01/Partition.cpp
new file mode 100644
index 00000000..5deeaf02
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01/Partition.cpp
@@ -0,0 +1,618 @@
+#include "Partition.h"
+#include "CgnsGrid.h"
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+bool CmpSplitZone::operator() ( SplitZone * a, SplitZone * b ) const
+{
+    return a->zoneIndex < b->zoneIndex;
+};
+
+
+double CalSumOfProcSpeed( std::vector<double> & procSpeed );
+double CalSumOfProcSpeed( std::vector<double> & procSpeed )
+{
+    int nProc = procSpeed.size();
+    double sumOfProcSpeed = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        sumOfProcSpeed += procSpeed[ iProc ];
+    }
+    return sumOfProcSpeed;
+}
+
+Partition::Partition()
+{
+    this->inputName = "../heat2d1blockv1.cgns";
+    this->outName =  "../heat2dpart.cgns";
+}
+
+Partition::~Partition()
+{
+    ;
+}
+
+int Partition::GetMinValueIndex( double * data, int numberOfData )
+{
+    double minValue = data[ 0 ];
+    int minimumValueIndex = 0;
+
+    for ( int iData = 1; iData < numberOfData; ++ iData )
+    {
+        if ( minValue > data[ iData ] )
+        {
+            minValue      = data[ iData ];
+            minimumValueIndex = iData;
+        }
+    }
+    return minimumValueIndex;
+}
+
+int Partition::GetMinLoadProc()
+{
+    return this->GetMinValueIndex( this->timeProc.data(), this->nProc );
+}
+
+SplitZone * Partition::GetLargestZone()
+{
+    SplitZone * largestZone = 0;
+
+    double nMaxCell = 0.0;
+
+    for ( std::set< SplitZone * >::iterator iter = unsignedZoneGroup.begin(); iter != unsignedZoneGroup.end(); ++ iter )
+    {
+        double nSize = ( * iter )->GetNCell();
+        if ( nMaxCell < nSize )
+        {
+            nMaxCell    = nSize;
+            largestZone = * iter;
+        }
+    }
+
+    return largestZone;
+}
+
+void Partition::Solve()
+{
+    std::cout << "Partition::Split()\n";
+    this->nProc = 2;
+    //this->nProc = 16;
+    this->ReadGrid();
+    this->Split();
+    this->DumpPartitionedGridFile();
+    this->FreeAllZones();
+}
+
+void Partition::ReadGrid()
+{
+    ReadCgnsGridBaseZone( this->inputName );
+    ReadCgnsGrid( this->inputName );
+
+    this->nOriZone = ::Global::zones.size();
+    Dim::dim = Global::cell_dim;
+
+    std::cout << "numberOfBlocks = " << nOriZone << "\n";
+
+    this->refZone.resize( nOriZone );
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = new SplitZone();
+        refZone[ iZone ] = splitZone;
+
+        splitZone->SetZoneIndex( iZone );
+        splitZone->SetProcId( 0 );
+        splitZone->SetParentAndChild( 0 );
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        Zone * zone = ::Global::zones[ iZone ];
+
+        splitZone->dimInfo.dimList = zone->nijk;
+
+        int nbccos = zone->bccos.size();
+        std::cout << "nbccos = " << nbccos << "\n";
+
+        for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+        {
+            ZoneBc * zoneBc = zone->bccos[ ibcco ];
+
+            PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+            splitZone->physicalSplitBcList.push_back( physicalSplitBc );
+            physicalSplitBc->bcType = zoneBc->bcType;
+            physicalSplitBc->SetRegion( zoneBc->pnts );
+            physicalSplitBc->splitZone = splitZone;
+        }
+
+        int nbc1to1s = zone->bc1to1s.size();
+
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * zoneBc1To1 = zone->bc1to1s[ ibc1to1 ];
+
+            InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+            splitZone->interfaceSplitBcList.push_back( interfaceSplitBc );
+            interfaceSplitBc->zone = splitZone;
+            interfaceSplitBc->region.SetRegion( zoneBc1To1->pnts );
+
+            interfaceSplitBc->transform = zoneBc1To1->transform;
+            interfaceSplitBc->CalcTransformMatrix();
+
+            interfaceSplitBc->donor_zone = refZone[ zoneBc1To1->donor_zoneid ];
+            interfaceSplitBc->donor_region.SetRegion( zoneBc1To1->donor_pnts );
+        }
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        int nbc1to1s = splitZone->interfaceSplitBcList.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            InterfaceSplitBc * interfaceSplitBc = splitZone->interfaceSplitBcList[ ibc1to1 ];
+            InterfaceInfo interfaceInfo;
+            interfaceSplitBc->donor_zone->FindDonorInterface( interfaceSplitBc, interfaceInfo );
+            interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+            interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+        }
+    }
+}
+
+void Partition::Split()
+{
+    this->InitSplit();
+    this->BinarySplit();
+    this->ModifyZoneIndex();
+    int kkk = 1;
+}
+
+void Partition::InitSplit()
+{
+    //nZone is the number of zones in the original grid
+    //nProc is not the number of blocks in the end, but the number of processes that need to be divided.
+    //This difference occurs because the structure grid can have many blocks per process.
+
+    //this->nProc    = nProc;
+    //this->nPhyBlocks = referenceBlock.size();
+    //this->nZone  = this->nPhyBlocks;
+
+    //tj Computation time on processor j
+    //Nk Number of internal grid-cells for zone j
+    //aveFloatOp:  Number of Real operations per gridcell
+    //Gj The set of blocks allocated to process j
+    //Pj Real operations per second for process j
+
+    //The Greedy Load Balancing Algorithm
+    //1.Compute an "ideal" uniprocessor time, Tuni = sum ( Nk * aveFloatOp )/ sum( Pj ).
+    //2.Set the group of unassigned blocks, Gu, to contain all blocks. The number of blocks in Nu=M, where M is the total number of blocks in the mesh.
+    //3.Start all processors with a very small fictitious zone to get a start tj=delt aveFloatOp/Pj, where delt<<1 is the size of the very small fictious zone.
+    //This is used to find the fastest processor in a heterogeneous system, tj could otherwise be set to 0 in the homogeneous case.
+    this->aveFloatOp = 1.0;
+    this->delta      = 1.0e-5;
+    this->procSpeed.resize( nProc );
+    this->timeProc.resize( nProc );
+
+    this->nTZone = this->nOriZone;
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        procSpeed[ iProc ] = 1.0;
+    }
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        timeProc[ iProc ] = delta * aveFloatOp / procSpeed[ iProc ];
+    }
+
+    double sumProcSpeed = CalSumOfProcSpeed( procSpeed );
+
+    double sumProcOp = 0.0;
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        sumProcOp += refZone[ iZone ]->GetNCell() * aveFloatOp;
+    }
+
+    this->idealUniProcTime = sumProcOp / sumProcSpeed;
+
+    this->eps = 0.05;
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        unsignedZoneGroup.insert( refZone[ iZone ] );
+    }
+
+    //Init zoneStorage
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        zoneStorage.insert( refZone[ iZone ] );
+    }
+
+    //Assign procSplitZone to each process
+    procSplitZone.resize( nProc );
+
+    this->minNumberCell = 1;
+    for ( int m = 0; m < Dim::dim; ++ m )
+    {
+        this->minNumberCell *= 1;
+    }
+
+    int kkk = 1;
+
+}
+
+void Partition::FreeAllZones()
+{
+    int iCount = 0;
+    for ( std::set < SplitZone * >::iterator iter = zoneStorage.begin(); iter != zoneStorage.end(); ++ iter )
+    {
+        //cout << "iCount = " << iCount << "\n";
+        ++ iCount;
+        delete * iter;
+    }
+}
+
+int Partition::GetNZones( int iProc )
+{
+    return this->procSplitZone[ iProc ].size();
+}
+
+SplitZone * Partition::GetSplitZone( int iProc, int zoneId )
+{
+    return this->procSplitZone[ iProc ][ zoneId ];
+}
+
+void Partition::AddZoneToUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.insert( zone );
+}
+
+void Partition::RemoveZoneFromUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.erase( zone );
+}
+
+void Partition::AddZoneToProcess( int iProc, SplitZone * zone )
+{
+    this->procSplitZone[ iProc ].push_back( zone );
+}
+
+void Partition::AddNewZone( SplitZone * zone )
+{
+    zone->SetZoneIndex( nTZone ++ );
+
+    this->AddZoneToUnsignedGroup( zone );
+
+    this->zoneStorage.insert( zone );
+}
+
+SplitZone * Partition::Split( SplitZone * zone, double nCell )
+{
+    SplitZone * zoneL = new SplitZone();
+    zoneL->SetParentAndChild( zone );
+
+    SplitZone * zoneR = new SplitZone();
+    zoneR->SetParentAndChild( zone );
+
+    //Remove the original block from the UnsignedGroup
+    this->RemoveZoneFromUnsignedGroup( zone );
+
+    this->AddNewZone( zoneL );
+    this->AddNewZone( zoneR );
+
+    zone->Split( zoneL, zoneR, nCell );
+
+    return zoneL;
+}
+
+void Partition::BinarySplit()
+{
+    while ( ! unsignedZoneGroup.empty() )
+    {
+        std::cout << "number of unsigned zone = " << unsignedZoneGroup.size() << "\n";
+        int iProc = this->GetMinLoadProc();
+
+        //Get the block with the largest number of grids and its size
+        SplitZone * largestZone = this->GetLargestZone();
+
+        double nMaxCell = largestZone->GetNCell();
+
+        double aveFloatOp = this->aveFloatOp;
+        double tau = timeProc[ iProc ] + nMaxCell * aveFloatOp / procSpeed[ iProc ];
+
+        //It seems that EPS is still necessary
+        //The idea here is as follows. For the candidate blocks which can be divided into blocks, 
+        //if the difference between the target blocks and the candidate blocks is too wide, 
+        //the binarySplit method is adopted. The binarySplit blocks do not directly join the process,
+        //but enter the next round of screening.
+
+        if ( tau > idealUniProcTime * ( 1.0 + eps ) )
+        {
+            double nRest = ( tau - idealUniProcTime ) * procSpeed[ iProc ] / aveFloatOp;
+
+            double nTarget = nMaxCell - nRest;
+            if ( nRest > this->minNumberCell && nTarget > this->minNumberCell )
+            {
+                //It is necessary to divide blocks only when a certain number of points are satisfied.
+                double nHalf = nMaxCell / 2.0;
+                nMaxCell = nTarget;
+                double ratio = nMaxCell / nRest;
+                double oRatio = 1.0 / ratio;
+
+                if ( std::max( ratio, oRatio ) < 3.0 )
+                {
+                    int kkk = 1;
+                    largestZone = this->Split( largestZone, nMaxCell );
+                    timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                    this->RemoveZoneFromUnsignedGroup( largestZone );
+                    this->AddZoneToProcess( iProc, largestZone );
+                }
+                else
+                {
+                    this->Split( largestZone, nHalf );
+                }
+            }
+            else
+            {
+                //If the block is of the right size, join the process directly, and there is no need to split it.
+                timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                this->RemoveZoneFromUnsignedGroup( largestZone );
+                this->AddZoneToProcess( iProc, largestZone );
+            }
+        }
+        else
+        {
+            //If the block is of the right size, join the process directly, and there is no need to split it.
+            timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+            this->RemoveZoneFromUnsignedGroup( largestZone );
+            this->AddZoneToProcess( iProc, largestZone );
+        }
+    }
+}
+
+void Partition::ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord )
+{
+    SplitZone * rootSplitZone = splitZone->GetRootZone();
+    Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+    int nNodes = splitZone->dimInfo.ComputeNumNodes();
+    std::cout << "nNodes = " << nNodes << "\n";
+
+    coord.resize( nNodes * sizeof(double) );
+
+    int index_dim = splitZone->dimInfo.dimList.size();
+    Coor * coor = zone->coors[ icoord ];
+
+    double * xlocal = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    double * xglobal = reinterpret_cast<double *>( const_cast<char *>( coor->coord.data() ) );
+    if ( index_dim == 1 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        for ( int i = imin; i < imax; ++ i )
+        {
+            xlocal[ icount++ ] = xglobal[ i ];
+        }
+    }
+    else if ( index_dim == 2 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        int jmin = splitZone->dimInfo.rmin[ 1 ] - 1;
+        int jmax = splitZone->dimInfo.rmax[ 1 ];
+        int ni = rootSplitZone->dimInfo.dimList[ 0 ];
+        int nj = rootSplitZone->dimInfo.dimList[ 1 ];
+        for ( int j = jmin; j < jmax; ++ j )
+        {
+            int jstride = j * ni;
+            for ( int i = imin; i < imax; ++ i )
+            {
+                xlocal[ icount++ ] = xglobal[ jstride + i ];
+            }
+        }
+    }
+}
+
+void Partition::DumpBc( SplitZone * splitZone )
+{
+}
+
+void Partition::DumpPartitionedGridFile()
+{
+    std::cout << "\n";
+    std::cout << "DumpPartitionedGridFile -------------------------------" << "\n";
+    std::cout << "\n";
+    int fileId = -1;
+    std::string filename = this->outName;
+    int ierr = cg_open( filename.c_str(), CG_MODE_WRITE, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+
+    std::vector<std::string> coordnames;
+    coordnames.push_back( "CoordinateX" );
+    coordnames.push_back( "CoordinateY" );
+    coordnames.push_back( "CoordinateZ" );
+
+    std::string basename = "Base";
+    int baseId = -1;
+    int icelldim = Global::cell_dim;
+    int iphysdim = Global::phys_dim;
+    cg_base_write( fileId, basename.c_str(), icelldim, iphysdim, &baseId );
+
+    std::cout << "baseId = " << baseId << "\n";
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        int nZones = this->GetNZones( iProc );
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            ZoneType_t zoneType = Structured;
+
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+
+            int index_dim = splitZone->dimInfo.dimList.size();
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            splitZone->dimInfo.ComputeISize();
+
+            int isize_dim = index_dim * 3;
+
+            std::vector<cgsize_t> isize( index_dim * 3, 0 );
+            for ( int m = 0; m < isize_dim; ++ m )
+            {
+                isize[ m ] = splitZone->dimInfo.isize[ m ];
+            }
+
+            int zoneId = -1;
+
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+
+            std::string zonename = "Zone" + std::to_string( splitZone->newIndex );
+
+            cg_zone_write( fileId, baseId, zonename.c_str(), isize.data(), zoneType, &zoneId );
+
+            std::cout << "zoneId = " << zoneId << "\n";
+            std::cout << "zonename = " << zonename << "\n";
+                
+            splitZone->ComputeRminmax();
+
+            SplitZone * rootSplitZone = splitZone->GetRootZone();
+
+            Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+            int ncoords = zone->coors.size();
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = -1;
+                DataType_t dataType = RealDouble;
+                std::string coordname = coordnames[ icoord ];
+                Coor * coor = zone->coors[ icoord ];
+
+                int nNodes = splitZone->dimInfo.ComputeNumNodes();
+                std::cout << "nNodes = " << nNodes << "\n";
+
+                std::vector<char> coord;
+                ComputeCoor( splitZone, icoord, coord );
+
+                cg_coord_write( fileId, baseId, zoneId, dataType, coordname.c_str(), coord.data(), &coorId );
+
+                std::cout << "fileId = " << fileId  << " baseId = " << baseId << " zoneId = " << zoneId  << " coorId = " << coorId << "\n";
+            }
+
+            std::vector< PhysicalSplitBc * > &bccoList = splitZone->physicalSplitBcList;
+
+            int nbocos = bccoList.size();
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = -1;
+                GridLocation_t location = Vertex;
+
+                std::string boconame = "BC" + std::to_string( iboco + 1 );
+
+                PhysicalSplitBc * physicalSplitBc = bccoList[ iboco ];
+                BCType_t bocotype = static_cast<BCType_t>( physicalSplitBc->bcType );
+                PointSetType_t ptset_type = PointRange;
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> pnts;
+                int nSize = physicalSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.end[ i ] );
+                }
+
+                cg_boco_write( fileId, baseId, zoneId, boconame.c_str(), bocotype, ptset_type, npnts, pnts.data(), & bccoId );
+            }
+
+            std::vector< InterfaceSplitBc * > & bc1to1List = splitZone->interfaceSplitBcList;
+
+            int n1to1 = bc1to1List.size();
+            std::cout << "n1to1 = " << n1to1 << "\n";
+
+            std::vector<int> itranfrm( index_dim );
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                itranfrm[ m ] = m + 1;
+            }
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int index_conn = -1;
+
+                InterfaceSplitBc * interfaceSplitBc = bc1to1List[ i1to1 ];
+
+                std::vector<cgsize_t> pnts;
+                std::vector<cgsize_t> pntsdonor;
+                int nSize = interfaceSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.end[ i ] );
+                }
+
+                int nPatchSize = interfaceSplitBc->donor_region.start.size();
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.start[ i ] );
+                }
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.end[ i ] );
+                }
+                int id = interfaceSplitBc->donor_zone->newIndex;
+                int oldZoneIndex = interfaceSplitBc->donor_zone->zoneIndex;
+                std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+                std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+                std::cout << "donor zone id = " << id << "\n";
+                std::cout << "donor zone oldZoneIndex = " << oldZoneIndex << "\n";
+                std::string donorname = "Zone" + std::to_string( id );
+                std::string connectname = "Interface" + std::to_string( i1to1 );
+
+                std::cout << "donorname = " << donorname << "\n";
+                std::cout << "connectname = " << connectname << "\n";
+
+                std::vector<int> & itranfrm = interfaceSplitBc->transform;
+
+                cg_1to1_write( fileId, baseId, zoneId, connectname.c_str(), donorname.c_str(), pnts.data(), pntsdonor.data(), itranfrm.data(), &index_conn );
+                std::cout << "index_conn = " << index_conn << "\n";
+            }
+        }
+    }
+    cg_close( fileId );
+}
+
+void Partition::ModifyZoneIndex()
+{
+    std::cout << "ModifyZoneIndex +++++++++++++++++++++++++ " << "\n";
+    int globalZoneId = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        std::cout << "iProc = " << iProc << "\n";
+        int nZones = this->GetNZones( iProc );
+        std::cout << "nZones in Proc " << iProc << "  = " << nZones << "\n";
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+            //splitZone->SetZoneIndex( globalZoneId++ );
+            splitZone->newIndex = ( globalZoneId++ );
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+        }
+    }
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage3/01/Partition.h b/example/partition/struct/2d/stage3/01/Partition.h
new file mode 100644
index 00000000..8a4a9731
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01/Partition.h
@@ -0,0 +1,59 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class SplitZone;
+
+struct CmpSplitZone 
+{
+    bool operator() ( SplitZone * a, SplitZone * b ) const;
+};
+
+class Partition
+{
+public:
+    Partition();
+    ~Partition();
+protected:
+    std::set < SplitZone * > zoneStorage;
+    std::set < SplitZone *, CmpSplitZone > unsignedZoneGroup;
+    std::vector< SplitZone * > refZone;
+    std::vector< std::vector< SplitZone * > > procSplitZone;
+    std::vector<double> procSpeed;
+    std::vector<double> timeProc;
+    double aveFloatOp, delta;
+    double idealUniProcTime, eps;
+    int minNumberCell;
+    int nTZone;
+    int nOriZone;
+    int nProc;
+public:
+    std::string inputName;
+    std::string outName;
+public:
+    void Solve();
+    void ReadGrid();
+    void Split();
+    void InitSplit();
+    void BinarySplit();
+    //void GreedySplit();
+public:
+    void AddNewZone( SplitZone * zone );
+    void AddZoneToUnsignedGroup( SplitZone * zone );
+    void RemoveZoneFromUnsignedGroup( SplitZone * zone );
+    void AddZoneToProcess( int iProc, SplitZone * zone );
+    void DumpPartitionedGridFile();
+    void ModifyZoneIndex();
+    void FreeAllZones();
+    int GetNZones( int iProc );
+    SplitZone * GetSplitZone( int iProc, int zoneId );
+    void ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord );
+    void DumpBc( SplitZone * splitZone );
+private:
+    int GetMinValueIndex( double * data, int numberOfData );
+    int GetMinLoadProc();
+    SplitZone * GetLargestZone();
+    SplitZone * Split( SplitZone * zone, double nCell );
+};
+
diff --git a/example/partition/struct/2d/stage3/01/README.txt b/example/partition/struct/2d/stage3/01/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/partition/struct/2d/stage3/01/SplitZone.cpp b/example/partition/struct/2d/stage3/01/SplitZone.cpp
new file mode 100644
index 00000000..e7ffa1b3
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01/SplitZone.cpp
@@ -0,0 +1,1065 @@
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+int Dim::dim = -1;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox  )
+{
+    domainBox.start = zoneBox.start;
+    domainBox.end = zoneBox.end;
+
+    int axis = iDomain / 2;
+    int direction = iDomain % 2;
+
+    if ( direction == 0 )
+    {
+        domainBox.end[ axis ] = domainBox.start[ axis ];
+    }
+    else if ( direction == 1 )
+    {
+        domainBox.start[ axis ] = domainBox.end[ axis ];
+    }
+}
+
+DimInfo::DimInfo()
+{
+    this->Init( 1 );
+}
+
+DimInfo::~DimInfo()
+{
+}
+
+void DimInfo::Init( int dim )
+{
+    this->dim = dim;
+    dimList.resize( this->dim, 1 );
+    oriPoint.resize( this->dim, 0 );
+}
+
+DimInfo & DimInfo::operator = ( const DimInfo & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->dim = rhs.dim;
+    this->dimList = rhs.dimList;
+    this->oriPoint = rhs.oriPoint;
+
+    return * this;
+}
+
+int DimInfo::ComputeNumNodes()
+{
+    int nNodes = 1;
+    for ( int m = 0; m < this->dimList.size(); ++ m )
+    {
+        nNodes *= this->dimList[ m ];
+    }
+    return nNodes;
+}
+
+void DimInfo::ComputeISize()
+{
+    int index_dim = this->dimList.size();
+    this->isize.resize( index_dim * 3, 0 );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        isize[ m ] = this->dimList[ m ];
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 1;
+        isize[ start + m ] = this->dimList[ m ] - 1;
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 2;
+        isize[ start + m ] = 0;
+    }
+
+    for ( int i = 0; i < isize.size(); ++ i )
+    {
+        std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+    }
+}
+
+void DimInfo::ComputeRminmax( std::vector<int> & ref )
+{
+    int index_dim = this->dimList.size();
+    this->rmin.resize( index_dim );
+    this->rmax.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        rmin[ m ] = ref[ m ] + 1;
+        rmax[ m ] = ref[ m ] + this->dimList[ m ];
+    }
+
+    std::cout << "rmin, rmax = \n";
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        std::cout << rmin[ m ] << " " << rmax[ m ] << "\n";
+    }
+}
+
+void DimInfo::Init( std::vector<int> & dimList )
+{
+    this->dim = dimList.size();
+    this->dimList = dimList;
+    std::vector<int> zero( dimList.size(), 0 );
+    this->oriPoint = zero;
+}
+
+void DimInfo::SetNewDimension( int axis, int newStart, int newWidth )
+{
+    this->oriPoint[ axis ] = newStart;
+    this->dimList [ axis ] = newWidth;
+}
+
+void DimInfo::GetZoneGlobalBox( RangeRegion &zoneBox )
+{
+    int index_dim = this->dimList.size();
+    zoneBox.start.resize( index_dim );
+    zoneBox.end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        zoneBox.start[ m ] = this->oriPoint[ m ] + 1;
+        zoneBox.end[ m ] = this->oriPoint[ m ] + this->dimList[ m ];
+    }
+}
+
+void DimInfo::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    int index_dim = this->dimList.size();
+    localBox.start.resize( index_dim );
+    localBox.end.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        localBox.start[ m ] = globalBox.start[ m ] - this->oriPoint[ m ];
+        localBox.end[ m ] = globalBox.end[ m ] - this->oriPoint[ m ];
+    }
+}
+
+RangeRegion::RangeRegion( int nSize )
+{
+    this->Init( nSize );
+}
+
+RangeRegion::~RangeRegion()
+{
+}
+
+void RangeRegion::Init( int nSize )
+{
+    this->start.resize( nSize );
+    this->end.resize( nSize );
+}
+
+RangeRegion & RangeRegion::operator = ( const RangeRegion & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+bool RangeRegion::operator == ( const RangeRegion & rhs ) const
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] != rhs.start[ m ] || 
+            this->end  [ m ] != rhs.end  [ m ] )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+bool RangeRegion::InRegion( const RangeRegion & region )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( ( this->start[ m ] < region.start[ m ] ) || ( this->end[ m ] > region.end[ m ] ) )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::Normalize()
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        int minv = std::min( this->start[ m ], this->end[ m ] );
+        int maxv = std::max( this->start[ m ], this->end[ m ] );
+        this->start[ m ] = minv;
+        this->end[ m ] = maxv;
+    }
+}
+
+void RangeRegion::Localize( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] -= oriPoint[ m ];
+        this->end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void RangeRegion::ToGlobal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] += oriPoint[ m ];
+        this->end[ m ] += oriPoint[ m ];
+    }
+}
+
+void RangeRegion::ToLocal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] -= oriPoint[ m ];
+        this->end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void RangeRegion::PrintGlobal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    std::cout << "global start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ] + oriPoint[m];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "global end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ] + oriPoint[m];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+void RangeRegion::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion );
+
+bool ComputeOverlapRegion( RangeRegion & region1, RangeRegion & region2, RangeRegion & overlapRegion )
+{
+    int index_dim = region1.start.size();
+    overlapRegion.Init( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int ijkmin1 = std::min( region1.start[ m ], region1.end[ m ] );
+        int ijkmax1 = std::max( region1.start[ m ], region1.end[ m ] );
+        int ijkmin2 = std::min( region2.start[ m ], region2.end[ m ] );
+        int ijkmax2 = std::max( region2.start[ m ], region2.end[ m ] );
+        if ( ( ijkmax1 < ijkmin2 ) || ( ijkmin1 > ijkmax2 ) )
+        {
+            return false;
+        }
+
+        int ijkmin = std::max( ijkmin1, ijkmin2 );
+        int ijkmax = std::min( ijkmax1, ijkmax2 );
+
+        overlapRegion.start[ m ] = ijkmin;
+        overlapRegion.end  [ m ] = ijkmax;
+    }
+
+    return CheckOverLapping( overlapRegion );
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion )
+{
+    int index_dim = overlapRegion.start.size();
+    int iCount = 0;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        if ( overlapRegion.start[ m ] == overlapRegion.end[ m ] )
+        {
+            ++ iCount;
+        }
+    }
+
+    return ( iCount == 1 );
+}
+
+bool GetInterfaceRegion( RangeRegion & zoneBoxL, RangeRegion & zoneBoxR, RangeRegion & interfaceRegion )
+{
+    int index_dim = zoneBoxL.start.size();
+    int nDomains = 2 * index_dim;
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegionL;
+        GetDomainRegion( zoneBoxL, iDomain, domainRegionL );
+
+        for ( int jDomain = 0; jDomain < nDomains; ++ jDomain )
+        {
+            RangeRegion domainRegionR;
+            GetDomainRegion( zoneBoxR, jDomain, domainRegionR );
+
+            if ( domainRegionL == domainRegionR )
+            {
+                interfaceRegion = domainRegionL;
+                return true;
+            }
+        }
+    }
+    return false;
+}
+
+void CreateInterfaceBc( SplitZone * zoneL, SplitZone * zoneR )
+{
+    RangeRegion globalBoxL, globalBoxR, globalInterfaceRegion;
+
+    zoneL->GetZoneGlobalBox( globalBoxL );
+    zoneR->GetZoneGlobalBox( globalBoxR );
+
+    if ( ! GetInterfaceRegion( globalBoxL, globalBoxR, globalInterfaceRegion ) )
+    {
+        return;
+    }
+
+    RangeRegion localInterfaceRegionL, localInterfaceRegionR;
+
+    zoneL->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionL );
+    zoneR->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionR );
+
+    int kkk = 1;
+
+    InterfaceSplitBc * interfaceSplitBcL = new InterfaceSplitBc();
+    zoneL->interfaceSplitBcList.push_back( interfaceSplitBcL );
+    interfaceSplitBcL->zone = zoneL;
+    interfaceSplitBcL->region = localInterfaceRegionL;
+
+    int nSize = localInterfaceRegionL.start.size();
+
+    std::vector<int> transform;
+
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        transform.push_back( m + 1 );
+    }
+
+    interfaceSplitBcL->transform = transform;
+    interfaceSplitBcL->CalcTransformMatrix();
+
+    interfaceSplitBcL->donor_zone = zoneR;
+    interfaceSplitBcL->donor_region = localInterfaceRegionR;
+
+    InterfaceSplitBc * interfaceSplitBcR = new InterfaceSplitBc();
+    zoneR->interfaceSplitBcList.push_back( interfaceSplitBcR );
+
+    interfaceSplitBcR->zone = zoneR;
+    interfaceSplitBcR->region = localInterfaceRegionR;
+
+    interfaceSplitBcR->transform = transform;
+    interfaceSplitBcR->CalcTransformMatrix();
+
+    interfaceSplitBcR->donor_zone = zoneL;
+    interfaceSplitBcR->donor_region = localInterfaceRegionL;
+}
+
+
+PhysicalSplitBc::PhysicalSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+PhysicalSplitBc::~PhysicalSplitBc()
+{
+}
+
+void PhysicalSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void PhysicalSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+void PhysicalSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = splitZone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+BasicSplitBc::BasicSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+BasicSplitBc::~BasicSplitBc()
+{
+    ;
+}
+
+void BasicSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void BasicSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+int trans::M[ 3 ][ 3 ];
+std::vector<int> trans::transform;
+
+int trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void trans::CalcTransformMatrix()
+{
+    int dim = trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = trans::transform[ 0 ];
+        int sgna = trans::sgn( a );
+        int a1 = trans::del( a, 1 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int c = trans::transform[ 2 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int sgnc = trans::sgn( c );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int a3 = trans::del( a, 3 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        int b3 = trans::del( b, 3 );
+        int c1 = trans::del( c, 1 );
+        int c2 = trans::del( c, 2 );
+        int c3 = trans::del( c, 3 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 2 ][ 0 ] = sgna * a3;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+        trans::M[ 2 ][ 1 ] = sgnb * b3;
+        trans::M[ 0 ][ 2 ] = sgnc * c1;
+        trans::M[ 1 ][ 2 ] = sgnc * c2;
+        trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+InterfaceInfo::InterfaceInfo()
+{
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceInfo::~InterfaceInfo()
+{
+}
+
+InterfaceSplitBc::InterfaceSplitBc()
+{
+    this->region.Init( Dim::dim );
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceSplitBc::~InterfaceSplitBc()
+{
+}
+
+void InterfaceSplitBc::CopyMatrix( InterfaceSplitBc * interfaceSplitBc )
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = interfaceSplitBc->Mt[ i ][ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::CalcTransformMatrix()
+{
+    trans::ZeroMatrix();
+    trans::transform = this->transform;
+    trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = trans::M[ i ][ j ];
+        }
+    }
+
+}
+
+void InterfaceSplitBc::mapindex( std::vector<int> & begin1, std::vector<int> & begin2,  std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = Dim::dim;
+    std::vector<int> diff( dim );
+    for ( int m = 0; m < dim; ++ m )
+    {
+        diff[ m ] = index1[ m ] - begin1[ m ];
+    }
+
+    std::vector<int> mul( dim );
+
+    Multiply( Mt, diff, mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = mul[ m ] + begin2[ m ];
+    }
+}
+
+void InterfaceSplitBc::Multiply( int Mt[][3], std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = Dim::dim;
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = this->zone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void InterfaceSplitBc::CalcSubDonorRegion( RangeRegion &subRegion, RangeRegion &subDonorRegion )
+{
+    std::vector<int> begin1 = this->region.start;
+    std::vector<int> end1 = this->region.end;
+    std::vector<int> begin2 = this->donor_region.start;
+    std::vector<int> end2 = this->donor_region.end;
+
+    std::vector<int> new_begin1 = subRegion.start;
+    std::vector<int> new_end1 = subRegion.end;
+
+    int dim = Dim::dim;
+    std::vector<int> new_begin2( dim );
+    std::vector<int> new_end2( dim );
+
+    mapindex( begin1, begin2, new_begin1, new_begin2 );
+    mapindex( begin1, begin2, new_end1, new_end2 );
+
+    subDonorRegion.start = new_begin2;
+    subDonorRegion.end = new_end2;
+}
+
+SplitZone::SplitZone()
+{
+    this->parent  = 0;
+    this->zoneIndex = 0;
+    this->iProc = 0;
+    dimInfo.Init( Dim::dim );
+    int kk = 1;
+}
+
+SplitZone::~SplitZone()
+{
+    ;
+}
+
+void SplitZone::GetZoneGlobalBox( RangeRegion & zoneBox )
+{
+    this->dimInfo.GetZoneGlobalBox( zoneBox );
+}
+
+void SplitZone::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    this->dimInfo.GetZoneLocalBox( globalBox, localBox );
+}
+
+
+void SplitZone::ComputeRminmax()
+{
+    int index_dim = this->dimInfo.dimList.size();
+    std::vector<int> ref( index_dim, 0 );
+
+    SplitZone * rootSplitZone = 0;
+    this->GetRootInfo( rootSplitZone, ref );
+
+    this->dimInfo.ComputeRminmax( ref );
+}
+
+SplitZone * SplitZone::GetRootZone()
+{
+    SplitZone * root = this;
+
+    while ( true )
+    {
+        if ( root->parent )
+        {
+            root = root->parent;
+        }
+        else
+        {
+            return root;
+        }
+    };
+}
+
+void SplitZone::GetRootInfo( SplitZone *& root, std::vector<int> & ref )
+{
+    for ( int i = 0; i < this->dimInfo.dimList.size(); ++ i )
+    {
+        ref[ i ] += this->dimInfo.oriPoint[ i ];
+    }
+
+    if ( this->parent )
+    {
+        this->parent->GetRootInfo( root, ref );
+    }
+    else
+    {
+        root = this;
+    }
+}
+
+void SplitZone::SetParentAndChild( SplitZone * parent )
+{
+    this->parent = parent;
+    if ( parent )
+    {
+        parent->child.push_back( this );
+    }
+}
+
+
+int SplitZone::GetNCell()
+{
+    int numberOfCells = 1;
+    for ( int i = 0; i < this->dimInfo.dim; ++ i )
+    {
+        numberOfCells *= std::max( 1, ( this->dimInfo.dimList[ i ] - 1 ) );
+    }
+
+    return numberOfCells; 
+}
+
+void SplitZone::SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int leftStart = 0;
+    int leftWidth = iSplit - 0;
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, leftStart , leftWidth  );
+}
+
+void SplitZone::SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int rightStart = iSplit - 1;
+    int rightWidth = dimList[ axisNeedSplit ] - ( iSplit - 1 );
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, rightStart, rightWidth );
+}
+
+void SplitZone::Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell )
+{
+    //Find the longest axis
+    int axisNeedSplit = this->FindAxisNeedSplit();
+    int iSplit        = this->FindSplitPosition( axisNeedSplit, nCell );
+
+    zoneL->SetLeftDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+    zoneR->SetRightDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+
+    zoneL->CreateBcFromParent();
+    zoneR->CreateBcFromParent();
+    
+    CreateInterfaceBc( zoneL, zoneR );
+}
+
+void SplitZone::CreateBcFromParent()
+{
+    this->CreatePhysicalBcFromParent();
+    this->CreateInterfaceBcFromParent();
+}
+
+void SplitZone::CreatePhysicalBcFromParent()
+{
+    int nParentPhysicalBcs = this->parent->physicalSplitBcList.size();
+
+    for ( int iParentPhysicalBcs = 0; iParentPhysicalBcs < nParentPhysicalBcs; ++ iParentPhysicalBcs )
+    {
+        PhysicalSplitBc * parentPhysicalSplitBc = this->parent->physicalSplitBcList[ iParentPhysicalBcs ];
+
+        this->CreatePhysicalBcFromParent( parentPhysicalSplitBc );
+    }
+}
+
+void SplitZone::CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentPhysicalSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreatePhysicalBc( overlapRegion, parentPhysicalSplitBc->bcType );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent()
+{
+    int nInterfaceSplitBcs = this->parent->interfaceSplitBcList.size();
+
+    for ( int iInterfaceSplitBcs = 0; iInterfaceSplitBcs < nInterfaceSplitBcs; ++ iInterfaceSplitBcs )
+    {
+        InterfaceSplitBc * parentInterfaceSplitBc = this->parent->interfaceSplitBcList[ iInterfaceSplitBcs ];
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc );
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentInterfaceSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc, overlapRegion );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::FindDonorInterface( InterfaceSplitBc * interfaceSplitBc, InterfaceInfo & interfaceInfo )
+{
+    RangeRegion donor_region = interfaceSplitBc->donor_region;
+    donor_region.Normalize();
+    interfaceInfo.donor_zone = this;
+    for ( int iInterface = 0; iInterface < interfaceSplitBcList.size(); ++ iInterface )
+    {
+        InterfaceSplitBc * candidateDonorBc = interfaceSplitBcList[ iInterface ];
+        bool flag = donor_region.InRegion( candidateDonorBc->region );
+        if ( flag )
+        {
+            if ( donor_region == candidateDonorBc->region )
+            {
+                interfaceInfo.donor_interface = candidateDonorBc;
+                return;
+            }
+            else
+            {
+                InterfaceSplitBc * donorBc = new InterfaceSplitBc();
+                candidateDonorBc->child.push_back( donorBc );
+                donorBc->region = donor_region;
+                donorBc->zone = candidateDonorBc->zone;
+                donorBc->donor_zone = interfaceSplitBc->zone;
+                donorBc->transform = candidateDonorBc->transform;
+                donorBc->CopyMatrix( candidateDonorBc );
+                RangeRegion subDonorRegion( Dim::dim );
+                candidateDonorBc->CalcSubDonorRegion( donorBc->region, subDonorRegion );
+                std::vector<int> & oriPoint = interfaceSplitBc->zone->dimInfo.oriPoint;
+                subDonorRegion.Localize( oriPoint );
+                donorBc->donor_region = subDonorRegion;
+                donorBc->donor_bc = interfaceSplitBc;
+                interfaceInfo.donor_interface = donorBc;
+                return;
+            }
+        }
+    }
+    return;
+}
+
+void SplitZone::GetChildDonorRegion( RangeRegion & subDonorRegion, InterfaceInfo & interfaceInfo )
+{
+    std::cout << "subDonorRegion = \n";
+    //subDonorRegion.Print();
+    RangeRegion normalizedDonorRegion = subDonorRegion;
+    normalizedDonorRegion.Normalize();
+    int nChild = this->child.size();
+    for ( int ichild = 0; ichild < nChild; ++ ichild )
+    {
+        std::cout << " iChild = " << ichild << " nChild = " << nChild << "\n";
+        SplitZone * sub_zone = this->child[ ichild ];
+        std::cout << " zoneIndex = " << sub_zone->zoneIndex << "\n";
+        int nInters = sub_zone->interfaceSplitBcList.size();
+        for ( int iInter = 0; iInter < nInters; ++ iInter )
+        {
+            std::cout << " iInter = " << iInter << "\n";
+            InterfaceSplitBc * interfaceSplitBc = sub_zone->interfaceSplitBcList[ iInter ];
+            std::cout << "interfaceSplitBc local = \n";
+            interfaceSplitBc->region.Print();
+            std::cout << "interfaceSplitBc global = \n";
+            interfaceSplitBc->region.PrintGlobal( sub_zone->dimInfo.oriPoint );
+            RangeRegion g_region = interfaceSplitBc->region;
+            g_region.ToGlobal( sub_zone->dimInfo.oriPoint );
+            if ( g_region == normalizedDonorRegion )
+            {
+                RangeRegion donorRegion = subDonorRegion;
+                donorRegion.ToLocal( sub_zone->dimInfo.oriPoint );
+
+                interfaceInfo.donor_zone = sub_zone;
+                interfaceInfo.donor_interface = interfaceSplitBc;
+                interfaceInfo.donor_region = donorRegion;
+                return;
+            }
+        }
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion )
+{
+    InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+    this->interfaceSplitBcList.push_back( interfaceSplitBc );
+
+    interfaceSplitBc->region = overlapRegion;
+    interfaceSplitBc->zone = this;
+    interfaceSplitBc->transform = parentInterfaceSplitBc->transform;
+    interfaceSplitBc->CopyMatrix( parentInterfaceSplitBc );
+    RangeRegion subDonorRegion( Dim::dim );
+    parentInterfaceSplitBc->CalcSubDonorRegion( overlapRegion, subDonorRegion );
+    interfaceSplitBc->ChangeRegionToLocalCoordinate();
+    interfaceSplitBc->donor_region = subDonorRegion;
+    SplitZone * parent_donor_zone = parentInterfaceSplitBc->donor_zone;
+    std::cout << " parentInterfaceSplitBc->zone->zoneIndex " << parentInterfaceSplitBc->zone->zoneIndex << "\n";
+    std::cout << " parentInterfaceSplitBc->donor_zone->zoneIndex " << parent_donor_zone->zoneIndex << "\n";
+    if ( parent_donor_zone->child.size() > 0 )
+    {
+        InterfaceInfo interfaceInfo;
+        parent_donor_zone->GetChildDonorRegion( subDonorRegion, interfaceInfo );
+        interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+        interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+        interfaceSplitBc->donor_region = interfaceInfo.donor_region;
+        //compatibility
+        InterfaceSplitBc * donor_bc = interfaceSplitBc->donor_bc;
+        SplitZone * donor_zone = interfaceSplitBc->donor_zone;
+        if ( interfaceSplitBc->zone != donor_bc->donor_zone )
+        {
+            if ( interfaceSplitBc->zone->parent == donor_bc->donor_zone )
+            {
+                RangeRegion d_region = donor_bc->donor_region;
+                d_region.ToLocal( interfaceSplitBc->zone->dimInfo.oriPoint );
+                donor_bc->donor_region = d_region;
+            }
+            donor_bc->donor_zone = interfaceSplitBc->zone;
+         
+            int kkk = 1;
+        }
+        int kkk = 1;
+    }
+    else
+    {
+        InterfaceInfo interfaceInfo;
+        parent_donor_zone->FindDonorInterface( interfaceSplitBc, interfaceInfo );
+        interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+        interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+    }
+    
+    int kkk = 1;
+}
+
+void SplitZone::CreatePhysicalBc( RangeRegion & overlapRegion, int bcType )
+{
+    PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+    this->physicalSplitBcList.push_back( physicalSplitBc );
+    physicalSplitBc->SetRegion( overlapRegion );
+    physicalSplitBc->bcType = bcType;
+    physicalSplitBc->splitZone = this;
+    physicalSplitBc->ChangeRegionToLocalCoordinate();
+}
+
+int SplitZone::FindAxisNeedSplit()
+{
+    //Find the longest axis
+    int axisNeedSplit = 0;
+    int maxN = this->dimInfo.dimList[ 0 ];
+
+    for ( int m = 1; m < this->dimInfo.dimList.size(); ++ m )
+    {
+        if ( this->IsPoleBc( m ) )
+        {
+            continue;
+        }
+        int Nm = this->dimInfo.dimList[ m ];
+        if ( maxN < Nm )
+        {
+            maxN = Nm;
+            axisNeedSplit = m;
+        }
+    }
+
+    return axisNeedSplit;
+}
+
+int SplitZone::GetCrossSection( int axis )
+{
+    int nDim = this->dimInfo.dimList.size();
+    int crossSection = 1;
+    int N = nDim - 1;
+    for ( int m = 0; m < N; ++ m )
+    {
+         int mm = ( axis + 1 ) % nDim;
+         int nLineElements = std::max( 1, ( this->dimInfo.dimList[ mm ] - 1 ) );
+         crossSection *= nLineElements;
+    }
+    return crossSection;
+}
+
+int SplitZone::FindSplitPosition( int axisNeedSplit, double nCell )
+{
+    int nDim = this->dimInfo.dimList.size();
+    std::vector<int> crossSections( nDim );
+    for ( int m = 0; m < nDim; ++ m )
+    {
+        crossSections[ m ] = this->GetCrossSection( m );
+    }
+
+    //guess the value
+    double dSplit = nCell / crossSections[ axisNeedSplit ];
+    int  iSplit = 1 + static_cast< int >( std::floor( dSplit + 0.5 ) );
+    return iSplit;
+}
+
+
+bool SplitZone::IsPoleBc( int splitDirection )
+{
+    return false;
+}
+
diff --git a/example/partition/struct/2d/stage3/01/SplitZone.h b/example/partition/struct/2d/stage3/01/SplitZone.h
new file mode 100644
index 00000000..6ba99614
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01/SplitZone.h
@@ -0,0 +1,194 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class Dim
+{
+public:
+    static int dim;
+};
+
+class SplitZone;
+class RangeRegion;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox );
+
+class DimInfo
+{
+public:
+    DimInfo();
+    ~DimInfo();
+public:
+    int dim;
+    std::vector<int> dimList;
+    std::vector<int> oriPoint;
+    std::vector<int> isize;
+    std::vector<int> rmin;
+    std::vector<int> rmax;
+public:
+    int GetSize() const { return dim; }
+    DimInfo & operator = ( const DimInfo & rhs );
+public:
+    int ComputeNumNodes();
+    void ComputeISize();
+    void ComputeRminmax( std::vector<int> & ref );
+    void Init( int dim );
+    void Init( std::vector<int> & dimList );
+    void SetNewDimension( int axis, int newStart, int newWidth );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+};
+
+class SplitZone;
+class SplitBcPatch;
+
+class RangeRegion
+{
+public:
+    RangeRegion( int nSize = 1 );
+    ~RangeRegion();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    void Init( int nSize );
+    RangeRegion & operator = ( const RangeRegion & rhs );
+    bool operator == ( const RangeRegion & rhs ) const;
+    bool InRegion( const RangeRegion & region );
+    void SetRegion( std::vector<int> &pnts );
+    void Normalize();
+    void Localize( std::vector<int> & oriPoint );
+    void ToGlobal( std::vector<int> & oriPoint );
+    void ToLocal( std::vector<int> & oriPoint );
+    void PrintGlobal( std::vector<int> & oriPoint );
+    void Print();
+};
+
+class PhysicalSplitBc
+{
+public:
+    PhysicalSplitBc();
+    ~PhysicalSplitBc();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class BasicSplitBc
+{
+public:
+    BasicSplitBc();
+    ~BasicSplitBc();
+public:
+    RangeRegion region;
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> & pnts );
+    void SetRegion( RangeRegion & region );
+};
+
+class trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class InterfaceSplitBc;
+class SplitZone;
+
+class InterfaceInfo
+{
+public:
+    InterfaceInfo();
+    ~InterfaceInfo();
+public:
+    InterfaceSplitBc * donor_interface = nullptr;
+    SplitZone * donor_zone = nullptr;
+    RangeRegion donor_region;
+};
+
+class InterfaceSplitBc
+{
+public:
+    InterfaceSplitBc();
+    ~InterfaceSplitBc();
+public:
+    std::vector<int> transform;
+    int Mt[ 3 ][ 3 ];
+    RangeRegion region;
+    SplitZone * zone = nullptr;
+    RangeRegion donor_region;
+    SplitZone * donor_zone = nullptr;
+    InterfaceSplitBc * donor_bc = nullptr;
+public:
+    std::vector<InterfaceSplitBc *> child;
+public:
+    void CopyMatrix( InterfaceSplitBc * interfaceSplitBc );
+    void CalcTransformMatrix();
+    void CalcSubDonorRegion( RangeRegion & subRegion, RangeRegion & subDonorRegion );
+    void mapindex( std::vector<int> & begin1, std::vector<int> & begin2, std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( int Mt[][ 3 ], std::vector<int> & a, std::vector<int> & b );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class SplitZone
+{
+public:
+    SplitZone();
+    ~SplitZone();
+public:
+    DimInfo dimInfo;
+    int zoneIndex, iProc;
+    int newIndex;
+protected:
+    SplitZone * parent;
+    std::vector<SplitZone *> child;
+public:
+    std::vector< PhysicalSplitBc * > physicalSplitBcList;
+    std::vector< InterfaceSplitBc * > interfaceSplitBcList;
+public:
+    int GetNCell();
+    void ComputeRminmax();
+    void GetRootInfo( SplitZone *& root, std::vector<int> & ref );
+    void SetZoneIndex( int zoneIndex ) { this->zoneIndex = zoneIndex; }
+    int  GetZoneIndex() { return zoneIndex; }
+    void SetProcId( int iProc ) { this->iProc = iProc; }
+    void SetParent( SplitZone * parent ) { this->parent = parent; };
+    void SetParentAndChild( SplitZone * parent );
+    void FindDonorInterface( InterfaceSplitBc * interfaceSplitBc, InterfaceInfo & interfaceInfo );
+    void GetChildDonorRegion( RangeRegion & subDonorRegion, InterfaceInfo & interfaceInfo );
+public:
+    void CreateBcFromParent();
+    void CreatePhysicalBcFromParent();
+    void CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc );
+    void CreatePhysicalBc( RangeRegion & overlapRegion, int bcType );
+    void CreateInterfaceBcFromParent();
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc );
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion );
+
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+    SplitZone * GetRootZone();
+public:
+    void Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell );
+    void SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+    void SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+private:
+    int FindAxisNeedSplit();
+    int FindSplitPosition( int axisNeedSplit, double nCell );
+    bool IsPoleBc( int splitDirection );
+    int GetCrossSection( int axis );
+};
+
diff --git a/example/partition/struct/2d/stage3/01/heat2d1blockv1.cgns b/example/partition/struct/2d/stage3/01/heat2d1blockv1.cgns
new file mode 100644
index 00000000..4aa7832a
Binary files /dev/null and b/example/partition/struct/2d/stage3/01/heat2d1blockv1.cgns differ
diff --git a/example/partition/struct/2d/stage3/01/heat2dpart.cgns b/example/partition/struct/2d/stage3/01/heat2dpart.cgns
new file mode 100644
index 00000000..b5a8e3aa
Binary files /dev/null and b/example/partition/struct/2d/stage3/01/heat2dpart.cgns differ
diff --git a/example/partition/struct/2d/stage3/01/main.cpp b/example/partition/struct/2d/stage3/01/main.cpp
new file mode 100644
index 00000000..5da1de7c
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01/main.cpp
@@ -0,0 +1,18 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include "Partition.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip>
+
+int main(int argc, char **argv)
+{
+    Partition * partition = new Partition();
+    partition->Solve();
+    delete partition;
+
+    return 0;
+}
diff --git a/example/partition/struct/2d/stage3/01a/CMakeLists.txt b/example/partition/struct/2d/stage3/01a/CMakeLists.txt
new file mode 100644
index 00000000..74ceea7d
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01a/CMakeLists.txt
@@ -0,0 +1,78 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	Partition.h Partition.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	SplitZone.h SplitZone.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/partition/struct/2d/stage3/01a/CgnsGrid.cpp b/example/partition/struct/2d/stage3/01a/CgnsGrid.cpp
new file mode 100644
index 00000000..dfe750bd
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01a/CgnsGrid.cpp
@@ -0,0 +1,349 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include <map>
+
+Grid::Grid()
+{
+    ;
+}
+
+Grid::~Grid()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if( (i+1)%5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+    delete this->patch;
+}
+
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+ZoneBcPatch::ZoneBcPatch()
+{
+    ;
+}
+
+ZoneBcPatch::~ZoneBcPatch()
+{
+}
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+Global::Global()
+{
+    ;
+}
+
+Global::~Global()
+{
+}
+
+void Global::FreeData()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+    zones.resize( 0 );
+}
+
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            //baseZone.baseId = baseId;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin( index_dim );
+            std::vector<cgsize_t> irmax( index_dim );
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                std::vector<char> coord( nNodes * sizeof(double) );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+                coor->DumpCoor();
+            }
+
+            int nbocos = -1;
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+                int kkk = 1;
+            }
+        }
+        int kkk = 1;
+    }
+    int kkk = 1;
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage3/01a/CgnsGrid.h b/example/partition/struct/2d/stage3/01a/CgnsGrid.h
new file mode 100644
index 00000000..053c467b
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01a/CgnsGrid.h
@@ -0,0 +1,140 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <map>
+
+class Grid;
+
+class Zone;
+
+class Grid
+{
+public:
+    Grid();
+    ~Grid();
+public:
+    int nZone;
+    std::vector<double> x;
+    std::vector<Zone *> zones;
+};
+
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+};
+
+class ZoneBc;
+class ZoneBc1To1;
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class ZoneBcPatch;
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+    ZoneBcPatch * patch = nullptr;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+class ZoneBcPatch
+{
+public:
+    ZoneBcPatch();
+    ~ZoneBcPatch();
+public:
+    int donor_zoneid;
+    std::vector<int> transform;
+    std::vector<int> donor_pnts;
+};
+
+class BaseZone
+{
+public:
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Global
+{
+public:
+    Global();
+    ~Global();
+public:
+    static int cell_dim;
+    static int phys_dim;
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+public:
+    static void FreeData();
+};
+
+void ReadCgnsGrid( const std::string & filename );
+void ReadCgnsGridBaseZone( const std::string & filename );
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage3/01a/Partition.cpp b/example/partition/struct/2d/stage3/01a/Partition.cpp
new file mode 100644
index 00000000..d1c039a3
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01a/Partition.cpp
@@ -0,0 +1,620 @@
+#include "Partition.h"
+#include "CgnsGrid.h"
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+bool CmpSplitZone::operator() ( SplitZone * a, SplitZone * b ) const
+{
+    return a->zoneIndex < b->zoneIndex;
+};
+
+
+double CalSumOfProcSpeed( std::vector<double> & procSpeed );
+double CalSumOfProcSpeed( std::vector<double> & procSpeed )
+{
+    int nProc = procSpeed.size();
+    double sumOfProcSpeed = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        sumOfProcSpeed += procSpeed[ iProc ];
+    }
+    return sumOfProcSpeed;
+}
+
+Partition::Partition()
+{
+    this->inputName = "../heat2d1blockv1.cgns";
+    this->outName =  "../heat2dpart.cgns";
+}
+
+Partition::~Partition()
+{
+    ;
+}
+
+int Partition::GetMinValueIndex( double * data, int numberOfData )
+{
+    double minValue = data[ 0 ];
+    int minimumValueIndex = 0;
+
+    for ( int iData = 1; iData < numberOfData; ++ iData )
+    {
+        if ( minValue > data[ iData ] )
+        {
+            minValue      = data[ iData ];
+            minimumValueIndex = iData;
+        }
+    }
+    return minimumValueIndex;
+}
+
+int Partition::GetMinLoadProc()
+{
+    return this->GetMinValueIndex( this->timeProc.data(), this->nProc );
+}
+
+SplitZone * Partition::GetLargestZone()
+{
+    SplitZone * largestZone = 0;
+
+    double nMaxCell = 0.0;
+
+    for ( std::set< SplitZone * >::iterator iter = unsignedZoneGroup.begin(); iter != unsignedZoneGroup.end(); ++ iter )
+    {
+        double nSize = ( * iter )->GetNCell();
+        if ( nMaxCell < nSize )
+        {
+            nMaxCell    = nSize;
+            largestZone = * iter;
+        }
+    }
+
+    return largestZone;
+}
+
+void Partition::Solve()
+{
+    std::cout << "Partition::Split()\n";
+    //this->nProc = 2;
+    this->nProc = 3;
+    this->ReadGrid();
+    this->Split();
+    this->DumpPartitionedGridFile();
+    this->FreeAllZones();
+}
+
+void Partition::ReadGrid()
+{
+    ReadCgnsGridBaseZone( this->inputName );
+    ReadCgnsGrid( this->inputName );
+
+    this->nOriZone = ::Global::zones.size();
+    Dim::dim = Global::cell_dim;
+
+    std::cout << "numberOfBlocks = " << nOriZone << "\n";
+
+    this->refZone.resize( nOriZone );
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = new SplitZone();
+        refZone[ iZone ] = splitZone;
+
+        splitZone->SetZoneIndex( iZone );
+        splitZone->SetProcId( 0 );
+        splitZone->SetParentAndChild( 0 );
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        Zone * zone = ::Global::zones[ iZone ];
+
+        splitZone->dimInfo.dimList = zone->nijk;
+
+        int nbccos = zone->bccos.size();
+        std::cout << "nbccos = " << nbccos << "\n";
+
+        for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+        {
+            ZoneBc * zoneBc = zone->bccos[ ibcco ];
+
+            PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+            splitZone->physicalSplitBcList.push_back( physicalSplitBc );
+            physicalSplitBc->bcType = zoneBc->bcType;
+            physicalSplitBc->SetRegion( zoneBc->pnts );
+            physicalSplitBc->splitZone = splitZone;
+        }
+
+        int nbc1to1s = zone->bc1to1s.size();
+
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * zoneBc1To1 = zone->bc1to1s[ ibc1to1 ];
+
+            InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+            splitZone->interfaceSplitBcList.push_back( interfaceSplitBc );
+            interfaceSplitBc->zone = splitZone;
+            interfaceSplitBc->region.SetRegion( zoneBc1To1->pnts );
+
+            interfaceSplitBc->transform = zoneBc1To1->transform;
+            interfaceSplitBc->CalcTransformMatrix();
+
+            interfaceSplitBc->donor_zone = refZone[ zoneBc1To1->donor_zoneid ];
+            interfaceSplitBc->donor_region.SetRegion( zoneBc1To1->donor_pnts );
+        }
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        int nbc1to1s = splitZone->interfaceSplitBcList.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            InterfaceSplitBc * interfaceSplitBc = splitZone->interfaceSplitBcList[ ibc1to1 ];
+            InterfaceInfo interfaceInfo;
+            interfaceSplitBc->donor_zone->FindDonorInterface( interfaceSplitBc, interfaceInfo );
+            interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+            interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+        }
+    }
+}
+
+void Partition::Split()
+{
+    this->InitSplit();
+    this->BinarySplit();
+    this->ModifyZoneIndex();
+    int kkk = 1;
+}
+
+void Partition::InitSplit()
+{
+    //nZone is the number of zones in the original grid
+    //nProc is not the number of blocks in the end, but the number of processes that need to be divided.
+    //This difference occurs because the structure grid can have many blocks per process.
+
+    //this->nProc    = nProc;
+    //this->nPhyBlocks = referenceBlock.size();
+    //this->nZone  = this->nPhyBlocks;
+
+    //tj Computation time on processor j
+    //Nk Number of internal grid-cells for zone j
+    //aveFloatOp:  Number of Real operations per gridcell
+    //Gj The set of blocks allocated to process j
+    //Pj Real operations per second for process j
+
+    //The Greedy Load Balancing Algorithm
+    //1.Compute an "ideal" uniprocessor time, Tuni = sum ( Nk * aveFloatOp )/ sum( Pj ).
+    //2.Set the group of unassigned blocks, Gu, to contain all blocks. The number of blocks in Nu=M, where M is the total number of blocks in the mesh.
+    //3.Start all processors with a very small fictitious zone to get a start tj=delt aveFloatOp/Pj, where delt<<1 is the size of the very small fictious zone.
+    //This is used to find the fastest processor in a heterogeneous system, tj could otherwise be set to 0 in the homogeneous case.
+    this->aveFloatOp = 1.0;
+    this->delta      = 1.0e-5;
+    this->procSpeed.resize( nProc );
+    this->timeProc.resize( nProc );
+
+    this->nTZone = this->nOriZone;
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        procSpeed[ iProc ] = 1.0;
+    }
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        timeProc[ iProc ] = delta * aveFloatOp / procSpeed[ iProc ];
+    }
+
+    double sumProcSpeed = CalSumOfProcSpeed( procSpeed );
+
+    double sumProcOp = 0.0;
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        sumProcOp += refZone[ iZone ]->GetNCell() * aveFloatOp;
+    }
+
+    this->idealUniProcTime = sumProcOp / sumProcSpeed;
+
+    this->eps = 0.05;
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        unsignedZoneGroup.insert( refZone[ iZone ] );
+    }
+
+    //Init zoneStorage
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        zoneStorage.insert( refZone[ iZone ] );
+    }
+
+    //Assign procSplitZone to each process
+    procSplitZone.resize( nProc );
+
+    this->minNumberCell = 1;
+    for ( int m = 0; m < Dim::dim; ++ m )
+    {
+        this->minNumberCell *= 1;
+    }
+
+    int kkk = 1;
+
+}
+
+void Partition::FreeAllZones()
+{
+    int iCount = 0;
+    for ( std::set < SplitZone * >::iterator iter = zoneStorage.begin(); iter != zoneStorage.end(); ++ iter )
+    {
+        //cout << "iCount = " << iCount << "\n";
+        ++ iCount;
+        delete * iter;
+    }
+}
+
+int Partition::GetNZones( int iProc )
+{
+    return this->procSplitZone[ iProc ].size();
+}
+
+SplitZone * Partition::GetSplitZone( int iProc, int zoneId )
+{
+    return this->procSplitZone[ iProc ][ zoneId ];
+}
+
+void Partition::AddZoneToUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.insert( zone );
+}
+
+void Partition::RemoveZoneFromUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.erase( zone );
+}
+
+void Partition::AddZoneToProcess( int iProc, SplitZone * zone )
+{
+    this->procSplitZone[ iProc ].push_back( zone );
+}
+
+void Partition::AddNewZone( SplitZone * zone )
+{
+    zone->SetZoneIndex( nTZone ++ );
+
+    this->AddZoneToUnsignedGroup( zone );
+
+    this->zoneStorage.insert( zone );
+}
+
+SplitZone * Partition::Split( SplitZone * zone, double nCell )
+{
+    SplitZone * zoneL = new SplitZone();
+    zoneL->SetParentAndChild( zone );
+
+    SplitZone * zoneR = new SplitZone();
+    zoneR->SetParentAndChild( zone );
+
+    //Remove the original block from the UnsignedGroup
+    this->RemoveZoneFromUnsignedGroup( zone );
+
+    this->AddNewZone( zoneL );
+    this->AddNewZone( zoneR );
+
+    zone->Split( zoneL, zoneR, nCell );
+
+    return zoneL;
+}
+
+void Partition::BinarySplit()
+{
+    while ( ! unsignedZoneGroup.empty() )
+    {
+        std::cout << "number of unsigned zone = " << unsignedZoneGroup.size() << "\n";
+        int iProc = this->GetMinLoadProc();
+
+        //Get the block with the largest number of grids and its size
+        SplitZone * largestZone = this->GetLargestZone();
+
+        double nMaxCell = largestZone->GetNCell();
+
+        double aveFloatOp = this->aveFloatOp;
+        double tau = timeProc[ iProc ] + nMaxCell * aveFloatOp / procSpeed[ iProc ];
+
+        //It seems that EPS is still necessary
+        //The idea here is as follows. For the candidate blocks which can be divided into blocks, 
+        //if the difference between the target blocks and the candidate blocks is too wide, 
+        //the binarySplit method is adopted. The binarySplit blocks do not directly join the process,
+        //but enter the next round of screening.
+
+        if ( tau > idealUniProcTime * ( 1.0 + eps ) )
+        {
+            double nRest = ( tau - idealUniProcTime ) * procSpeed[ iProc ] / aveFloatOp;
+
+            double nTarget = nMaxCell - nRest;
+            if ( nRest > this->minNumberCell && nTarget > this->minNumberCell )
+            {
+                //It is necessary to divide blocks only when a certain number of points are satisfied.
+                double nHalf = nMaxCell / 2.0;
+                nMaxCell = nTarget;
+                double ratio = nMaxCell / nRest;
+                double oRatio = 1.0 / ratio;
+
+                if ( std::max( ratio, oRatio ) < 3.0 )
+                {
+                    int kkk = 1;
+                    largestZone = this->Split( largestZone, nMaxCell );
+                    timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                    this->RemoveZoneFromUnsignedGroup( largestZone );
+                    this->AddZoneToProcess( iProc, largestZone );
+                }
+                else
+                {
+                    this->Split( largestZone, nHalf );
+                }
+            }
+            else
+            {
+                //If the block is of the right size, join the process directly, and there is no need to split it.
+                timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                this->RemoveZoneFromUnsignedGroup( largestZone );
+                this->AddZoneToProcess( iProc, largestZone );
+            }
+        }
+        else
+        {
+            //If the block is of the right size, join the process directly, and there is no need to split it.
+            timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+            this->RemoveZoneFromUnsignedGroup( largestZone );
+            this->AddZoneToProcess( iProc, largestZone );
+        }
+    }
+}
+
+void Partition::ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord )
+{
+    SplitZone * rootSplitZone = splitZone->GetRootZone();
+    Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+    int nNodes = splitZone->dimInfo.ComputeNumNodes();
+    std::cout << "nNodes = " << nNodes << "\n";
+
+    coord.resize( nNodes * sizeof(double) );
+
+    int index_dim = splitZone->dimInfo.dimList.size();
+    Coor * coor = zone->coors[ icoord ];
+
+    double * xlocal = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    double * xglobal = reinterpret_cast<double *>( const_cast<char *>( coor->coord.data() ) );
+    if ( index_dim == 1 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        for ( int i = imin; i < imax; ++ i )
+        {
+            xlocal[ icount++ ] = xglobal[ i ];
+        }
+    }
+    else if ( index_dim == 2 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        int jmin = splitZone->dimInfo.rmin[ 1 ] - 1;
+        int jmax = splitZone->dimInfo.rmax[ 1 ];
+        int ni = rootSplitZone->dimInfo.dimList[ 0 ];
+        int nj = rootSplitZone->dimInfo.dimList[ 1 ];
+        for ( int j = jmin; j < jmax; ++ j )
+        {
+            int jstride = j * ni;
+            for ( int i = imin; i < imax; ++ i )
+            {
+                xlocal[ icount++ ] = xglobal[ jstride + i ];
+            }
+        }
+    }
+}
+
+void Partition::DumpBc( SplitZone * splitZone )
+{
+}
+
+void Partition::DumpPartitionedGridFile()
+{
+    std::cout << "\n";
+    std::cout << "DumpPartitionedGridFile -------------------------------" << "\n";
+    std::cout << "\n";
+    int fileId = -1;
+    std::string filename = this->outName;
+    int ierr = cg_open( filename.c_str(), CG_MODE_WRITE, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+
+    std::vector<std::string> coordnames;
+    coordnames.push_back( "CoordinateX" );
+    coordnames.push_back( "CoordinateY" );
+    coordnames.push_back( "CoordinateZ" );
+
+    std::string basename = "Base";
+    int baseId = -1;
+    int icelldim = Global::cell_dim;
+    int iphysdim = Global::phys_dim;
+    cg_base_write( fileId, basename.c_str(), icelldim, iphysdim, &baseId );
+
+    std::cout << "baseId = " << baseId << "\n";
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        int nZones = this->GetNZones( iProc );
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            ZoneType_t zoneType = Structured;
+
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+
+            int index_dim = splitZone->dimInfo.dimList.size();
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            splitZone->dimInfo.ComputeISize();
+
+            int isize_dim = index_dim * 3;
+
+            std::vector<cgsize_t> isize( index_dim * 3, 0 );
+            for ( int m = 0; m < isize_dim; ++ m )
+            {
+                isize[ m ] = splitZone->dimInfo.isize[ m ];
+            }
+
+            int zoneId = -1;
+
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+
+            std::string zonename = "Zone" + std::to_string( splitZone->newIndex );
+
+            cg_zone_write( fileId, baseId, zonename.c_str(), isize.data(), zoneType, &zoneId );
+
+            std::cout << "zoneId = " << zoneId << "\n";
+            std::cout << "zonename = " << zonename << "\n";
+                
+            splitZone->ComputeRminmax();
+
+            SplitZone * rootSplitZone = splitZone->GetRootZone();
+
+            Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+            int ncoords = zone->coors.size();
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = -1;
+                DataType_t dataType = RealDouble;
+                std::string coordname = coordnames[ icoord ];
+                Coor * coor = zone->coors[ icoord ];
+
+                int nNodes = splitZone->dimInfo.ComputeNumNodes();
+                std::cout << "nNodes = " << nNodes << "\n";
+
+                std::vector<char> coord;
+                ComputeCoor( splitZone, icoord, coord );
+
+                cg_coord_write( fileId, baseId, zoneId, dataType, coordname.c_str(), coord.data(), &coorId );
+
+                std::cout << "fileId = " << fileId  << " baseId = " << baseId << " zoneId = " << zoneId  << " coorId = " << coorId << "\n";
+            }
+
+            std::vector< PhysicalSplitBc * > &bccoList = splitZone->physicalSplitBcList;
+
+            int nbocos = bccoList.size();
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = -1;
+                GridLocation_t location = Vertex;
+
+                std::string boconame = "BC" + std::to_string( iboco + 1 );
+
+                PhysicalSplitBc * physicalSplitBc = bccoList[ iboco ];
+                BCType_t bocotype = static_cast<BCType_t>( physicalSplitBc->bcType );
+                PointSetType_t ptset_type = PointRange;
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> pnts;
+                int nSize = physicalSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.end[ i ] );
+                }
+
+                cg_boco_write( fileId, baseId, zoneId, boconame.c_str(), bocotype, ptset_type, npnts, pnts.data(), & bccoId );
+            }
+
+            //std::vector< InterfaceSplitBc * > & bc1to1List = splitZone->interfaceSplitBcList;
+            std::vector< InterfaceSplitBc * > bc1to1List;
+            splitZone->GetLeafInterfaceBc( bc1to1List );
+
+            int n1to1 = bc1to1List.size();
+            std::cout << "n1to1 = " << n1to1 << "\n";
+
+            std::vector<int> itranfrm( index_dim );
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                itranfrm[ m ] = m + 1;
+            }
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int index_conn = -1;
+
+                InterfaceSplitBc * interfaceSplitBc = bc1to1List[ i1to1 ];
+
+                std::vector<cgsize_t> pnts;
+                std::vector<cgsize_t> pntsdonor;
+                int nSize = interfaceSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.end[ i ] );
+                }
+
+                int nPatchSize = interfaceSplitBc->donor_region.start.size();
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.start[ i ] );
+                }
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.end[ i ] );
+                }
+                int id = interfaceSplitBc->donor_zone->newIndex;
+                int oldZoneIndex = interfaceSplitBc->donor_zone->zoneIndex;
+                std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+                std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+                std::cout << "donor zone id = " << id << "\n";
+                std::cout << "donor zone oldZoneIndex = " << oldZoneIndex << "\n";
+                std::string donorname = "Zone" + std::to_string( id );
+                std::string connectname = "Interface" + std::to_string( i1to1 );
+
+                std::cout << "donorname = " << donorname << "\n";
+                std::cout << "connectname = " << connectname << "\n";
+
+                std::vector<int> & itranfrm = interfaceSplitBc->transform;
+
+                cg_1to1_write( fileId, baseId, zoneId, connectname.c_str(), donorname.c_str(), pnts.data(), pntsdonor.data(), itranfrm.data(), &index_conn );
+                std::cout << "index_conn = " << index_conn << "\n";
+            }
+        }
+    }
+    cg_close( fileId );
+}
+
+void Partition::ModifyZoneIndex()
+{
+    std::cout << "ModifyZoneIndex +++++++++++++++++++++++++ " << "\n";
+    int globalZoneId = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        std::cout << "iProc = " << iProc << "\n";
+        int nZones = this->GetNZones( iProc );
+        std::cout << "nZones in Proc " << iProc << "  = " << nZones << "\n";
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+            //splitZone->SetZoneIndex( globalZoneId++ );
+            splitZone->newIndex = ( globalZoneId++ );
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+        }
+    }
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage3/01a/Partition.h b/example/partition/struct/2d/stage3/01a/Partition.h
new file mode 100644
index 00000000..8a4a9731
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01a/Partition.h
@@ -0,0 +1,59 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class SplitZone;
+
+struct CmpSplitZone 
+{
+    bool operator() ( SplitZone * a, SplitZone * b ) const;
+};
+
+class Partition
+{
+public:
+    Partition();
+    ~Partition();
+protected:
+    std::set < SplitZone * > zoneStorage;
+    std::set < SplitZone *, CmpSplitZone > unsignedZoneGroup;
+    std::vector< SplitZone * > refZone;
+    std::vector< std::vector< SplitZone * > > procSplitZone;
+    std::vector<double> procSpeed;
+    std::vector<double> timeProc;
+    double aveFloatOp, delta;
+    double idealUniProcTime, eps;
+    int minNumberCell;
+    int nTZone;
+    int nOriZone;
+    int nProc;
+public:
+    std::string inputName;
+    std::string outName;
+public:
+    void Solve();
+    void ReadGrid();
+    void Split();
+    void InitSplit();
+    void BinarySplit();
+    //void GreedySplit();
+public:
+    void AddNewZone( SplitZone * zone );
+    void AddZoneToUnsignedGroup( SplitZone * zone );
+    void RemoveZoneFromUnsignedGroup( SplitZone * zone );
+    void AddZoneToProcess( int iProc, SplitZone * zone );
+    void DumpPartitionedGridFile();
+    void ModifyZoneIndex();
+    void FreeAllZones();
+    int GetNZones( int iProc );
+    SplitZone * GetSplitZone( int iProc, int zoneId );
+    void ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord );
+    void DumpBc( SplitZone * splitZone );
+private:
+    int GetMinValueIndex( double * data, int numberOfData );
+    int GetMinLoadProc();
+    SplitZone * GetLargestZone();
+    SplitZone * Split( SplitZone * zone, double nCell );
+};
+
diff --git a/example/partition/struct/2d/stage3/01a/README.txt b/example/partition/struct/2d/stage3/01a/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01a/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/partition/struct/2d/stage3/01a/SplitZone.cpp b/example/partition/struct/2d/stage3/01a/SplitZone.cpp
new file mode 100644
index 00000000..aef70754
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01a/SplitZone.cpp
@@ -0,0 +1,1091 @@
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+int Dim::dim = -1;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox  )
+{
+    domainBox.start = zoneBox.start;
+    domainBox.end = zoneBox.end;
+
+    int axis = iDomain / 2;
+    int direction = iDomain % 2;
+
+    if ( direction == 0 )
+    {
+        domainBox.end[ axis ] = domainBox.start[ axis ];
+    }
+    else if ( direction == 1 )
+    {
+        domainBox.start[ axis ] = domainBox.end[ axis ];
+    }
+}
+
+DimInfo::DimInfo()
+{
+    this->Init( 1 );
+}
+
+DimInfo::~DimInfo()
+{
+}
+
+void DimInfo::Init( int dim )
+{
+    this->dim = dim;
+    dimList.resize( this->dim, 1 );
+    oriPoint.resize( this->dim, 0 );
+}
+
+DimInfo & DimInfo::operator = ( const DimInfo & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->dim = rhs.dim;
+    this->dimList = rhs.dimList;
+    this->oriPoint = rhs.oriPoint;
+
+    return * this;
+}
+
+int DimInfo::ComputeNumNodes()
+{
+    int nNodes = 1;
+    for ( int m = 0; m < this->dimList.size(); ++ m )
+    {
+        nNodes *= this->dimList[ m ];
+    }
+    return nNodes;
+}
+
+void DimInfo::ComputeISize()
+{
+    int index_dim = this->dimList.size();
+    this->isize.resize( index_dim * 3, 0 );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        isize[ m ] = this->dimList[ m ];
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 1;
+        isize[ start + m ] = this->dimList[ m ] - 1;
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 2;
+        isize[ start + m ] = 0;
+    }
+
+    for ( int i = 0; i < isize.size(); ++ i )
+    {
+        std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+    }
+}
+
+void DimInfo::ComputeRminmax( std::vector<int> & ref )
+{
+    int index_dim = this->dimList.size();
+    this->rmin.resize( index_dim );
+    this->rmax.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        rmin[ m ] = ref[ m ] + 1;
+        rmax[ m ] = ref[ m ] + this->dimList[ m ];
+    }
+
+    std::cout << "rmin, rmax = \n";
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        std::cout << rmin[ m ] << " " << rmax[ m ] << "\n";
+    }
+}
+
+void DimInfo::Init( std::vector<int> & dimList )
+{
+    this->dim = dimList.size();
+    this->dimList = dimList;
+    std::vector<int> zero( dimList.size(), 0 );
+    this->oriPoint = zero;
+}
+
+void DimInfo::SetNewDimension( int axis, int newStart, int newWidth )
+{
+    this->oriPoint[ axis ] = newStart;
+    this->dimList [ axis ] = newWidth;
+}
+
+void DimInfo::GetZoneGlobalBox( RangeRegion &zoneBox )
+{
+    int index_dim = this->dimList.size();
+    zoneBox.start.resize( index_dim );
+    zoneBox.end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        zoneBox.start[ m ] = this->oriPoint[ m ] + 1;
+        zoneBox.end[ m ] = this->oriPoint[ m ] + this->dimList[ m ];
+    }
+}
+
+void DimInfo::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    int index_dim = this->dimList.size();
+    localBox.start.resize( index_dim );
+    localBox.end.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        localBox.start[ m ] = globalBox.start[ m ] - this->oriPoint[ m ];
+        localBox.end[ m ] = globalBox.end[ m ] - this->oriPoint[ m ];
+    }
+}
+
+RangeRegion::RangeRegion( int nSize )
+{
+    this->Init( nSize );
+}
+
+RangeRegion::~RangeRegion()
+{
+}
+
+void RangeRegion::Init( int nSize )
+{
+    this->start.resize( nSize );
+    this->end.resize( nSize );
+}
+
+RangeRegion & RangeRegion::operator = ( const RangeRegion & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+bool RangeRegion::operator == ( const RangeRegion & rhs ) const
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] != rhs.start[ m ] || 
+            this->end  [ m ] != rhs.end  [ m ] )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+bool RangeRegion::InRegion( const RangeRegion & region )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( ( this->start[ m ] < region.start[ m ] ) || ( this->end[ m ] > region.end[ m ] ) )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::Normalize()
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        int minv = std::min( this->start[ m ], this->end[ m ] );
+        int maxv = std::max( this->start[ m ], this->end[ m ] );
+        this->start[ m ] = minv;
+        this->end[ m ] = maxv;
+    }
+}
+
+void RangeRegion::Localize( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] -= oriPoint[ m ];
+        this->end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void RangeRegion::ToGlobal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] += oriPoint[ m ];
+        this->end[ m ] += oriPoint[ m ];
+    }
+}
+
+void RangeRegion::ToLocal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] -= oriPoint[ m ];
+        this->end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void RangeRegion::PrintGlobal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    std::cout << "global start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ] + oriPoint[m];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "global end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ] + oriPoint[m];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+void RangeRegion::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion );
+
+bool ComputeOverlapRegion( RangeRegion & region1, RangeRegion & region2, RangeRegion & overlapRegion )
+{
+    int index_dim = region1.start.size();
+    overlapRegion.Init( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int ijkmin1 = std::min( region1.start[ m ], region1.end[ m ] );
+        int ijkmax1 = std::max( region1.start[ m ], region1.end[ m ] );
+        int ijkmin2 = std::min( region2.start[ m ], region2.end[ m ] );
+        int ijkmax2 = std::max( region2.start[ m ], region2.end[ m ] );
+        if ( ( ijkmax1 < ijkmin2 ) || ( ijkmin1 > ijkmax2 ) )
+        {
+            return false;
+        }
+
+        int ijkmin = std::max( ijkmin1, ijkmin2 );
+        int ijkmax = std::min( ijkmax1, ijkmax2 );
+
+        overlapRegion.start[ m ] = ijkmin;
+        overlapRegion.end  [ m ] = ijkmax;
+    }
+
+    return CheckOverLapping( overlapRegion );
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion )
+{
+    int index_dim = overlapRegion.start.size();
+    int iCount = 0;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        if ( overlapRegion.start[ m ] == overlapRegion.end[ m ] )
+        {
+            ++ iCount;
+        }
+    }
+
+    return ( iCount == 1 );
+}
+
+bool GetInterfaceRegion( RangeRegion & zoneBoxL, RangeRegion & zoneBoxR, RangeRegion & interfaceRegion )
+{
+    int index_dim = zoneBoxL.start.size();
+    int nDomains = 2 * index_dim;
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegionL;
+        GetDomainRegion( zoneBoxL, iDomain, domainRegionL );
+
+        for ( int jDomain = 0; jDomain < nDomains; ++ jDomain )
+        {
+            RangeRegion domainRegionR;
+            GetDomainRegion( zoneBoxR, jDomain, domainRegionR );
+
+            if ( domainRegionL == domainRegionR )
+            {
+                interfaceRegion = domainRegionL;
+                return true;
+            }
+        }
+    }
+    return false;
+}
+
+void CreateInterfaceBc( SplitZone * zoneL, SplitZone * zoneR )
+{
+    RangeRegion globalBoxL, globalBoxR, globalInterfaceRegion;
+
+    zoneL->GetZoneGlobalBox( globalBoxL );
+    zoneR->GetZoneGlobalBox( globalBoxR );
+
+    if ( ! GetInterfaceRegion( globalBoxL, globalBoxR, globalInterfaceRegion ) )
+    {
+        return;
+    }
+
+    RangeRegion localInterfaceRegionL, localInterfaceRegionR;
+
+    zoneL->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionL );
+    zoneR->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionR );
+
+    int kkk = 1;
+
+    InterfaceSplitBc * interfaceSplitBcL = new InterfaceSplitBc();
+    zoneL->interfaceSplitBcList.push_back( interfaceSplitBcL );
+    interfaceSplitBcL->zone = zoneL;
+    interfaceSplitBcL->region = localInterfaceRegionL;
+
+    int nSize = localInterfaceRegionL.start.size();
+
+    std::vector<int> transform;
+
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        transform.push_back( m + 1 );
+    }
+
+    interfaceSplitBcL->transform = transform;
+    interfaceSplitBcL->CalcTransformMatrix();
+
+    interfaceSplitBcL->donor_zone = zoneR;
+    interfaceSplitBcL->donor_region = localInterfaceRegionR;
+
+    InterfaceSplitBc * interfaceSplitBcR = new InterfaceSplitBc();
+    zoneR->interfaceSplitBcList.push_back( interfaceSplitBcR );
+
+    interfaceSplitBcR->zone = zoneR;
+    interfaceSplitBcR->region = localInterfaceRegionR;
+
+    interfaceSplitBcR->transform = transform;
+    interfaceSplitBcR->CalcTransformMatrix();
+
+    interfaceSplitBcR->donor_zone = zoneL;
+    interfaceSplitBcR->donor_region = localInterfaceRegionL;
+}
+
+
+PhysicalSplitBc::PhysicalSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+PhysicalSplitBc::~PhysicalSplitBc()
+{
+}
+
+void PhysicalSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void PhysicalSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+void PhysicalSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = splitZone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+BasicSplitBc::BasicSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+BasicSplitBc::~BasicSplitBc()
+{
+    ;
+}
+
+void BasicSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void BasicSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+int trans::M[ 3 ][ 3 ];
+std::vector<int> trans::transform;
+
+int trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void trans::CalcTransformMatrix()
+{
+    int dim = trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = trans::transform[ 0 ];
+        int sgna = trans::sgn( a );
+        int a1 = trans::del( a, 1 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int c = trans::transform[ 2 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int sgnc = trans::sgn( c );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int a3 = trans::del( a, 3 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        int b3 = trans::del( b, 3 );
+        int c1 = trans::del( c, 1 );
+        int c2 = trans::del( c, 2 );
+        int c3 = trans::del( c, 3 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 2 ][ 0 ] = sgna * a3;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+        trans::M[ 2 ][ 1 ] = sgnb * b3;
+        trans::M[ 0 ][ 2 ] = sgnc * c1;
+        trans::M[ 1 ][ 2 ] = sgnc * c2;
+        trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+InterfaceInfo::InterfaceInfo()
+{
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceInfo::~InterfaceInfo()
+{
+}
+
+InterfaceSplitBc::InterfaceSplitBc()
+{
+    this->region.Init( Dim::dim );
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceSplitBc::~InterfaceSplitBc()
+{
+}
+
+void InterfaceSplitBc::GetLeafInterfaceBc( std::vector< InterfaceSplitBc * > & leafInterfaceBcList )
+{
+    int nChild = this->child.size();
+    if ( nChild == 0 )
+    {
+        leafInterfaceBcList.push_back( this );
+    }
+    else
+    {
+        for ( int iChild = 0; iChild < nChild; ++ iChild )
+        {
+            InterfaceSplitBc * interfaceSplitBc = this->child[ iChild ];
+            interfaceSplitBc->GetLeafInterfaceBc( leafInterfaceBcList );
+        }
+    }
+}
+
+void InterfaceSplitBc::CopyMatrix( InterfaceSplitBc * interfaceSplitBc )
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = interfaceSplitBc->Mt[ i ][ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::CalcTransformMatrix()
+{
+    trans::ZeroMatrix();
+    trans::transform = this->transform;
+    trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = trans::M[ i ][ j ];
+        }
+    }
+
+}
+
+void InterfaceSplitBc::mapindex( std::vector<int> & begin1, std::vector<int> & begin2,  std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = Dim::dim;
+    std::vector<int> diff( dim );
+    for ( int m = 0; m < dim; ++ m )
+    {
+        diff[ m ] = index1[ m ] - begin1[ m ];
+    }
+
+    std::vector<int> mul( dim );
+
+    Multiply( Mt, diff, mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = mul[ m ] + begin2[ m ];
+    }
+}
+
+void InterfaceSplitBc::Multiply( int Mt[][3], std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = Dim::dim;
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = this->zone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void InterfaceSplitBc::CalcSubDonorRegion( RangeRegion &subRegion, RangeRegion &subDonorRegion )
+{
+    std::vector<int> begin1 = this->region.start;
+    std::vector<int> end1 = this->region.end;
+    std::vector<int> begin2 = this->donor_region.start;
+    std::vector<int> end2 = this->donor_region.end;
+
+    std::vector<int> new_begin1 = subRegion.start;
+    std::vector<int> new_end1 = subRegion.end;
+
+    int dim = Dim::dim;
+    std::vector<int> new_begin2( dim );
+    std::vector<int> new_end2( dim );
+
+    mapindex( begin1, begin2, new_begin1, new_begin2 );
+    mapindex( begin1, begin2, new_end1, new_end2 );
+
+    subDonorRegion.start = new_begin2;
+    subDonorRegion.end = new_end2;
+}
+
+SplitZone::SplitZone()
+{
+    this->parent  = 0;
+    this->zoneIndex = 0;
+    this->iProc = 0;
+    dimInfo.Init( Dim::dim );
+    int kk = 1;
+}
+
+SplitZone::~SplitZone()
+{
+    ;
+}
+
+void SplitZone::GetZoneGlobalBox( RangeRegion & zoneBox )
+{
+    this->dimInfo.GetZoneGlobalBox( zoneBox );
+}
+
+void SplitZone::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    this->dimInfo.GetZoneLocalBox( globalBox, localBox );
+}
+
+
+void SplitZone::ComputeRminmax()
+{
+    int index_dim = this->dimInfo.dimList.size();
+    std::vector<int> ref( index_dim, 0 );
+
+    SplitZone * rootSplitZone = 0;
+    this->GetRootInfo( rootSplitZone, ref );
+
+    this->dimInfo.ComputeRminmax( ref );
+}
+
+SplitZone * SplitZone::GetRootZone()
+{
+    SplitZone * root = this;
+
+    while ( true )
+    {
+        if ( root->parent )
+        {
+            root = root->parent;
+        }
+        else
+        {
+            return root;
+        }
+    };
+}
+
+void SplitZone::GetRootInfo( SplitZone *& root, std::vector<int> & ref )
+{
+    for ( int i = 0; i < this->dimInfo.dimList.size(); ++ i )
+    {
+        ref[ i ] += this->dimInfo.oriPoint[ i ];
+    }
+
+    if ( this->parent )
+    {
+        this->parent->GetRootInfo( root, ref );
+    }
+    else
+    {
+        root = this;
+    }
+}
+
+void SplitZone::SetParentAndChild( SplitZone * parent )
+{
+    this->parent = parent;
+    if ( parent )
+    {
+        parent->child.push_back( this );
+    }
+}
+
+void SplitZone::GetLeafInterfaceBc( std::vector< InterfaceSplitBc * > & leafInterfaceBcList )
+{
+    int nInterfaceBcs = this->interfaceSplitBcList.size();
+    for ( int i = 0; i < nInterfaceBcs; ++ i )
+    {
+        InterfaceSplitBc * interfaceSplitBc = this->interfaceSplitBcList[ i ];
+        interfaceSplitBc->GetLeafInterfaceBc( leafInterfaceBcList );
+    }
+}
+
+int SplitZone::GetNCell()
+{
+    int numberOfCells = 1;
+    for ( int i = 0; i < this->dimInfo.dim; ++ i )
+    {
+        numberOfCells *= std::max( 1, ( this->dimInfo.dimList[ i ] - 1 ) );
+    }
+
+    return numberOfCells; 
+}
+
+void SplitZone::SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int leftStart = 0;
+    int leftWidth = iSplit - 0;
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, leftStart , leftWidth  );
+}
+
+void SplitZone::SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int rightStart = iSplit - 1;
+    int rightWidth = dimList[ axisNeedSplit ] - ( iSplit - 1 );
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, rightStart, rightWidth );
+}
+
+void SplitZone::Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell )
+{
+    //Find the longest axis
+    int axisNeedSplit = this->FindAxisNeedSplit();
+    int iSplit        = this->FindSplitPosition( axisNeedSplit, nCell );
+
+    zoneL->SetLeftDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+    zoneR->SetRightDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+
+    zoneL->CreateBcFromParent();
+    zoneR->CreateBcFromParent();
+    
+    CreateInterfaceBc( zoneL, zoneR );
+}
+
+void SplitZone::CreateBcFromParent()
+{
+    this->CreatePhysicalBcFromParent();
+    this->CreateInterfaceBcFromParent();
+}
+
+void SplitZone::CreatePhysicalBcFromParent()
+{
+    int nParentPhysicalBcs = this->parent->physicalSplitBcList.size();
+
+    for ( int iParentPhysicalBcs = 0; iParentPhysicalBcs < nParentPhysicalBcs; ++ iParentPhysicalBcs )
+    {
+        PhysicalSplitBc * parentPhysicalSplitBc = this->parent->physicalSplitBcList[ iParentPhysicalBcs ];
+
+        this->CreatePhysicalBcFromParent( parentPhysicalSplitBc );
+    }
+}
+
+void SplitZone::CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentPhysicalSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreatePhysicalBc( overlapRegion, parentPhysicalSplitBc->bcType );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent()
+{
+    int nInterfaceSplitBcs = this->parent->interfaceSplitBcList.size();
+
+    for ( int iInterfaceSplitBcs = 0; iInterfaceSplitBcs < nInterfaceSplitBcs; ++ iInterfaceSplitBcs )
+    {
+        InterfaceSplitBc * parentInterfaceSplitBc = this->parent->interfaceSplitBcList[ iInterfaceSplitBcs ];
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc );
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentInterfaceSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc, overlapRegion );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::FindDonorInterface( InterfaceSplitBc * interfaceSplitBc, InterfaceInfo & interfaceInfo )
+{
+    RangeRegion donor_region = interfaceSplitBc->donor_region;
+    donor_region.Normalize();
+    interfaceInfo.donor_zone = this;
+    for ( int iInterface = 0; iInterface < interfaceSplitBcList.size(); ++ iInterface )
+    {
+        InterfaceSplitBc * candidateDonorBc = interfaceSplitBcList[ iInterface ];
+        bool flag = donor_region.InRegion( candidateDonorBc->region );
+        if ( flag )
+        {
+            if ( donor_region == candidateDonorBc->region )
+            {
+                interfaceInfo.donor_interface = candidateDonorBc;
+                return;
+            }
+            else
+            {
+                InterfaceSplitBc * donorBc = new InterfaceSplitBc();
+                candidateDonorBc->child.push_back( donorBc );
+                donorBc->region = donor_region;
+                donorBc->zone = candidateDonorBc->zone;
+                donorBc->donor_zone = interfaceSplitBc->zone;
+                donorBc->transform = candidateDonorBc->transform;
+                donorBc->CopyMatrix( candidateDonorBc );
+                RangeRegion subDonorRegion( Dim::dim );
+                candidateDonorBc->CalcSubDonorRegion( donorBc->region, subDonorRegion );
+                std::vector<int> & oriPoint = interfaceSplitBc->zone->dimInfo.oriPoint;
+                subDonorRegion.Localize( oriPoint );
+                donorBc->donor_region = subDonorRegion;
+                donorBc->donor_bc = interfaceSplitBc;
+                interfaceInfo.donor_interface = donorBc;
+                return;
+            }
+        }
+    }
+    return;
+}
+
+void SplitZone::GetChildDonorRegion( RangeRegion & subDonorRegion, InterfaceInfo & interfaceInfo )
+{
+    std::cout << "subDonorRegion = \n";
+    //subDonorRegion.Print();
+    RangeRegion normalizedDonorRegion = subDonorRegion;
+    normalizedDonorRegion.Normalize();
+    int nChild = this->child.size();
+    for ( int ichild = 0; ichild < nChild; ++ ichild )
+    {
+        std::cout << " iChild = " << ichild << " nChild = " << nChild << "\n";
+        SplitZone * sub_zone = this->child[ ichild ];
+        std::cout << " zoneIndex = " << sub_zone->zoneIndex << "\n";
+        int nInters = sub_zone->interfaceSplitBcList.size();
+        for ( int iInter = 0; iInter < nInters; ++ iInter )
+        {
+            std::cout << " iInter = " << iInter << "\n";
+            InterfaceSplitBc * interfaceSplitBc = sub_zone->interfaceSplitBcList[ iInter ];
+            std::cout << "interfaceSplitBc local = \n";
+            interfaceSplitBc->region.Print();
+            std::cout << "interfaceSplitBc global = \n";
+            interfaceSplitBc->region.PrintGlobal( sub_zone->dimInfo.oriPoint );
+            RangeRegion g_region = interfaceSplitBc->region;
+            g_region.ToGlobal( sub_zone->dimInfo.oriPoint );
+            if ( g_region == normalizedDonorRegion )
+            {
+                RangeRegion donorRegion = subDonorRegion;
+                donorRegion.ToLocal( sub_zone->dimInfo.oriPoint );
+
+                interfaceInfo.donor_zone = sub_zone;
+                interfaceInfo.donor_interface = interfaceSplitBc;
+                interfaceInfo.donor_region = donorRegion;
+                return;
+            }
+        }
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion )
+{
+    InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+    this->interfaceSplitBcList.push_back( interfaceSplitBc );
+
+    interfaceSplitBc->region = overlapRegion;
+    interfaceSplitBc->zone = this;
+    interfaceSplitBc->transform = parentInterfaceSplitBc->transform;
+    interfaceSplitBc->CopyMatrix( parentInterfaceSplitBc );
+    RangeRegion subDonorRegion( Dim::dim );
+    parentInterfaceSplitBc->CalcSubDonorRegion( overlapRegion, subDonorRegion );
+    interfaceSplitBc->ChangeRegionToLocalCoordinate();
+    interfaceSplitBc->donor_region = subDonorRegion;
+    SplitZone * parent_donor_zone = parentInterfaceSplitBc->donor_zone;
+    std::cout << " parentInterfaceSplitBc->zone->zoneIndex " << parentInterfaceSplitBc->zone->zoneIndex << "\n";
+    std::cout << " parentInterfaceSplitBc->donor_zone->zoneIndex " << parent_donor_zone->zoneIndex << "\n";
+    if ( parent_donor_zone->child.size() > 0 )
+    {
+        InterfaceInfo interfaceInfo;
+        parent_donor_zone->GetChildDonorRegion( subDonorRegion, interfaceInfo );
+        interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+        interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+        interfaceSplitBc->donor_region = interfaceInfo.donor_region;
+        //compatibility
+        InterfaceSplitBc * donor_bc = interfaceSplitBc->donor_bc;
+        SplitZone * donor_zone = interfaceSplitBc->donor_zone;
+        if ( interfaceSplitBc->zone != donor_bc->donor_zone )
+        {
+            if ( interfaceSplitBc->zone->parent == donor_bc->donor_zone )
+            {
+                RangeRegion d_region = donor_bc->donor_region;
+                d_region.ToLocal( interfaceSplitBc->zone->dimInfo.oriPoint );
+                donor_bc->donor_region = d_region;
+            }
+            donor_bc->donor_zone = interfaceSplitBc->zone;
+         
+            int kkk = 1;
+        }
+        int kkk = 1;
+    }
+    else
+    {
+        InterfaceInfo interfaceInfo;
+        parent_donor_zone->FindDonorInterface( interfaceSplitBc, interfaceInfo );
+        interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+        interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+    }
+    
+    int kkk = 1;
+}
+
+void SplitZone::CreatePhysicalBc( RangeRegion & overlapRegion, int bcType )
+{
+    PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+    this->physicalSplitBcList.push_back( physicalSplitBc );
+    physicalSplitBc->SetRegion( overlapRegion );
+    physicalSplitBc->bcType = bcType;
+    physicalSplitBc->splitZone = this;
+    physicalSplitBc->ChangeRegionToLocalCoordinate();
+}
+
+int SplitZone::FindAxisNeedSplit()
+{
+    //Find the longest axis
+    int axisNeedSplit = 0;
+    int maxN = this->dimInfo.dimList[ 0 ];
+
+    for ( int m = 1; m < this->dimInfo.dimList.size(); ++ m )
+    {
+        if ( this->IsPoleBc( m ) )
+        {
+            continue;
+        }
+        int Nm = this->dimInfo.dimList[ m ];
+        if ( maxN < Nm )
+        {
+            maxN = Nm;
+            axisNeedSplit = m;
+        }
+    }
+
+    return axisNeedSplit;
+}
+
+int SplitZone::GetCrossSection( int axis )
+{
+    int nDim = this->dimInfo.dimList.size();
+    int crossSection = 1;
+    int N = nDim - 1;
+    for ( int m = 0; m < N; ++ m )
+    {
+         int mm = ( axis + 1 ) % nDim;
+         int nLineElements = std::max( 1, ( this->dimInfo.dimList[ mm ] - 1 ) );
+         crossSection *= nLineElements;
+    }
+    return crossSection;
+}
+
+int SplitZone::FindSplitPosition( int axisNeedSplit, double nCell )
+{
+    int nDim = this->dimInfo.dimList.size();
+    std::vector<int> crossSections( nDim );
+    for ( int m = 0; m < nDim; ++ m )
+    {
+        crossSections[ m ] = this->GetCrossSection( m );
+    }
+
+    //guess the value
+    double dSplit = nCell / crossSections[ axisNeedSplit ];
+    int  iSplit = 1 + static_cast< int >( std::floor( dSplit + 0.5 ) );
+    return iSplit;
+}
+
+
+bool SplitZone::IsPoleBc( int splitDirection )
+{
+    return false;
+}
+
diff --git a/example/partition/struct/2d/stage3/01a/SplitZone.h b/example/partition/struct/2d/stage3/01a/SplitZone.h
new file mode 100644
index 00000000..ffe1e306
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01a/SplitZone.h
@@ -0,0 +1,196 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class Dim
+{
+public:
+    static int dim;
+};
+
+class SplitZone;
+class RangeRegion;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox );
+
+class DimInfo
+{
+public:
+    DimInfo();
+    ~DimInfo();
+public:
+    int dim;
+    std::vector<int> dimList;
+    std::vector<int> oriPoint;
+    std::vector<int> isize;
+    std::vector<int> rmin;
+    std::vector<int> rmax;
+public:
+    int GetSize() const { return dim; }
+    DimInfo & operator = ( const DimInfo & rhs );
+public:
+    int ComputeNumNodes();
+    void ComputeISize();
+    void ComputeRminmax( std::vector<int> & ref );
+    void Init( int dim );
+    void Init( std::vector<int> & dimList );
+    void SetNewDimension( int axis, int newStart, int newWidth );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+};
+
+class SplitZone;
+class SplitBcPatch;
+
+class RangeRegion
+{
+public:
+    RangeRegion( int nSize = 1 );
+    ~RangeRegion();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    void Init( int nSize );
+    RangeRegion & operator = ( const RangeRegion & rhs );
+    bool operator == ( const RangeRegion & rhs ) const;
+    bool InRegion( const RangeRegion & region );
+    void SetRegion( std::vector<int> &pnts );
+    void Normalize();
+    void Localize( std::vector<int> & oriPoint );
+    void ToGlobal( std::vector<int> & oriPoint );
+    void ToLocal( std::vector<int> & oriPoint );
+    void PrintGlobal( std::vector<int> & oriPoint );
+    void Print();
+};
+
+class PhysicalSplitBc
+{
+public:
+    PhysicalSplitBc();
+    ~PhysicalSplitBc();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class BasicSplitBc
+{
+public:
+    BasicSplitBc();
+    ~BasicSplitBc();
+public:
+    RangeRegion region;
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> & pnts );
+    void SetRegion( RangeRegion & region );
+};
+
+class trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class InterfaceSplitBc;
+class SplitZone;
+
+class InterfaceInfo
+{
+public:
+    InterfaceInfo();
+    ~InterfaceInfo();
+public:
+    InterfaceSplitBc * donor_interface = nullptr;
+    SplitZone * donor_zone = nullptr;
+    RangeRegion donor_region;
+};
+
+class InterfaceSplitBc
+{
+public:
+    InterfaceSplitBc();
+    ~InterfaceSplitBc();
+public:
+    std::vector<int> transform;
+    int Mt[ 3 ][ 3 ];
+    RangeRegion region;
+    SplitZone * zone = nullptr;
+    RangeRegion donor_region;
+    SplitZone * donor_zone = nullptr;
+    InterfaceSplitBc * donor_bc = nullptr;
+public:
+    std::vector<InterfaceSplitBc *> child;
+    void GetLeafInterfaceBc( std::vector< InterfaceSplitBc * > & leafInterfaceBcList );
+public:
+    void CopyMatrix( InterfaceSplitBc * interfaceSplitBc );
+    void CalcTransformMatrix();
+    void CalcSubDonorRegion( RangeRegion & subRegion, RangeRegion & subDonorRegion );
+    void mapindex( std::vector<int> & begin1, std::vector<int> & begin2, std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( int Mt[][ 3 ], std::vector<int> & a, std::vector<int> & b );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class SplitZone
+{
+public:
+    SplitZone();
+    ~SplitZone();
+public:
+    DimInfo dimInfo;
+    int zoneIndex, iProc;
+    int newIndex;
+protected:
+    SplitZone * parent;
+    std::vector<SplitZone *> child;
+public:
+    std::vector< PhysicalSplitBc * > physicalSplitBcList;
+    std::vector< InterfaceSplitBc * > interfaceSplitBcList;
+    void GetLeafInterfaceBc( std::vector< InterfaceSplitBc * > & leafInterfaceBcList );
+public:
+    int GetNCell();
+    void ComputeRminmax();
+    void GetRootInfo( SplitZone *& root, std::vector<int> & ref );
+    void SetZoneIndex( int zoneIndex ) { this->zoneIndex = zoneIndex; }
+    int  GetZoneIndex() { return zoneIndex; }
+    void SetProcId( int iProc ) { this->iProc = iProc; }
+    void SetParent( SplitZone * parent ) { this->parent = parent; };
+    void SetParentAndChild( SplitZone * parent );
+    void FindDonorInterface( InterfaceSplitBc * interfaceSplitBc, InterfaceInfo & interfaceInfo );
+    void GetChildDonorRegion( RangeRegion & subDonorRegion, InterfaceInfo & interfaceInfo );
+public:
+    void CreateBcFromParent();
+    void CreatePhysicalBcFromParent();
+    void CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc );
+    void CreatePhysicalBc( RangeRegion & overlapRegion, int bcType );
+    void CreateInterfaceBcFromParent();
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc );
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion );
+
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+    SplitZone * GetRootZone();
+public:
+    void Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell );
+    void SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+    void SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+private:
+    int FindAxisNeedSplit();
+    int FindSplitPosition( int axisNeedSplit, double nCell );
+    bool IsPoleBc( int splitDirection );
+    int GetCrossSection( int axis );
+};
+
diff --git a/example/partition/struct/2d/stage3/01a/heat2d1blockv1.cgns b/example/partition/struct/2d/stage3/01a/heat2d1blockv1.cgns
new file mode 100644
index 00000000..4aa7832a
Binary files /dev/null and b/example/partition/struct/2d/stage3/01a/heat2d1blockv1.cgns differ
diff --git a/example/partition/struct/2d/stage3/01a/heat2dpart.cgns b/example/partition/struct/2d/stage3/01a/heat2dpart.cgns
new file mode 100644
index 00000000..8e4fd883
Binary files /dev/null and b/example/partition/struct/2d/stage3/01a/heat2dpart.cgns differ
diff --git a/example/partition/struct/2d/stage3/01a/main.cpp b/example/partition/struct/2d/stage3/01a/main.cpp
new file mode 100644
index 00000000..5da1de7c
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01a/main.cpp
@@ -0,0 +1,18 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include "Partition.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip>
+
+int main(int argc, char **argv)
+{
+    Partition * partition = new Partition();
+    partition->Solve();
+    delete partition;
+
+    return 0;
+}
diff --git a/example/partition/struct/2d/stage3/01b/CMakeLists.txt b/example/partition/struct/2d/stage3/01b/CMakeLists.txt
new file mode 100644
index 00000000..74ceea7d
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01b/CMakeLists.txt
@@ -0,0 +1,78 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	Partition.h Partition.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	SplitZone.h SplitZone.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/partition/struct/2d/stage3/01b/CgnsGrid.cpp b/example/partition/struct/2d/stage3/01b/CgnsGrid.cpp
new file mode 100644
index 00000000..dfe750bd
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01b/CgnsGrid.cpp
@@ -0,0 +1,349 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include <map>
+
+Grid::Grid()
+{
+    ;
+}
+
+Grid::~Grid()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if( (i+1)%5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+    delete this->patch;
+}
+
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+ZoneBcPatch::ZoneBcPatch()
+{
+    ;
+}
+
+ZoneBcPatch::~ZoneBcPatch()
+{
+}
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+Global::Global()
+{
+    ;
+}
+
+Global::~Global()
+{
+}
+
+void Global::FreeData()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+    zones.resize( 0 );
+}
+
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            //baseZone.baseId = baseId;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin( index_dim );
+            std::vector<cgsize_t> irmax( index_dim );
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                std::vector<char> coord( nNodes * sizeof(double) );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+                coor->DumpCoor();
+            }
+
+            int nbocos = -1;
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+                int kkk = 1;
+            }
+        }
+        int kkk = 1;
+    }
+    int kkk = 1;
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage3/01b/CgnsGrid.h b/example/partition/struct/2d/stage3/01b/CgnsGrid.h
new file mode 100644
index 00000000..053c467b
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01b/CgnsGrid.h
@@ -0,0 +1,140 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <map>
+
+class Grid;
+
+class Zone;
+
+class Grid
+{
+public:
+    Grid();
+    ~Grid();
+public:
+    int nZone;
+    std::vector<double> x;
+    std::vector<Zone *> zones;
+};
+
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+};
+
+class ZoneBc;
+class ZoneBc1To1;
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class ZoneBcPatch;
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+    ZoneBcPatch * patch = nullptr;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+class ZoneBcPatch
+{
+public:
+    ZoneBcPatch();
+    ~ZoneBcPatch();
+public:
+    int donor_zoneid;
+    std::vector<int> transform;
+    std::vector<int> donor_pnts;
+};
+
+class BaseZone
+{
+public:
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Global
+{
+public:
+    Global();
+    ~Global();
+public:
+    static int cell_dim;
+    static int phys_dim;
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+public:
+    static void FreeData();
+};
+
+void ReadCgnsGrid( const std::string & filename );
+void ReadCgnsGridBaseZone( const std::string & filename );
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage3/01b/Partition.cpp b/example/partition/struct/2d/stage3/01b/Partition.cpp
new file mode 100644
index 00000000..f509f1d1
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01b/Partition.cpp
@@ -0,0 +1,621 @@
+#include "Partition.h"
+#include "CgnsGrid.h"
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+bool CmpSplitZone::operator() ( SplitZone * a, SplitZone * b ) const
+{
+    return a->zoneIndex < b->zoneIndex;
+};
+
+
+double CalSumOfProcSpeed( std::vector<double> & procSpeed );
+double CalSumOfProcSpeed( std::vector<double> & procSpeed )
+{
+    int nProc = procSpeed.size();
+    double sumOfProcSpeed = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        sumOfProcSpeed += procSpeed[ iProc ];
+    }
+    return sumOfProcSpeed;
+}
+
+Partition::Partition()
+{
+    this->inputName = "../heat2d1blockv1.cgns";
+    this->outName =  "../heat2dpart.cgns";
+}
+
+Partition::~Partition()
+{
+    ;
+}
+
+int Partition::GetMinValueIndex( double * data, int numberOfData )
+{
+    double minValue = data[ 0 ];
+    int minimumValueIndex = 0;
+
+    for ( int iData = 1; iData < numberOfData; ++ iData )
+    {
+        if ( minValue > data[ iData ] )
+        {
+            minValue      = data[ iData ];
+            minimumValueIndex = iData;
+        }
+    }
+    return minimumValueIndex;
+}
+
+int Partition::GetMinLoadProc()
+{
+    return this->GetMinValueIndex( this->timeProc.data(), this->nProc );
+}
+
+SplitZone * Partition::GetLargestZone()
+{
+    SplitZone * largestZone = 0;
+
+    double nMaxCell = 0.0;
+
+    for ( std::set< SplitZone * >::iterator iter = unsignedZoneGroup.begin(); iter != unsignedZoneGroup.end(); ++ iter )
+    {
+        double nSize = ( * iter )->GetNCell();
+        if ( nMaxCell < nSize )
+        {
+            nMaxCell    = nSize;
+            largestZone = * iter;
+        }
+    }
+
+    return largestZone;
+}
+
+void Partition::Solve()
+{
+    std::cout << "Partition::Split()\n";
+    //this->nProc = 2;
+    //this->nProc = 3;
+    this->nProc = 4;
+    this->ReadGrid();
+    this->Split();
+    this->DumpPartitionedGridFile();
+    this->FreeAllZones();
+}
+
+void Partition::ReadGrid()
+{
+    ReadCgnsGridBaseZone( this->inputName );
+    ReadCgnsGrid( this->inputName );
+
+    this->nOriZone = ::Global::zones.size();
+    Dim::dim = Global::cell_dim;
+
+    std::cout << "numberOfBlocks = " << nOriZone << "\n";
+
+    this->refZone.resize( nOriZone );
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = new SplitZone();
+        refZone[ iZone ] = splitZone;
+
+        splitZone->SetZoneIndex( iZone );
+        splitZone->SetProcId( 0 );
+        splitZone->SetParentAndChild( 0 );
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        Zone * zone = ::Global::zones[ iZone ];
+
+        splitZone->dimInfo.dimList = zone->nijk;
+
+        int nbccos = zone->bccos.size();
+        std::cout << "nbccos = " << nbccos << "\n";
+
+        for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+        {
+            ZoneBc * zoneBc = zone->bccos[ ibcco ];
+
+            PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+            splitZone->physicalSplitBcList.push_back( physicalSplitBc );
+            physicalSplitBc->bcType = zoneBc->bcType;
+            physicalSplitBc->SetRegion( zoneBc->pnts );
+            physicalSplitBc->splitZone = splitZone;
+        }
+
+        int nbc1to1s = zone->bc1to1s.size();
+
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * zoneBc1To1 = zone->bc1to1s[ ibc1to1 ];
+
+            InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+            splitZone->interfaceSplitBcList.push_back( interfaceSplitBc );
+            interfaceSplitBc->zone = splitZone;
+            interfaceSplitBc->region.SetRegion( zoneBc1To1->pnts );
+
+            interfaceSplitBc->transform = zoneBc1To1->transform;
+            interfaceSplitBc->CalcTransformMatrix();
+
+            interfaceSplitBc->donor_zone = refZone[ zoneBc1To1->donor_zoneid ];
+            interfaceSplitBc->donor_region.SetRegion( zoneBc1To1->donor_pnts );
+        }
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        int nbc1to1s = splitZone->interfaceSplitBcList.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            InterfaceSplitBc * interfaceSplitBc = splitZone->interfaceSplitBcList[ ibc1to1 ];
+            InterfaceInfo interfaceInfo;
+            interfaceSplitBc->donor_zone->FindDonorInterface( interfaceSplitBc, interfaceInfo );
+            interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+            interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+        }
+    }
+}
+
+void Partition::Split()
+{
+    this->InitSplit();
+    this->BinarySplit();
+    this->ModifyZoneIndex();
+    int kkk = 1;
+}
+
+void Partition::InitSplit()
+{
+    //nZone is the number of zones in the original grid
+    //nProc is not the number of blocks in the end, but the number of processes that need to be divided.
+    //This difference occurs because the structure grid can have many blocks per process.
+
+    //this->nProc    = nProc;
+    //this->nPhyBlocks = referenceBlock.size();
+    //this->nZone  = this->nPhyBlocks;
+
+    //tj Computation time on processor j
+    //Nk Number of internal grid-cells for zone j
+    //aveFloatOp:  Number of Real operations per gridcell
+    //Gj The set of blocks allocated to process j
+    //Pj Real operations per second for process j
+
+    //The Greedy Load Balancing Algorithm
+    //1.Compute an "ideal" uniprocessor time, Tuni = sum ( Nk * aveFloatOp )/ sum( Pj ).
+    //2.Set the group of unassigned blocks, Gu, to contain all blocks. The number of blocks in Nu=M, where M is the total number of blocks in the mesh.
+    //3.Start all processors with a very small fictitious zone to get a start tj=delt aveFloatOp/Pj, where delt<<1 is the size of the very small fictious zone.
+    //This is used to find the fastest processor in a heterogeneous system, tj could otherwise be set to 0 in the homogeneous case.
+    this->aveFloatOp = 1.0;
+    this->delta      = 1.0e-5;
+    this->procSpeed.resize( nProc );
+    this->timeProc.resize( nProc );
+
+    this->nTZone = this->nOriZone;
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        procSpeed[ iProc ] = 1.0;
+    }
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        timeProc[ iProc ] = delta * aveFloatOp / procSpeed[ iProc ];
+    }
+
+    double sumProcSpeed = CalSumOfProcSpeed( procSpeed );
+
+    double sumProcOp = 0.0;
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        sumProcOp += refZone[ iZone ]->GetNCell() * aveFloatOp;
+    }
+
+    this->idealUniProcTime = sumProcOp / sumProcSpeed;
+
+    this->eps = 0.05;
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        unsignedZoneGroup.insert( refZone[ iZone ] );
+    }
+
+    //Init zoneStorage
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        zoneStorage.insert( refZone[ iZone ] );
+    }
+
+    //Assign procSplitZone to each process
+    procSplitZone.resize( nProc );
+
+    this->minNumberCell = 1;
+    for ( int m = 0; m < Dim::dim; ++ m )
+    {
+        this->minNumberCell *= 1;
+    }
+
+    int kkk = 1;
+
+}
+
+void Partition::FreeAllZones()
+{
+    int iCount = 0;
+    for ( std::set < SplitZone * >::iterator iter = zoneStorage.begin(); iter != zoneStorage.end(); ++ iter )
+    {
+        //cout << "iCount = " << iCount << "\n";
+        ++ iCount;
+        delete * iter;
+    }
+}
+
+int Partition::GetNZones( int iProc )
+{
+    return this->procSplitZone[ iProc ].size();
+}
+
+SplitZone * Partition::GetSplitZone( int iProc, int zoneId )
+{
+    return this->procSplitZone[ iProc ][ zoneId ];
+}
+
+void Partition::AddZoneToUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.insert( zone );
+}
+
+void Partition::RemoveZoneFromUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.erase( zone );
+}
+
+void Partition::AddZoneToProcess( int iProc, SplitZone * zone )
+{
+    this->procSplitZone[ iProc ].push_back( zone );
+}
+
+void Partition::AddNewZone( SplitZone * zone )
+{
+    zone->SetZoneIndex( nTZone ++ );
+
+    this->AddZoneToUnsignedGroup( zone );
+
+    this->zoneStorage.insert( zone );
+}
+
+SplitZone * Partition::Split( SplitZone * zone, double nCell )
+{
+    SplitZone * zoneL = new SplitZone();
+    zoneL->SetParentAndChild( zone );
+
+    SplitZone * zoneR = new SplitZone();
+    zoneR->SetParentAndChild( zone );
+
+    //Remove the original block from the UnsignedGroup
+    this->RemoveZoneFromUnsignedGroup( zone );
+
+    this->AddNewZone( zoneL );
+    this->AddNewZone( zoneR );
+
+    zone->Split( zoneL, zoneR, nCell );
+
+    return zoneL;
+}
+
+void Partition::BinarySplit()
+{
+    while ( ! unsignedZoneGroup.empty() )
+    {
+        std::cout << "number of unsigned zone = " << unsignedZoneGroup.size() << "\n";
+        int iProc = this->GetMinLoadProc();
+
+        //Get the block with the largest number of grids and its size
+        SplitZone * largestZone = this->GetLargestZone();
+
+        double nMaxCell = largestZone->GetNCell();
+
+        double aveFloatOp = this->aveFloatOp;
+        double tau = timeProc[ iProc ] + nMaxCell * aveFloatOp / procSpeed[ iProc ];
+
+        //It seems that EPS is still necessary
+        //The idea here is as follows. For the candidate blocks which can be divided into blocks, 
+        //if the difference between the target blocks and the candidate blocks is too wide, 
+        //the binarySplit method is adopted. The binarySplit blocks do not directly join the process,
+        //but enter the next round of screening.
+
+        if ( tau > idealUniProcTime * ( 1.0 + eps ) )
+        {
+            double nRest = ( tau - idealUniProcTime ) * procSpeed[ iProc ] / aveFloatOp;
+
+            double nTarget = nMaxCell - nRest;
+            if ( nRest > this->minNumberCell && nTarget > this->minNumberCell )
+            {
+                //It is necessary to divide blocks only when a certain number of points are satisfied.
+                double nHalf = nMaxCell / 2.0;
+                nMaxCell = nTarget;
+                double ratio = nMaxCell / nRest;
+                double oRatio = 1.0 / ratio;
+
+                if ( std::max( ratio, oRatio ) < 3.0 )
+                {
+                    int kkk = 1;
+                    largestZone = this->Split( largestZone, nMaxCell );
+                    timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                    this->RemoveZoneFromUnsignedGroup( largestZone );
+                    this->AddZoneToProcess( iProc, largestZone );
+                }
+                else
+                {
+                    this->Split( largestZone, nHalf );
+                }
+            }
+            else
+            {
+                //If the block is of the right size, join the process directly, and there is no need to split it.
+                timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                this->RemoveZoneFromUnsignedGroup( largestZone );
+                this->AddZoneToProcess( iProc, largestZone );
+            }
+        }
+        else
+        {
+            //If the block is of the right size, join the process directly, and there is no need to split it.
+            timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+            this->RemoveZoneFromUnsignedGroup( largestZone );
+            this->AddZoneToProcess( iProc, largestZone );
+        }
+    }
+}
+
+void Partition::ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord )
+{
+    SplitZone * rootSplitZone = splitZone->GetRootZone();
+    Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+    int nNodes = splitZone->dimInfo.ComputeNumNodes();
+    std::cout << "nNodes = " << nNodes << "\n";
+
+    coord.resize( nNodes * sizeof(double) );
+
+    int index_dim = splitZone->dimInfo.dimList.size();
+    Coor * coor = zone->coors[ icoord ];
+
+    double * xlocal = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    double * xglobal = reinterpret_cast<double *>( const_cast<char *>( coor->coord.data() ) );
+    if ( index_dim == 1 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        for ( int i = imin; i < imax; ++ i )
+        {
+            xlocal[ icount++ ] = xglobal[ i ];
+        }
+    }
+    else if ( index_dim == 2 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        int jmin = splitZone->dimInfo.rmin[ 1 ] - 1;
+        int jmax = splitZone->dimInfo.rmax[ 1 ];
+        int ni = rootSplitZone->dimInfo.dimList[ 0 ];
+        int nj = rootSplitZone->dimInfo.dimList[ 1 ];
+        for ( int j = jmin; j < jmax; ++ j )
+        {
+            int jstride = j * ni;
+            for ( int i = imin; i < imax; ++ i )
+            {
+                xlocal[ icount++ ] = xglobal[ jstride + i ];
+            }
+        }
+    }
+}
+
+void Partition::DumpBc( SplitZone * splitZone )
+{
+}
+
+void Partition::DumpPartitionedGridFile()
+{
+    std::cout << "\n";
+    std::cout << "DumpPartitionedGridFile -------------------------------" << "\n";
+    std::cout << "\n";
+    int fileId = -1;
+    std::string filename = this->outName;
+    int ierr = cg_open( filename.c_str(), CG_MODE_WRITE, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+
+    std::vector<std::string> coordnames;
+    coordnames.push_back( "CoordinateX" );
+    coordnames.push_back( "CoordinateY" );
+    coordnames.push_back( "CoordinateZ" );
+
+    std::string basename = "Base";
+    int baseId = -1;
+    int icelldim = Global::cell_dim;
+    int iphysdim = Global::phys_dim;
+    cg_base_write( fileId, basename.c_str(), icelldim, iphysdim, &baseId );
+
+    std::cout << "baseId = " << baseId << "\n";
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        int nZones = this->GetNZones( iProc );
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            ZoneType_t zoneType = Structured;
+
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+
+            int index_dim = splitZone->dimInfo.dimList.size();
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            splitZone->dimInfo.ComputeISize();
+
+            int isize_dim = index_dim * 3;
+
+            std::vector<cgsize_t> isize( index_dim * 3, 0 );
+            for ( int m = 0; m < isize_dim; ++ m )
+            {
+                isize[ m ] = splitZone->dimInfo.isize[ m ];
+            }
+
+            int zoneId = -1;
+
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+
+            std::string zonename = "Zone" + std::to_string( splitZone->newIndex );
+
+            cg_zone_write( fileId, baseId, zonename.c_str(), isize.data(), zoneType, &zoneId );
+
+            std::cout << "zoneId = " << zoneId << "\n";
+            std::cout << "zonename = " << zonename << "\n";
+                
+            splitZone->ComputeRminmax();
+
+            SplitZone * rootSplitZone = splitZone->GetRootZone();
+
+            Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+            int ncoords = zone->coors.size();
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = -1;
+                DataType_t dataType = RealDouble;
+                std::string coordname = coordnames[ icoord ];
+                Coor * coor = zone->coors[ icoord ];
+
+                int nNodes = splitZone->dimInfo.ComputeNumNodes();
+                std::cout << "nNodes = " << nNodes << "\n";
+
+                std::vector<char> coord;
+                ComputeCoor( splitZone, icoord, coord );
+
+                cg_coord_write( fileId, baseId, zoneId, dataType, coordname.c_str(), coord.data(), &coorId );
+
+                std::cout << "fileId = " << fileId  << " baseId = " << baseId << " zoneId = " << zoneId  << " coorId = " << coorId << "\n";
+            }
+
+            std::vector< PhysicalSplitBc * > &bccoList = splitZone->physicalSplitBcList;
+
+            int nbocos = bccoList.size();
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = -1;
+                GridLocation_t location = Vertex;
+
+                std::string boconame = "BC" + std::to_string( iboco + 1 );
+
+                PhysicalSplitBc * physicalSplitBc = bccoList[ iboco ];
+                BCType_t bocotype = static_cast<BCType_t>( physicalSplitBc->bcType );
+                PointSetType_t ptset_type = PointRange;
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> pnts;
+                int nSize = physicalSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.end[ i ] );
+                }
+
+                cg_boco_write( fileId, baseId, zoneId, boconame.c_str(), bocotype, ptset_type, npnts, pnts.data(), & bccoId );
+            }
+
+            //std::vector< InterfaceSplitBc * > & bc1to1List = splitZone->interfaceSplitBcList;
+            std::vector< InterfaceSplitBc * > bc1to1List;
+            splitZone->GetLeafInterfaceBc( bc1to1List );
+
+            int n1to1 = bc1to1List.size();
+            std::cout << "n1to1 = " << n1to1 << "\n";
+
+            std::vector<int> itranfrm( index_dim );
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                itranfrm[ m ] = m + 1;
+            }
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int index_conn = -1;
+
+                InterfaceSplitBc * interfaceSplitBc = bc1to1List[ i1to1 ];
+
+                std::vector<cgsize_t> pnts;
+                std::vector<cgsize_t> pntsdonor;
+                int nSize = interfaceSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.end[ i ] );
+                }
+
+                int nPatchSize = interfaceSplitBc->donor_region.start.size();
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.start[ i ] );
+                }
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.end[ i ] );
+                }
+                int id = interfaceSplitBc->donor_zone->newIndex;
+                int oldZoneIndex = interfaceSplitBc->donor_zone->zoneIndex;
+                std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+                std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+                std::cout << "donor zone id = " << id << "\n";
+                std::cout << "donor zone oldZoneIndex = " << oldZoneIndex << "\n";
+                std::string donorname = "Zone" + std::to_string( id );
+                std::string connectname = "Interface" + std::to_string( i1to1 );
+
+                std::cout << "donorname = " << donorname << "\n";
+                std::cout << "connectname = " << connectname << "\n";
+
+                std::vector<int> & itranfrm = interfaceSplitBc->transform;
+
+                cg_1to1_write( fileId, baseId, zoneId, connectname.c_str(), donorname.c_str(), pnts.data(), pntsdonor.data(), itranfrm.data(), &index_conn );
+                std::cout << "index_conn = " << index_conn << "\n";
+            }
+        }
+    }
+    cg_close( fileId );
+}
+
+void Partition::ModifyZoneIndex()
+{
+    std::cout << "ModifyZoneIndex +++++++++++++++++++++++++ " << "\n";
+    int globalZoneId = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        std::cout << "iProc = " << iProc << "\n";
+        int nZones = this->GetNZones( iProc );
+        std::cout << "nZones in Proc " << iProc << "  = " << nZones << "\n";
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+            //splitZone->SetZoneIndex( globalZoneId++ );
+            splitZone->newIndex = ( globalZoneId++ );
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+        }
+    }
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage3/01b/Partition.h b/example/partition/struct/2d/stage3/01b/Partition.h
new file mode 100644
index 00000000..8a4a9731
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01b/Partition.h
@@ -0,0 +1,59 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class SplitZone;
+
+struct CmpSplitZone 
+{
+    bool operator() ( SplitZone * a, SplitZone * b ) const;
+};
+
+class Partition
+{
+public:
+    Partition();
+    ~Partition();
+protected:
+    std::set < SplitZone * > zoneStorage;
+    std::set < SplitZone *, CmpSplitZone > unsignedZoneGroup;
+    std::vector< SplitZone * > refZone;
+    std::vector< std::vector< SplitZone * > > procSplitZone;
+    std::vector<double> procSpeed;
+    std::vector<double> timeProc;
+    double aveFloatOp, delta;
+    double idealUniProcTime, eps;
+    int minNumberCell;
+    int nTZone;
+    int nOriZone;
+    int nProc;
+public:
+    std::string inputName;
+    std::string outName;
+public:
+    void Solve();
+    void ReadGrid();
+    void Split();
+    void InitSplit();
+    void BinarySplit();
+    //void GreedySplit();
+public:
+    void AddNewZone( SplitZone * zone );
+    void AddZoneToUnsignedGroup( SplitZone * zone );
+    void RemoveZoneFromUnsignedGroup( SplitZone * zone );
+    void AddZoneToProcess( int iProc, SplitZone * zone );
+    void DumpPartitionedGridFile();
+    void ModifyZoneIndex();
+    void FreeAllZones();
+    int GetNZones( int iProc );
+    SplitZone * GetSplitZone( int iProc, int zoneId );
+    void ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord );
+    void DumpBc( SplitZone * splitZone );
+private:
+    int GetMinValueIndex( double * data, int numberOfData );
+    int GetMinLoadProc();
+    SplitZone * GetLargestZone();
+    SplitZone * Split( SplitZone * zone, double nCell );
+};
+
diff --git a/example/partition/struct/2d/stage3/01b/README.txt b/example/partition/struct/2d/stage3/01b/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01b/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/partition/struct/2d/stage3/01b/SplitZone.cpp b/example/partition/struct/2d/stage3/01b/SplitZone.cpp
new file mode 100644
index 00000000..aef70754
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01b/SplitZone.cpp
@@ -0,0 +1,1091 @@
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+int Dim::dim = -1;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox  )
+{
+    domainBox.start = zoneBox.start;
+    domainBox.end = zoneBox.end;
+
+    int axis = iDomain / 2;
+    int direction = iDomain % 2;
+
+    if ( direction == 0 )
+    {
+        domainBox.end[ axis ] = domainBox.start[ axis ];
+    }
+    else if ( direction == 1 )
+    {
+        domainBox.start[ axis ] = domainBox.end[ axis ];
+    }
+}
+
+DimInfo::DimInfo()
+{
+    this->Init( 1 );
+}
+
+DimInfo::~DimInfo()
+{
+}
+
+void DimInfo::Init( int dim )
+{
+    this->dim = dim;
+    dimList.resize( this->dim, 1 );
+    oriPoint.resize( this->dim, 0 );
+}
+
+DimInfo & DimInfo::operator = ( const DimInfo & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->dim = rhs.dim;
+    this->dimList = rhs.dimList;
+    this->oriPoint = rhs.oriPoint;
+
+    return * this;
+}
+
+int DimInfo::ComputeNumNodes()
+{
+    int nNodes = 1;
+    for ( int m = 0; m < this->dimList.size(); ++ m )
+    {
+        nNodes *= this->dimList[ m ];
+    }
+    return nNodes;
+}
+
+void DimInfo::ComputeISize()
+{
+    int index_dim = this->dimList.size();
+    this->isize.resize( index_dim * 3, 0 );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        isize[ m ] = this->dimList[ m ];
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 1;
+        isize[ start + m ] = this->dimList[ m ] - 1;
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 2;
+        isize[ start + m ] = 0;
+    }
+
+    for ( int i = 0; i < isize.size(); ++ i )
+    {
+        std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+    }
+}
+
+void DimInfo::ComputeRminmax( std::vector<int> & ref )
+{
+    int index_dim = this->dimList.size();
+    this->rmin.resize( index_dim );
+    this->rmax.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        rmin[ m ] = ref[ m ] + 1;
+        rmax[ m ] = ref[ m ] + this->dimList[ m ];
+    }
+
+    std::cout << "rmin, rmax = \n";
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        std::cout << rmin[ m ] << " " << rmax[ m ] << "\n";
+    }
+}
+
+void DimInfo::Init( std::vector<int> & dimList )
+{
+    this->dim = dimList.size();
+    this->dimList = dimList;
+    std::vector<int> zero( dimList.size(), 0 );
+    this->oriPoint = zero;
+}
+
+void DimInfo::SetNewDimension( int axis, int newStart, int newWidth )
+{
+    this->oriPoint[ axis ] = newStart;
+    this->dimList [ axis ] = newWidth;
+}
+
+void DimInfo::GetZoneGlobalBox( RangeRegion &zoneBox )
+{
+    int index_dim = this->dimList.size();
+    zoneBox.start.resize( index_dim );
+    zoneBox.end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        zoneBox.start[ m ] = this->oriPoint[ m ] + 1;
+        zoneBox.end[ m ] = this->oriPoint[ m ] + this->dimList[ m ];
+    }
+}
+
+void DimInfo::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    int index_dim = this->dimList.size();
+    localBox.start.resize( index_dim );
+    localBox.end.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        localBox.start[ m ] = globalBox.start[ m ] - this->oriPoint[ m ];
+        localBox.end[ m ] = globalBox.end[ m ] - this->oriPoint[ m ];
+    }
+}
+
+RangeRegion::RangeRegion( int nSize )
+{
+    this->Init( nSize );
+}
+
+RangeRegion::~RangeRegion()
+{
+}
+
+void RangeRegion::Init( int nSize )
+{
+    this->start.resize( nSize );
+    this->end.resize( nSize );
+}
+
+RangeRegion & RangeRegion::operator = ( const RangeRegion & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+bool RangeRegion::operator == ( const RangeRegion & rhs ) const
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] != rhs.start[ m ] || 
+            this->end  [ m ] != rhs.end  [ m ] )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+bool RangeRegion::InRegion( const RangeRegion & region )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( ( this->start[ m ] < region.start[ m ] ) || ( this->end[ m ] > region.end[ m ] ) )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::Normalize()
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        int minv = std::min( this->start[ m ], this->end[ m ] );
+        int maxv = std::max( this->start[ m ], this->end[ m ] );
+        this->start[ m ] = minv;
+        this->end[ m ] = maxv;
+    }
+}
+
+void RangeRegion::Localize( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] -= oriPoint[ m ];
+        this->end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void RangeRegion::ToGlobal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] += oriPoint[ m ];
+        this->end[ m ] += oriPoint[ m ];
+    }
+}
+
+void RangeRegion::ToLocal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] -= oriPoint[ m ];
+        this->end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void RangeRegion::PrintGlobal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    std::cout << "global start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ] + oriPoint[m];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "global end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ] + oriPoint[m];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+void RangeRegion::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion );
+
+bool ComputeOverlapRegion( RangeRegion & region1, RangeRegion & region2, RangeRegion & overlapRegion )
+{
+    int index_dim = region1.start.size();
+    overlapRegion.Init( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int ijkmin1 = std::min( region1.start[ m ], region1.end[ m ] );
+        int ijkmax1 = std::max( region1.start[ m ], region1.end[ m ] );
+        int ijkmin2 = std::min( region2.start[ m ], region2.end[ m ] );
+        int ijkmax2 = std::max( region2.start[ m ], region2.end[ m ] );
+        if ( ( ijkmax1 < ijkmin2 ) || ( ijkmin1 > ijkmax2 ) )
+        {
+            return false;
+        }
+
+        int ijkmin = std::max( ijkmin1, ijkmin2 );
+        int ijkmax = std::min( ijkmax1, ijkmax2 );
+
+        overlapRegion.start[ m ] = ijkmin;
+        overlapRegion.end  [ m ] = ijkmax;
+    }
+
+    return CheckOverLapping( overlapRegion );
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion )
+{
+    int index_dim = overlapRegion.start.size();
+    int iCount = 0;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        if ( overlapRegion.start[ m ] == overlapRegion.end[ m ] )
+        {
+            ++ iCount;
+        }
+    }
+
+    return ( iCount == 1 );
+}
+
+bool GetInterfaceRegion( RangeRegion & zoneBoxL, RangeRegion & zoneBoxR, RangeRegion & interfaceRegion )
+{
+    int index_dim = zoneBoxL.start.size();
+    int nDomains = 2 * index_dim;
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegionL;
+        GetDomainRegion( zoneBoxL, iDomain, domainRegionL );
+
+        for ( int jDomain = 0; jDomain < nDomains; ++ jDomain )
+        {
+            RangeRegion domainRegionR;
+            GetDomainRegion( zoneBoxR, jDomain, domainRegionR );
+
+            if ( domainRegionL == domainRegionR )
+            {
+                interfaceRegion = domainRegionL;
+                return true;
+            }
+        }
+    }
+    return false;
+}
+
+void CreateInterfaceBc( SplitZone * zoneL, SplitZone * zoneR )
+{
+    RangeRegion globalBoxL, globalBoxR, globalInterfaceRegion;
+
+    zoneL->GetZoneGlobalBox( globalBoxL );
+    zoneR->GetZoneGlobalBox( globalBoxR );
+
+    if ( ! GetInterfaceRegion( globalBoxL, globalBoxR, globalInterfaceRegion ) )
+    {
+        return;
+    }
+
+    RangeRegion localInterfaceRegionL, localInterfaceRegionR;
+
+    zoneL->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionL );
+    zoneR->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionR );
+
+    int kkk = 1;
+
+    InterfaceSplitBc * interfaceSplitBcL = new InterfaceSplitBc();
+    zoneL->interfaceSplitBcList.push_back( interfaceSplitBcL );
+    interfaceSplitBcL->zone = zoneL;
+    interfaceSplitBcL->region = localInterfaceRegionL;
+
+    int nSize = localInterfaceRegionL.start.size();
+
+    std::vector<int> transform;
+
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        transform.push_back( m + 1 );
+    }
+
+    interfaceSplitBcL->transform = transform;
+    interfaceSplitBcL->CalcTransformMatrix();
+
+    interfaceSplitBcL->donor_zone = zoneR;
+    interfaceSplitBcL->donor_region = localInterfaceRegionR;
+
+    InterfaceSplitBc * interfaceSplitBcR = new InterfaceSplitBc();
+    zoneR->interfaceSplitBcList.push_back( interfaceSplitBcR );
+
+    interfaceSplitBcR->zone = zoneR;
+    interfaceSplitBcR->region = localInterfaceRegionR;
+
+    interfaceSplitBcR->transform = transform;
+    interfaceSplitBcR->CalcTransformMatrix();
+
+    interfaceSplitBcR->donor_zone = zoneL;
+    interfaceSplitBcR->donor_region = localInterfaceRegionL;
+}
+
+
+PhysicalSplitBc::PhysicalSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+PhysicalSplitBc::~PhysicalSplitBc()
+{
+}
+
+void PhysicalSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void PhysicalSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+void PhysicalSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = splitZone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+BasicSplitBc::BasicSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+BasicSplitBc::~BasicSplitBc()
+{
+    ;
+}
+
+void BasicSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void BasicSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+int trans::M[ 3 ][ 3 ];
+std::vector<int> trans::transform;
+
+int trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void trans::CalcTransformMatrix()
+{
+    int dim = trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = trans::transform[ 0 ];
+        int sgna = trans::sgn( a );
+        int a1 = trans::del( a, 1 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int c = trans::transform[ 2 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int sgnc = trans::sgn( c );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int a3 = trans::del( a, 3 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        int b3 = trans::del( b, 3 );
+        int c1 = trans::del( c, 1 );
+        int c2 = trans::del( c, 2 );
+        int c3 = trans::del( c, 3 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 2 ][ 0 ] = sgna * a3;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+        trans::M[ 2 ][ 1 ] = sgnb * b3;
+        trans::M[ 0 ][ 2 ] = sgnc * c1;
+        trans::M[ 1 ][ 2 ] = sgnc * c2;
+        trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+InterfaceInfo::InterfaceInfo()
+{
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceInfo::~InterfaceInfo()
+{
+}
+
+InterfaceSplitBc::InterfaceSplitBc()
+{
+    this->region.Init( Dim::dim );
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceSplitBc::~InterfaceSplitBc()
+{
+}
+
+void InterfaceSplitBc::GetLeafInterfaceBc( std::vector< InterfaceSplitBc * > & leafInterfaceBcList )
+{
+    int nChild = this->child.size();
+    if ( nChild == 0 )
+    {
+        leafInterfaceBcList.push_back( this );
+    }
+    else
+    {
+        for ( int iChild = 0; iChild < nChild; ++ iChild )
+        {
+            InterfaceSplitBc * interfaceSplitBc = this->child[ iChild ];
+            interfaceSplitBc->GetLeafInterfaceBc( leafInterfaceBcList );
+        }
+    }
+}
+
+void InterfaceSplitBc::CopyMatrix( InterfaceSplitBc * interfaceSplitBc )
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = interfaceSplitBc->Mt[ i ][ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::CalcTransformMatrix()
+{
+    trans::ZeroMatrix();
+    trans::transform = this->transform;
+    trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = trans::M[ i ][ j ];
+        }
+    }
+
+}
+
+void InterfaceSplitBc::mapindex( std::vector<int> & begin1, std::vector<int> & begin2,  std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = Dim::dim;
+    std::vector<int> diff( dim );
+    for ( int m = 0; m < dim; ++ m )
+    {
+        diff[ m ] = index1[ m ] - begin1[ m ];
+    }
+
+    std::vector<int> mul( dim );
+
+    Multiply( Mt, diff, mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = mul[ m ] + begin2[ m ];
+    }
+}
+
+void InterfaceSplitBc::Multiply( int Mt[][3], std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = Dim::dim;
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = this->zone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void InterfaceSplitBc::CalcSubDonorRegion( RangeRegion &subRegion, RangeRegion &subDonorRegion )
+{
+    std::vector<int> begin1 = this->region.start;
+    std::vector<int> end1 = this->region.end;
+    std::vector<int> begin2 = this->donor_region.start;
+    std::vector<int> end2 = this->donor_region.end;
+
+    std::vector<int> new_begin1 = subRegion.start;
+    std::vector<int> new_end1 = subRegion.end;
+
+    int dim = Dim::dim;
+    std::vector<int> new_begin2( dim );
+    std::vector<int> new_end2( dim );
+
+    mapindex( begin1, begin2, new_begin1, new_begin2 );
+    mapindex( begin1, begin2, new_end1, new_end2 );
+
+    subDonorRegion.start = new_begin2;
+    subDonorRegion.end = new_end2;
+}
+
+SplitZone::SplitZone()
+{
+    this->parent  = 0;
+    this->zoneIndex = 0;
+    this->iProc = 0;
+    dimInfo.Init( Dim::dim );
+    int kk = 1;
+}
+
+SplitZone::~SplitZone()
+{
+    ;
+}
+
+void SplitZone::GetZoneGlobalBox( RangeRegion & zoneBox )
+{
+    this->dimInfo.GetZoneGlobalBox( zoneBox );
+}
+
+void SplitZone::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    this->dimInfo.GetZoneLocalBox( globalBox, localBox );
+}
+
+
+void SplitZone::ComputeRminmax()
+{
+    int index_dim = this->dimInfo.dimList.size();
+    std::vector<int> ref( index_dim, 0 );
+
+    SplitZone * rootSplitZone = 0;
+    this->GetRootInfo( rootSplitZone, ref );
+
+    this->dimInfo.ComputeRminmax( ref );
+}
+
+SplitZone * SplitZone::GetRootZone()
+{
+    SplitZone * root = this;
+
+    while ( true )
+    {
+        if ( root->parent )
+        {
+            root = root->parent;
+        }
+        else
+        {
+            return root;
+        }
+    };
+}
+
+void SplitZone::GetRootInfo( SplitZone *& root, std::vector<int> & ref )
+{
+    for ( int i = 0; i < this->dimInfo.dimList.size(); ++ i )
+    {
+        ref[ i ] += this->dimInfo.oriPoint[ i ];
+    }
+
+    if ( this->parent )
+    {
+        this->parent->GetRootInfo( root, ref );
+    }
+    else
+    {
+        root = this;
+    }
+}
+
+void SplitZone::SetParentAndChild( SplitZone * parent )
+{
+    this->parent = parent;
+    if ( parent )
+    {
+        parent->child.push_back( this );
+    }
+}
+
+void SplitZone::GetLeafInterfaceBc( std::vector< InterfaceSplitBc * > & leafInterfaceBcList )
+{
+    int nInterfaceBcs = this->interfaceSplitBcList.size();
+    for ( int i = 0; i < nInterfaceBcs; ++ i )
+    {
+        InterfaceSplitBc * interfaceSplitBc = this->interfaceSplitBcList[ i ];
+        interfaceSplitBc->GetLeafInterfaceBc( leafInterfaceBcList );
+    }
+}
+
+int SplitZone::GetNCell()
+{
+    int numberOfCells = 1;
+    for ( int i = 0; i < this->dimInfo.dim; ++ i )
+    {
+        numberOfCells *= std::max( 1, ( this->dimInfo.dimList[ i ] - 1 ) );
+    }
+
+    return numberOfCells; 
+}
+
+void SplitZone::SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int leftStart = 0;
+    int leftWidth = iSplit - 0;
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, leftStart , leftWidth  );
+}
+
+void SplitZone::SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int rightStart = iSplit - 1;
+    int rightWidth = dimList[ axisNeedSplit ] - ( iSplit - 1 );
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, rightStart, rightWidth );
+}
+
+void SplitZone::Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell )
+{
+    //Find the longest axis
+    int axisNeedSplit = this->FindAxisNeedSplit();
+    int iSplit        = this->FindSplitPosition( axisNeedSplit, nCell );
+
+    zoneL->SetLeftDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+    zoneR->SetRightDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+
+    zoneL->CreateBcFromParent();
+    zoneR->CreateBcFromParent();
+    
+    CreateInterfaceBc( zoneL, zoneR );
+}
+
+void SplitZone::CreateBcFromParent()
+{
+    this->CreatePhysicalBcFromParent();
+    this->CreateInterfaceBcFromParent();
+}
+
+void SplitZone::CreatePhysicalBcFromParent()
+{
+    int nParentPhysicalBcs = this->parent->physicalSplitBcList.size();
+
+    for ( int iParentPhysicalBcs = 0; iParentPhysicalBcs < nParentPhysicalBcs; ++ iParentPhysicalBcs )
+    {
+        PhysicalSplitBc * parentPhysicalSplitBc = this->parent->physicalSplitBcList[ iParentPhysicalBcs ];
+
+        this->CreatePhysicalBcFromParent( parentPhysicalSplitBc );
+    }
+}
+
+void SplitZone::CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentPhysicalSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreatePhysicalBc( overlapRegion, parentPhysicalSplitBc->bcType );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent()
+{
+    int nInterfaceSplitBcs = this->parent->interfaceSplitBcList.size();
+
+    for ( int iInterfaceSplitBcs = 0; iInterfaceSplitBcs < nInterfaceSplitBcs; ++ iInterfaceSplitBcs )
+    {
+        InterfaceSplitBc * parentInterfaceSplitBc = this->parent->interfaceSplitBcList[ iInterfaceSplitBcs ];
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc );
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentInterfaceSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc, overlapRegion );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::FindDonorInterface( InterfaceSplitBc * interfaceSplitBc, InterfaceInfo & interfaceInfo )
+{
+    RangeRegion donor_region = interfaceSplitBc->donor_region;
+    donor_region.Normalize();
+    interfaceInfo.donor_zone = this;
+    for ( int iInterface = 0; iInterface < interfaceSplitBcList.size(); ++ iInterface )
+    {
+        InterfaceSplitBc * candidateDonorBc = interfaceSplitBcList[ iInterface ];
+        bool flag = donor_region.InRegion( candidateDonorBc->region );
+        if ( flag )
+        {
+            if ( donor_region == candidateDonorBc->region )
+            {
+                interfaceInfo.donor_interface = candidateDonorBc;
+                return;
+            }
+            else
+            {
+                InterfaceSplitBc * donorBc = new InterfaceSplitBc();
+                candidateDonorBc->child.push_back( donorBc );
+                donorBc->region = donor_region;
+                donorBc->zone = candidateDonorBc->zone;
+                donorBc->donor_zone = interfaceSplitBc->zone;
+                donorBc->transform = candidateDonorBc->transform;
+                donorBc->CopyMatrix( candidateDonorBc );
+                RangeRegion subDonorRegion( Dim::dim );
+                candidateDonorBc->CalcSubDonorRegion( donorBc->region, subDonorRegion );
+                std::vector<int> & oriPoint = interfaceSplitBc->zone->dimInfo.oriPoint;
+                subDonorRegion.Localize( oriPoint );
+                donorBc->donor_region = subDonorRegion;
+                donorBc->donor_bc = interfaceSplitBc;
+                interfaceInfo.donor_interface = donorBc;
+                return;
+            }
+        }
+    }
+    return;
+}
+
+void SplitZone::GetChildDonorRegion( RangeRegion & subDonorRegion, InterfaceInfo & interfaceInfo )
+{
+    std::cout << "subDonorRegion = \n";
+    //subDonorRegion.Print();
+    RangeRegion normalizedDonorRegion = subDonorRegion;
+    normalizedDonorRegion.Normalize();
+    int nChild = this->child.size();
+    for ( int ichild = 0; ichild < nChild; ++ ichild )
+    {
+        std::cout << " iChild = " << ichild << " nChild = " << nChild << "\n";
+        SplitZone * sub_zone = this->child[ ichild ];
+        std::cout << " zoneIndex = " << sub_zone->zoneIndex << "\n";
+        int nInters = sub_zone->interfaceSplitBcList.size();
+        for ( int iInter = 0; iInter < nInters; ++ iInter )
+        {
+            std::cout << " iInter = " << iInter << "\n";
+            InterfaceSplitBc * interfaceSplitBc = sub_zone->interfaceSplitBcList[ iInter ];
+            std::cout << "interfaceSplitBc local = \n";
+            interfaceSplitBc->region.Print();
+            std::cout << "interfaceSplitBc global = \n";
+            interfaceSplitBc->region.PrintGlobal( sub_zone->dimInfo.oriPoint );
+            RangeRegion g_region = interfaceSplitBc->region;
+            g_region.ToGlobal( sub_zone->dimInfo.oriPoint );
+            if ( g_region == normalizedDonorRegion )
+            {
+                RangeRegion donorRegion = subDonorRegion;
+                donorRegion.ToLocal( sub_zone->dimInfo.oriPoint );
+
+                interfaceInfo.donor_zone = sub_zone;
+                interfaceInfo.donor_interface = interfaceSplitBc;
+                interfaceInfo.donor_region = donorRegion;
+                return;
+            }
+        }
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion )
+{
+    InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+    this->interfaceSplitBcList.push_back( interfaceSplitBc );
+
+    interfaceSplitBc->region = overlapRegion;
+    interfaceSplitBc->zone = this;
+    interfaceSplitBc->transform = parentInterfaceSplitBc->transform;
+    interfaceSplitBc->CopyMatrix( parentInterfaceSplitBc );
+    RangeRegion subDonorRegion( Dim::dim );
+    parentInterfaceSplitBc->CalcSubDonorRegion( overlapRegion, subDonorRegion );
+    interfaceSplitBc->ChangeRegionToLocalCoordinate();
+    interfaceSplitBc->donor_region = subDonorRegion;
+    SplitZone * parent_donor_zone = parentInterfaceSplitBc->donor_zone;
+    std::cout << " parentInterfaceSplitBc->zone->zoneIndex " << parentInterfaceSplitBc->zone->zoneIndex << "\n";
+    std::cout << " parentInterfaceSplitBc->donor_zone->zoneIndex " << parent_donor_zone->zoneIndex << "\n";
+    if ( parent_donor_zone->child.size() > 0 )
+    {
+        InterfaceInfo interfaceInfo;
+        parent_donor_zone->GetChildDonorRegion( subDonorRegion, interfaceInfo );
+        interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+        interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+        interfaceSplitBc->donor_region = interfaceInfo.donor_region;
+        //compatibility
+        InterfaceSplitBc * donor_bc = interfaceSplitBc->donor_bc;
+        SplitZone * donor_zone = interfaceSplitBc->donor_zone;
+        if ( interfaceSplitBc->zone != donor_bc->donor_zone )
+        {
+            if ( interfaceSplitBc->zone->parent == donor_bc->donor_zone )
+            {
+                RangeRegion d_region = donor_bc->donor_region;
+                d_region.ToLocal( interfaceSplitBc->zone->dimInfo.oriPoint );
+                donor_bc->donor_region = d_region;
+            }
+            donor_bc->donor_zone = interfaceSplitBc->zone;
+         
+            int kkk = 1;
+        }
+        int kkk = 1;
+    }
+    else
+    {
+        InterfaceInfo interfaceInfo;
+        parent_donor_zone->FindDonorInterface( interfaceSplitBc, interfaceInfo );
+        interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+        interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+    }
+    
+    int kkk = 1;
+}
+
+void SplitZone::CreatePhysicalBc( RangeRegion & overlapRegion, int bcType )
+{
+    PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+    this->physicalSplitBcList.push_back( physicalSplitBc );
+    physicalSplitBc->SetRegion( overlapRegion );
+    physicalSplitBc->bcType = bcType;
+    physicalSplitBc->splitZone = this;
+    physicalSplitBc->ChangeRegionToLocalCoordinate();
+}
+
+int SplitZone::FindAxisNeedSplit()
+{
+    //Find the longest axis
+    int axisNeedSplit = 0;
+    int maxN = this->dimInfo.dimList[ 0 ];
+
+    for ( int m = 1; m < this->dimInfo.dimList.size(); ++ m )
+    {
+        if ( this->IsPoleBc( m ) )
+        {
+            continue;
+        }
+        int Nm = this->dimInfo.dimList[ m ];
+        if ( maxN < Nm )
+        {
+            maxN = Nm;
+            axisNeedSplit = m;
+        }
+    }
+
+    return axisNeedSplit;
+}
+
+int SplitZone::GetCrossSection( int axis )
+{
+    int nDim = this->dimInfo.dimList.size();
+    int crossSection = 1;
+    int N = nDim - 1;
+    for ( int m = 0; m < N; ++ m )
+    {
+         int mm = ( axis + 1 ) % nDim;
+         int nLineElements = std::max( 1, ( this->dimInfo.dimList[ mm ] - 1 ) );
+         crossSection *= nLineElements;
+    }
+    return crossSection;
+}
+
+int SplitZone::FindSplitPosition( int axisNeedSplit, double nCell )
+{
+    int nDim = this->dimInfo.dimList.size();
+    std::vector<int> crossSections( nDim );
+    for ( int m = 0; m < nDim; ++ m )
+    {
+        crossSections[ m ] = this->GetCrossSection( m );
+    }
+
+    //guess the value
+    double dSplit = nCell / crossSections[ axisNeedSplit ];
+    int  iSplit = 1 + static_cast< int >( std::floor( dSplit + 0.5 ) );
+    return iSplit;
+}
+
+
+bool SplitZone::IsPoleBc( int splitDirection )
+{
+    return false;
+}
+
diff --git a/example/partition/struct/2d/stage3/01b/SplitZone.h b/example/partition/struct/2d/stage3/01b/SplitZone.h
new file mode 100644
index 00000000..ffe1e306
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01b/SplitZone.h
@@ -0,0 +1,196 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class Dim
+{
+public:
+    static int dim;
+};
+
+class SplitZone;
+class RangeRegion;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox );
+
+class DimInfo
+{
+public:
+    DimInfo();
+    ~DimInfo();
+public:
+    int dim;
+    std::vector<int> dimList;
+    std::vector<int> oriPoint;
+    std::vector<int> isize;
+    std::vector<int> rmin;
+    std::vector<int> rmax;
+public:
+    int GetSize() const { return dim; }
+    DimInfo & operator = ( const DimInfo & rhs );
+public:
+    int ComputeNumNodes();
+    void ComputeISize();
+    void ComputeRminmax( std::vector<int> & ref );
+    void Init( int dim );
+    void Init( std::vector<int> & dimList );
+    void SetNewDimension( int axis, int newStart, int newWidth );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+};
+
+class SplitZone;
+class SplitBcPatch;
+
+class RangeRegion
+{
+public:
+    RangeRegion( int nSize = 1 );
+    ~RangeRegion();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    void Init( int nSize );
+    RangeRegion & operator = ( const RangeRegion & rhs );
+    bool operator == ( const RangeRegion & rhs ) const;
+    bool InRegion( const RangeRegion & region );
+    void SetRegion( std::vector<int> &pnts );
+    void Normalize();
+    void Localize( std::vector<int> & oriPoint );
+    void ToGlobal( std::vector<int> & oriPoint );
+    void ToLocal( std::vector<int> & oriPoint );
+    void PrintGlobal( std::vector<int> & oriPoint );
+    void Print();
+};
+
+class PhysicalSplitBc
+{
+public:
+    PhysicalSplitBc();
+    ~PhysicalSplitBc();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class BasicSplitBc
+{
+public:
+    BasicSplitBc();
+    ~BasicSplitBc();
+public:
+    RangeRegion region;
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> & pnts );
+    void SetRegion( RangeRegion & region );
+};
+
+class trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class InterfaceSplitBc;
+class SplitZone;
+
+class InterfaceInfo
+{
+public:
+    InterfaceInfo();
+    ~InterfaceInfo();
+public:
+    InterfaceSplitBc * donor_interface = nullptr;
+    SplitZone * donor_zone = nullptr;
+    RangeRegion donor_region;
+};
+
+class InterfaceSplitBc
+{
+public:
+    InterfaceSplitBc();
+    ~InterfaceSplitBc();
+public:
+    std::vector<int> transform;
+    int Mt[ 3 ][ 3 ];
+    RangeRegion region;
+    SplitZone * zone = nullptr;
+    RangeRegion donor_region;
+    SplitZone * donor_zone = nullptr;
+    InterfaceSplitBc * donor_bc = nullptr;
+public:
+    std::vector<InterfaceSplitBc *> child;
+    void GetLeafInterfaceBc( std::vector< InterfaceSplitBc * > & leafInterfaceBcList );
+public:
+    void CopyMatrix( InterfaceSplitBc * interfaceSplitBc );
+    void CalcTransformMatrix();
+    void CalcSubDonorRegion( RangeRegion & subRegion, RangeRegion & subDonorRegion );
+    void mapindex( std::vector<int> & begin1, std::vector<int> & begin2, std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( int Mt[][ 3 ], std::vector<int> & a, std::vector<int> & b );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class SplitZone
+{
+public:
+    SplitZone();
+    ~SplitZone();
+public:
+    DimInfo dimInfo;
+    int zoneIndex, iProc;
+    int newIndex;
+protected:
+    SplitZone * parent;
+    std::vector<SplitZone *> child;
+public:
+    std::vector< PhysicalSplitBc * > physicalSplitBcList;
+    std::vector< InterfaceSplitBc * > interfaceSplitBcList;
+    void GetLeafInterfaceBc( std::vector< InterfaceSplitBc * > & leafInterfaceBcList );
+public:
+    int GetNCell();
+    void ComputeRminmax();
+    void GetRootInfo( SplitZone *& root, std::vector<int> & ref );
+    void SetZoneIndex( int zoneIndex ) { this->zoneIndex = zoneIndex; }
+    int  GetZoneIndex() { return zoneIndex; }
+    void SetProcId( int iProc ) { this->iProc = iProc; }
+    void SetParent( SplitZone * parent ) { this->parent = parent; };
+    void SetParentAndChild( SplitZone * parent );
+    void FindDonorInterface( InterfaceSplitBc * interfaceSplitBc, InterfaceInfo & interfaceInfo );
+    void GetChildDonorRegion( RangeRegion & subDonorRegion, InterfaceInfo & interfaceInfo );
+public:
+    void CreateBcFromParent();
+    void CreatePhysicalBcFromParent();
+    void CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc );
+    void CreatePhysicalBc( RangeRegion & overlapRegion, int bcType );
+    void CreateInterfaceBcFromParent();
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc );
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion );
+
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+    SplitZone * GetRootZone();
+public:
+    void Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell );
+    void SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+    void SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+private:
+    int FindAxisNeedSplit();
+    int FindSplitPosition( int axisNeedSplit, double nCell );
+    bool IsPoleBc( int splitDirection );
+    int GetCrossSection( int axis );
+};
+
diff --git a/example/partition/struct/2d/stage3/01b/heat2d1blockv1.cgns b/example/partition/struct/2d/stage3/01b/heat2d1blockv1.cgns
new file mode 100644
index 00000000..4aa7832a
Binary files /dev/null and b/example/partition/struct/2d/stage3/01b/heat2d1blockv1.cgns differ
diff --git a/example/partition/struct/2d/stage3/01b/heat2dpart.cgns b/example/partition/struct/2d/stage3/01b/heat2dpart.cgns
new file mode 100644
index 00000000..e583dfce
Binary files /dev/null and b/example/partition/struct/2d/stage3/01b/heat2dpart.cgns differ
diff --git a/example/partition/struct/2d/stage3/01b/main.cpp b/example/partition/struct/2d/stage3/01b/main.cpp
new file mode 100644
index 00000000..5da1de7c
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01b/main.cpp
@@ -0,0 +1,18 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include "Partition.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip>
+
+int main(int argc, char **argv)
+{
+    Partition * partition = new Partition();
+    partition->Solve();
+    delete partition;
+
+    return 0;
+}
diff --git a/example/partition/struct/2d/stage3/01c/CMakeLists.txt b/example/partition/struct/2d/stage3/01c/CMakeLists.txt
new file mode 100644
index 00000000..74ceea7d
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01c/CMakeLists.txt
@@ -0,0 +1,78 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	Partition.h Partition.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	SplitZone.h SplitZone.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/partition/struct/2d/stage3/01c/CgnsGrid.cpp b/example/partition/struct/2d/stage3/01c/CgnsGrid.cpp
new file mode 100644
index 00000000..dfe750bd
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01c/CgnsGrid.cpp
@@ -0,0 +1,349 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include <map>
+
+Grid::Grid()
+{
+    ;
+}
+
+Grid::~Grid()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if( (i+1)%5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+    delete this->patch;
+}
+
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+ZoneBcPatch::ZoneBcPatch()
+{
+    ;
+}
+
+ZoneBcPatch::~ZoneBcPatch()
+{
+}
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+Global::Global()
+{
+    ;
+}
+
+Global::~Global()
+{
+}
+
+void Global::FreeData()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+    zones.resize( 0 );
+}
+
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            //baseZone.baseId = baseId;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin( index_dim );
+            std::vector<cgsize_t> irmax( index_dim );
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                std::vector<char> coord( nNodes * sizeof(double) );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+                coor->DumpCoor();
+            }
+
+            int nbocos = -1;
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+                int kkk = 1;
+            }
+        }
+        int kkk = 1;
+    }
+    int kkk = 1;
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage3/01c/CgnsGrid.h b/example/partition/struct/2d/stage3/01c/CgnsGrid.h
new file mode 100644
index 00000000..053c467b
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01c/CgnsGrid.h
@@ -0,0 +1,140 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <map>
+
+class Grid;
+
+class Zone;
+
+class Grid
+{
+public:
+    Grid();
+    ~Grid();
+public:
+    int nZone;
+    std::vector<double> x;
+    std::vector<Zone *> zones;
+};
+
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+};
+
+class ZoneBc;
+class ZoneBc1To1;
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class ZoneBcPatch;
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+    ZoneBcPatch * patch = nullptr;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+class ZoneBcPatch
+{
+public:
+    ZoneBcPatch();
+    ~ZoneBcPatch();
+public:
+    int donor_zoneid;
+    std::vector<int> transform;
+    std::vector<int> donor_pnts;
+};
+
+class BaseZone
+{
+public:
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Global
+{
+public:
+    Global();
+    ~Global();
+public:
+    static int cell_dim;
+    static int phys_dim;
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+public:
+    static void FreeData();
+};
+
+void ReadCgnsGrid( const std::string & filename );
+void ReadCgnsGridBaseZone( const std::string & filename );
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage3/01c/Partition.cpp b/example/partition/struct/2d/stage3/01c/Partition.cpp
new file mode 100644
index 00000000..060c5c0b
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01c/Partition.cpp
@@ -0,0 +1,621 @@
+#include "Partition.h"
+#include "CgnsGrid.h"
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+bool CmpSplitZone::operator() ( SplitZone * a, SplitZone * b ) const
+{
+    return a->zoneIndex < b->zoneIndex;
+};
+
+
+double CalSumOfProcSpeed( std::vector<double> & procSpeed );
+double CalSumOfProcSpeed( std::vector<double> & procSpeed )
+{
+    int nProc = procSpeed.size();
+    double sumOfProcSpeed = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        sumOfProcSpeed += procSpeed[ iProc ];
+    }
+    return sumOfProcSpeed;
+}
+
+Partition::Partition()
+{
+    this->inputName = "../heat2d1blockv2.cgns";
+    this->outName =  "../heat2dpart.cgns";
+}
+
+Partition::~Partition()
+{
+    ;
+}
+
+int Partition::GetMinValueIndex( double * data, int numberOfData )
+{
+    double minValue = data[ 0 ];
+    int minimumValueIndex = 0;
+
+    for ( int iData = 1; iData < numberOfData; ++ iData )
+    {
+        if ( minValue > data[ iData ] )
+        {
+            minValue      = data[ iData ];
+            minimumValueIndex = iData;
+        }
+    }
+    return minimumValueIndex;
+}
+
+int Partition::GetMinLoadProc()
+{
+    return this->GetMinValueIndex( this->timeProc.data(), this->nProc );
+}
+
+SplitZone * Partition::GetLargestZone()
+{
+    SplitZone * largestZone = 0;
+
+    double nMaxCell = 0.0;
+
+    for ( std::set< SplitZone * >::iterator iter = unsignedZoneGroup.begin(); iter != unsignedZoneGroup.end(); ++ iter )
+    {
+        double nSize = ( * iter )->GetNCell();
+        if ( nMaxCell < nSize )
+        {
+            nMaxCell    = nSize;
+            largestZone = * iter;
+        }
+    }
+
+    return largestZone;
+}
+
+void Partition::Solve()
+{
+    std::cout << "Partition::Split()\n";
+    //this->nProc = 2;
+    //this->nProc = 3;
+    this->nProc = 8;
+    this->ReadGrid();
+    this->Split();
+    this->DumpPartitionedGridFile();
+    this->FreeAllZones();
+}
+
+void Partition::ReadGrid()
+{
+    ReadCgnsGridBaseZone( this->inputName );
+    ReadCgnsGrid( this->inputName );
+
+    this->nOriZone = ::Global::zones.size();
+    Dim::dim = Global::cell_dim;
+
+    std::cout << "numberOfBlocks = " << nOriZone << "\n";
+
+    this->refZone.resize( nOriZone );
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = new SplitZone();
+        refZone[ iZone ] = splitZone;
+
+        splitZone->SetZoneIndex( iZone );
+        splitZone->SetProcId( 0 );
+        splitZone->SetParentAndChild( 0 );
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        Zone * zone = ::Global::zones[ iZone ];
+
+        splitZone->dimInfo.dimList = zone->nijk;
+
+        int nbccos = zone->bccos.size();
+        std::cout << "nbccos = " << nbccos << "\n";
+
+        for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+        {
+            ZoneBc * zoneBc = zone->bccos[ ibcco ];
+
+            PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+            splitZone->physicalSplitBcList.push_back( physicalSplitBc );
+            physicalSplitBc->bcType = zoneBc->bcType;
+            physicalSplitBc->SetRegion( zoneBc->pnts );
+            physicalSplitBc->splitZone = splitZone;
+        }
+
+        int nbc1to1s = zone->bc1to1s.size();
+
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * zoneBc1To1 = zone->bc1to1s[ ibc1to1 ];
+
+            InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+            splitZone->interfaceSplitBcList.push_back( interfaceSplitBc );
+            interfaceSplitBc->zone = splitZone;
+            interfaceSplitBc->region.SetRegion( zoneBc1To1->pnts );
+
+            interfaceSplitBc->transform = zoneBc1To1->transform;
+            interfaceSplitBc->CalcTransformMatrix();
+
+            interfaceSplitBc->donor_zone = refZone[ zoneBc1To1->donor_zoneid ];
+            interfaceSplitBc->donor_region.SetRegion( zoneBc1To1->donor_pnts );
+        }
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        int nbc1to1s = splitZone->interfaceSplitBcList.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            InterfaceSplitBc * interfaceSplitBc = splitZone->interfaceSplitBcList[ ibc1to1 ];
+            InterfaceInfo interfaceInfo;
+            interfaceSplitBc->donor_zone->FindDonorInterface( interfaceSplitBc, interfaceInfo );
+            interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+            interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+        }
+    }
+}
+
+void Partition::Split()
+{
+    this->InitSplit();
+    this->BinarySplit();
+    this->ModifyZoneIndex();
+    int kkk = 1;
+}
+
+void Partition::InitSplit()
+{
+    //nZone is the number of zones in the original grid
+    //nProc is not the number of blocks in the end, but the number of processes that need to be divided.
+    //This difference occurs because the structure grid can have many blocks per process.
+
+    //this->nProc    = nProc;
+    //this->nPhyBlocks = referenceBlock.size();
+    //this->nZone  = this->nPhyBlocks;
+
+    //tj Computation time on processor j
+    //Nk Number of internal grid-cells for zone j
+    //aveFloatOp:  Number of Real operations per gridcell
+    //Gj The set of blocks allocated to process j
+    //Pj Real operations per second for process j
+
+    //The Greedy Load Balancing Algorithm
+    //1.Compute an "ideal" uniprocessor time, Tuni = sum ( Nk * aveFloatOp )/ sum( Pj ).
+    //2.Set the group of unassigned blocks, Gu, to contain all blocks. The number of blocks in Nu=M, where M is the total number of blocks in the mesh.
+    //3.Start all processors with a very small fictitious zone to get a start tj=delt aveFloatOp/Pj, where delt<<1 is the size of the very small fictious zone.
+    //This is used to find the fastest processor in a heterogeneous system, tj could otherwise be set to 0 in the homogeneous case.
+    this->aveFloatOp = 1.0;
+    this->delta      = 1.0e-5;
+    this->procSpeed.resize( nProc );
+    this->timeProc.resize( nProc );
+
+    this->nTZone = this->nOriZone;
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        procSpeed[ iProc ] = 1.0;
+    }
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        timeProc[ iProc ] = delta * aveFloatOp / procSpeed[ iProc ];
+    }
+
+    double sumProcSpeed = CalSumOfProcSpeed( procSpeed );
+
+    double sumProcOp = 0.0;
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        sumProcOp += refZone[ iZone ]->GetNCell() * aveFloatOp;
+    }
+
+    this->idealUniProcTime = sumProcOp / sumProcSpeed;
+
+    this->eps = 0.05;
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        unsignedZoneGroup.insert( refZone[ iZone ] );
+    }
+
+    //Init zoneStorage
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        zoneStorage.insert( refZone[ iZone ] );
+    }
+
+    //Assign procSplitZone to each process
+    procSplitZone.resize( nProc );
+
+    this->minNumberCell = 1;
+    for ( int m = 0; m < Dim::dim; ++ m )
+    {
+        this->minNumberCell *= 1;
+    }
+
+    int kkk = 1;
+
+}
+
+void Partition::FreeAllZones()
+{
+    int iCount = 0;
+    for ( std::set < SplitZone * >::iterator iter = zoneStorage.begin(); iter != zoneStorage.end(); ++ iter )
+    {
+        //cout << "iCount = " << iCount << "\n";
+        ++ iCount;
+        delete * iter;
+    }
+}
+
+int Partition::GetNZones( int iProc )
+{
+    return this->procSplitZone[ iProc ].size();
+}
+
+SplitZone * Partition::GetSplitZone( int iProc, int zoneId )
+{
+    return this->procSplitZone[ iProc ][ zoneId ];
+}
+
+void Partition::AddZoneToUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.insert( zone );
+}
+
+void Partition::RemoveZoneFromUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.erase( zone );
+}
+
+void Partition::AddZoneToProcess( int iProc, SplitZone * zone )
+{
+    this->procSplitZone[ iProc ].push_back( zone );
+}
+
+void Partition::AddNewZone( SplitZone * zone )
+{
+    zone->SetZoneIndex( nTZone ++ );
+
+    this->AddZoneToUnsignedGroup( zone );
+
+    this->zoneStorage.insert( zone );
+}
+
+SplitZone * Partition::Split( SplitZone * zone, double nCell )
+{
+    SplitZone * zoneL = new SplitZone();
+    zoneL->SetParentAndChild( zone );
+
+    SplitZone * zoneR = new SplitZone();
+    zoneR->SetParentAndChild( zone );
+
+    //Remove the original block from the UnsignedGroup
+    this->RemoveZoneFromUnsignedGroup( zone );
+
+    this->AddNewZone( zoneL );
+    this->AddNewZone( zoneR );
+
+    zone->Split( zoneL, zoneR, nCell );
+
+    return zoneL;
+}
+
+void Partition::BinarySplit()
+{
+    while ( ! unsignedZoneGroup.empty() )
+    {
+        std::cout << "number of unsigned zone = " << unsignedZoneGroup.size() << "\n";
+        int iProc = this->GetMinLoadProc();
+
+        //Get the block with the largest number of grids and its size
+        SplitZone * largestZone = this->GetLargestZone();
+
+        double nMaxCell = largestZone->GetNCell();
+
+        double aveFloatOp = this->aveFloatOp;
+        double tau = timeProc[ iProc ] + nMaxCell * aveFloatOp / procSpeed[ iProc ];
+
+        //It seems that EPS is still necessary
+        //The idea here is as follows. For the candidate blocks which can be divided into blocks, 
+        //if the difference between the target blocks and the candidate blocks is too wide, 
+        //the binarySplit method is adopted. The binarySplit blocks do not directly join the process,
+        //but enter the next round of screening.
+
+        if ( tau > idealUniProcTime * ( 1.0 + eps ) )
+        {
+            double nRest = ( tau - idealUniProcTime ) * procSpeed[ iProc ] / aveFloatOp;
+
+            double nTarget = nMaxCell - nRest;
+            if ( nRest > this->minNumberCell && nTarget > this->minNumberCell )
+            {
+                //It is necessary to divide blocks only when a certain number of points are satisfied.
+                double nHalf = nMaxCell / 2.0;
+                nMaxCell = nTarget;
+                double ratio = nMaxCell / nRest;
+                double oRatio = 1.0 / ratio;
+
+                if ( std::max( ratio, oRatio ) < 3.0 )
+                {
+                    int kkk = 1;
+                    largestZone = this->Split( largestZone, nMaxCell );
+                    timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                    this->RemoveZoneFromUnsignedGroup( largestZone );
+                    this->AddZoneToProcess( iProc, largestZone );
+                }
+                else
+                {
+                    this->Split( largestZone, nHalf );
+                }
+            }
+            else
+            {
+                //If the block is of the right size, join the process directly, and there is no need to split it.
+                timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                this->RemoveZoneFromUnsignedGroup( largestZone );
+                this->AddZoneToProcess( iProc, largestZone );
+            }
+        }
+        else
+        {
+            //If the block is of the right size, join the process directly, and there is no need to split it.
+            timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+            this->RemoveZoneFromUnsignedGroup( largestZone );
+            this->AddZoneToProcess( iProc, largestZone );
+        }
+    }
+}
+
+void Partition::ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord )
+{
+    SplitZone * rootSplitZone = splitZone->GetRootZone();
+    Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+    int nNodes = splitZone->dimInfo.ComputeNumNodes();
+    std::cout << "nNodes = " << nNodes << "\n";
+
+    coord.resize( nNodes * sizeof(double) );
+
+    int index_dim = splitZone->dimInfo.dimList.size();
+    Coor * coor = zone->coors[ icoord ];
+
+    double * xlocal = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    double * xglobal = reinterpret_cast<double *>( const_cast<char *>( coor->coord.data() ) );
+    if ( index_dim == 1 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        for ( int i = imin; i < imax; ++ i )
+        {
+            xlocal[ icount++ ] = xglobal[ i ];
+        }
+    }
+    else if ( index_dim == 2 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        int jmin = splitZone->dimInfo.rmin[ 1 ] - 1;
+        int jmax = splitZone->dimInfo.rmax[ 1 ];
+        int ni = rootSplitZone->dimInfo.dimList[ 0 ];
+        int nj = rootSplitZone->dimInfo.dimList[ 1 ];
+        for ( int j = jmin; j < jmax; ++ j )
+        {
+            int jstride = j * ni;
+            for ( int i = imin; i < imax; ++ i )
+            {
+                xlocal[ icount++ ] = xglobal[ jstride + i ];
+            }
+        }
+    }
+}
+
+void Partition::DumpBc( SplitZone * splitZone )
+{
+}
+
+void Partition::DumpPartitionedGridFile()
+{
+    std::cout << "\n";
+    std::cout << "DumpPartitionedGridFile -------------------------------" << "\n";
+    std::cout << "\n";
+    int fileId = -1;
+    std::string filename = this->outName;
+    int ierr = cg_open( filename.c_str(), CG_MODE_WRITE, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+
+    std::vector<std::string> coordnames;
+    coordnames.push_back( "CoordinateX" );
+    coordnames.push_back( "CoordinateY" );
+    coordnames.push_back( "CoordinateZ" );
+
+    std::string basename = "Base";
+    int baseId = -1;
+    int icelldim = Global::cell_dim;
+    int iphysdim = Global::phys_dim;
+    cg_base_write( fileId, basename.c_str(), icelldim, iphysdim, &baseId );
+
+    std::cout << "baseId = " << baseId << "\n";
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        int nZones = this->GetNZones( iProc );
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            ZoneType_t zoneType = Structured;
+
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+
+            int index_dim = splitZone->dimInfo.dimList.size();
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            splitZone->dimInfo.ComputeISize();
+
+            int isize_dim = index_dim * 3;
+
+            std::vector<cgsize_t> isize( index_dim * 3, 0 );
+            for ( int m = 0; m < isize_dim; ++ m )
+            {
+                isize[ m ] = splitZone->dimInfo.isize[ m ];
+            }
+
+            int zoneId = -1;
+
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+
+            std::string zonename = "Zone" + std::to_string( splitZone->newIndex );
+
+            cg_zone_write( fileId, baseId, zonename.c_str(), isize.data(), zoneType, &zoneId );
+
+            std::cout << "zoneId = " << zoneId << "\n";
+            std::cout << "zonename = " << zonename << "\n";
+                
+            splitZone->ComputeRminmax();
+
+            SplitZone * rootSplitZone = splitZone->GetRootZone();
+
+            Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+            int ncoords = zone->coors.size();
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = -1;
+                DataType_t dataType = RealDouble;
+                std::string coordname = coordnames[ icoord ];
+                Coor * coor = zone->coors[ icoord ];
+
+                int nNodes = splitZone->dimInfo.ComputeNumNodes();
+                std::cout << "nNodes = " << nNodes << "\n";
+
+                std::vector<char> coord;
+                ComputeCoor( splitZone, icoord, coord );
+
+                cg_coord_write( fileId, baseId, zoneId, dataType, coordname.c_str(), coord.data(), &coorId );
+
+                std::cout << "fileId = " << fileId  << " baseId = " << baseId << " zoneId = " << zoneId  << " coorId = " << coorId << "\n";
+            }
+
+            std::vector< PhysicalSplitBc * > &bccoList = splitZone->physicalSplitBcList;
+
+            int nbocos = bccoList.size();
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = -1;
+                GridLocation_t location = Vertex;
+
+                std::string boconame = "BC" + std::to_string( iboco + 1 );
+
+                PhysicalSplitBc * physicalSplitBc = bccoList[ iboco ];
+                BCType_t bocotype = static_cast<BCType_t>( physicalSplitBc->bcType );
+                PointSetType_t ptset_type = PointRange;
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> pnts;
+                int nSize = physicalSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.end[ i ] );
+                }
+
+                cg_boco_write( fileId, baseId, zoneId, boconame.c_str(), bocotype, ptset_type, npnts, pnts.data(), & bccoId );
+            }
+
+            //std::vector< InterfaceSplitBc * > & bc1to1List = splitZone->interfaceSplitBcList;
+            std::vector< InterfaceSplitBc * > bc1to1List;
+            splitZone->GetLeafInterfaceBc( bc1to1List );
+
+            int n1to1 = bc1to1List.size();
+            std::cout << "n1to1 = " << n1to1 << "\n";
+
+            std::vector<int> itranfrm( index_dim );
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                itranfrm[ m ] = m + 1;
+            }
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int index_conn = -1;
+
+                InterfaceSplitBc * interfaceSplitBc = bc1to1List[ i1to1 ];
+
+                std::vector<cgsize_t> pnts;
+                std::vector<cgsize_t> pntsdonor;
+                int nSize = interfaceSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.end[ i ] );
+                }
+
+                int nPatchSize = interfaceSplitBc->donor_region.start.size();
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.start[ i ] );
+                }
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.end[ i ] );
+                }
+                int id = interfaceSplitBc->donor_zone->newIndex;
+                int oldZoneIndex = interfaceSplitBc->donor_zone->zoneIndex;
+                std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+                std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+                std::cout << "donor zone id = " << id << "\n";
+                std::cout << "donor zone oldZoneIndex = " << oldZoneIndex << "\n";
+                std::string donorname = "Zone" + std::to_string( id );
+                std::string connectname = "Interface" + std::to_string( i1to1 );
+
+                std::cout << "donorname = " << donorname << "\n";
+                std::cout << "connectname = " << connectname << "\n";
+
+                std::vector<int> & itranfrm = interfaceSplitBc->transform;
+
+                cg_1to1_write( fileId, baseId, zoneId, connectname.c_str(), donorname.c_str(), pnts.data(), pntsdonor.data(), itranfrm.data(), &index_conn );
+                std::cout << "index_conn = " << index_conn << "\n";
+            }
+        }
+    }
+    cg_close( fileId );
+}
+
+void Partition::ModifyZoneIndex()
+{
+    std::cout << "ModifyZoneIndex +++++++++++++++++++++++++ " << "\n";
+    int globalZoneId = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        std::cout << "iProc = " << iProc << "\n";
+        int nZones = this->GetNZones( iProc );
+        std::cout << "nZones in Proc " << iProc << "  = " << nZones << "\n";
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+            //splitZone->SetZoneIndex( globalZoneId++ );
+            splitZone->newIndex = ( globalZoneId++ );
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+        }
+    }
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage3/01c/Partition.h b/example/partition/struct/2d/stage3/01c/Partition.h
new file mode 100644
index 00000000..8a4a9731
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01c/Partition.h
@@ -0,0 +1,59 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class SplitZone;
+
+struct CmpSplitZone 
+{
+    bool operator() ( SplitZone * a, SplitZone * b ) const;
+};
+
+class Partition
+{
+public:
+    Partition();
+    ~Partition();
+protected:
+    std::set < SplitZone * > zoneStorage;
+    std::set < SplitZone *, CmpSplitZone > unsignedZoneGroup;
+    std::vector< SplitZone * > refZone;
+    std::vector< std::vector< SplitZone * > > procSplitZone;
+    std::vector<double> procSpeed;
+    std::vector<double> timeProc;
+    double aveFloatOp, delta;
+    double idealUniProcTime, eps;
+    int minNumberCell;
+    int nTZone;
+    int nOriZone;
+    int nProc;
+public:
+    std::string inputName;
+    std::string outName;
+public:
+    void Solve();
+    void ReadGrid();
+    void Split();
+    void InitSplit();
+    void BinarySplit();
+    //void GreedySplit();
+public:
+    void AddNewZone( SplitZone * zone );
+    void AddZoneToUnsignedGroup( SplitZone * zone );
+    void RemoveZoneFromUnsignedGroup( SplitZone * zone );
+    void AddZoneToProcess( int iProc, SplitZone * zone );
+    void DumpPartitionedGridFile();
+    void ModifyZoneIndex();
+    void FreeAllZones();
+    int GetNZones( int iProc );
+    SplitZone * GetSplitZone( int iProc, int zoneId );
+    void ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord );
+    void DumpBc( SplitZone * splitZone );
+private:
+    int GetMinValueIndex( double * data, int numberOfData );
+    int GetMinLoadProc();
+    SplitZone * GetLargestZone();
+    SplitZone * Split( SplitZone * zone, double nCell );
+};
+
diff --git a/example/partition/struct/2d/stage3/01c/README.txt b/example/partition/struct/2d/stage3/01c/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01c/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/partition/struct/2d/stage3/01c/SplitZone.cpp b/example/partition/struct/2d/stage3/01c/SplitZone.cpp
new file mode 100644
index 00000000..aef70754
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01c/SplitZone.cpp
@@ -0,0 +1,1091 @@
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+int Dim::dim = -1;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox  )
+{
+    domainBox.start = zoneBox.start;
+    domainBox.end = zoneBox.end;
+
+    int axis = iDomain / 2;
+    int direction = iDomain % 2;
+
+    if ( direction == 0 )
+    {
+        domainBox.end[ axis ] = domainBox.start[ axis ];
+    }
+    else if ( direction == 1 )
+    {
+        domainBox.start[ axis ] = domainBox.end[ axis ];
+    }
+}
+
+DimInfo::DimInfo()
+{
+    this->Init( 1 );
+}
+
+DimInfo::~DimInfo()
+{
+}
+
+void DimInfo::Init( int dim )
+{
+    this->dim = dim;
+    dimList.resize( this->dim, 1 );
+    oriPoint.resize( this->dim, 0 );
+}
+
+DimInfo & DimInfo::operator = ( const DimInfo & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->dim = rhs.dim;
+    this->dimList = rhs.dimList;
+    this->oriPoint = rhs.oriPoint;
+
+    return * this;
+}
+
+int DimInfo::ComputeNumNodes()
+{
+    int nNodes = 1;
+    for ( int m = 0; m < this->dimList.size(); ++ m )
+    {
+        nNodes *= this->dimList[ m ];
+    }
+    return nNodes;
+}
+
+void DimInfo::ComputeISize()
+{
+    int index_dim = this->dimList.size();
+    this->isize.resize( index_dim * 3, 0 );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        isize[ m ] = this->dimList[ m ];
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 1;
+        isize[ start + m ] = this->dimList[ m ] - 1;
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 2;
+        isize[ start + m ] = 0;
+    }
+
+    for ( int i = 0; i < isize.size(); ++ i )
+    {
+        std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+    }
+}
+
+void DimInfo::ComputeRminmax( std::vector<int> & ref )
+{
+    int index_dim = this->dimList.size();
+    this->rmin.resize( index_dim );
+    this->rmax.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        rmin[ m ] = ref[ m ] + 1;
+        rmax[ m ] = ref[ m ] + this->dimList[ m ];
+    }
+
+    std::cout << "rmin, rmax = \n";
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        std::cout << rmin[ m ] << " " << rmax[ m ] << "\n";
+    }
+}
+
+void DimInfo::Init( std::vector<int> & dimList )
+{
+    this->dim = dimList.size();
+    this->dimList = dimList;
+    std::vector<int> zero( dimList.size(), 0 );
+    this->oriPoint = zero;
+}
+
+void DimInfo::SetNewDimension( int axis, int newStart, int newWidth )
+{
+    this->oriPoint[ axis ] = newStart;
+    this->dimList [ axis ] = newWidth;
+}
+
+void DimInfo::GetZoneGlobalBox( RangeRegion &zoneBox )
+{
+    int index_dim = this->dimList.size();
+    zoneBox.start.resize( index_dim );
+    zoneBox.end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        zoneBox.start[ m ] = this->oriPoint[ m ] + 1;
+        zoneBox.end[ m ] = this->oriPoint[ m ] + this->dimList[ m ];
+    }
+}
+
+void DimInfo::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    int index_dim = this->dimList.size();
+    localBox.start.resize( index_dim );
+    localBox.end.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        localBox.start[ m ] = globalBox.start[ m ] - this->oriPoint[ m ];
+        localBox.end[ m ] = globalBox.end[ m ] - this->oriPoint[ m ];
+    }
+}
+
+RangeRegion::RangeRegion( int nSize )
+{
+    this->Init( nSize );
+}
+
+RangeRegion::~RangeRegion()
+{
+}
+
+void RangeRegion::Init( int nSize )
+{
+    this->start.resize( nSize );
+    this->end.resize( nSize );
+}
+
+RangeRegion & RangeRegion::operator = ( const RangeRegion & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+bool RangeRegion::operator == ( const RangeRegion & rhs ) const
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] != rhs.start[ m ] || 
+            this->end  [ m ] != rhs.end  [ m ] )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+bool RangeRegion::InRegion( const RangeRegion & region )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( ( this->start[ m ] < region.start[ m ] ) || ( this->end[ m ] > region.end[ m ] ) )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::Normalize()
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        int minv = std::min( this->start[ m ], this->end[ m ] );
+        int maxv = std::max( this->start[ m ], this->end[ m ] );
+        this->start[ m ] = minv;
+        this->end[ m ] = maxv;
+    }
+}
+
+void RangeRegion::Localize( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] -= oriPoint[ m ];
+        this->end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void RangeRegion::ToGlobal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] += oriPoint[ m ];
+        this->end[ m ] += oriPoint[ m ];
+    }
+}
+
+void RangeRegion::ToLocal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] -= oriPoint[ m ];
+        this->end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void RangeRegion::PrintGlobal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    std::cout << "global start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ] + oriPoint[m];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "global end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ] + oriPoint[m];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+void RangeRegion::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion );
+
+bool ComputeOverlapRegion( RangeRegion & region1, RangeRegion & region2, RangeRegion & overlapRegion )
+{
+    int index_dim = region1.start.size();
+    overlapRegion.Init( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int ijkmin1 = std::min( region1.start[ m ], region1.end[ m ] );
+        int ijkmax1 = std::max( region1.start[ m ], region1.end[ m ] );
+        int ijkmin2 = std::min( region2.start[ m ], region2.end[ m ] );
+        int ijkmax2 = std::max( region2.start[ m ], region2.end[ m ] );
+        if ( ( ijkmax1 < ijkmin2 ) || ( ijkmin1 > ijkmax2 ) )
+        {
+            return false;
+        }
+
+        int ijkmin = std::max( ijkmin1, ijkmin2 );
+        int ijkmax = std::min( ijkmax1, ijkmax2 );
+
+        overlapRegion.start[ m ] = ijkmin;
+        overlapRegion.end  [ m ] = ijkmax;
+    }
+
+    return CheckOverLapping( overlapRegion );
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion )
+{
+    int index_dim = overlapRegion.start.size();
+    int iCount = 0;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        if ( overlapRegion.start[ m ] == overlapRegion.end[ m ] )
+        {
+            ++ iCount;
+        }
+    }
+
+    return ( iCount == 1 );
+}
+
+bool GetInterfaceRegion( RangeRegion & zoneBoxL, RangeRegion & zoneBoxR, RangeRegion & interfaceRegion )
+{
+    int index_dim = zoneBoxL.start.size();
+    int nDomains = 2 * index_dim;
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegionL;
+        GetDomainRegion( zoneBoxL, iDomain, domainRegionL );
+
+        for ( int jDomain = 0; jDomain < nDomains; ++ jDomain )
+        {
+            RangeRegion domainRegionR;
+            GetDomainRegion( zoneBoxR, jDomain, domainRegionR );
+
+            if ( domainRegionL == domainRegionR )
+            {
+                interfaceRegion = domainRegionL;
+                return true;
+            }
+        }
+    }
+    return false;
+}
+
+void CreateInterfaceBc( SplitZone * zoneL, SplitZone * zoneR )
+{
+    RangeRegion globalBoxL, globalBoxR, globalInterfaceRegion;
+
+    zoneL->GetZoneGlobalBox( globalBoxL );
+    zoneR->GetZoneGlobalBox( globalBoxR );
+
+    if ( ! GetInterfaceRegion( globalBoxL, globalBoxR, globalInterfaceRegion ) )
+    {
+        return;
+    }
+
+    RangeRegion localInterfaceRegionL, localInterfaceRegionR;
+
+    zoneL->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionL );
+    zoneR->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionR );
+
+    int kkk = 1;
+
+    InterfaceSplitBc * interfaceSplitBcL = new InterfaceSplitBc();
+    zoneL->interfaceSplitBcList.push_back( interfaceSplitBcL );
+    interfaceSplitBcL->zone = zoneL;
+    interfaceSplitBcL->region = localInterfaceRegionL;
+
+    int nSize = localInterfaceRegionL.start.size();
+
+    std::vector<int> transform;
+
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        transform.push_back( m + 1 );
+    }
+
+    interfaceSplitBcL->transform = transform;
+    interfaceSplitBcL->CalcTransformMatrix();
+
+    interfaceSplitBcL->donor_zone = zoneR;
+    interfaceSplitBcL->donor_region = localInterfaceRegionR;
+
+    InterfaceSplitBc * interfaceSplitBcR = new InterfaceSplitBc();
+    zoneR->interfaceSplitBcList.push_back( interfaceSplitBcR );
+
+    interfaceSplitBcR->zone = zoneR;
+    interfaceSplitBcR->region = localInterfaceRegionR;
+
+    interfaceSplitBcR->transform = transform;
+    interfaceSplitBcR->CalcTransformMatrix();
+
+    interfaceSplitBcR->donor_zone = zoneL;
+    interfaceSplitBcR->donor_region = localInterfaceRegionL;
+}
+
+
+PhysicalSplitBc::PhysicalSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+PhysicalSplitBc::~PhysicalSplitBc()
+{
+}
+
+void PhysicalSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void PhysicalSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+void PhysicalSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = splitZone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+BasicSplitBc::BasicSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+BasicSplitBc::~BasicSplitBc()
+{
+    ;
+}
+
+void BasicSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void BasicSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+int trans::M[ 3 ][ 3 ];
+std::vector<int> trans::transform;
+
+int trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void trans::CalcTransformMatrix()
+{
+    int dim = trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = trans::transform[ 0 ];
+        int sgna = trans::sgn( a );
+        int a1 = trans::del( a, 1 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int c = trans::transform[ 2 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int sgnc = trans::sgn( c );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int a3 = trans::del( a, 3 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        int b3 = trans::del( b, 3 );
+        int c1 = trans::del( c, 1 );
+        int c2 = trans::del( c, 2 );
+        int c3 = trans::del( c, 3 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 2 ][ 0 ] = sgna * a3;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+        trans::M[ 2 ][ 1 ] = sgnb * b3;
+        trans::M[ 0 ][ 2 ] = sgnc * c1;
+        trans::M[ 1 ][ 2 ] = sgnc * c2;
+        trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+InterfaceInfo::InterfaceInfo()
+{
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceInfo::~InterfaceInfo()
+{
+}
+
+InterfaceSplitBc::InterfaceSplitBc()
+{
+    this->region.Init( Dim::dim );
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceSplitBc::~InterfaceSplitBc()
+{
+}
+
+void InterfaceSplitBc::GetLeafInterfaceBc( std::vector< InterfaceSplitBc * > & leafInterfaceBcList )
+{
+    int nChild = this->child.size();
+    if ( nChild == 0 )
+    {
+        leafInterfaceBcList.push_back( this );
+    }
+    else
+    {
+        for ( int iChild = 0; iChild < nChild; ++ iChild )
+        {
+            InterfaceSplitBc * interfaceSplitBc = this->child[ iChild ];
+            interfaceSplitBc->GetLeafInterfaceBc( leafInterfaceBcList );
+        }
+    }
+}
+
+void InterfaceSplitBc::CopyMatrix( InterfaceSplitBc * interfaceSplitBc )
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = interfaceSplitBc->Mt[ i ][ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::CalcTransformMatrix()
+{
+    trans::ZeroMatrix();
+    trans::transform = this->transform;
+    trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = trans::M[ i ][ j ];
+        }
+    }
+
+}
+
+void InterfaceSplitBc::mapindex( std::vector<int> & begin1, std::vector<int> & begin2,  std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = Dim::dim;
+    std::vector<int> diff( dim );
+    for ( int m = 0; m < dim; ++ m )
+    {
+        diff[ m ] = index1[ m ] - begin1[ m ];
+    }
+
+    std::vector<int> mul( dim );
+
+    Multiply( Mt, diff, mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = mul[ m ] + begin2[ m ];
+    }
+}
+
+void InterfaceSplitBc::Multiply( int Mt[][3], std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = Dim::dim;
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = this->zone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void InterfaceSplitBc::CalcSubDonorRegion( RangeRegion &subRegion, RangeRegion &subDonorRegion )
+{
+    std::vector<int> begin1 = this->region.start;
+    std::vector<int> end1 = this->region.end;
+    std::vector<int> begin2 = this->donor_region.start;
+    std::vector<int> end2 = this->donor_region.end;
+
+    std::vector<int> new_begin1 = subRegion.start;
+    std::vector<int> new_end1 = subRegion.end;
+
+    int dim = Dim::dim;
+    std::vector<int> new_begin2( dim );
+    std::vector<int> new_end2( dim );
+
+    mapindex( begin1, begin2, new_begin1, new_begin2 );
+    mapindex( begin1, begin2, new_end1, new_end2 );
+
+    subDonorRegion.start = new_begin2;
+    subDonorRegion.end = new_end2;
+}
+
+SplitZone::SplitZone()
+{
+    this->parent  = 0;
+    this->zoneIndex = 0;
+    this->iProc = 0;
+    dimInfo.Init( Dim::dim );
+    int kk = 1;
+}
+
+SplitZone::~SplitZone()
+{
+    ;
+}
+
+void SplitZone::GetZoneGlobalBox( RangeRegion & zoneBox )
+{
+    this->dimInfo.GetZoneGlobalBox( zoneBox );
+}
+
+void SplitZone::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    this->dimInfo.GetZoneLocalBox( globalBox, localBox );
+}
+
+
+void SplitZone::ComputeRminmax()
+{
+    int index_dim = this->dimInfo.dimList.size();
+    std::vector<int> ref( index_dim, 0 );
+
+    SplitZone * rootSplitZone = 0;
+    this->GetRootInfo( rootSplitZone, ref );
+
+    this->dimInfo.ComputeRminmax( ref );
+}
+
+SplitZone * SplitZone::GetRootZone()
+{
+    SplitZone * root = this;
+
+    while ( true )
+    {
+        if ( root->parent )
+        {
+            root = root->parent;
+        }
+        else
+        {
+            return root;
+        }
+    };
+}
+
+void SplitZone::GetRootInfo( SplitZone *& root, std::vector<int> & ref )
+{
+    for ( int i = 0; i < this->dimInfo.dimList.size(); ++ i )
+    {
+        ref[ i ] += this->dimInfo.oriPoint[ i ];
+    }
+
+    if ( this->parent )
+    {
+        this->parent->GetRootInfo( root, ref );
+    }
+    else
+    {
+        root = this;
+    }
+}
+
+void SplitZone::SetParentAndChild( SplitZone * parent )
+{
+    this->parent = parent;
+    if ( parent )
+    {
+        parent->child.push_back( this );
+    }
+}
+
+void SplitZone::GetLeafInterfaceBc( std::vector< InterfaceSplitBc * > & leafInterfaceBcList )
+{
+    int nInterfaceBcs = this->interfaceSplitBcList.size();
+    for ( int i = 0; i < nInterfaceBcs; ++ i )
+    {
+        InterfaceSplitBc * interfaceSplitBc = this->interfaceSplitBcList[ i ];
+        interfaceSplitBc->GetLeafInterfaceBc( leafInterfaceBcList );
+    }
+}
+
+int SplitZone::GetNCell()
+{
+    int numberOfCells = 1;
+    for ( int i = 0; i < this->dimInfo.dim; ++ i )
+    {
+        numberOfCells *= std::max( 1, ( this->dimInfo.dimList[ i ] - 1 ) );
+    }
+
+    return numberOfCells; 
+}
+
+void SplitZone::SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int leftStart = 0;
+    int leftWidth = iSplit - 0;
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, leftStart , leftWidth  );
+}
+
+void SplitZone::SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int rightStart = iSplit - 1;
+    int rightWidth = dimList[ axisNeedSplit ] - ( iSplit - 1 );
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, rightStart, rightWidth );
+}
+
+void SplitZone::Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell )
+{
+    //Find the longest axis
+    int axisNeedSplit = this->FindAxisNeedSplit();
+    int iSplit        = this->FindSplitPosition( axisNeedSplit, nCell );
+
+    zoneL->SetLeftDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+    zoneR->SetRightDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+
+    zoneL->CreateBcFromParent();
+    zoneR->CreateBcFromParent();
+    
+    CreateInterfaceBc( zoneL, zoneR );
+}
+
+void SplitZone::CreateBcFromParent()
+{
+    this->CreatePhysicalBcFromParent();
+    this->CreateInterfaceBcFromParent();
+}
+
+void SplitZone::CreatePhysicalBcFromParent()
+{
+    int nParentPhysicalBcs = this->parent->physicalSplitBcList.size();
+
+    for ( int iParentPhysicalBcs = 0; iParentPhysicalBcs < nParentPhysicalBcs; ++ iParentPhysicalBcs )
+    {
+        PhysicalSplitBc * parentPhysicalSplitBc = this->parent->physicalSplitBcList[ iParentPhysicalBcs ];
+
+        this->CreatePhysicalBcFromParent( parentPhysicalSplitBc );
+    }
+}
+
+void SplitZone::CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentPhysicalSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreatePhysicalBc( overlapRegion, parentPhysicalSplitBc->bcType );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent()
+{
+    int nInterfaceSplitBcs = this->parent->interfaceSplitBcList.size();
+
+    for ( int iInterfaceSplitBcs = 0; iInterfaceSplitBcs < nInterfaceSplitBcs; ++ iInterfaceSplitBcs )
+    {
+        InterfaceSplitBc * parentInterfaceSplitBc = this->parent->interfaceSplitBcList[ iInterfaceSplitBcs ];
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc );
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentInterfaceSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc, overlapRegion );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::FindDonorInterface( InterfaceSplitBc * interfaceSplitBc, InterfaceInfo & interfaceInfo )
+{
+    RangeRegion donor_region = interfaceSplitBc->donor_region;
+    donor_region.Normalize();
+    interfaceInfo.donor_zone = this;
+    for ( int iInterface = 0; iInterface < interfaceSplitBcList.size(); ++ iInterface )
+    {
+        InterfaceSplitBc * candidateDonorBc = interfaceSplitBcList[ iInterface ];
+        bool flag = donor_region.InRegion( candidateDonorBc->region );
+        if ( flag )
+        {
+            if ( donor_region == candidateDonorBc->region )
+            {
+                interfaceInfo.donor_interface = candidateDonorBc;
+                return;
+            }
+            else
+            {
+                InterfaceSplitBc * donorBc = new InterfaceSplitBc();
+                candidateDonorBc->child.push_back( donorBc );
+                donorBc->region = donor_region;
+                donorBc->zone = candidateDonorBc->zone;
+                donorBc->donor_zone = interfaceSplitBc->zone;
+                donorBc->transform = candidateDonorBc->transform;
+                donorBc->CopyMatrix( candidateDonorBc );
+                RangeRegion subDonorRegion( Dim::dim );
+                candidateDonorBc->CalcSubDonorRegion( donorBc->region, subDonorRegion );
+                std::vector<int> & oriPoint = interfaceSplitBc->zone->dimInfo.oriPoint;
+                subDonorRegion.Localize( oriPoint );
+                donorBc->donor_region = subDonorRegion;
+                donorBc->donor_bc = interfaceSplitBc;
+                interfaceInfo.donor_interface = donorBc;
+                return;
+            }
+        }
+    }
+    return;
+}
+
+void SplitZone::GetChildDonorRegion( RangeRegion & subDonorRegion, InterfaceInfo & interfaceInfo )
+{
+    std::cout << "subDonorRegion = \n";
+    //subDonorRegion.Print();
+    RangeRegion normalizedDonorRegion = subDonorRegion;
+    normalizedDonorRegion.Normalize();
+    int nChild = this->child.size();
+    for ( int ichild = 0; ichild < nChild; ++ ichild )
+    {
+        std::cout << " iChild = " << ichild << " nChild = " << nChild << "\n";
+        SplitZone * sub_zone = this->child[ ichild ];
+        std::cout << " zoneIndex = " << sub_zone->zoneIndex << "\n";
+        int nInters = sub_zone->interfaceSplitBcList.size();
+        for ( int iInter = 0; iInter < nInters; ++ iInter )
+        {
+            std::cout << " iInter = " << iInter << "\n";
+            InterfaceSplitBc * interfaceSplitBc = sub_zone->interfaceSplitBcList[ iInter ];
+            std::cout << "interfaceSplitBc local = \n";
+            interfaceSplitBc->region.Print();
+            std::cout << "interfaceSplitBc global = \n";
+            interfaceSplitBc->region.PrintGlobal( sub_zone->dimInfo.oriPoint );
+            RangeRegion g_region = interfaceSplitBc->region;
+            g_region.ToGlobal( sub_zone->dimInfo.oriPoint );
+            if ( g_region == normalizedDonorRegion )
+            {
+                RangeRegion donorRegion = subDonorRegion;
+                donorRegion.ToLocal( sub_zone->dimInfo.oriPoint );
+
+                interfaceInfo.donor_zone = sub_zone;
+                interfaceInfo.donor_interface = interfaceSplitBc;
+                interfaceInfo.donor_region = donorRegion;
+                return;
+            }
+        }
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion )
+{
+    InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+    this->interfaceSplitBcList.push_back( interfaceSplitBc );
+
+    interfaceSplitBc->region = overlapRegion;
+    interfaceSplitBc->zone = this;
+    interfaceSplitBc->transform = parentInterfaceSplitBc->transform;
+    interfaceSplitBc->CopyMatrix( parentInterfaceSplitBc );
+    RangeRegion subDonorRegion( Dim::dim );
+    parentInterfaceSplitBc->CalcSubDonorRegion( overlapRegion, subDonorRegion );
+    interfaceSplitBc->ChangeRegionToLocalCoordinate();
+    interfaceSplitBc->donor_region = subDonorRegion;
+    SplitZone * parent_donor_zone = parentInterfaceSplitBc->donor_zone;
+    std::cout << " parentInterfaceSplitBc->zone->zoneIndex " << parentInterfaceSplitBc->zone->zoneIndex << "\n";
+    std::cout << " parentInterfaceSplitBc->donor_zone->zoneIndex " << parent_donor_zone->zoneIndex << "\n";
+    if ( parent_donor_zone->child.size() > 0 )
+    {
+        InterfaceInfo interfaceInfo;
+        parent_donor_zone->GetChildDonorRegion( subDonorRegion, interfaceInfo );
+        interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+        interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+        interfaceSplitBc->donor_region = interfaceInfo.donor_region;
+        //compatibility
+        InterfaceSplitBc * donor_bc = interfaceSplitBc->donor_bc;
+        SplitZone * donor_zone = interfaceSplitBc->donor_zone;
+        if ( interfaceSplitBc->zone != donor_bc->donor_zone )
+        {
+            if ( interfaceSplitBc->zone->parent == donor_bc->donor_zone )
+            {
+                RangeRegion d_region = donor_bc->donor_region;
+                d_region.ToLocal( interfaceSplitBc->zone->dimInfo.oriPoint );
+                donor_bc->donor_region = d_region;
+            }
+            donor_bc->donor_zone = interfaceSplitBc->zone;
+         
+            int kkk = 1;
+        }
+        int kkk = 1;
+    }
+    else
+    {
+        InterfaceInfo interfaceInfo;
+        parent_donor_zone->FindDonorInterface( interfaceSplitBc, interfaceInfo );
+        interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+        interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+    }
+    
+    int kkk = 1;
+}
+
+void SplitZone::CreatePhysicalBc( RangeRegion & overlapRegion, int bcType )
+{
+    PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+    this->physicalSplitBcList.push_back( physicalSplitBc );
+    physicalSplitBc->SetRegion( overlapRegion );
+    physicalSplitBc->bcType = bcType;
+    physicalSplitBc->splitZone = this;
+    physicalSplitBc->ChangeRegionToLocalCoordinate();
+}
+
+int SplitZone::FindAxisNeedSplit()
+{
+    //Find the longest axis
+    int axisNeedSplit = 0;
+    int maxN = this->dimInfo.dimList[ 0 ];
+
+    for ( int m = 1; m < this->dimInfo.dimList.size(); ++ m )
+    {
+        if ( this->IsPoleBc( m ) )
+        {
+            continue;
+        }
+        int Nm = this->dimInfo.dimList[ m ];
+        if ( maxN < Nm )
+        {
+            maxN = Nm;
+            axisNeedSplit = m;
+        }
+    }
+
+    return axisNeedSplit;
+}
+
+int SplitZone::GetCrossSection( int axis )
+{
+    int nDim = this->dimInfo.dimList.size();
+    int crossSection = 1;
+    int N = nDim - 1;
+    for ( int m = 0; m < N; ++ m )
+    {
+         int mm = ( axis + 1 ) % nDim;
+         int nLineElements = std::max( 1, ( this->dimInfo.dimList[ mm ] - 1 ) );
+         crossSection *= nLineElements;
+    }
+    return crossSection;
+}
+
+int SplitZone::FindSplitPosition( int axisNeedSplit, double nCell )
+{
+    int nDim = this->dimInfo.dimList.size();
+    std::vector<int> crossSections( nDim );
+    for ( int m = 0; m < nDim; ++ m )
+    {
+        crossSections[ m ] = this->GetCrossSection( m );
+    }
+
+    //guess the value
+    double dSplit = nCell / crossSections[ axisNeedSplit ];
+    int  iSplit = 1 + static_cast< int >( std::floor( dSplit + 0.5 ) );
+    return iSplit;
+}
+
+
+bool SplitZone::IsPoleBc( int splitDirection )
+{
+    return false;
+}
+
diff --git a/example/partition/struct/2d/stage3/01c/SplitZone.h b/example/partition/struct/2d/stage3/01c/SplitZone.h
new file mode 100644
index 00000000..ffe1e306
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01c/SplitZone.h
@@ -0,0 +1,196 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class Dim
+{
+public:
+    static int dim;
+};
+
+class SplitZone;
+class RangeRegion;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox );
+
+class DimInfo
+{
+public:
+    DimInfo();
+    ~DimInfo();
+public:
+    int dim;
+    std::vector<int> dimList;
+    std::vector<int> oriPoint;
+    std::vector<int> isize;
+    std::vector<int> rmin;
+    std::vector<int> rmax;
+public:
+    int GetSize() const { return dim; }
+    DimInfo & operator = ( const DimInfo & rhs );
+public:
+    int ComputeNumNodes();
+    void ComputeISize();
+    void ComputeRminmax( std::vector<int> & ref );
+    void Init( int dim );
+    void Init( std::vector<int> & dimList );
+    void SetNewDimension( int axis, int newStart, int newWidth );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+};
+
+class SplitZone;
+class SplitBcPatch;
+
+class RangeRegion
+{
+public:
+    RangeRegion( int nSize = 1 );
+    ~RangeRegion();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    void Init( int nSize );
+    RangeRegion & operator = ( const RangeRegion & rhs );
+    bool operator == ( const RangeRegion & rhs ) const;
+    bool InRegion( const RangeRegion & region );
+    void SetRegion( std::vector<int> &pnts );
+    void Normalize();
+    void Localize( std::vector<int> & oriPoint );
+    void ToGlobal( std::vector<int> & oriPoint );
+    void ToLocal( std::vector<int> & oriPoint );
+    void PrintGlobal( std::vector<int> & oriPoint );
+    void Print();
+};
+
+class PhysicalSplitBc
+{
+public:
+    PhysicalSplitBc();
+    ~PhysicalSplitBc();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class BasicSplitBc
+{
+public:
+    BasicSplitBc();
+    ~BasicSplitBc();
+public:
+    RangeRegion region;
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> & pnts );
+    void SetRegion( RangeRegion & region );
+};
+
+class trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class InterfaceSplitBc;
+class SplitZone;
+
+class InterfaceInfo
+{
+public:
+    InterfaceInfo();
+    ~InterfaceInfo();
+public:
+    InterfaceSplitBc * donor_interface = nullptr;
+    SplitZone * donor_zone = nullptr;
+    RangeRegion donor_region;
+};
+
+class InterfaceSplitBc
+{
+public:
+    InterfaceSplitBc();
+    ~InterfaceSplitBc();
+public:
+    std::vector<int> transform;
+    int Mt[ 3 ][ 3 ];
+    RangeRegion region;
+    SplitZone * zone = nullptr;
+    RangeRegion donor_region;
+    SplitZone * donor_zone = nullptr;
+    InterfaceSplitBc * donor_bc = nullptr;
+public:
+    std::vector<InterfaceSplitBc *> child;
+    void GetLeafInterfaceBc( std::vector< InterfaceSplitBc * > & leafInterfaceBcList );
+public:
+    void CopyMatrix( InterfaceSplitBc * interfaceSplitBc );
+    void CalcTransformMatrix();
+    void CalcSubDonorRegion( RangeRegion & subRegion, RangeRegion & subDonorRegion );
+    void mapindex( std::vector<int> & begin1, std::vector<int> & begin2, std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( int Mt[][ 3 ], std::vector<int> & a, std::vector<int> & b );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class SplitZone
+{
+public:
+    SplitZone();
+    ~SplitZone();
+public:
+    DimInfo dimInfo;
+    int zoneIndex, iProc;
+    int newIndex;
+protected:
+    SplitZone * parent;
+    std::vector<SplitZone *> child;
+public:
+    std::vector< PhysicalSplitBc * > physicalSplitBcList;
+    std::vector< InterfaceSplitBc * > interfaceSplitBcList;
+    void GetLeafInterfaceBc( std::vector< InterfaceSplitBc * > & leafInterfaceBcList );
+public:
+    int GetNCell();
+    void ComputeRminmax();
+    void GetRootInfo( SplitZone *& root, std::vector<int> & ref );
+    void SetZoneIndex( int zoneIndex ) { this->zoneIndex = zoneIndex; }
+    int  GetZoneIndex() { return zoneIndex; }
+    void SetProcId( int iProc ) { this->iProc = iProc; }
+    void SetParent( SplitZone * parent ) { this->parent = parent; };
+    void SetParentAndChild( SplitZone * parent );
+    void FindDonorInterface( InterfaceSplitBc * interfaceSplitBc, InterfaceInfo & interfaceInfo );
+    void GetChildDonorRegion( RangeRegion & subDonorRegion, InterfaceInfo & interfaceInfo );
+public:
+    void CreateBcFromParent();
+    void CreatePhysicalBcFromParent();
+    void CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc );
+    void CreatePhysicalBc( RangeRegion & overlapRegion, int bcType );
+    void CreateInterfaceBcFromParent();
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc );
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion );
+
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+    SplitZone * GetRootZone();
+public:
+    void Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell );
+    void SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+    void SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+private:
+    int FindAxisNeedSplit();
+    int FindSplitPosition( int axisNeedSplit, double nCell );
+    bool IsPoleBc( int splitDirection );
+    int GetCrossSection( int axis );
+};
+
diff --git a/example/partition/struct/2d/stage3/01c/heat2d1blockv2.cgns b/example/partition/struct/2d/stage3/01c/heat2d1blockv2.cgns
new file mode 100644
index 00000000..93a1b73e
Binary files /dev/null and b/example/partition/struct/2d/stage3/01c/heat2d1blockv2.cgns differ
diff --git a/example/partition/struct/2d/stage3/01c/main.cpp b/example/partition/struct/2d/stage3/01c/main.cpp
new file mode 100644
index 00000000..5da1de7c
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01c/main.cpp
@@ -0,0 +1,18 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include "Partition.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip>
+
+int main(int argc, char **argv)
+{
+    Partition * partition = new Partition();
+    partition->Solve();
+    delete partition;
+
+    return 0;
+}
diff --git a/example/partition/struct/2d/stage3/01d/CMakeLists.txt b/example/partition/struct/2d/stage3/01d/CMakeLists.txt
new file mode 100644
index 00000000..74ceea7d
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01d/CMakeLists.txt
@@ -0,0 +1,78 @@
+cmake_minimum_required(VERSION 3.30)
+
+project( testprj )
+
+set ( PRJ_COMPILE_FEATURES )
+set ( PRJ_COMPILE_DEFINITIONS )
+set ( PRJ_LIBRARIES )
+set ( PRJ_INCLUDE_DIRS )
+
+list ( APPEND PRJ_COMPILE_FEATURES cxx_std_23 )
+
+find_package(Eigen3 CONFIG REQUIRED)
+
+message ( STATUS "EIGEN3_INCLUDE_DIR    = ${EIGEN3_INCLUDE_DIR}" )
+
+#list ( APPEND PRJ_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR} )
+list ( APPEND PRJ_LIBRARIES Eigen3::Eigen )
+set ( CGNS_INCLUDE_DIRS $ENV{CGNS_INC} )
+set ( CGNS_LIBRARIES $ENV{CGNS_LIB_SHARED_NAME} )
+
+if ( ${CMAKE_SYSTEM_NAME} MATCHES "Windows" )
+    set ( CGNS_ROOT "C:/dev/cgns/4.4.0" )
+    set ( CGNS_LIBNAME "cgnsdll.lib" )
+
+    set ( CGNS_INCLUDE_DIRS "${CGNS_ROOT}/include" CACHE PATH "path to CGNS headers" )
+    set ( CGNS_LIBRARIES "${CGNS_ROOT}/lib/${CGNS_LIBNAME}" CACHE PATH "path to CGNS library" )
+endif()
+
+list ( APPEND PRJ_LIBRARIES ${CGNS_LIBRARIES} )
+list ( APPEND PRJ_INCLUDE_DIRS ${CGNS_INCLUDE_DIRS} )
+
+if ( WIN32 )
+    list ( APPEND PRJ_COMPILE_DEFINITIONS USE_DLL )
+endif ()
+
+message( STATUS "PRJ_INCLUDE_DIRS = ${PRJ_INCLUDE_DIRS}")
+
+if ( MSVC )
+    set_property( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${PROJECT_NAME} )
+endif()
+
+add_executable( ${PROJECT_NAME}
+)
+
+set( PROJECT_SOURCES
+    main.cpp
+	Partition.h Partition.cpp
+	CgnsGrid.h CgnsGrid.cpp
+	SplitZone.h SplitZone.cpp
+)
+
+message( STATUS "PROJECT_NAME = ${PROJECT_NAME}")
+message( STATUS "PROJECT_SOURCES = ${PROJECT_SOURCES}")
+
+target_sources( ${PROJECT_NAME}
+  PRIVATE
+	${PROJECT_SOURCES}
+)
+
+target_include_directories ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_INCLUDE_DIRS}
+)
+
+target_link_libraries( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_LIBRARIES}
+)
+
+target_compile_features ( ${PROJECT_NAME} 
+  PRIVATE 
+    ${PRJ_COMPILE_FEATURES}
+)
+
+target_compile_definitions ( ${PROJECT_NAME}
+  PRIVATE
+    ${PRJ_COMPILE_DEFINITIONS} 
+)
diff --git a/example/partition/struct/2d/stage3/01d/CgnsGrid.cpp b/example/partition/struct/2d/stage3/01d/CgnsGrid.cpp
new file mode 100644
index 00000000..dfe750bd
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01d/CgnsGrid.cpp
@@ -0,0 +1,349 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include <map>
+
+Grid::Grid()
+{
+    ;
+}
+
+Grid::~Grid()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+}
+
+Coor::Coor()
+{
+    ;
+}
+
+Coor::~Coor()
+{
+}
+
+void Coor::DumpCoor()
+{
+    double * xd = reinterpret_cast<double*>(const_cast<char *>(coord.data()));
+    for ( int i = 0; i < this->nNodes; ++ i )
+    {
+        //std::cout << coord[i] << " ";
+        std::cout << xd[ i ] << " ";
+        if( (i+1)%5 == 0 ) std::cout << "\n";
+    }
+    std::cout << "\n";
+}
+
+Zone::Zone()
+{
+    ;
+}
+
+Zone::~Zone()
+{
+    for ( int i = 0; i < bccos.size(); ++ i )
+    {
+        delete bccos[ i ];
+    }
+
+    for ( int i = 0; i < coors.size(); ++ i )
+    {
+        delete coors[ i ];
+    }
+}
+
+ZoneBc::ZoneBc()
+{
+    ;
+}
+
+ZoneBc::~ZoneBc()
+{
+    delete this->patch;
+}
+
+
+ZoneBc1To1::ZoneBc1To1()
+{
+    ;
+}
+
+ZoneBc1To1::~ZoneBc1To1()
+{
+}
+
+ZoneBcPatch::ZoneBcPatch()
+{
+    ;
+}
+
+ZoneBcPatch::~ZoneBcPatch()
+{
+}
+
+std::vector<Zone *> Global::zones;
+BaseZoneList Global::zone_names;
+int Global::cell_dim = -1;
+int Global::phys_dim = -1;
+
+Global::Global()
+{
+    ;
+}
+
+Global::~Global()
+{
+}
+
+void Global::FreeData()
+{
+    for ( int i = 0; i < zones.size(); ++ i )
+    {
+        delete zones[ i ];
+    }
+    zones.resize( 0 );
+}
+
+
+void ReadCgnsGridBaseZone( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId);
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            BaseZone baseZone;
+            //baseZone.baseId = baseId;
+            baseZone.zone_name = zonename;
+
+            Global::zone_names.AddBaseZone( baseZone );
+        }
+    }
+    cg_close( fileId );
+}
+
+void ReadCgnsGrid( const std::string & filename )
+{
+    int fileId = -1;
+    cg_open( filename.c_str(), CG_MODE_READ, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+    int nbases = -1;
+    cg_nbases( fileId, &nbases );
+    std::cout << "nbases = " << nbases << "\n";
+    for ( int iBase = 0; iBase < nbases; ++ iBase )
+    {
+        char basename[ 33 ];
+        int baseId = iBase + 1;
+        int icelldim = -1;
+        int iphysdim = -1;
+        cg_base_read( fileId, baseId, basename, &icelldim, &iphysdim );
+        std::cout << "icelldim = " << icelldim << " iphysdim = " << iphysdim << "\n";
+        Global::cell_dim = icelldim;
+        Global::phys_dim = iphysdim;
+        int nzones = -1;
+        cg_nzones( fileId, baseId, &nzones );
+        std::cout << "nzones = " << nzones << "\n";
+        for ( int iZone = 0; iZone < nzones; ++ iZone )
+        {
+            int zoneId = iZone + 1;
+            int index_dim = -1;
+            cg_index_dim( fileId, baseId, zoneId, &index_dim );
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            std::vector<cgsize_t> isize( index_dim * 3 );
+
+            Zone * zone = new Zone();
+            Global::zones.push_back( zone );
+
+            char zonename[33];
+            cg_zone_read( fileId, baseId, zoneId, zonename, isize.data() );
+
+            BaseZone baseZone;
+            baseZone.zone_name = zonename;
+            int gZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+            for ( int i = 0; i < isize.size(); ++ i )
+            {
+                std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+            }
+
+            std::vector<cgsize_t> irmin( index_dim );
+            std::vector<cgsize_t> irmax( index_dim );
+            int nNodes = 1;
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                /* lower range index */
+                irmin[ m ] = 1;
+                /* upper range index of vertices */
+                irmax[ m ] = isize[ m ];
+                nNodes *= irmax[ m ];
+                zone->nijk.push_back( isize[ m ] );
+            }
+            std::cout << "nNodes = " << nNodes << "\n";
+
+            ZoneType_t zoneType;
+            cg_zone_type( fileId, baseId, zoneId, &zoneType );
+            std::cout << "zoneType = " << zoneType << " ZoneTypeName = " << ZoneTypeName[zoneType] << "\n";
+            int ncoords = -1;
+            cg_ncoords( fileId, baseId, zoneId, &ncoords );
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = icoord + 1;
+                DataType_t dataType;
+                char coordname[ 33 ];
+                cg_coord_info( fileId, baseId, zoneId, coorId, &dataType, coordname );
+                std::cout << "coordname = " << coordname << "\n";
+                std::cout << "dataType = " << dataType << " DataTypeName = " <<  DataTypeName[dataType] << "\n";
+                std::vector<char> coord( nNodes * sizeof(double) );
+
+                Coor * coor = new Coor();
+                zone->coors.push_back( coor );
+                coor->coorname = coordname;
+                coor->nNodes = nNodes;
+                coor->coord.resize( nNodes * sizeof( double ) );
+
+                cg_coord_read( fileId, baseId, zoneId, coordname, dataType, irmin.data(), irmax.data(), coor->coord.data() );
+                coor->DumpCoor();
+            }
+
+            int nbocos = -1;
+            cg_nbocos( fileId, baseId, zoneId, &nbocos );
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = iboco + 1;
+                GridLocation_t location;
+                cg_boco_gridlocation_read( fileId, baseId, zoneId, bccoId, &location );
+                std::cout << "iboco = " << iboco <<  " location = " << location << " GridLocationName = " << GridLocationName[location] << "\n";
+
+                ZoneBc * zonebc = new ZoneBc();
+                zone->bccos.push_back( zonebc );
+
+                char boconame[ 33 ];
+                BCType_t bocotype;
+                PointSetType_t ptset_type;
+                cgsize_t npnts = 0;
+                std::vector<int> normalIndex( index_dim, -1 );
+                cgsize_t normalListSize = 0;
+                DataType_t normalDataType;
+                int ndataset = -1;
+
+                cg_boco_info( fileId, baseId, zoneId, bccoId, boconame, &bocotype, &ptset_type,
+                    &npnts, normalIndex.data(), &normalListSize, &normalDataType, &ndataset );
+                zonebc->bcType = bocotype;
+                std::cout << "boconame = " << boconame <<  " bocotype = " << bocotype << " BCTypeName = " << BCTypeName[bocotype] << "\n";
+                std::cout << "ptset_type = " << ptset_type <<  " PointSetTypeName = " << PointSetTypeName[ptset_type] << "\n";
+                std::cout << "npnts = " << npnts << "\n";
+                std::cout << "normalIndex = ";
+                for ( int i = 0; i < index_dim; ++ i )
+                {
+                    std::cout << normalIndex[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "normalListSize = " << normalListSize << "\n";
+                std::cout << "normalDataType = " << normalDataType << " DataTypeName = " << DataTypeName[ normalDataType ] << "\n";
+                std::cout << "ndataset = " << ndataset << "\n";
+
+                std::vector<char> normalList( nNodes * iphysdim * sizeof( double ) );
+
+                std::vector<cgsize_t> pnts( npnts * index_dim );
+                cg_boco_read( fileId, baseId, zoneId, bccoId, pnts.data(), normalList.data() );
+                std::cout << "pnts = ";
+                for ( int i = 0; i < pnts.size(); ++ i )
+                {
+                    std::cout << pnts[ i ] << " ";
+                    zonebc->pnts.push_back( pnts[ i ] );
+                }
+                std::cout << "\n";
+
+                double * normal_d = reinterpret_cast<double *>( const_cast<char *>( normalList.data() ) );
+            }
+
+            int n1to1 = -1;
+            cg_n1to1( fileId, baseId, zoneId, &n1to1 );
+            std::cout << "n1to1 = " << n1to1 << "\n";
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int i1to1Id = i1to1 + 1;
+
+                ZoneBc1To1 * zonebc_1to1 = new ZoneBc1To1();
+                zone->bc1to1s.push_back( zonebc_1to1 );
+
+                char connectname[ 33 ];
+                char donorname[ 33 ];
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> range( npnts * index_dim );
+                std::vector<cgsize_t> donor_range( npnts * index_dim );
+                std::vector<int> transform( index_dim );
+                cg_1to1_read( fileId, baseId, zoneId, i1to1Id, connectname, donorname, range.data(), donor_range.data(), transform.data() );
+                std::cout << "connectname = " << connectname << "\n";
+                std::cout << "donorname = " << donorname << "\n";
+
+                std::cout << "range = \n";
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    std::cout << range[ i ] << " ";
+                }
+                std::cout << "\n";
+                std::cout << "donor_range = \n";
+                for ( int i = 0; i < donor_range.size(); ++ i )
+                {
+                    std::cout << donor_range[ i ] << " ";
+                }
+                std::cout << "\n";
+
+                BaseZone baseZone;
+                baseZone.zone_name = donorname;
+                int gDonorZoneId = Global::zone_names.FindBaseZone( baseZone );
+
+                zonebc_1to1->zoneid = gZoneId;
+                zonebc_1to1->transform = transform;
+                zonebc_1to1->donor_zoneid = gDonorZoneId;
+
+                for ( int i = 0; i < range.size(); ++ i )
+                {
+                    zonebc_1to1->pnts.push_back( range[ i ] );
+                    zonebc_1to1->donor_pnts.push_back( donor_range[ i ] );
+                }
+
+                int kkk = 1;
+            }
+        }
+        int kkk = 1;
+    }
+    int kkk = 1;
+    cg_close( fileId );
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage3/01d/CgnsGrid.h b/example/partition/struct/2d/stage3/01d/CgnsGrid.h
new file mode 100644
index 00000000..053c467b
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01d/CgnsGrid.h
@@ -0,0 +1,140 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <map>
+
+class Grid;
+
+class Zone;
+
+class Grid
+{
+public:
+    Grid();
+    ~Grid();
+public:
+    int nZone;
+    std::vector<double> x;
+    std::vector<Zone *> zones;
+};
+
+
+class Coor
+{
+public:
+    Coor();
+    ~Coor();
+public:
+    std::string coorname;
+    int nNodes;
+    std::vector<int> nijk;
+    std::vector<char> coord;
+public:
+    void DumpCoor();
+};
+
+class ZoneBc;
+class ZoneBc1To1;
+
+class Zone
+{
+public:
+    Zone();
+    ~Zone();
+public:
+    std::vector<int> nijk;
+    std::vector<ZoneBc *> bccos;
+    std::vector<ZoneBc1To1 *> bc1to1s;
+    std::vector<Coor *> coors;
+};
+
+class ZoneBcPatch;
+class ZoneBc
+{
+public:
+    ZoneBc();
+    ~ZoneBc();
+public:
+    int bcType;
+    int zoneid;
+    std::vector<int> pnts;
+    ZoneBcPatch * patch = nullptr;
+};
+
+class ZoneBc1To1
+{
+public:
+    ZoneBc1To1();
+    ~ZoneBc1To1();
+public:
+    int zoneid;
+    int donor_zoneid;
+    std::vector<int> pnts;
+    std::vector<int> donor_pnts;
+    std::vector<int> transform;
+};
+
+class ZoneBcPatch
+{
+public:
+    ZoneBcPatch();
+    ~ZoneBcPatch();
+public:
+    int donor_zoneid;
+    std::vector<int> transform;
+    std::vector<int> donor_pnts;
+};
+
+class BaseZone
+{
+public:
+    std::string zone_name;
+    bool operator < ( const BaseZone & rhs ) const
+    {
+        return this->zone_name < rhs.zone_name;
+    } 
+};
+
+class BaseZoneList
+{
+public:
+    std::map<BaseZone, int> basezone_map;
+public:
+    void AddBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter;
+        iter = basezone_map.find( baseZone );
+        if ( iter == basezone_map.end() )
+        {
+            int id = basezone_map.size();
+            basezone_map.insert( std::make_pair( baseZone, id ) );
+        }
+    }
+
+    int FindBaseZone( const BaseZone & baseZone )
+    {
+        std::map<BaseZone, int>::iterator iter = basezone_map.find( baseZone );
+        if ( iter != basezone_map.end() )
+        {
+            return iter->second;
+        }
+        return -1;
+    }
+};
+
+class Global
+{
+public:
+    Global();
+    ~Global();
+public:
+    static int cell_dim;
+    static int phys_dim;
+    static std::vector<Zone *> zones;
+    static BaseZoneList zone_names;
+public:
+    static void FreeData();
+};
+
+void ReadCgnsGrid( const std::string & filename );
+void ReadCgnsGridBaseZone( const std::string & filename );
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage3/01d/Partition.cpp b/example/partition/struct/2d/stage3/01d/Partition.cpp
new file mode 100644
index 00000000..18f11ac2
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01d/Partition.cpp
@@ -0,0 +1,621 @@
+#include "Partition.h"
+#include "CgnsGrid.h"
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+bool CmpSplitZone::operator() ( SplitZone * a, SplitZone * b ) const
+{
+    return a->zoneIndex < b->zoneIndex;
+};
+
+
+double CalSumOfProcSpeed( std::vector<double> & procSpeed );
+double CalSumOfProcSpeed( std::vector<double> & procSpeed )
+{
+    int nProc = procSpeed.size();
+    double sumOfProcSpeed = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        sumOfProcSpeed += procSpeed[ iProc ];
+    }
+    return sumOfProcSpeed;
+}
+
+Partition::Partition()
+{
+    this->inputName = "../heat2d1blockv2.cgns";
+    this->outName =  "../heat2dpart.cgns";
+}
+
+Partition::~Partition()
+{
+    ;
+}
+
+int Partition::GetMinValueIndex( double * data, int numberOfData )
+{
+    double minValue = data[ 0 ];
+    int minimumValueIndex = 0;
+
+    for ( int iData = 1; iData < numberOfData; ++ iData )
+    {
+        if ( minValue > data[ iData ] )
+        {
+            minValue      = data[ iData ];
+            minimumValueIndex = iData;
+        }
+    }
+    return minimumValueIndex;
+}
+
+int Partition::GetMinLoadProc()
+{
+    return this->GetMinValueIndex( this->timeProc.data(), this->nProc );
+}
+
+SplitZone * Partition::GetLargestZone()
+{
+    SplitZone * largestZone = 0;
+
+    double nMaxCell = 0.0;
+
+    for ( std::set< SplitZone * >::iterator iter = unsignedZoneGroup.begin(); iter != unsignedZoneGroup.end(); ++ iter )
+    {
+        double nSize = ( * iter )->GetNCell();
+        if ( nMaxCell < nSize )
+        {
+            nMaxCell    = nSize;
+            largestZone = * iter;
+        }
+    }
+
+    return largestZone;
+}
+
+void Partition::Solve()
+{
+    std::cout << "Partition::Split()\n";
+    //this->nProc = 2;
+    //this->nProc = 3;
+    this->nProc = 16;
+    this->ReadGrid();
+    this->Split();
+    this->DumpPartitionedGridFile();
+    this->FreeAllZones();
+}
+
+void Partition::ReadGrid()
+{
+    ReadCgnsGridBaseZone( this->inputName );
+    ReadCgnsGrid( this->inputName );
+
+    this->nOriZone = ::Global::zones.size();
+    Dim::dim = Global::cell_dim;
+
+    std::cout << "numberOfBlocks = " << nOriZone << "\n";
+
+    this->refZone.resize( nOriZone );
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = new SplitZone();
+        refZone[ iZone ] = splitZone;
+
+        splitZone->SetZoneIndex( iZone );
+        splitZone->SetProcId( 0 );
+        splitZone->SetParentAndChild( 0 );
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        Zone * zone = ::Global::zones[ iZone ];
+
+        splitZone->dimInfo.dimList = zone->nijk;
+
+        int nbccos = zone->bccos.size();
+        std::cout << "nbccos = " << nbccos << "\n";
+
+        for ( int ibcco = 0; ibcco < nbccos; ++ ibcco )
+        {
+            ZoneBc * zoneBc = zone->bccos[ ibcco ];
+
+            PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+            splitZone->physicalSplitBcList.push_back( physicalSplitBc );
+            physicalSplitBc->bcType = zoneBc->bcType;
+            physicalSplitBc->SetRegion( zoneBc->pnts );
+            physicalSplitBc->splitZone = splitZone;
+        }
+
+        int nbc1to1s = zone->bc1to1s.size();
+
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            ZoneBc1To1 * zoneBc1To1 = zone->bc1to1s[ ibc1to1 ];
+
+            InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+            splitZone->interfaceSplitBcList.push_back( interfaceSplitBc );
+            interfaceSplitBc->zone = splitZone;
+            interfaceSplitBc->region.SetRegion( zoneBc1To1->pnts );
+
+            interfaceSplitBc->transform = zoneBc1To1->transform;
+            interfaceSplitBc->CalcTransformMatrix();
+
+            interfaceSplitBc->donor_zone = refZone[ zoneBc1To1->donor_zoneid ];
+            interfaceSplitBc->donor_region.SetRegion( zoneBc1To1->donor_pnts );
+        }
+    }
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        SplitZone * splitZone = refZone[ iZone ];
+
+        int nbc1to1s = splitZone->interfaceSplitBcList.size();
+        for ( int ibc1to1 = 0; ibc1to1 < nbc1to1s; ++ ibc1to1 )
+        {
+            InterfaceSplitBc * interfaceSplitBc = splitZone->interfaceSplitBcList[ ibc1to1 ];
+            InterfaceInfo interfaceInfo;
+            interfaceSplitBc->donor_zone->FindDonorInterface( interfaceSplitBc, interfaceInfo );
+            interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+            interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+        }
+    }
+}
+
+void Partition::Split()
+{
+    this->InitSplit();
+    this->BinarySplit();
+    this->ModifyZoneIndex();
+    int kkk = 1;
+}
+
+void Partition::InitSplit()
+{
+    //nZone is the number of zones in the original grid
+    //nProc is not the number of blocks in the end, but the number of processes that need to be divided.
+    //This difference occurs because the structure grid can have many blocks per process.
+
+    //this->nProc    = nProc;
+    //this->nPhyBlocks = referenceBlock.size();
+    //this->nZone  = this->nPhyBlocks;
+
+    //tj Computation time on processor j
+    //Nk Number of internal grid-cells for zone j
+    //aveFloatOp:  Number of Real operations per gridcell
+    //Gj The set of blocks allocated to process j
+    //Pj Real operations per second for process j
+
+    //The Greedy Load Balancing Algorithm
+    //1.Compute an "ideal" uniprocessor time, Tuni = sum ( Nk * aveFloatOp )/ sum( Pj ).
+    //2.Set the group of unassigned blocks, Gu, to contain all blocks. The number of blocks in Nu=M, where M is the total number of blocks in the mesh.
+    //3.Start all processors with a very small fictitious zone to get a start tj=delt aveFloatOp/Pj, where delt<<1 is the size of the very small fictious zone.
+    //This is used to find the fastest processor in a heterogeneous system, tj could otherwise be set to 0 in the homogeneous case.
+    this->aveFloatOp = 1.0;
+    this->delta      = 1.0e-5;
+    this->procSpeed.resize( nProc );
+    this->timeProc.resize( nProc );
+
+    this->nTZone = this->nOriZone;
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        procSpeed[ iProc ] = 1.0;
+    }
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        timeProc[ iProc ] = delta * aveFloatOp / procSpeed[ iProc ];
+    }
+
+    double sumProcSpeed = CalSumOfProcSpeed( procSpeed );
+
+    double sumProcOp = 0.0;
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        sumProcOp += refZone[ iZone ]->GetNCell() * aveFloatOp;
+    }
+
+    this->idealUniProcTime = sumProcOp / sumProcSpeed;
+
+    this->eps = 0.05;
+
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        unsignedZoneGroup.insert( refZone[ iZone ] );
+    }
+
+    //Init zoneStorage
+    for ( int iZone = 0; iZone < nOriZone; ++ iZone )
+    {
+        zoneStorage.insert( refZone[ iZone ] );
+    }
+
+    //Assign procSplitZone to each process
+    procSplitZone.resize( nProc );
+
+    this->minNumberCell = 1;
+    for ( int m = 0; m < Dim::dim; ++ m )
+    {
+        this->minNumberCell *= 1;
+    }
+
+    int kkk = 1;
+
+}
+
+void Partition::FreeAllZones()
+{
+    int iCount = 0;
+    for ( std::set < SplitZone * >::iterator iter = zoneStorage.begin(); iter != zoneStorage.end(); ++ iter )
+    {
+        //cout << "iCount = " << iCount << "\n";
+        ++ iCount;
+        delete * iter;
+    }
+}
+
+int Partition::GetNZones( int iProc )
+{
+    return this->procSplitZone[ iProc ].size();
+}
+
+SplitZone * Partition::GetSplitZone( int iProc, int zoneId )
+{
+    return this->procSplitZone[ iProc ][ zoneId ];
+}
+
+void Partition::AddZoneToUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.insert( zone );
+}
+
+void Partition::RemoveZoneFromUnsignedGroup( SplitZone * zone )
+{
+    this->unsignedZoneGroup.erase( zone );
+}
+
+void Partition::AddZoneToProcess( int iProc, SplitZone * zone )
+{
+    this->procSplitZone[ iProc ].push_back( zone );
+}
+
+void Partition::AddNewZone( SplitZone * zone )
+{
+    zone->SetZoneIndex( nTZone ++ );
+
+    this->AddZoneToUnsignedGroup( zone );
+
+    this->zoneStorage.insert( zone );
+}
+
+SplitZone * Partition::Split( SplitZone * zone, double nCell )
+{
+    SplitZone * zoneL = new SplitZone();
+    zoneL->SetParentAndChild( zone );
+
+    SplitZone * zoneR = new SplitZone();
+    zoneR->SetParentAndChild( zone );
+
+    //Remove the original block from the UnsignedGroup
+    this->RemoveZoneFromUnsignedGroup( zone );
+
+    this->AddNewZone( zoneL );
+    this->AddNewZone( zoneR );
+
+    zone->Split( zoneL, zoneR, nCell );
+
+    return zoneL;
+}
+
+void Partition::BinarySplit()
+{
+    while ( ! unsignedZoneGroup.empty() )
+    {
+        std::cout << "number of unsigned zone = " << unsignedZoneGroup.size() << "\n";
+        int iProc = this->GetMinLoadProc();
+
+        //Get the block with the largest number of grids and its size
+        SplitZone * largestZone = this->GetLargestZone();
+
+        double nMaxCell = largestZone->GetNCell();
+
+        double aveFloatOp = this->aveFloatOp;
+        double tau = timeProc[ iProc ] + nMaxCell * aveFloatOp / procSpeed[ iProc ];
+
+        //It seems that EPS is still necessary
+        //The idea here is as follows. For the candidate blocks which can be divided into blocks, 
+        //if the difference between the target blocks and the candidate blocks is too wide, 
+        //the binarySplit method is adopted. The binarySplit blocks do not directly join the process,
+        //but enter the next round of screening.
+
+        if ( tau > idealUniProcTime * ( 1.0 + eps ) )
+        {
+            double nRest = ( tau - idealUniProcTime ) * procSpeed[ iProc ] / aveFloatOp;
+
+            double nTarget = nMaxCell - nRest;
+            if ( nRest > this->minNumberCell && nTarget > this->minNumberCell )
+            {
+                //It is necessary to divide blocks only when a certain number of points are satisfied.
+                double nHalf = nMaxCell / 2.0;
+                nMaxCell = nTarget;
+                double ratio = nMaxCell / nRest;
+                double oRatio = 1.0 / ratio;
+
+                if ( std::max( ratio, oRatio ) < 3.0 )
+                {
+                    int kkk = 1;
+                    largestZone = this->Split( largestZone, nMaxCell );
+                    timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                    this->RemoveZoneFromUnsignedGroup( largestZone );
+                    this->AddZoneToProcess( iProc, largestZone );
+                }
+                else
+                {
+                    this->Split( largestZone, nHalf );
+                }
+            }
+            else
+            {
+                //If the block is of the right size, join the process directly, and there is no need to split it.
+                timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+                this->RemoveZoneFromUnsignedGroup( largestZone );
+                this->AddZoneToProcess( iProc, largestZone );
+            }
+        }
+        else
+        {
+            //If the block is of the right size, join the process directly, and there is no need to split it.
+            timeProc[ iProc ] += nMaxCell * aveFloatOp / procSpeed[ iProc ];
+            this->RemoveZoneFromUnsignedGroup( largestZone );
+            this->AddZoneToProcess( iProc, largestZone );
+        }
+    }
+}
+
+void Partition::ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord )
+{
+    SplitZone * rootSplitZone = splitZone->GetRootZone();
+    Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+    int nNodes = splitZone->dimInfo.ComputeNumNodes();
+    std::cout << "nNodes = " << nNodes << "\n";
+
+    coord.resize( nNodes * sizeof(double) );
+
+    int index_dim = splitZone->dimInfo.dimList.size();
+    Coor * coor = zone->coors[ icoord ];
+
+    double * xlocal = reinterpret_cast<double *>( const_cast<char *>( coord.data() ) );
+    double * xglobal = reinterpret_cast<double *>( const_cast<char *>( coor->coord.data() ) );
+    if ( index_dim == 1 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        for ( int i = imin; i < imax; ++ i )
+        {
+            xlocal[ icount++ ] = xglobal[ i ];
+        }
+    }
+    else if ( index_dim == 2 )
+    {
+        int icount = 0;
+        int imin = splitZone->dimInfo.rmin[ 0 ] - 1;
+        int imax = splitZone->dimInfo.rmax[ 0 ];
+        int jmin = splitZone->dimInfo.rmin[ 1 ] - 1;
+        int jmax = splitZone->dimInfo.rmax[ 1 ];
+        int ni = rootSplitZone->dimInfo.dimList[ 0 ];
+        int nj = rootSplitZone->dimInfo.dimList[ 1 ];
+        for ( int j = jmin; j < jmax; ++ j )
+        {
+            int jstride = j * ni;
+            for ( int i = imin; i < imax; ++ i )
+            {
+                xlocal[ icount++ ] = xglobal[ jstride + i ];
+            }
+        }
+    }
+}
+
+void Partition::DumpBc( SplitZone * splitZone )
+{
+}
+
+void Partition::DumpPartitionedGridFile()
+{
+    std::cout << "\n";
+    std::cout << "DumpPartitionedGridFile -------------------------------" << "\n";
+    std::cout << "\n";
+    int fileId = -1;
+    std::string filename = this->outName;
+    int ierr = cg_open( filename.c_str(), CG_MODE_WRITE, &fileId );
+    std::cout << "fileId = " << fileId << "\n";
+
+    std::vector<std::string> coordnames;
+    coordnames.push_back( "CoordinateX" );
+    coordnames.push_back( "CoordinateY" );
+    coordnames.push_back( "CoordinateZ" );
+
+    std::string basename = "Base";
+    int baseId = -1;
+    int icelldim = Global::cell_dim;
+    int iphysdim = Global::phys_dim;
+    cg_base_write( fileId, basename.c_str(), icelldim, iphysdim, &baseId );
+
+    std::cout << "baseId = " << baseId << "\n";
+
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        int nZones = this->GetNZones( iProc );
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            ZoneType_t zoneType = Structured;
+
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+
+            int index_dim = splitZone->dimInfo.dimList.size();
+            std::cout << "index_dim = " << index_dim << "\n";
+
+            splitZone->dimInfo.ComputeISize();
+
+            int isize_dim = index_dim * 3;
+
+            std::vector<cgsize_t> isize( index_dim * 3, 0 );
+            for ( int m = 0; m < isize_dim; ++ m )
+            {
+                isize[ m ] = splitZone->dimInfo.isize[ m ];
+            }
+
+            int zoneId = -1;
+
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+
+            std::string zonename = "Zone" + std::to_string( splitZone->newIndex );
+
+            cg_zone_write( fileId, baseId, zonename.c_str(), isize.data(), zoneType, &zoneId );
+
+            std::cout << "zoneId = " << zoneId << "\n";
+            std::cout << "zonename = " << zonename << "\n";
+                
+            splitZone->ComputeRminmax();
+
+            SplitZone * rootSplitZone = splitZone->GetRootZone();
+
+            Zone * zone = Global::zones[ rootSplitZone->zoneIndex ];
+
+            int ncoords = zone->coors.size();
+            std::cout << "ncoords = " << ncoords << "\n";
+
+            for ( int icoord = 0; icoord < ncoords; ++ icoord )
+            {
+                int coorId = -1;
+                DataType_t dataType = RealDouble;
+                std::string coordname = coordnames[ icoord ];
+                Coor * coor = zone->coors[ icoord ];
+
+                int nNodes = splitZone->dimInfo.ComputeNumNodes();
+                std::cout << "nNodes = " << nNodes << "\n";
+
+                std::vector<char> coord;
+                ComputeCoor( splitZone, icoord, coord );
+
+                cg_coord_write( fileId, baseId, zoneId, dataType, coordname.c_str(), coord.data(), &coorId );
+
+                std::cout << "fileId = " << fileId  << " baseId = " << baseId << " zoneId = " << zoneId  << " coorId = " << coorId << "\n";
+            }
+
+            std::vector< PhysicalSplitBc * > &bccoList = splitZone->physicalSplitBcList;
+
+            int nbocos = bccoList.size();
+            std::cout << "nbocos = " << nbocos << "\n";
+            for ( int iboco = 0; iboco < nbocos; ++ iboco )
+            {
+                int bccoId = -1;
+                GridLocation_t location = Vertex;
+
+                std::string boconame = "BC" + std::to_string( iboco + 1 );
+
+                PhysicalSplitBc * physicalSplitBc = bccoList[ iboco ];
+                BCType_t bocotype = static_cast<BCType_t>( physicalSplitBc->bcType );
+                PointSetType_t ptset_type = PointRange;
+                cgsize_t npnts = 2;
+                std::vector<cgsize_t> pnts;
+                int nSize = physicalSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( physicalSplitBc->region.end[ i ] );
+                }
+
+                cg_boco_write( fileId, baseId, zoneId, boconame.c_str(), bocotype, ptset_type, npnts, pnts.data(), & bccoId );
+            }
+
+            //std::vector< InterfaceSplitBc * > & bc1to1List = splitZone->interfaceSplitBcList;
+            std::vector< InterfaceSplitBc * > bc1to1List;
+            splitZone->GetLeafInterfaceBc( bc1to1List );
+
+            int n1to1 = bc1to1List.size();
+            std::cout << "n1to1 = " << n1to1 << "\n";
+
+            std::vector<int> itranfrm( index_dim );
+            for ( int m = 0; m < index_dim; ++ m )
+            {
+                itranfrm[ m ] = m + 1;
+            }
+            for ( int i1to1 = 0; i1to1 < n1to1; ++ i1to1 )
+            {
+                int index_conn = -1;
+
+                InterfaceSplitBc * interfaceSplitBc = bc1to1List[ i1to1 ];
+
+                std::vector<cgsize_t> pnts;
+                std::vector<cgsize_t> pntsdonor;
+                int nSize = interfaceSplitBc->region.start.size();
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.start[ i ] );
+                }
+                for ( int i = 0; i < nSize; ++ i )
+                {
+                    pnts.push_back( interfaceSplitBc->region.end[ i ] );
+                }
+
+                int nPatchSize = interfaceSplitBc->donor_region.start.size();
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.start[ i ] );
+                }
+                for ( int i = 0; i < nPatchSize; ++ i )
+                {
+                    pntsdonor.push_back( interfaceSplitBc->donor_region.end[ i ] );
+                }
+                int id = interfaceSplitBc->donor_zone->newIndex;
+                int oldZoneIndex = interfaceSplitBc->donor_zone->zoneIndex;
+                std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+                std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+                std::cout << "donor zone id = " << id << "\n";
+                std::cout << "donor zone oldZoneIndex = " << oldZoneIndex << "\n";
+                std::string donorname = "Zone" + std::to_string( id );
+                std::string connectname = "Interface" + std::to_string( i1to1 );
+
+                std::cout << "donorname = " << donorname << "\n";
+                std::cout << "connectname = " << connectname << "\n";
+
+                std::vector<int> & itranfrm = interfaceSplitBc->transform;
+
+                cg_1to1_write( fileId, baseId, zoneId, connectname.c_str(), donorname.c_str(), pnts.data(), pntsdonor.data(), itranfrm.data(), &index_conn );
+                std::cout << "index_conn = " << index_conn << "\n";
+            }
+        }
+    }
+    cg_close( fileId );
+}
+
+void Partition::ModifyZoneIndex()
+{
+    std::cout << "ModifyZoneIndex +++++++++++++++++++++++++ " << "\n";
+    int globalZoneId = 0;
+    for ( int iProc = 0; iProc < nProc; ++ iProc )
+    {
+        std::cout << "iProc = " << iProc << "\n";
+        int nZones = this->GetNZones( iProc );
+        std::cout << "nZones in Proc " << iProc << "  = " << nZones << "\n";
+
+        for ( int iZone = 0; iZone < nZones; ++ iZone )
+        {
+            SplitZone * splitZone = this->GetSplitZone( iProc, iZone );
+            //splitZone->SetZoneIndex( globalZoneId++ );
+            splitZone->newIndex = ( globalZoneId++ );
+            std::cout << "splitZone->newIndex = " << splitZone->newIndex << "\n";
+            std::cout << "splitZone->zoneIndex = " << splitZone->zoneIndex << "\n";
+        }
+    }
+}
\ No newline at end of file
diff --git a/example/partition/struct/2d/stage3/01d/Partition.h b/example/partition/struct/2d/stage3/01d/Partition.h
new file mode 100644
index 00000000..8a4a9731
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01d/Partition.h
@@ -0,0 +1,59 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class SplitZone;
+
+struct CmpSplitZone 
+{
+    bool operator() ( SplitZone * a, SplitZone * b ) const;
+};
+
+class Partition
+{
+public:
+    Partition();
+    ~Partition();
+protected:
+    std::set < SplitZone * > zoneStorage;
+    std::set < SplitZone *, CmpSplitZone > unsignedZoneGroup;
+    std::vector< SplitZone * > refZone;
+    std::vector< std::vector< SplitZone * > > procSplitZone;
+    std::vector<double> procSpeed;
+    std::vector<double> timeProc;
+    double aveFloatOp, delta;
+    double idealUniProcTime, eps;
+    int minNumberCell;
+    int nTZone;
+    int nOriZone;
+    int nProc;
+public:
+    std::string inputName;
+    std::string outName;
+public:
+    void Solve();
+    void ReadGrid();
+    void Split();
+    void InitSplit();
+    void BinarySplit();
+    //void GreedySplit();
+public:
+    void AddNewZone( SplitZone * zone );
+    void AddZoneToUnsignedGroup( SplitZone * zone );
+    void RemoveZoneFromUnsignedGroup( SplitZone * zone );
+    void AddZoneToProcess( int iProc, SplitZone * zone );
+    void DumpPartitionedGridFile();
+    void ModifyZoneIndex();
+    void FreeAllZones();
+    int GetNZones( int iProc );
+    SplitZone * GetSplitZone( int iProc, int zoneId );
+    void ComputeCoor( SplitZone * splitZone, int icoord, std::vector<char> & coord );
+    void DumpBc( SplitZone * splitZone );
+private:
+    int GetMinValueIndex( double * data, int numberOfData );
+    int GetMinLoadProc();
+    SplitZone * GetLargestZone();
+    SplitZone * Split( SplitZone * zone, double nCell );
+};
+
diff --git a/example/partition/struct/2d/stage3/01d/README.txt b/example/partition/struct/2d/stage3/01d/README.txt
new file mode 100644
index 00000000..13dc2f91
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01d/README.txt
@@ -0,0 +1 @@
+cmake -DCMAKE_TOOLCHAIN_FILE="c:/dev/vcpkg/scripts/buildsystems/vcpkg.cmake" ..
diff --git a/example/partition/struct/2d/stage3/01d/SplitZone.cpp b/example/partition/struct/2d/stage3/01d/SplitZone.cpp
new file mode 100644
index 00000000..aef70754
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01d/SplitZone.cpp
@@ -0,0 +1,1091 @@
+#include "SplitZone.h"
+#include "cgnslib.h"
+#include <string>
+
+int Dim::dim = -1;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox  )
+{
+    domainBox.start = zoneBox.start;
+    domainBox.end = zoneBox.end;
+
+    int axis = iDomain / 2;
+    int direction = iDomain % 2;
+
+    if ( direction == 0 )
+    {
+        domainBox.end[ axis ] = domainBox.start[ axis ];
+    }
+    else if ( direction == 1 )
+    {
+        domainBox.start[ axis ] = domainBox.end[ axis ];
+    }
+}
+
+DimInfo::DimInfo()
+{
+    this->Init( 1 );
+}
+
+DimInfo::~DimInfo()
+{
+}
+
+void DimInfo::Init( int dim )
+{
+    this->dim = dim;
+    dimList.resize( this->dim, 1 );
+    oriPoint.resize( this->dim, 0 );
+}
+
+DimInfo & DimInfo::operator = ( const DimInfo & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->dim = rhs.dim;
+    this->dimList = rhs.dimList;
+    this->oriPoint = rhs.oriPoint;
+
+    return * this;
+}
+
+int DimInfo::ComputeNumNodes()
+{
+    int nNodes = 1;
+    for ( int m = 0; m < this->dimList.size(); ++ m )
+    {
+        nNodes *= this->dimList[ m ];
+    }
+    return nNodes;
+}
+
+void DimInfo::ComputeISize()
+{
+    int index_dim = this->dimList.size();
+    this->isize.resize( index_dim * 3, 0 );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        isize[ m ] = this->dimList[ m ];
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 1;
+        isize[ start + m ] = this->dimList[ m ] - 1;
+    }
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int start = index_dim * 2;
+        isize[ start + m ] = 0;
+    }
+
+    for ( int i = 0; i < isize.size(); ++ i )
+    {
+        std::cout << "i = " << i << " isize = " << isize[i] << "\n";
+    }
+}
+
+void DimInfo::ComputeRminmax( std::vector<int> & ref )
+{
+    int index_dim = this->dimList.size();
+    this->rmin.resize( index_dim );
+    this->rmax.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        rmin[ m ] = ref[ m ] + 1;
+        rmax[ m ] = ref[ m ] + this->dimList[ m ];
+    }
+
+    std::cout << "rmin, rmax = \n";
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        std::cout << rmin[ m ] << " " << rmax[ m ] << "\n";
+    }
+}
+
+void DimInfo::Init( std::vector<int> & dimList )
+{
+    this->dim = dimList.size();
+    this->dimList = dimList;
+    std::vector<int> zero( dimList.size(), 0 );
+    this->oriPoint = zero;
+}
+
+void DimInfo::SetNewDimension( int axis, int newStart, int newWidth )
+{
+    this->oriPoint[ axis ] = newStart;
+    this->dimList [ axis ] = newWidth;
+}
+
+void DimInfo::GetZoneGlobalBox( RangeRegion &zoneBox )
+{
+    int index_dim = this->dimList.size();
+    zoneBox.start.resize( index_dim );
+    zoneBox.end.resize( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        zoneBox.start[ m ] = this->oriPoint[ m ] + 1;
+        zoneBox.end[ m ] = this->oriPoint[ m ] + this->dimList[ m ];
+    }
+}
+
+void DimInfo::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    int index_dim = this->dimList.size();
+    localBox.start.resize( index_dim );
+    localBox.end.resize( index_dim );
+
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        localBox.start[ m ] = globalBox.start[ m ] - this->oriPoint[ m ];
+        localBox.end[ m ] = globalBox.end[ m ] - this->oriPoint[ m ];
+    }
+}
+
+RangeRegion::RangeRegion( int nSize )
+{
+    this->Init( nSize );
+}
+
+RangeRegion::~RangeRegion()
+{
+}
+
+void RangeRegion::Init( int nSize )
+{
+    this->start.resize( nSize );
+    this->end.resize( nSize );
+}
+
+RangeRegion & RangeRegion::operator = ( const RangeRegion & rhs )
+{
+    if ( this == & rhs ) return * this;
+
+    this->start = rhs.start;
+    this->end = rhs.end;
+
+    return * this;
+}
+
+bool RangeRegion::operator == ( const RangeRegion & rhs ) const
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( this->start[ m ] != rhs.start[ m ] || 
+            this->end  [ m ] != rhs.end  [ m ] )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::SetRegion( std::vector<int> & pnts )
+{
+    int index_dim = pnts.size() / 2;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->start[ m ] = pnts[ m ];
+        this->end[ m ] = pnts[ index_dim + m ];
+    }
+}
+
+bool RangeRegion::InRegion( const RangeRegion & region )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        if ( ( this->start[ m ] < region.start[ m ] ) || ( this->end[ m ] > region.end[ m ] ) )
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+void RangeRegion::Normalize()
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        int minv = std::min( this->start[ m ], this->end[ m ] );
+        int maxv = std::max( this->start[ m ], this->end[ m ] );
+        this->start[ m ] = minv;
+        this->end[ m ] = maxv;
+    }
+}
+
+void RangeRegion::Localize( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] -= oriPoint[ m ];
+        this->end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void RangeRegion::ToGlobal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] += oriPoint[ m ];
+        this->end[ m ] += oriPoint[ m ];
+    }
+}
+
+void RangeRegion::ToLocal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        this->start[ m ] -= oriPoint[ m ];
+        this->end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void RangeRegion::PrintGlobal( std::vector<int> & oriPoint )
+{
+    int nSize = this->start.size();
+    std::cout << "global start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ] + oriPoint[m];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "global end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ] + oriPoint[m];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+void RangeRegion::Print()
+{
+    int nSize = this->start.size();
+    std::cout << "start:(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->start[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+    std::cout << "end  :(";
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        std::cout << this->end[ m ];
+        if ( m != nSize - 1 )
+        {
+            std::cout << ",";
+        }
+    }
+    std::cout << ")\n";
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion );
+
+bool ComputeOverlapRegion( RangeRegion & region1, RangeRegion & region2, RangeRegion & overlapRegion )
+{
+    int index_dim = region1.start.size();
+    overlapRegion.Init( index_dim );
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        int ijkmin1 = std::min( region1.start[ m ], region1.end[ m ] );
+        int ijkmax1 = std::max( region1.start[ m ], region1.end[ m ] );
+        int ijkmin2 = std::min( region2.start[ m ], region2.end[ m ] );
+        int ijkmax2 = std::max( region2.start[ m ], region2.end[ m ] );
+        if ( ( ijkmax1 < ijkmin2 ) || ( ijkmin1 > ijkmax2 ) )
+        {
+            return false;
+        }
+
+        int ijkmin = std::max( ijkmin1, ijkmin2 );
+        int ijkmax = std::min( ijkmax1, ijkmax2 );
+
+        overlapRegion.start[ m ] = ijkmin;
+        overlapRegion.end  [ m ] = ijkmax;
+    }
+
+    return CheckOverLapping( overlapRegion );
+}
+
+bool CheckOverLapping( RangeRegion & overlapRegion )
+{
+    int index_dim = overlapRegion.start.size();
+    int iCount = 0;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        if ( overlapRegion.start[ m ] == overlapRegion.end[ m ] )
+        {
+            ++ iCount;
+        }
+    }
+
+    return ( iCount == 1 );
+}
+
+bool GetInterfaceRegion( RangeRegion & zoneBoxL, RangeRegion & zoneBoxR, RangeRegion & interfaceRegion )
+{
+    int index_dim = zoneBoxL.start.size();
+    int nDomains = 2 * index_dim;
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegionL;
+        GetDomainRegion( zoneBoxL, iDomain, domainRegionL );
+
+        for ( int jDomain = 0; jDomain < nDomains; ++ jDomain )
+        {
+            RangeRegion domainRegionR;
+            GetDomainRegion( zoneBoxR, jDomain, domainRegionR );
+
+            if ( domainRegionL == domainRegionR )
+            {
+                interfaceRegion = domainRegionL;
+                return true;
+            }
+        }
+    }
+    return false;
+}
+
+void CreateInterfaceBc( SplitZone * zoneL, SplitZone * zoneR )
+{
+    RangeRegion globalBoxL, globalBoxR, globalInterfaceRegion;
+
+    zoneL->GetZoneGlobalBox( globalBoxL );
+    zoneR->GetZoneGlobalBox( globalBoxR );
+
+    if ( ! GetInterfaceRegion( globalBoxL, globalBoxR, globalInterfaceRegion ) )
+    {
+        return;
+    }
+
+    RangeRegion localInterfaceRegionL, localInterfaceRegionR;
+
+    zoneL->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionL );
+    zoneR->GetZoneLocalBox( globalInterfaceRegion, localInterfaceRegionR );
+
+    int kkk = 1;
+
+    InterfaceSplitBc * interfaceSplitBcL = new InterfaceSplitBc();
+    zoneL->interfaceSplitBcList.push_back( interfaceSplitBcL );
+    interfaceSplitBcL->zone = zoneL;
+    interfaceSplitBcL->region = localInterfaceRegionL;
+
+    int nSize = localInterfaceRegionL.start.size();
+
+    std::vector<int> transform;
+
+    for ( int m = 0; m < nSize; ++ m )
+    {
+        transform.push_back( m + 1 );
+    }
+
+    interfaceSplitBcL->transform = transform;
+    interfaceSplitBcL->CalcTransformMatrix();
+
+    interfaceSplitBcL->donor_zone = zoneR;
+    interfaceSplitBcL->donor_region = localInterfaceRegionR;
+
+    InterfaceSplitBc * interfaceSplitBcR = new InterfaceSplitBc();
+    zoneR->interfaceSplitBcList.push_back( interfaceSplitBcR );
+
+    interfaceSplitBcR->zone = zoneR;
+    interfaceSplitBcR->region = localInterfaceRegionR;
+
+    interfaceSplitBcR->transform = transform;
+    interfaceSplitBcR->CalcTransformMatrix();
+
+    interfaceSplitBcR->donor_zone = zoneL;
+    interfaceSplitBcR->donor_region = localInterfaceRegionL;
+}
+
+
+PhysicalSplitBc::PhysicalSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+PhysicalSplitBc::~PhysicalSplitBc()
+{
+}
+
+void PhysicalSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void PhysicalSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+void PhysicalSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = splitZone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+BasicSplitBc::BasicSplitBc()
+{
+    this->region.Init( Dim::dim );
+}
+
+BasicSplitBc::~BasicSplitBc()
+{
+    ;
+}
+
+void BasicSplitBc::SetRegion( std::vector<int> & pnts )
+{
+    this->region.SetRegion( pnts );
+}
+
+void BasicSplitBc::SetRegion( RangeRegion & region )
+{
+    this->region = region;
+}
+
+int trans::M[ 3 ][ 3 ];
+std::vector<int> trans::transform;
+
+int trans::sgn( int x )
+{
+    if ( x >= 0 )
+    {
+        return 1;
+    }
+    else
+    {
+        return -1;
+    }
+}
+
+int trans::del( int x, int y )
+{
+    if ( std::abs( x ) == std::abs( y ) )
+    {
+        return 1;
+    }
+    return 0;
+}
+
+void trans::ZeroMatrix()
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            trans::M[ i ][ j ] = 0;
+        }
+    }
+}
+
+void trans::CalcTransformMatrix()
+{
+    int dim = trans::transform.size();
+    if ( dim == 1 )
+    {
+        int a = trans::transform[ 0 ];
+        int sgna = trans::sgn( a );
+        int a1 = trans::del( a, 1 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+    }
+    else if ( dim == 2 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+    }
+    else if ( dim == 3 )
+    {
+        int a = trans::transform[ 0 ];
+        int b = trans::transform[ 1 ];
+        int c = trans::transform[ 2 ];
+        int sgna = trans::sgn( a );
+        int sgnb = trans::sgn( b );
+        int sgnc = trans::sgn( c );
+        int a1 = trans::del( a, 1 );
+        int a2 = trans::del( a, 2 );
+        int a3 = trans::del( a, 3 );
+        int b1 = trans::del( b, 1 );
+        int b2 = trans::del( b, 2 );
+        int b3 = trans::del( b, 3 );
+        int c1 = trans::del( c, 1 );
+        int c2 = trans::del( c, 2 );
+        int c3 = trans::del( c, 3 );
+        trans::M[ 0 ][ 0 ] = sgna * a1;
+        trans::M[ 1 ][ 0 ] = sgna * a2;
+        trans::M[ 2 ][ 0 ] = sgna * a3;
+        trans::M[ 0 ][ 1 ] = sgnb * b1;
+        trans::M[ 1 ][ 1 ] = sgnb * b2;
+        trans::M[ 2 ][ 1 ] = sgnb * b3;
+        trans::M[ 0 ][ 2 ] = sgnc * c1;
+        trans::M[ 1 ][ 2 ] = sgnc * c2;
+        trans::M[ 2 ][ 2 ] = sgnc * c3;
+    }
+}
+
+InterfaceInfo::InterfaceInfo()
+{
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceInfo::~InterfaceInfo()
+{
+}
+
+InterfaceSplitBc::InterfaceSplitBc()
+{
+    this->region.Init( Dim::dim );
+    this->donor_region.Init( Dim::dim );
+}
+
+InterfaceSplitBc::~InterfaceSplitBc()
+{
+}
+
+void InterfaceSplitBc::GetLeafInterfaceBc( std::vector< InterfaceSplitBc * > & leafInterfaceBcList )
+{
+    int nChild = this->child.size();
+    if ( nChild == 0 )
+    {
+        leafInterfaceBcList.push_back( this );
+    }
+    else
+    {
+        for ( int iChild = 0; iChild < nChild; ++ iChild )
+        {
+            InterfaceSplitBc * interfaceSplitBc = this->child[ iChild ];
+            interfaceSplitBc->GetLeafInterfaceBc( leafInterfaceBcList );
+        }
+    }
+}
+
+void InterfaceSplitBc::CopyMatrix( InterfaceSplitBc * interfaceSplitBc )
+{
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = interfaceSplitBc->Mt[ i ][ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::CalcTransformMatrix()
+{
+    trans::ZeroMatrix();
+    trans::transform = this->transform;
+    trans::CalcTransformMatrix();
+
+    int dim = 3;
+    for ( int j = 0; j < dim; ++ j )
+    {
+        for ( int i = 0; i < dim; ++ i )
+        {
+            this->Mt[ i ][ j ] = trans::M[ i ][ j ];
+        }
+    }
+
+}
+
+void InterfaceSplitBc::mapindex( std::vector<int> & begin1, std::vector<int> & begin2,  std::vector<int> & index1, std::vector<int> & index2 )
+{
+    int dim = Dim::dim;
+    std::vector<int> diff( dim );
+    for ( int m = 0; m < dim; ++ m )
+    {
+        diff[ m ] = index1[ m ] - begin1[ m ];
+    }
+
+    std::vector<int> mul( dim );
+
+    Multiply( Mt, diff, mul );
+
+    for ( int m = 0; m < dim; ++ m )
+    {
+        index2[ m ] = mul[ m ] + begin2[ m ];
+    }
+}
+
+void InterfaceSplitBc::Multiply( int Mt[][3], std::vector<int> & a, std::vector<int> & b )
+{
+    int dim = Dim::dim;
+    for ( int i = 0; i < dim; ++ i )
+    {
+        b[ i ] = 0;
+        for ( int j = 0; j < dim; ++ j )
+        {
+            b[ i ] += Mt[ i ][ j ] * a[ j ];
+        }
+    }
+}
+
+void InterfaceSplitBc::ChangeRegionToLocalCoordinate()
+{
+    int index_dim = this->region.start.size();
+    std::vector<int> & oriPoint = this->zone->dimInfo.oriPoint;
+    for ( int m = 0; m < index_dim; ++ m )
+    {
+        this->region.start[ m ] -= oriPoint[ m ];
+        this->region.end[ m ] -= oriPoint[ m ];
+    }
+}
+
+void InterfaceSplitBc::CalcSubDonorRegion( RangeRegion &subRegion, RangeRegion &subDonorRegion )
+{
+    std::vector<int> begin1 = this->region.start;
+    std::vector<int> end1 = this->region.end;
+    std::vector<int> begin2 = this->donor_region.start;
+    std::vector<int> end2 = this->donor_region.end;
+
+    std::vector<int> new_begin1 = subRegion.start;
+    std::vector<int> new_end1 = subRegion.end;
+
+    int dim = Dim::dim;
+    std::vector<int> new_begin2( dim );
+    std::vector<int> new_end2( dim );
+
+    mapindex( begin1, begin2, new_begin1, new_begin2 );
+    mapindex( begin1, begin2, new_end1, new_end2 );
+
+    subDonorRegion.start = new_begin2;
+    subDonorRegion.end = new_end2;
+}
+
+SplitZone::SplitZone()
+{
+    this->parent  = 0;
+    this->zoneIndex = 0;
+    this->iProc = 0;
+    dimInfo.Init( Dim::dim );
+    int kk = 1;
+}
+
+SplitZone::~SplitZone()
+{
+    ;
+}
+
+void SplitZone::GetZoneGlobalBox( RangeRegion & zoneBox )
+{
+    this->dimInfo.GetZoneGlobalBox( zoneBox );
+}
+
+void SplitZone::GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox )
+{
+    this->dimInfo.GetZoneLocalBox( globalBox, localBox );
+}
+
+
+void SplitZone::ComputeRminmax()
+{
+    int index_dim = this->dimInfo.dimList.size();
+    std::vector<int> ref( index_dim, 0 );
+
+    SplitZone * rootSplitZone = 0;
+    this->GetRootInfo( rootSplitZone, ref );
+
+    this->dimInfo.ComputeRminmax( ref );
+}
+
+SplitZone * SplitZone::GetRootZone()
+{
+    SplitZone * root = this;
+
+    while ( true )
+    {
+        if ( root->parent )
+        {
+            root = root->parent;
+        }
+        else
+        {
+            return root;
+        }
+    };
+}
+
+void SplitZone::GetRootInfo( SplitZone *& root, std::vector<int> & ref )
+{
+    for ( int i = 0; i < this->dimInfo.dimList.size(); ++ i )
+    {
+        ref[ i ] += this->dimInfo.oriPoint[ i ];
+    }
+
+    if ( this->parent )
+    {
+        this->parent->GetRootInfo( root, ref );
+    }
+    else
+    {
+        root = this;
+    }
+}
+
+void SplitZone::SetParentAndChild( SplitZone * parent )
+{
+    this->parent = parent;
+    if ( parent )
+    {
+        parent->child.push_back( this );
+    }
+}
+
+void SplitZone::GetLeafInterfaceBc( std::vector< InterfaceSplitBc * > & leafInterfaceBcList )
+{
+    int nInterfaceBcs = this->interfaceSplitBcList.size();
+    for ( int i = 0; i < nInterfaceBcs; ++ i )
+    {
+        InterfaceSplitBc * interfaceSplitBc = this->interfaceSplitBcList[ i ];
+        interfaceSplitBc->GetLeafInterfaceBc( leafInterfaceBcList );
+    }
+}
+
+int SplitZone::GetNCell()
+{
+    int numberOfCells = 1;
+    for ( int i = 0; i < this->dimInfo.dim; ++ i )
+    {
+        numberOfCells *= std::max( 1, ( this->dimInfo.dimList[ i ] - 1 ) );
+    }
+
+    return numberOfCells; 
+}
+
+void SplitZone::SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int leftStart = 0;
+    int leftWidth = iSplit - 0;
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, leftStart , leftWidth  );
+}
+
+void SplitZone::SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit )
+{
+    int rightStart = iSplit - 1;
+    int rightWidth = dimList[ axisNeedSplit ] - ( iSplit - 1 );
+
+    this->dimInfo.Init( dimList );
+    this->dimInfo.SetNewDimension( axisNeedSplit, rightStart, rightWidth );
+}
+
+void SplitZone::Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell )
+{
+    //Find the longest axis
+    int axisNeedSplit = this->FindAxisNeedSplit();
+    int iSplit        = this->FindSplitPosition( axisNeedSplit, nCell );
+
+    zoneL->SetLeftDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+    zoneR->SetRightDimension( this->dimInfo.dimList, axisNeedSplit, iSplit );
+
+    zoneL->CreateBcFromParent();
+    zoneR->CreateBcFromParent();
+    
+    CreateInterfaceBc( zoneL, zoneR );
+}
+
+void SplitZone::CreateBcFromParent()
+{
+    this->CreatePhysicalBcFromParent();
+    this->CreateInterfaceBcFromParent();
+}
+
+void SplitZone::CreatePhysicalBcFromParent()
+{
+    int nParentPhysicalBcs = this->parent->physicalSplitBcList.size();
+
+    for ( int iParentPhysicalBcs = 0; iParentPhysicalBcs < nParentPhysicalBcs; ++ iParentPhysicalBcs )
+    {
+        PhysicalSplitBc * parentPhysicalSplitBc = this->parent->physicalSplitBcList[ iParentPhysicalBcs ];
+
+        this->CreatePhysicalBcFromParent( parentPhysicalSplitBc );
+    }
+}
+
+void SplitZone::CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentPhysicalSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreatePhysicalBc( overlapRegion, parentPhysicalSplitBc->bcType );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent()
+{
+    int nInterfaceSplitBcs = this->parent->interfaceSplitBcList.size();
+
+    for ( int iInterfaceSplitBcs = 0; iInterfaceSplitBcs < nInterfaceSplitBcs; ++ iInterfaceSplitBcs )
+    {
+        InterfaceSplitBc * parentInterfaceSplitBc = this->parent->interfaceSplitBcList[ iInterfaceSplitBcs ];
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc );
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc )
+{
+    int index_dim = this->dimInfo.dimList.size();
+    int nDomains = 2 * index_dim;
+    RangeRegion zoneBoxRegion( index_dim );
+    this->dimInfo.GetZoneGlobalBox( zoneBoxRegion );
+
+    for ( int iDomain = 0; iDomain < nDomains; ++ iDomain )
+    {
+        RangeRegion domainRegion( index_dim );
+        GetDomainRegion( zoneBoxRegion, iDomain, domainRegion );
+
+        RangeRegion overlapRegion;
+        bool overlap_flag = ComputeOverlapRegion( parentInterfaceSplitBc->region, domainRegion, overlapRegion );
+        if ( ! overlap_flag ) continue;
+
+        this->CreateInterfaceBcFromParent( parentInterfaceSplitBc, overlapRegion );
+
+        int kkk = 1;
+    }
+}
+
+void SplitZone::FindDonorInterface( InterfaceSplitBc * interfaceSplitBc, InterfaceInfo & interfaceInfo )
+{
+    RangeRegion donor_region = interfaceSplitBc->donor_region;
+    donor_region.Normalize();
+    interfaceInfo.donor_zone = this;
+    for ( int iInterface = 0; iInterface < interfaceSplitBcList.size(); ++ iInterface )
+    {
+        InterfaceSplitBc * candidateDonorBc = interfaceSplitBcList[ iInterface ];
+        bool flag = donor_region.InRegion( candidateDonorBc->region );
+        if ( flag )
+        {
+            if ( donor_region == candidateDonorBc->region )
+            {
+                interfaceInfo.donor_interface = candidateDonorBc;
+                return;
+            }
+            else
+            {
+                InterfaceSplitBc * donorBc = new InterfaceSplitBc();
+                candidateDonorBc->child.push_back( donorBc );
+                donorBc->region = donor_region;
+                donorBc->zone = candidateDonorBc->zone;
+                donorBc->donor_zone = interfaceSplitBc->zone;
+                donorBc->transform = candidateDonorBc->transform;
+                donorBc->CopyMatrix( candidateDonorBc );
+                RangeRegion subDonorRegion( Dim::dim );
+                candidateDonorBc->CalcSubDonorRegion( donorBc->region, subDonorRegion );
+                std::vector<int> & oriPoint = interfaceSplitBc->zone->dimInfo.oriPoint;
+                subDonorRegion.Localize( oriPoint );
+                donorBc->donor_region = subDonorRegion;
+                donorBc->donor_bc = interfaceSplitBc;
+                interfaceInfo.donor_interface = donorBc;
+                return;
+            }
+        }
+    }
+    return;
+}
+
+void SplitZone::GetChildDonorRegion( RangeRegion & subDonorRegion, InterfaceInfo & interfaceInfo )
+{
+    std::cout << "subDonorRegion = \n";
+    //subDonorRegion.Print();
+    RangeRegion normalizedDonorRegion = subDonorRegion;
+    normalizedDonorRegion.Normalize();
+    int nChild = this->child.size();
+    for ( int ichild = 0; ichild < nChild; ++ ichild )
+    {
+        std::cout << " iChild = " << ichild << " nChild = " << nChild << "\n";
+        SplitZone * sub_zone = this->child[ ichild ];
+        std::cout << " zoneIndex = " << sub_zone->zoneIndex << "\n";
+        int nInters = sub_zone->interfaceSplitBcList.size();
+        for ( int iInter = 0; iInter < nInters; ++ iInter )
+        {
+            std::cout << " iInter = " << iInter << "\n";
+            InterfaceSplitBc * interfaceSplitBc = sub_zone->interfaceSplitBcList[ iInter ];
+            std::cout << "interfaceSplitBc local = \n";
+            interfaceSplitBc->region.Print();
+            std::cout << "interfaceSplitBc global = \n";
+            interfaceSplitBc->region.PrintGlobal( sub_zone->dimInfo.oriPoint );
+            RangeRegion g_region = interfaceSplitBc->region;
+            g_region.ToGlobal( sub_zone->dimInfo.oriPoint );
+            if ( g_region == normalizedDonorRegion )
+            {
+                RangeRegion donorRegion = subDonorRegion;
+                donorRegion.ToLocal( sub_zone->dimInfo.oriPoint );
+
+                interfaceInfo.donor_zone = sub_zone;
+                interfaceInfo.donor_interface = interfaceSplitBc;
+                interfaceInfo.donor_region = donorRegion;
+                return;
+            }
+        }
+    }
+}
+
+void SplitZone::CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion )
+{
+    InterfaceSplitBc * interfaceSplitBc = new InterfaceSplitBc();
+    this->interfaceSplitBcList.push_back( interfaceSplitBc );
+
+    interfaceSplitBc->region = overlapRegion;
+    interfaceSplitBc->zone = this;
+    interfaceSplitBc->transform = parentInterfaceSplitBc->transform;
+    interfaceSplitBc->CopyMatrix( parentInterfaceSplitBc );
+    RangeRegion subDonorRegion( Dim::dim );
+    parentInterfaceSplitBc->CalcSubDonorRegion( overlapRegion, subDonorRegion );
+    interfaceSplitBc->ChangeRegionToLocalCoordinate();
+    interfaceSplitBc->donor_region = subDonorRegion;
+    SplitZone * parent_donor_zone = parentInterfaceSplitBc->donor_zone;
+    std::cout << " parentInterfaceSplitBc->zone->zoneIndex " << parentInterfaceSplitBc->zone->zoneIndex << "\n";
+    std::cout << " parentInterfaceSplitBc->donor_zone->zoneIndex " << parent_donor_zone->zoneIndex << "\n";
+    if ( parent_donor_zone->child.size() > 0 )
+    {
+        InterfaceInfo interfaceInfo;
+        parent_donor_zone->GetChildDonorRegion( subDonorRegion, interfaceInfo );
+        interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+        interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+        interfaceSplitBc->donor_region = interfaceInfo.donor_region;
+        //compatibility
+        InterfaceSplitBc * donor_bc = interfaceSplitBc->donor_bc;
+        SplitZone * donor_zone = interfaceSplitBc->donor_zone;
+        if ( interfaceSplitBc->zone != donor_bc->donor_zone )
+        {
+            if ( interfaceSplitBc->zone->parent == donor_bc->donor_zone )
+            {
+                RangeRegion d_region = donor_bc->donor_region;
+                d_region.ToLocal( interfaceSplitBc->zone->dimInfo.oriPoint );
+                donor_bc->donor_region = d_region;
+            }
+            donor_bc->donor_zone = interfaceSplitBc->zone;
+         
+            int kkk = 1;
+        }
+        int kkk = 1;
+    }
+    else
+    {
+        InterfaceInfo interfaceInfo;
+        parent_donor_zone->FindDonorInterface( interfaceSplitBc, interfaceInfo );
+        interfaceSplitBc->donor_zone = interfaceInfo.donor_zone;
+        interfaceSplitBc->donor_bc = interfaceInfo.donor_interface;
+    }
+    
+    int kkk = 1;
+}
+
+void SplitZone::CreatePhysicalBc( RangeRegion & overlapRegion, int bcType )
+{
+    PhysicalSplitBc * physicalSplitBc = new PhysicalSplitBc();
+    this->physicalSplitBcList.push_back( physicalSplitBc );
+    physicalSplitBc->SetRegion( overlapRegion );
+    physicalSplitBc->bcType = bcType;
+    physicalSplitBc->splitZone = this;
+    physicalSplitBc->ChangeRegionToLocalCoordinate();
+}
+
+int SplitZone::FindAxisNeedSplit()
+{
+    //Find the longest axis
+    int axisNeedSplit = 0;
+    int maxN = this->dimInfo.dimList[ 0 ];
+
+    for ( int m = 1; m < this->dimInfo.dimList.size(); ++ m )
+    {
+        if ( this->IsPoleBc( m ) )
+        {
+            continue;
+        }
+        int Nm = this->dimInfo.dimList[ m ];
+        if ( maxN < Nm )
+        {
+            maxN = Nm;
+            axisNeedSplit = m;
+        }
+    }
+
+    return axisNeedSplit;
+}
+
+int SplitZone::GetCrossSection( int axis )
+{
+    int nDim = this->dimInfo.dimList.size();
+    int crossSection = 1;
+    int N = nDim - 1;
+    for ( int m = 0; m < N; ++ m )
+    {
+         int mm = ( axis + 1 ) % nDim;
+         int nLineElements = std::max( 1, ( this->dimInfo.dimList[ mm ] - 1 ) );
+         crossSection *= nLineElements;
+    }
+    return crossSection;
+}
+
+int SplitZone::FindSplitPosition( int axisNeedSplit, double nCell )
+{
+    int nDim = this->dimInfo.dimList.size();
+    std::vector<int> crossSections( nDim );
+    for ( int m = 0; m < nDim; ++ m )
+    {
+        crossSections[ m ] = this->GetCrossSection( m );
+    }
+
+    //guess the value
+    double dSplit = nCell / crossSections[ axisNeedSplit ];
+    int  iSplit = 1 + static_cast< int >( std::floor( dSplit + 0.5 ) );
+    return iSplit;
+}
+
+
+bool SplitZone::IsPoleBc( int splitDirection )
+{
+    return false;
+}
+
diff --git a/example/partition/struct/2d/stage3/01d/SplitZone.h b/example/partition/struct/2d/stage3/01d/SplitZone.h
new file mode 100644
index 00000000..ffe1e306
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01d/SplitZone.h
@@ -0,0 +1,196 @@
+#pragma once
+#include <iostream>
+#include <vector>
+#include <set>
+
+class Dim
+{
+public:
+    static int dim;
+};
+
+class SplitZone;
+class RangeRegion;
+
+void GetDomainRegion( RangeRegion & zoneBox, int iDomain, RangeRegion & domainBox );
+
+class DimInfo
+{
+public:
+    DimInfo();
+    ~DimInfo();
+public:
+    int dim;
+    std::vector<int> dimList;
+    std::vector<int> oriPoint;
+    std::vector<int> isize;
+    std::vector<int> rmin;
+    std::vector<int> rmax;
+public:
+    int GetSize() const { return dim; }
+    DimInfo & operator = ( const DimInfo & rhs );
+public:
+    int ComputeNumNodes();
+    void ComputeISize();
+    void ComputeRminmax( std::vector<int> & ref );
+    void Init( int dim );
+    void Init( std::vector<int> & dimList );
+    void SetNewDimension( int axis, int newStart, int newWidth );
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+};
+
+class SplitZone;
+class SplitBcPatch;
+
+class RangeRegion
+{
+public:
+    RangeRegion( int nSize = 1 );
+    ~RangeRegion();
+public:
+    std::vector<int> start;
+    std::vector<int> end;
+public:
+    void Init( int nSize );
+    RangeRegion & operator = ( const RangeRegion & rhs );
+    bool operator == ( const RangeRegion & rhs ) const;
+    bool InRegion( const RangeRegion & region );
+    void SetRegion( std::vector<int> &pnts );
+    void Normalize();
+    void Localize( std::vector<int> & oriPoint );
+    void ToGlobal( std::vector<int> & oriPoint );
+    void ToLocal( std::vector<int> & oriPoint );
+    void PrintGlobal( std::vector<int> & oriPoint );
+    void Print();
+};
+
+class PhysicalSplitBc
+{
+public:
+    PhysicalSplitBc();
+    ~PhysicalSplitBc();
+public:
+    int bcType;
+    RangeRegion region;
+public:
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> &pnts );
+    void SetRegion( RangeRegion &region );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class BasicSplitBc
+{
+public:
+    BasicSplitBc();
+    ~BasicSplitBc();
+public:
+    RangeRegion region;
+    SplitZone * splitZone = nullptr;
+public:
+    void SetRegion( std::vector<int> & pnts );
+    void SetRegion( RangeRegion & region );
+};
+
+class trans
+{
+public:
+    static int M[ 3 ][ 3 ];
+    static std::vector<int> transform;
+    static int sgn( int x );
+    static int del( int x, int y );
+    static void ZeroMatrix();
+    static void CalcTransformMatrix();
+};
+
+class InterfaceSplitBc;
+class SplitZone;
+
+class InterfaceInfo
+{
+public:
+    InterfaceInfo();
+    ~InterfaceInfo();
+public:
+    InterfaceSplitBc * donor_interface = nullptr;
+    SplitZone * donor_zone = nullptr;
+    RangeRegion donor_region;
+};
+
+class InterfaceSplitBc
+{
+public:
+    InterfaceSplitBc();
+    ~InterfaceSplitBc();
+public:
+    std::vector<int> transform;
+    int Mt[ 3 ][ 3 ];
+    RangeRegion region;
+    SplitZone * zone = nullptr;
+    RangeRegion donor_region;
+    SplitZone * donor_zone = nullptr;
+    InterfaceSplitBc * donor_bc = nullptr;
+public:
+    std::vector<InterfaceSplitBc *> child;
+    void GetLeafInterfaceBc( std::vector< InterfaceSplitBc * > & leafInterfaceBcList );
+public:
+    void CopyMatrix( InterfaceSplitBc * interfaceSplitBc );
+    void CalcTransformMatrix();
+    void CalcSubDonorRegion( RangeRegion & subRegion, RangeRegion & subDonorRegion );
+    void mapindex( std::vector<int> & begin1, std::vector<int> & begin2, std::vector<int> & index1, std::vector<int> & index2 );
+    void Multiply( int Mt[][ 3 ], std::vector<int> & a, std::vector<int> & b );
+    void ChangeRegionToLocalCoordinate();
+};
+
+class SplitZone
+{
+public:
+    SplitZone();
+    ~SplitZone();
+public:
+    DimInfo dimInfo;
+    int zoneIndex, iProc;
+    int newIndex;
+protected:
+    SplitZone * parent;
+    std::vector<SplitZone *> child;
+public:
+    std::vector< PhysicalSplitBc * > physicalSplitBcList;
+    std::vector< InterfaceSplitBc * > interfaceSplitBcList;
+    void GetLeafInterfaceBc( std::vector< InterfaceSplitBc * > & leafInterfaceBcList );
+public:
+    int GetNCell();
+    void ComputeRminmax();
+    void GetRootInfo( SplitZone *& root, std::vector<int> & ref );
+    void SetZoneIndex( int zoneIndex ) { this->zoneIndex = zoneIndex; }
+    int  GetZoneIndex() { return zoneIndex; }
+    void SetProcId( int iProc ) { this->iProc = iProc; }
+    void SetParent( SplitZone * parent ) { this->parent = parent; };
+    void SetParentAndChild( SplitZone * parent );
+    void FindDonorInterface( InterfaceSplitBc * interfaceSplitBc, InterfaceInfo & interfaceInfo );
+    void GetChildDonorRegion( RangeRegion & subDonorRegion, InterfaceInfo & interfaceInfo );
+public:
+    void CreateBcFromParent();
+    void CreatePhysicalBcFromParent();
+    void CreatePhysicalBcFromParent( PhysicalSplitBc * parentPhysicalSplitBc );
+    void CreatePhysicalBc( RangeRegion & overlapRegion, int bcType );
+    void CreateInterfaceBcFromParent();
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc );
+    void CreateInterfaceBcFromParent( InterfaceSplitBc * parentInterfaceSplitBc, RangeRegion & overlapRegion );
+
+    void GetZoneGlobalBox( RangeRegion & zoneBox );
+    void GetZoneLocalBox( RangeRegion & globalBox, RangeRegion & localBox );
+    SplitZone * GetRootZone();
+public:
+    void Split( SplitZone *& zoneL, SplitZone *& zoneR, double nCell );
+    void SetLeftDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+    void SetRightDimension( std::vector<int> & dimList, int axisNeedSplit, int iSplit );
+private:
+    int FindAxisNeedSplit();
+    int FindSplitPosition( int axisNeedSplit, double nCell );
+    bool IsPoleBc( int splitDirection );
+    int GetCrossSection( int axis );
+};
+
diff --git a/example/partition/struct/2d/stage3/01d/heat2d1blockv2.cgns b/example/partition/struct/2d/stage3/01d/heat2d1blockv2.cgns
new file mode 100644
index 00000000..93a1b73e
Binary files /dev/null and b/example/partition/struct/2d/stage3/01d/heat2d1blockv2.cgns differ
diff --git a/example/partition/struct/2d/stage3/01d/heat2dpart.cgns b/example/partition/struct/2d/stage3/01d/heat2dpart.cgns
new file mode 100644
index 00000000..0f631a2e
Binary files /dev/null and b/example/partition/struct/2d/stage3/01d/heat2dpart.cgns differ
diff --git a/example/partition/struct/2d/stage3/01d/main.cpp b/example/partition/struct/2d/stage3/01d/main.cpp
new file mode 100644
index 00000000..5da1de7c
--- /dev/null
+++ b/example/partition/struct/2d/stage3/01d/main.cpp
@@ -0,0 +1,18 @@
+#include "cgnslib.h"
+#include "CgnsGrid.h"
+#include "Partition.h"
+#include <iostream>
+#include <vector>
+#include <numbers>
+#include <cmath>
+#include <fstream>
+#include <iomanip>
+
+int main(int argc, char **argv)
+{
+    Partition * partition = new Partition();
+    partition->Solve();
+    delete partition;
+
+    return 0;
+}
diff --git a/tools/CMakeLists.txt.user b/tools/CMakeLists.txt.user
new file mode 100644
index 00000000..f1fc6354
--- /dev/null
+++ b/tools/CMakeLists.txt.user
@@ -0,0 +1,416 @@
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+      <valuelist type="QVariantList" key="CMakeProjectManager.MakeStep.BuildTargets">
+       <value type="QString">clean</value>
+      </valuelist>
+      <value type="bool" key="CMakeProjectManager.MakeStep.ClearSystemEnvironment">false</value>
+      <valuelist type="QVariantList" key="CMakeProjectManager.MakeStep.UserEnvironmentChanges"/>
+      <value type="bool" key="ProjectExplorer.BuildStep.Enabled">true</value>
+      <value type="QString" key="ProjectExplorer.ProjectConfiguration.DisplayName">Build</value>
+      <value type="QString" key="ProjectExplorer.ProjectConfiguration.Id">CMakeProjectManager.MakeStep</value>
+     </valuemap>
+     <value type="qlonglong" key="ProjectExplorer.BuildStepList.StepsCount">1</value>
+     <value type="QString" key="ProjectExplorer.ProjectConfiguration.DefaultDisplayName">Clean</value>
+     <value type="QString" key="ProjectExplorer.ProjectConfiguration.DisplayName">Clean</value>
+     <value type="QString" key="ProjectExplorer.ProjectConfiguration.Id">ProjectExplorer.BuildSteps.Clean</value>
+    </valuemap>
+    <value type="int" key="ProjectExplorer.BuildConfiguration.BuildStepListCount">2</value>
+    <value type="bool" key="ProjectExplorer.BuildConfiguration.ClearSystemEnvironment">false</value>
+    <valuelist type="QVariantList" key="ProjectExplorer.BuildConfiguration.CustomParsers"/>
+    <value type="bool" key="ProjectExplorer.BuildConfiguration.ParseStandardOutput">false</value>
+    <valuelist type="QVariantList" key="ProjectExplorer.BuildConfiguration.UserEnvironmentChanges"/>
+    <value type="QString" key="ProjectExplorer.ProjectConfiguration.DisplayName">Debug</value>
+    <value type="QString" key="ProjectExplorer.ProjectConfiguration.Id">CMakeProjectManager.CMakeBuildConfiguration</value>
+   </valuemap>
+   <valuemap type="QVariantMap" key="ProjectExplorer.Target.BuildConfiguration.1">
+    <value type="QString" key="CMake.Build.Type">Release</value>
+    <value type="int" key="CMake.Configure.BaseEnvironment">2</value>
+    <value type="bool" key="CMake.Configure.ClearSystemEnvironment">false</value>
+    <valuelist type="QVariantList" key="CMake.Configure.UserEnvironmentChanges"/>
+    <value type="QString" key="CMake.Initial.Parameters">-DCMAKE_PREFIX_PATH:PATH=%{Qt:QT_INSTALL_PREFIX}
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+    <value type="QString" key="ProjectExplorer.BuildConfiguration.BuildDirectory">D:\github\OneFLOW\tools\build\Desktop_x86_windows_msvc2022_pe_64bit-Release</value>
+    <valuemap type="QVariantMap" key="ProjectExplorer.BuildConfiguration.BuildStepList.0">
+     <valuemap type="QVariantMap" key="ProjectExplorer.BuildStepList.Step.0">
+      <value type="QString" key="CMakeProjectManager.MakeStep.BuildPreset"></value>
+      <valuelist type="QVariantList" key="CMakeProjectManager.MakeStep.BuildTargets">
+       <value type="QString">all</value>
+      </valuelist>
+      <value type="bool" key="CMakeProjectManager.MakeStep.ClearSystemEnvironment">false</value>
+      <valuelist type="QVariantList" key="CMakeProjectManager.MakeStep.UserEnvironmentChanges"/>
+      <value type="bool" key="ProjectExplorer.BuildStep.Enabled">true</value>
+      <value type="QString" key="ProjectExplorer.ProjectConfiguration.Id">CMakeProjectManager.MakeStep</value>
+     </valuemap>
+     <value type="qlonglong" key="ProjectExplorer.BuildStepList.StepsCount">1</value>
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+     <value type="QString" key="ProjectExplorer.ProjectConfiguration.Id">ProjectExplorer.BuildSteps.Build</value>
+    </valuemap>
+    <valuemap type="QVariantMap" key="ProjectExplorer.BuildConfiguration.BuildStepList.1">
+     <valuemap type="QVariantMap" key="ProjectExplorer.BuildStepList.Step.0">
+      <value type="QString" key="CMakeProjectManager.MakeStep.BuildPreset"></value>
+      <valuelist type="QVariantList" key="CMakeProjectManager.MakeStep.BuildTargets">
+       <value type="QString">clean</value>
+      </valuelist>
+      <value type="bool" key="CMakeProjectManager.MakeStep.ClearSystemEnvironment">false</value>
+      <valuelist type="QVariantList" key="CMakeProjectManager.MakeStep.UserEnvironmentChanges"/>
+      <value type="bool" key="ProjectExplorer.BuildStep.Enabled">true</value>
+      <value type="QString" key="ProjectExplorer.ProjectConfiguration.Id">CMakeProjectManager.MakeStep</value>
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+     <value type="qlonglong" key="ProjectExplorer.BuildStepList.StepsCount">1</value>
+     <value type="QString" key="ProjectExplorer.ProjectConfiguration.DefaultDisplayName">Clean</value>
+     <value type="QString" key="ProjectExplorer.ProjectConfiguration.DisplayName">Clean</value>
+     <value type="QString" key="ProjectExplorer.ProjectConfiguration.Id">ProjectExplorer.BuildSteps.Clean</value>
+    </valuemap>
+    <value type="int" key="ProjectExplorer.BuildConfiguration.BuildStepListCount">2</value>
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+    <valuelist type="QVariantList" key="ProjectExplorer.BuildConfiguration.CustomParsers"/>
+    <value type="bool" key="ProjectExplorer.BuildConfiguration.ParseStandardOutput">false</value>
+    <valuelist type="QVariantList" key="ProjectExplorer.BuildConfiguration.UserEnvironmentChanges"/>
+    <value type="QString" key="ProjectExplorer.ProjectConfiguration.DisplayName">Release</value>
+    <value type="QString" key="ProjectExplorer.ProjectConfiguration.Id">CMakeProjectManager.CMakeBuildConfiguration</value>
+   </valuemap>
+   <valuemap type="QVariantMap" key="ProjectExplorer.Target.BuildConfiguration.2">
+    <value type="QString" key="CMake.Build.Type">RelWithDebInfo</value>
+    <value type="int" key="CMake.Configure.BaseEnvironment">2</value>
+    <value type="bool" key="CMake.Configure.ClearSystemEnvironment">false</value>
+    <valuelist type="QVariantList" key="CMake.Configure.UserEnvironmentChanges"/>
+    <value type="QString" key="CMake.Initial.Parameters">-DCMAKE_PREFIX_PATH:PATH=%{Qt:QT_INSTALL_PREFIX}
+-DCMAKE_PROJECT_INCLUDE_BEFORE:FILEPATH=%{BuildConfig:BuildDirectory:NativeFilePath}/.qtc/package-manager/auto-setup.cmake
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+-DQT_QMAKE_EXECUTABLE:FILEPATH=%{Qt:qmakeExecutable}
+-DCMAKE_CXX_COMPILER:FILEPATH=%{Compiler:Executable:Cxx}</value>
+    <value type="QString" key="ProjectExplorer.BuildConfiguration.BuildDirectory">D:\github\OneFLOW\tools\build\Desktop_x86_windows_msvc2022_pe_64bit-RelWithDebInfo</value>
+    <valuemap type="QVariantMap" key="ProjectExplorer.BuildConfiguration.BuildStepList.0">
+     <valuemap type="QVariantMap" key="ProjectExplorer.BuildStepList.Step.0">
+      <value type="QString" key="CMakeProjectManager.MakeStep.BuildPreset"></value>
+      <valuelist type="QVariantList" key="CMakeProjectManager.MakeStep.BuildTargets">
+       <value type="QString">all</value>
+      </valuelist>
+      <value type="bool" key="CMakeProjectManager.MakeStep.ClearSystemEnvironment">false</value>
+      <valuelist type="QVariantList" key="CMakeProjectManager.MakeStep.UserEnvironmentChanges"/>
+      <value type="bool" key="ProjectExplorer.BuildStep.Enabled">true</value>
+      <value type="QString" key="ProjectExplorer.ProjectConfiguration.Id">CMakeProjectManager.MakeStep</value>
+     </valuemap>
+     <value type="qlonglong" key="ProjectExplorer.BuildStepList.StepsCount">1</value>
+     <value type="QString" key="ProjectExplorer.ProjectConfiguration.DefaultDisplayName">Build</value>
+     <value type="QString" key="ProjectExplorer.ProjectConfiguration.DisplayName">Build</value>
+     <value type="QString" key="ProjectExplorer.ProjectConfiguration.Id">ProjectExplorer.BuildSteps.Build</value>
+    </valuemap>
+    <valuemap type="QVariantMap" key="ProjectExplorer.BuildConfiguration.BuildStepList.1">
+     <valuemap type="QVariantMap" key="ProjectExplorer.BuildStepList.Step.0">
+      <value type="QString" key="CMakeProjectManager.MakeStep.BuildPreset"></value>
+      <valuelist type="QVariantList" key="CMakeProjectManager.MakeStep.BuildTargets">
+       <value type="QString">clean</value>
+      </valuelist>
+      <value type="bool" key="CMakeProjectManager.MakeStep.ClearSystemEnvironment">false</value>
+      <valuelist type="QVariantList" key="CMakeProjectManager.MakeStep.UserEnvironmentChanges"/>
+      <value type="bool" key="ProjectExplorer.BuildStep.Enabled">true</value>
+      <value type="QString" key="ProjectExplorer.ProjectConfiguration.Id">CMakeProjectManager.MakeStep</value>
+     </valuemap>
+     <value type="qlonglong" key="ProjectExplorer.BuildStepList.StepsCount">1</value>
+     <value type="QString" key="ProjectExplorer.ProjectConfiguration.DefaultDisplayName">Clean</value>
+     <value type="QString" key="ProjectExplorer.ProjectConfiguration.DisplayName">Clean</value>
+     <value type="QString" key="ProjectExplorer.ProjectConfiguration.Id">ProjectExplorer.BuildSteps.Clean</value>
+    </valuemap>
+    <value type="int" key="ProjectExplorer.BuildConfiguration.BuildStepListCount">2</value>
+    <value type="bool" key="ProjectExplorer.BuildConfiguration.ClearSystemEnvironment">false</value>
+    <valuelist type="QVariantList" key="ProjectExplorer.BuildConfiguration.CustomParsers"/>
+    <value type="bool" key="ProjectExplorer.BuildConfiguration.ParseStandardOutput">false</value>
+    <valuelist type="QVariantList" key="ProjectExplorer.BuildConfiguration.UserEnvironmentChanges"/>
+    <value type="QString" key="ProjectExplorer.ProjectConfiguration.DisplayName">Release with Debug Information</value>
+    <value type="QString" key="ProjectExplorer.ProjectConfiguration.Id">CMakeProjectManager.CMakeBuildConfiguration</value>
+   </valuemap>
+   <valuemap type="QVariantMap" key="ProjectExplorer.Target.BuildConfiguration.3">
+    <value type="QString" key="CMake.Build.Type">RelWithDebInfo</value>
+    <value type="int" key="CMake.Configure.BaseEnvironment">2</value>
+    <value type="bool" key="CMake.Configure.ClearSystemEnvironment">false</value>
+    <valuelist type="QVariantList" key="CMake.Configure.UserEnvironmentChanges"/>
+    <value type="QString" key="CMake.Initial.Parameters">-DCMAKE_PREFIX_PATH:PATH=%{Qt:QT_INSTALL_PREFIX}
+-DCMAKE_PROJECT_INCLUDE_BEFORE:FILEPATH=%{BuildConfig:BuildDirectory:NativeFilePath}/.qtc/package-manager/auto-setup.cmake
+-DCMAKE_GENERATOR:STRING=Ninja
+-DCMAKE_C_COMPILER:FILEPATH=%{Compiler:Executable:C}
+-DCMAKE_BUILD_TYPE:STRING=RelWithDebInfo
+-DQT_QMAKE_EXECUTABLE:FILEPATH=%{Qt:qmakeExecutable}
+-DCMAKE_CXX_COMPILER:FILEPATH=%{Compiler:Executable:Cxx}</value>
+    <value type="int" key="EnableQmlDebugging">0</value>
+    <value type="QString" key="ProjectExplorer.BuildConfiguration.BuildDirectory">D:\github\OneFLOW\tools\build\Desktop_x86_windows_msvc2022_pe_64bit-Profile</value>
+    <valuemap type="QVariantMap" key="ProjectExplorer.BuildConfiguration.BuildStepList.0">
+     <valuemap type="QVariantMap" key="ProjectExplorer.BuildStepList.Step.0">
+      <value type="QString" key="CMakeProjectManager.MakeStep.BuildPreset"></value>
+      <valuelist type="QVariantList" key="CMakeProjectManager.MakeStep.BuildTargets">
+       <value type="QString">all</value>
+      </valuelist>
+      <value type="bool" key="CMakeProjectManager.MakeStep.ClearSystemEnvironment">false</value>
+      <valuelist type="QVariantList" key="CMakeProjectManager.MakeStep.UserEnvironmentChanges"/>
+      <value type="bool" key="ProjectExplorer.BuildStep.Enabled">true</value>
+      <value type="QString" key="ProjectExplorer.ProjectConfiguration.Id">CMakeProjectManager.MakeStep</value>
+     </valuemap>
+     <value type="qlonglong" key="ProjectExplorer.BuildStepList.StepsCount">1</value>
+     <value type="QString" key="ProjectExplorer.ProjectConfiguration.DefaultDisplayName">Build</value>
+     <value type="QString" key="ProjectExplorer.ProjectConfiguration.DisplayName">Build</value>
+     <value type="QString" key="ProjectExplorer.ProjectConfiguration.Id">ProjectExplorer.BuildSteps.Build</value>
+    </valuemap>
+    <valuemap type="QVariantMap" key="ProjectExplorer.BuildConfiguration.BuildStepList.1">
+     <valuemap type="QVariantMap" key="ProjectExplorer.BuildStepList.Step.0">
+      <value type="QString" key="CMakeProjectManager.MakeStep.BuildPreset"></value>
+      <valuelist type="QVariantList" key="CMakeProjectManager.MakeStep.BuildTargets">
+       <value type="QString">clean</value>
+      </valuelist>
+      <value type="bool" key="CMakeProjectManager.MakeStep.ClearSystemEnvironment">false</value>
+      <valuelist type="QVariantList" key="CMakeProjectManager.MakeStep.UserEnvironmentChanges"/>
+      <value type="bool" key="ProjectExplorer.BuildStep.Enabled">true</value>
+      <value type="QString" key="ProjectExplorer.ProjectConfiguration.Id">CMakeProjectManager.MakeStep</value>
+     </valuemap>
+     <value type="qlonglong" key="ProjectExplorer.BuildStepList.StepsCount">1</value>
+     <value type="QString" key="ProjectExplorer.ProjectConfiguration.DefaultDisplayName">Clean</value>
+     <value type="QString" key="ProjectExplorer.ProjectConfiguration.DisplayName">Clean</value>
+     <value type="QString" key="ProjectExplorer.ProjectConfiguration.Id">ProjectExplorer.BuildSteps.Clean</value>
+    </valuemap>
+    <value type="int" key="ProjectExplorer.BuildConfiguration.BuildStepListCount">2</value>
+    <value type="bool" key="ProjectExplorer.BuildConfiguration.ClearSystemEnvironment">false</value>
+    <valuelist type="QVariantList" key="ProjectExplorer.BuildConfiguration.CustomParsers"/>
+    <value type="bool" key="ProjectExplorer.BuildConfiguration.ParseStandardOutput">false</value>
+    <valuelist type="QVariantList" key="ProjectExplorer.BuildConfiguration.UserEnvironmentChanges"/>
+    <value type="QString" key="ProjectExplorer.ProjectConfiguration.DisplayName">Profile</value>
+    <value type="QString" key="ProjectExplorer.ProjectConfiguration.Id">CMakeProjectManager.CMakeBuildConfiguration</value>
+   </valuemap>
+   <valuemap type="QVariantMap" key="ProjectExplorer.Target.BuildConfiguration.4">
+    <value type="QString" key="CMake.Build.Type">MinSizeRel</value>
+    <value type="int" key="CMake.Configure.BaseEnvironment">2</value>
+    <value type="bool" key="CMake.Configure.ClearSystemEnvironment">false</value>
+    <valuelist type="QVariantList" key="CMake.Configure.UserEnvironmentChanges"/>
+    <value type="QString" key="CMake.Initial.Parameters">-DCMAKE_PREFIX_PATH:PATH=%{Qt:QT_INSTALL_PREFIX}
+-DCMAKE_PROJECT_INCLUDE_BEFORE:FILEPATH=%{BuildConfig:BuildDirectory:NativeFilePath}/.qtc/package-manager/auto-setup.cmake
+-DCMAKE_GENERATOR:STRING=Ninja
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+-DCMAKE_BUILD_TYPE:STRING=MinSizeRel
+-DQT_QMAKE_EXECUTABLE:FILEPATH=%{Qt:qmakeExecutable}
+-DCMAKE_CXX_COMPILER:FILEPATH=%{Compiler:Executable:Cxx}</value>
+    <value type="QString" key="ProjectExplorer.BuildConfiguration.BuildDirectory">D:\github\OneFLOW\tools\build\Desktop_x86_windows_msvc2022_pe_64bit-MinSizeRel</value>
+    <valuemap type="QVariantMap" key="ProjectExplorer.BuildConfiguration.BuildStepList.0">
+     <valuemap type="QVariantMap" key="ProjectExplorer.BuildStepList.Step.0">
+      <value type="QString" key="CMakeProjectManager.MakeStep.BuildPreset"></value>
+      <valuelist type="QVariantList" key="CMakeProjectManager.MakeStep.BuildTargets">
+       <value type="QString">all</value>
+      </valuelist>
+      <value type="bool" key="CMakeProjectManager.MakeStep.ClearSystemEnvironment">false</value>
+      <valuelist type="QVariantList" key="CMakeProjectManager.MakeStep.UserEnvironmentChanges"/>
+      <value type="bool" key="ProjectExplorer.BuildStep.Enabled">true</value>
+      <value type="QString" key="ProjectExplorer.ProjectConfiguration.Id">CMakeProjectManager.MakeStep</value>
+     </valuemap>
+     <value type="qlonglong" key="ProjectExplorer.BuildStepList.StepsCount">1</value>
+     <value type="QString" key="ProjectExplorer.ProjectConfiguration.DefaultDisplayName">Build</value>
+     <value type="QString" key="ProjectExplorer.ProjectConfiguration.DisplayName">Build</value>
+     <value type="QString" key="ProjectExplorer.ProjectConfiguration.Id">ProjectExplorer.BuildSteps.Build</value>
+    </valuemap>
+    <valuemap type="QVariantMap" key="ProjectExplorer.BuildConfiguration.BuildStepList.1">
+     <valuemap type="QVariantMap" key="ProjectExplorer.BuildStepList.Step.0">
+      <value type="QString" key="CMakeProjectManager.MakeStep.BuildPreset"></value>
+      <valuelist type="QVariantList" key="CMakeProjectManager.MakeStep.BuildTargets">
+       <value type="QString">clean</value>
+      </valuelist>
+      <value type="bool" key="CMakeProjectManager.MakeStep.ClearSystemEnvironment">false</value>
+      <valuelist type="QVariantList" key="CMakeProjectManager.MakeStep.UserEnvironmentChanges"/>
+      <value type="bool" key="ProjectExplorer.BuildStep.Enabled">true</value>
+      <value type="QString" key="ProjectExplorer.ProjectConfiguration.Id">CMakeProjectManager.MakeStep</value>
+     </valuemap>
+     <value type="qlonglong" key="ProjectExplorer.BuildStepList.StepsCount">1</value>
+     <value type="QString" key="ProjectExplorer.ProjectConfiguration.DefaultDisplayName">Clean</value>
+     <value type="QString" key="ProjectExplorer.ProjectConfiguration.DisplayName">Clean</value>
+     <value type="QString" key="ProjectExplorer.ProjectConfiguration.Id">ProjectExplorer.BuildSteps.Clean</value>
+    </valuemap>
+    <value type="int" key="ProjectExplorer.BuildConfiguration.BuildStepListCount">2</value>
+    <value type="bool" key="ProjectExplorer.BuildConfiguration.ClearSystemEnvironment">false</value>
+    <valuelist type="QVariantList" key="ProjectExplorer.BuildConfiguration.CustomParsers"/>
+    <value type="bool" key="ProjectExplorer.BuildConfiguration.ParseStandardOutput">false</value>
+    <valuelist type="QVariantList" key="ProjectExplorer.BuildConfiguration.UserEnvironmentChanges"/>
+    <value type="QString" key="ProjectExplorer.ProjectConfiguration.DisplayName">Minimum Size Release</value>
+    <value type="QString" key="ProjectExplorer.ProjectConfiguration.Id">CMakeProjectManager.CMakeBuildConfiguration</value>
+   </valuemap>
+   <value type="qlonglong" key="ProjectExplorer.Target.BuildConfigurationCount">5</value>
+   <valuemap type="QVariantMap" key="ProjectExplorer.Target.DeployConfiguration.0">
+    <valuemap type="QVariantMap" key="ProjectExplorer.BuildConfiguration.BuildStepList.0">
+     <value type="qlonglong" key="ProjectExplorer.BuildStepList.StepsCount">0</value>
+     <value type="QString" key="ProjectExplorer.ProjectConfiguration.DefaultDisplayName">Deploy</value>
+     <value type="QString" key="ProjectExplorer.ProjectConfiguration.DisplayName">Deploy</value>
+     <value type="QString" key="ProjectExplorer.ProjectConfiguration.Id">ProjectExplorer.BuildSteps.Deploy</value>
+    </valuemap>
+    <value type="int" key="ProjectExplorer.BuildConfiguration.BuildStepListCount">1</value>
+    <valuemap type="QVariantMap" key="ProjectExplorer.DeployConfiguration.CustomData"/>
+    <value type="bool" key="ProjectExplorer.DeployConfiguration.CustomDataEnabled">false</value>
+    <value type="QString" key="ProjectExplorer.ProjectConfiguration.Id">ProjectExplorer.DefaultDeployConfiguration</value>
+   </valuemap>
+   <value type="qlonglong" key="ProjectExplorer.Target.DeployConfigurationCount">1</value>
+   <valuemap type="QVariantMap" key="ProjectExplorer.Target.RunConfiguration.0">
+    <value type="bool" key="Analyzer.Perf.Settings.UseGlobalSettings">true</value>
+    <value type="bool" key="Analyzer.QmlProfiler.Settings.UseGlobalSettings">true</value>
+    <value type="int" key="Analyzer.Valgrind.Callgrind.CostFormat">0</value>
+    <value type="bool" key="Analyzer.Valgrind.Settings.UseGlobalSettings">true</value>
+    <valuelist type="QVariantList" key="CustomOutputParsers"/>
+    <value type="int" key="PE.EnvironmentAspect.Base">2</value>
+    <valuelist type="QVariantList" key="PE.EnvironmentAspect.Changes"/>
+    <value type="bool" key="PE.EnvironmentAspect.PrintOnRun">false</value>
+    <value type="QString" key="PerfRecordArgsId">-e cpu-cycles --call-graph &quot;dwarf,4096&quot; -F 250</value>
+    <value type="QString" key="ProjectExplorer.ProjectConfiguration.DisplayName">ModernCFD</value>
+    <value type="QString" key="ProjectExplorer.ProjectConfiguration.Id">CMakeProjectManager.CMakeRunConfiguration.ModernCFD</value>
+    <value type="QString" key="ProjectExplorer.RunConfiguration.BuildKey">ModernCFD</value>
+    <value type="bool" key="ProjectExplorer.RunConfiguration.Customized">false</value>
+    <value type="bool" key="RunConfiguration.UseCppDebuggerAuto">true</value>
+    <value type="bool" key="RunConfiguration.UseLibrarySearchPath">true</value>
+    <value type="bool" key="RunConfiguration.UseQmlDebuggerAuto">true</value>
+    <value type="QString" key="RunConfiguration.WorkingDirectory.default">D:/github/OneFLOW/tools/build/Desktop_x86_windows_msvc2022_pe_64bit-Debug</value>
+   </valuemap>
+   <value type="qlonglong" key="ProjectExplorer.Target.RunConfigurationCount">1</value>
+  </valuemap>
+ </data>
+ <data>
+  <variable>ProjectExplorer.Project.TargetCount</variable>
+  <value type="qlonglong">1</value>
+ </data>
+ <data>
+  <variable>ProjectExplorer.Project.Updater.FileVersion</variable>
+  <value type="int">22</value>
+ </data>
+ <data>
+  <variable>Version</variable>
+  <value type="int">22</value>
+ </data>
+</qtcreator>
diff --git a/tools/codes/cgnsview.cpp b/tools/codes/cgnsview.cpp
index 38c07985..860e4434 100644
--- a/tools/codes/cgnsview.cpp
+++ b/tools/codes/cgnsview.cpp
@@ -245,6 +245,7 @@ void CgnsView::SetUpCgnsInfo()
     QString fileName = "D:/work/cgns_work/cgnsgrid_example/yf17_hdf5.cgns";
     //QString fileName = "D:/work/cgns_work/ModernCGNS/codes/UserGuideCode/read_complex/complex_data.cgns";
     //QString fileName = "D:/work/cgns_work/ModernCGNS/codes/UserGuideCode/cg_link_write/grid/links.cgns";
+    //QString fileName = "D:/work/cgns_work/ModernCGNS/codes/UserGuideCode/cg_base_read/example.cgns";
 
     ::ReadCgnsFile( fileName.toLatin1().data() );