1332 上白泽慧音

#include<cstdio>
#include<algorithm>
#include<vector>
#include<stack>
using namespace std;
const int N=1e5+10;
struct node{
    int w;
    vector<int>p;
    void px(){sort(p.begin(),p.end());}
    bool operator < (const node &a) const{
        if(w==a.w){
            for(int i=0;i<w;i++){
                if(p[i]==a.p[i]) continue;
                return p[i]<a.p[i];
            }
        }
        return w>a.w;
    }
}ans[N];
int pd,sd,dfn[N],low[N];
bool mark[N];
vector<int>grap[N];
stack<int>s;
inline const int read(int &x){
    register char ch=getchar();x=0;
    while(ch<‘0‘||ch>‘9‘) ch=getchar();
    while(ch>=‘0‘&&ch<=‘9‘) x=(x<<3)+(x<<1)+ch-‘0‘,ch=getchar();
}
void tarjan(int v){
    dfn[v]=low[v]=++pd;
    mark[v]=1;
    s.push(v);
    for(int i=0;i<grap[v].size();i++){
        int w=grap[v][i];
        if(!dfn[w]){
            tarjan(w);
            low[v]=min(low[v],low[w]);
        }
        else if(mark[w]){
            low[v]=min(low[v],dfn[w]);
        }
    }
    int u;
    if(dfn[v]==low[v]){
        sd++;
        do{
            u=s.top();
            s.pop();
            ans[sd].w++;
            ans[sd].p.push_back(u); 
            mark[u]=0;
        }while(u!=v);
    }
}
int main(){
    int n,m,x,y,z;
    read(n);read(m);
    for(int i=1;i<=m;i++){
        read(x);read(y);read(z);
        if(x==y) continue;
        if(z==1) grap[x].push_back(y); 
        else grap[x].push_back(y),grap[y].push_back(x); 
    }
    for(int i=1;i<=n;i++) if(!dfn[i]) tarjan(i);
    sort(ans+1,ans+sd+1);
    ans[1].px();
    printf("%d\n",ans[1].w);
    for(int i=0;i<ans[1].w;i++) printf("%d ",ans[1].p[i]);
    return 0;
}