Tarjan 求强连通分量模板 

 1 vector<int> G[MAXN];
 2 int dfn[MAXN], low[MAXN], instk[MAXN], sccno[MAXN], ans[MAXN];
 3 stack<int> S;
 4 int Time, cnt ,n, res;
 5 void Tarjan(int u)
 6 {
 7     dfn[u] = low[u] = ++Time;
 8     S.push(u);
 9     instk[u] = 1;
10     for (int i = 0; i < G[u].size(); ++i) {
11         int v = G[u][i];
12         if (!dfn[v]) {
13             Tarjan(v);
14             low[u] = min(low[u], low[v]);
15         }
16         else if (instk[v]) {
17             low[u] = min(low[u], dfn[v]);
18         }
19     }
20     if (low[u] == dfn[u]) {
21         cnt++;
22         int v;
23         do{
24             v = S.top();
25             S.pop();
26             instk[v] = 0;
27             sccno[v] = cnt;
28         } while (v != u);
29     }
30 }
31 
32 void find_scc()
33 {
34     for (int i = 1; i <= n; ++i)
35         if (!dfn[i]) Tarjan(i);
36 }

 

posted @ 2015-03-08 19:53  UsedRose  阅读(195)  评论(0)    收藏  举报