/// <summary>Finds strongly connected components in given directed graph.</summary>
/// <param name="graph">The directed graph.</param>
/// <returns>List of vertices in strongly connected components.</returns>
public static List <HashSet <Vertex <TVertexId> > > FindScc <TVertexId, TVertexProperty, TEdgeProperty>(
this IDirectedGraph <TVertexId, TVertexProperty, TEdgeProperty> graph)
{
var postOrderStrategy = new PostOrderStrategy <TVertexId>();
Searching.DfsRecursive(graph, postOrderStrategy, graph.Vertices);
var vertices = postOrderStrategy.postTimes
.OrderByDescending(kv => kv.Value)
.Select(kv => kv.Key)
.ToList();
IDirectedGraph <TVertexId, TVertexProperty, TEdgeProperty> reversedGraph = graph.ReversedCopy();
var sccStrategy = new SCCStrategy <TVertexId>();
Searching.DfsRecursive(reversedGraph, sccStrategy, vertices);
return(sccStrategy.components);
}