bzoj1123 [POI2008]BLO（tarjan求割点）

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define inf 0x3f3f3f3f
#define M 500010
#define N 100010
inline int read(){
int x=0,f=1;char ch=getchar();
while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
while(ch>='0'&&
4000
amp;ch<='9') x=x*10+ch-'0',ch=getchar();
return x*f;
}
int n,m,h
,num=0,dfn
,low
,dfnum=0,fa
,sz
;
ll ans
;
struct edge{
int to,next;
}data[M<<1];
inline void add(int x,int y){data[++num].to=x;data[num].next=h[y];h[y]=num;}
void tarjan(int x){
dfn[x]=low[x]=++dfnum;sz[x]=1;int tmp=0;
for(int i=h[x];i;i=data[i].next){
int y=data[i].to;
if(fa[x]==y) continue;
if(dfn[y]) low[x]=min(low[x],dfn[y]);
else{
fa[y]=x;tarjan(y);low[x]=min(low[x],low[y]);sz[x]+=sz[y];
if(low[y]>=dfn[x]){
ans[x]+=(ll)tmp*sz[y];tmp+=sz[y];
}
}
}
ans[x]+=(ll)tmp*(n-tmp-1);
}
int main(){
//  freopen("a.in","r",stdin);
n=read();m=read();
while(m--){int x=read(),y=read();add(x,y);add(y,x);}
tarjan(1);
for(int i=1;i<=n;++i) printf("%lld\n",(ans[i]+n-1)*2);
return 0;
}