[Lemon-user] Topological sort of a subgraph

[Ron Mayerson]

Hi everybody,

I'm faced with the problem of topologically sorting the nodes of a subgraph. The actual code looks something like this:

lemon::ListDigraph digraph;
// add arcs + nodes to digraph

lemon::ListDigraph::NodeMap<bool> nodeMap(digraph);
lemon::ListDigraph::ArcMap<bool> arcMap(digraph);
lemon::SubDigraph<lemon::ListDigraph> subgraph(digraph, nodeMap, arcMap);
// disable some arcs + node

if( dag(subgraph) )
{
    std::vector<lemon::SubDigraph<lemon::ListDigraph>::Node> nodes;
    lemon::LoggerBoolMap<std::back_insert_iterator<std::vector<lemon::SubDigraph<lemon::ListDigraph>::Node> > > map(std::back_inserter(nodes));
    lemon::topologicalSort(subgraph, map);

    for (std::vector<lemon::SubDigraph<lemon::ListDigraph>::Node>::reverse_iterator it = nodes.rbegin();
        it != nodes.rend(); ++it) 
    {
        // do something with node (*it)
    }
}

The last part is mainly adopted from: http://lemon.cs.elte.hu/pipermail/lemon-user/2012-August/000609.html
The problem with this solution is that one of the nodes (the root node of subgraph) does not show up when iterating through the nodes.
Does anyone have an explanation for this? Are there any other possible solutions for a topological sort of subgraph + iteration? (a code example would be great)

Thanks very much!
Ron