undo relaxed lifting. Set binsolval to be fractional for simple case

Author: Opt-Mucca

highs/mip/HighsCutGeneration.cpp

@@ -576,16 +576,6 @@ bool HighsCutGeneration::separateLiftedFlowCover() {
   }
   ld.t++;
 
-  const HighsSolution& lpSolution = lpRelaxation.getLpSolver().getSolution();
-  auto getLpSolution = [&](const HighsInt col) {
-    HighsInt numCols = lpRelaxation.numCols();
-    if (col < numCols) {
-      return lpSolution.col_value[col];
-    } else {
-      return lpSolution.row_value[col - numCols];
-    }
-  };
-
   auto getAlphaBeta = [&](double vubcoef) {
     HighsInt alpha;
     HighsCDouble beta{};
@@ -706,14 +696,6 @@ bool HighsCutGeneration::separateLiftedFlowCover() {
       assert(alphabeta.first == 0 || alphabeta.first == 1);
       if (alphabeta.first == 1) {
         assert(alphabeta.second > 0);
-        // Do not lift the column if doing so decreases the violation
-        double viol = snfr.aggrConstant[i];
-        if (snfr.origContCols[i] != -1 && snfr.aggrContCoef[i] != 0) {
-          viol += snfr.aggrContCoef[i] * getLpSolution(snfr.origContCols[i]);
-        }
-        viol += (snfr.aggrBinCoef[i] - static_cast<double>(alphabeta.second)) *
-                (snfr.binSolval[i]);
-        if (viol <= 0) continue;
         if (snfr.origContCols[i] != -1 && snfr.aggrContCoef[i] != 0) {
           vals[rowlen] = snfr.aggrContCoef[i];
           inds[rowlen] = snfr.origContCols[i];

highs/mip/HighsTransformedLp.cpp

@@ -876,10 +876,10 @@ bool HighsTransformedLp::transformSNFRelaxation(
           aggrvbcoef = static_cast<double>(vals[i] * (HighsCDouble(ub) - lb));
           aggrconstant = static_cast<double>(HighsCDouble(vals[i]) * ub);
           if (vals[i] >= 0) {
-            addSNFRentry(-1, col, 1.0, -1, aggrvbcoef, aggrconstant, 0,
+            addSNFRentry(-1, col, (ub - getLpSolution(col)) / (ub - lb), -1, aggrvbcoef, aggrconstant, 0,
                          -vals[i], false);
           } else {
-            addSNFRentry(-1, col, 1, 1, -aggrvbcoef, -aggrconstant, 0, vals[i],
+            addSNFRentry(-1, col, (ub - getLpSolution(col)) / (ub - lb), 1, -aggrvbcoef, -aggrconstant, 0, vals[i],
                          false);
           }
           tmpSnfrRhs -= aggrconstant;
@@ -893,10 +893,10 @@ bool HighsTransformedLp::transformSNFRelaxation(
           aggrvbcoef = static_cast<double>(vals[i] * (HighsCDouble(ub) - lb));
           aggrconstant = static_cast<double>(HighsCDouble(vals[i]) * lb);
           if (vals[i] >= 0) {
-            addSNFRentry(-1, col, 1, 1, aggrvbcoef, -aggrconstant, 0, vals[i],
+            addSNFRentry(-1, col, (getLpSolution(col) - lb) / (ub - lb), 1, aggrvbcoef, -aggrconstant, 0, vals[i],
                          false);
           } else {
-            addSNFRentry(-1, col, 1, -1, -aggrvbcoef, aggrconstant, 0, -vals[i],
+            addSNFRentry(-1, col, (getLpSolution(col) - lb) / (ub - lb), -1, -aggrvbcoef, aggrconstant, 0, -vals[i],
                          false);
           }
           tmpSnfrRhs -= aggrconstant;