private void BFS(Digraph G, IEnumerable <int> sources)
{
Queue <int> q = new Queue <int>();
foreach (int source in sources)
{
q.Enqueue(source);
}
while (!(q.Count == 0))
{
int v = q.Dequeue();
foreach (int w in G.Adj(v))
{
if (!marked[w])
{
q.Enqueue(w);
marked[w] = true;
edgeTo[w] = v;
}
}
}
}
