public static System.Collections.Generic.IEnumerable <T> Sort <T, E>
(IGraph <T, E> graph, IEnumerable <T> source)
where E : IEdge <T>
{
Dictionary <T, bool> Visited = new Dictionary <T, bool>();
StackQueue <T> Stack = new StackQueue <T>();
foreach (T v in graph.Vertices)
{
Visited[v] = false;
}
foreach (T v in source)
{
Stack.Push(v);
}
while (Stack.Count != 0)
{
T u = Stack.Pop();
Visited[u] = true;
yield return(u);
foreach (T v in graph.ReversePredecessors(u))
{
if (!Visited[v] && !Stack.Contains(v))
{
Stack.Push(v);
}
}
}
}