版权声明:本文为博主原创文章。 https://blog.csdn.net/qq_37657307/article/details/84582625
#include<cstdio>
#include<algorithm>
#include<cstring>
#include<vector>
using namespace std;
vector<int>g[20005];
int n,m,cnt;
int low[20005],dfn[20005],fa[20005];
bool f1[20005];
inline void dfs(int x)
{
low[x]=dfn[x]=++cnt;
int num=0;
for(int i=0;i<g[x].size();i++)
{
int v=g[x][i];
if(!dfn[v])
{
num++;
fa[v]=x;//
dfs(v);
low[x]=min(low[x],low[v]);//
if(!fa[x]&&num>1)
f1[x]=1;
if(fa[x]&&low[v]>=dfn[x])//
f1[x]=1;
//if(low[v]>dfn[x])
}
else if(fa[x]!=v)//
low[x]=min(low[x],dfn[v]);
}
}
int main()
{
scanf("%d%d",&n,&m);
for(int i=1;i<=m;i++)
{
int x,y;
scanf("%d%d",&x,&y);
g[x].push_back(y);
g[y].push_back(x);
}
for(int i=1;i<=n;i++)
if(!dfn[i])
dfs(i);
int ans=0;
for(int i=1;i<=n;i++)
if(f1[i])
ans++;
printf("%d\n",ans);
for(int i=1;i<=n;i++)
if(f1[i])
printf("%d ",i);
}