tarjan缩点

整理了下模板。。。

 #include<iostream>
 #include<cstdio>
 #include<cmath>
 #include<algorithm>
 #include<queue>
 #include<cstring>
 #define PAU putchar(' ')
 #define ENT putchar('\n')
 using namespace std;
 const int maxn=+,maxm=+;
 int low[maxn],dfn[maxn],s[maxn],beg[maxn],top,scc,cz;bool ins[maxn];
 struct ted{int x,y;ted*nxt;}adj[maxm],*fch[maxn],*ms=adj;
 void add(int x,int y){*ms=(ted){x,y,fch[x]};fch[x]=ms++;return;}
 void tarjan(int u){
     low[u]=dfn[u]=++cz;ins[u]=true;s[++top]=u;
     for(ted*e=fch[u];e;e=e->nxt){
         int v=e->y;if(!dfn[v])tarjan(v),low[u]=min(low[u],low[v]);
         else if(ins[v])low[u]=min(low[u],dfn[v]);
     }if(low[u]==dfn[u]){
         scc++;int t=-;while(t!=u)beg[t=s[top--]]=scc,ins[t]=false;
     }return;
 }
 inline int read(){
     int x=,sig=;char ch=getchar();
     while(!isdigit(ch)){if(ch=='-')sig=-;ch=getchar();}
     while(isdigit(ch))x=*x+ch-'',ch=getchar();
     return x*=sig;
 }
 inline void write(int x){
     if(x==){putchar('');return;}if(x<)putchar('-'),x=-x;
     int len=,buf[];while(x)buf[len++]=x%,x/=;
     for(int i=len-;i>=;i--)putchar(buf[i]+'');return;
 }
 int n,m;
 void init(){
     n=read();m=read();int x,y;
     while(m--){x=read();y=read();add(x,y);}
     for(int i=;i<=n;i++) if(!dfn[i]) tarjan(i);
     for(int i=;i<=n;i++){
         printf("%d:%d\n",i,beg[i]);
     }
     return;
 }
 void work(){
     return;
 }
 void print(){
     return;
 }
 int main(){init();work();print();return ;}
 /*
 5 5
 1 2
 2 3
 3 4
 4 5
 5 1
 */