void Find(DirectedGraph graph)
{
//1. Postorder + stack
//2. Reverse graph
//3. Classic DFS
//1. Postorder
var stack = new Stack <int>();
bool[] visited = new bool[graph.V];
for (int i = 0; i < graph.V; i++)
{
if (!visited[i])
{
PostOrder(i, stack, visited, graph);
}
}
//2. Reverse graph
var reversed = graph.Reverse();
//3. Classic DFS
visited.Fill(false);
while (stack.Count > 0)
{
var vertex = stack.Pop();
if (!visited[vertex])
{
var scc = new StronglyConnectedComponent();
FillStronglyConnectedComponent(vertex, visited, reversed, scc);
StronglyConnectedComponents.Add(scc);
}
}
}
void FillStronglyConnectedComponent(int vertex, bool[] visited, DirectedGraph graph, StronglyConnectedComponent scc)
{
visited[vertex] = true;
scc.Vertices.Add(vertex);
foreach (var adj in graph.GetVertexAdjcency(vertex))
{
if (!visited[adj])
{
FillStronglyConnectedComponent(adj, visited, graph, scc);
}
}
}