E-sport อีกรอบ

#include <iostream>
#include <vector>

using namespace std;

vector<int> g[100010];
int visited[100010];
bool dfs(int x){
    if(visited[x]==1){
        return true;
    }
    visited[x]=1;
    for(auto c:g[x]){
        if(visited[c]!=2)
        if(dfs(c)){
            return true;
        }
    }
    visited[x]=2;
    return false;
}


int main(){
    int n ,m;

    cin >> n >> m;
    int u ,v;
    for(int i=1;i<=m;++i){
        cin >> u >> v;
        g[u].push_back(v);
    }
    bool check=false;
    for(int i=1;i<=n;++i){
        if(visited[i]!=2){
            if(dfs(i)){
                check=true;
                break;
            }
        }
    }

    if(check){
        cout << "Yes";
    }
    else{
        cout << "No";
    }

    return 0;
}