public LayeredTopologicalSortAlgorithm(IVertexAndEdgeListGraph <TVertex, TEdge> g)
: base(g)
{
tmpGraph = new BidirectionalGraph <TVertex, TEdge>();
//create a copy from the graph
tmpGraph.AddVertexRange(g.Vertices);
foreach (var e in g.Edges)
{
tmpGraph.AddEdge(e);
}
}