自认为Tarjan写的没问题

求条

#include<bits/stdc++.h>
using namespace std;
const int maxn=5e5+5;
int n,m;
vector<int> E[maxn];
int dfn[maxn],low[maxn],num,cnt,ans[maxn],size[maxn];
inline void tarjan(int u,int fa){
    dfn[u]=low[u]=++num;
    long long sum=0;
    size[u]=1;
    int s=0;
    for(auto v:E[u]){
        if(!dfn[v]){
            s++;
            tarjan(v,u);
            size[u]+=size[v];
            low[u]=min(low[v],low[u]);
            if(low[v]>=dfn[u]){
                ans[u]+=size[v]*sum;
				sum+=size[v];
            }
        }else if(v!=fa){
            low[u]=min(low[u],dfn[v]);
        }
    }
    ans[u]+=(n-sum-1)*sum;
	ans[u]+=n-1;
}
int main(){
    
    scanf("%d%d",&n,&m);
    for(int i=0;i<m;i++){
        int u,v;
        cin>>u>>v;
        E[u].push_back(v);
        E[v].push_back(u);
    }
    tarjan(1,0);
    for(int i=1;i<=n;++i){
		cout<<ans[i]*2;
		putchar('\n');
	}
    
    return 0;
}