Files
OI-source/1.3388.cpp
2023-08-03 09:22:52 +08:00

49 lines
1006 B
C++

#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
const int maxn=100005;
struct Edge { int v; Edge *next; };
Edge *G[maxn],mem[maxn*2],*ecnt=mem;
void AddEdge(int u,int v) { ecnt->v=v; ecnt->next=G[u]; G[u]=ecnt++; }
int n,m,x,y;
int low[maxn],dfn[maxn],dfs_clock;
bool iscut[maxn];
int dfs(int u,int fa)
{
int lowu=dfn[u]=++dfs_clock,child=0;
for(Edge *it=G[u];it;it=it->next)
{
int v=it->v;
if(!dfn[v])
{
++child;
int lowv=dfs(v,u);
lowu=min(lowu,lowv);
if(lowv>=dfn[u]) iscut[u]=true;
}
else if(dfn[v]<dfn[u]&&v!=fa) lowu=min(lowu,dfn[v]);
}
if(fa<0&&child<=1) iscut[u]=false;
return lowu;
}
int main()
{
#ifdef local
freopen("pro.in","r",stdin);
#endif
scanf("%d%d",&n,&m);
while(m-->0)
{
scanf("%d%d",&x,&y);
AddEdge(x,y); AddEdge(y,x);
}
for(int i=1;i<=n;i++) if(!dfn[i]) dfs(i,-1);
int sum=0;
for(int i=1;i<=n;i++) sum+=iscut[i];
printf("%d\n",sum);
for(int i=1;i<=n;i++) if(iscut[i]) printf("%d ",i);
printf("\n");
return 0;
}