update ordering_driver.cpp to insert vertices in order of id

Author: bipashabg

docqueries/ordering/sloanOrdering.result

@@ -10,17 +10,17 @@ SELECT * FROM pgr_sloanOrdering(
 -----+------
    1 |    1
    2 |    3
-   3 |    6
-   4 |    5
-   5 |   10
+   3 |    8
+   4 |    9
+   5 |   12
    6 |    7
-   7 |    9
-   8 |   15
-   9 |    8
+   7 |    5
+   8 |   17
+   9 |    6
   10 |   11
   11 |   16
-  12 |   12
-  13 |   17
+  12 |   10
+  13 |   15
   14 |    1
   15 |    1
   16 |    1

src/ordering/ordering_driver.cpp

@@ -89,9 +89,15 @@ do_ordering(
 
         std::vector<int64_t> results;
 
-        pgrouting::UndirectedGraph undigraph;
+#if 0
+	pgrouting::UndirectedGraph undigraph;
+#else
+	auto vertices(pgrouting::extract_vertices(edges));
+	pgrouting::UndirectedGraph undigraph(vertices);
+#endif
         undigraph.insert_edges(edges);
 
+        // log << undigraph;
         if (which == 0) {
                 results = sloanOrdering(undigraph);
         }