hdu 1269

hdu 1269强连同分量，赤裸裸的算法，我只用一种方法写，留着以后当模板。。具体算法是如何实现的？我就不讲了，直接百度或是看算法导论都有

#include <iostream>#include <string>#include <vector>using namespace std;int n,m,cnt,k;vector<int>G[10001];vector<int>G1[10001];int vis[10001],ord[10001];void dfs(int cur){int i;//memset(vis,0,sizeof(vis));vis[cur] = 1;for(i = 0; i<G[cur].size(); i++)if(!vis[G[cur][i]])dfs(G[cur][i]);ord[k++] = cur;}void dfs1(int cur){int i;vis[cur] = 1;for(i = 0; i<G1[cur].size(); i++)if(!vis[G1[cur][i]])dfs1(G1[cur][i]);}int main(){int i,u,v,cnt,ct;while(scanf("%d %d",&n,&m)!=EOF){if(n == 0 && m == 0)break;for(i = 0; i<=n; i++){G[i].clear();G1[i].clear();}for(i = 0; i<m; i++){scanf("%d %d",&u,&v);G[u].push_back(v);G1[v].push_back(u);}k = ct = 0;memset(vis,0,sizeof(vis));for(i = 1; i<=n; i++)if(!vis[i])dfs(i);//cout<<k<<endl;memset(vis,0,sizeof(vis));for(i = k - 1; i>=0; i--)if(!vis[ord[i]]){ct++;dfs1(ord[i]);}if(ct == 1)puts("Yes");else puts("No");}return 0;}