贴板子。求割边。将>改为>=即可判断u是否为割点。

#include
     
      #include
      
       #include
       
        using namespace std;const int INF=0x3f3f3f3f;const int maxn=20008;const int maxm=100008;struct fuck{	int u,v,next;	bool ban;}edge[maxm<<1];int tol;int head[maxn];void init(){	tol=0;	memset(head,-1,sizeof(head));}void addedge(int u,int v){	edge[tol].u=u;	edge[tol].v=v;	edge[tol].next=head[u];	edge[tol].ban=false;	head[u]=tol++;}int tim=0;int pre[maxn],low[maxn];int tarj(int u,int fa){	int lowu=pre[u]=++tim;	int child=0;	int i,v,lowv;	for(i=head[u];i!=-1;i=edge[i].next)	{		v=edge[i].v;		if(!pre[v])		{			child++;			lowv=tarj(v,u);			lowu=min(lowu,lowv);			if(lowv>pre[u])			{				edge[i].ban=true;				edge[i^1].ban=true;			}		}		else	if(pre[v]