improvements

examples/dimacs_assignment.cc

@@ -139,8 +139,16 @@ int solve_dimacs_assignment(int argc, char* argv[]) {
     LOG(FATAL) << error_message;
   }
   if (!FLAGS_assignment_problem_output_file.empty()) {
-    PrintDimacsAssignmentProblem(*assignment,
+    // The following tail array management stuff is done in a generic
+    // way so we can plug in different types of graphs for which the
+    // TailArrayManager template can be instantiated, even though we
+    // know the type of the graph explicitly. In this way, the type of
+    // the graph can be switched just by changing the graph type in
+    // this file and making no other changes to the code.
+    TailArrayManager<ForwardStarGraph> tail_array_manager(graph);
+    PrintDimacsAssignmentProblem(*assignment, tail_array_manager,
                                  FLAGS_assignment_problem_output_file);
+    tail_array_manager.ReleaseTailArrayIfForwardGraph();
   }
   CostValue hungarian_cost = 0.0;
   bool hungarian_solved = false;

examples/print_dimacs_assignment.cc

@@ -37,6 +37,7 @@ static void WriteOrDie(const char* buffer,
 
 void PrintDimacsAssignmentProblem(
     const LinearSumAssignment<ForwardStarGraph>& assignment,
+    const TailArrayManager<ForwardStarGraph>& tail_array_manager,
     const string& output_filename) {
   FILE* output = fopen(output_filename.c_str(), "w");
   const ForwardStarGraph& graph(assignment.Graph());
@@ -55,6 +56,8 @@ void PrintDimacsAssignmentProblem(
                output);
   }
 
+  tail_array_manager.BuildTailArrayFromAdjacencyListsIfForwardGraph();
+
   for (ForwardStarGraph::ArcIterator arc_it(assignment.Graph());
        arc_it.Ok();
        arc_it.Next()) {

examples/print_dimacs_assignment.h

@@ -20,6 +20,7 @@ template <typename GraphType> class LinearSumAssignment;
 // http://lpsolve.sourceforge.net/5.5/DIMACS_asn.htm
 void PrintDimacsAssignmentProblem(
     const LinearSumAssignment<ForwardStarGraph>& assignment,
+    const TailArrayManager<ForwardStarGraph>& tail_array_manager,
     const string& output_filename);
 
 }  // namespace operations_research