private void Dfs(Digraph dg, int v)
{
preQueue.Enqueue(v);
marked[v] = true;
foreach (int w in dg.Adj(v))
{
if (!marked[w])
{
Dfs(dg, w);
}
}
postQueue.Enqueue(v);
reversePost.Push(v);
}
public KosarajuSCC(Digraph g)
{
marked = new bool[g.V()];
id = new int[g.V()];
// 以g的 逆后序 遍历g中的节点，然后记录s可达的点
//原理： { s可达的Vi } 交 { 逆后序中比s早结束的Vj } =》 强连通分量
DepthFirstOrder order = new DepthFirstOrder(g.Reverse());
foreach (int s in order.Reverse)
{
if (!marked[s])
{
Dfs(g, s);
count++;
}
}
}
static void Main(string[] args)
{
Digraph g = new Digraph(9);
//g.Visualize()
g.AddEdge(0, 2);
g.AddEdge(0, 6);
g.AddEdge(1, 0);
g.AddEdge(2, 3);
g.AddEdge(2, 4);
g.AddEdge(3, 4);
g.AddEdge(3, 2);
g.AddEdge(4, 5);
g.AddEdge(4, 6);
g.AddEdge(5, 0);
g.AddEdge(5, 3);
g.AddEdge(6, 7);
g.AddEdge(7, 8);
g.AddEdge(8, 7);
var topo = new Topological(g);
Console.WriteLine("Order: ");
foreach (int s in topo.Order)
{
Console.Write(s + " ");
}
Console.WriteLine("\nReverOrder: ");
DepthFirstOrder order = new DepthFirstOrder(g.Reverse());
foreach (int s in order.Reverse)
{
Console.Write(s + " ");
}
KosarajuSCC ks = new KosarajuSCC(g);
Console.WriteLine($"\nks:{ks.Count()}");
}
public DirectedDFS(Digraph g, int s)
{
_marked = new bool[g.V()];
Dfs(g, s);
}
public Topological(Digraph dg)
{
DepthFirstOrder dfo = new DepthFirstOrder(dg);
_order = dfo.Reverse;
}