这个人并不懒，可这里确实是空的呀 ╰(*°▽°*)╯ #include<bits/stdc++.h> #define ll long long #define vt vector #define pb push_back #define endl '\n' using namespace std; const ll N=1e4+10; ll n; vt<ll>p[N]; ll sz[N],vis[N]; void dfs(ll x,ll fa){ sz[x]=1; for(auto v:p[x]){ if(v==fa) continue; dfs(v,x); sz[x]+=sz[v]; if(sz[v]>n/2) vis[x]=1; } if(n-sz[x]>n/2) vis[x]=1; } int main(){ cin>>n; for(ll i=1;i<=n;++i){ ll g,u; cin>>g>>u; p[g].pb(u); p[u].pb(g); } dfs(1,0); ll f=0; for(ll i=1;i<=n;++i){ if(!vis[i]){ cout<<i<<endl; f=1; } } if(!f) cout<<"NONE"; }