func_code_string: #include <bits/stdc++.h>   using namespace std;   signed main() {     long long int n, m;     cin >> n >> m;     if (m == 0) {       cout << 0;       return 0;     }     vector<vector<long long int>> v[n + 1];     long long int in[n + 1];     memset(in, 0, sizeof(in));     for (long long int i = 0; i < m; i++) {       long long int x, y, z;       cin >> x >> y >> z;       v[x].push_back({y, z});       in[y] += 1;     }     queue<vector<long long int>> q;     for (long long int i = 1; i <= n; i++) {       if (in[i] == 0 && v[i].size()) {         q.push({i, INT_MAX, i});       }     }     vector<vector<long long int>> ans;     while (q.size()) {       vector<long long int> p = q.front();       q.pop();       if (p.size() && v[p[0]].size() == 0) {         ans.push_back({p[2], p[0], p[1]});       }       for (auto x : v[p[0]]) {         in[x[0]] -= 1;         if (in[x[0]] == 0) {           q.push({x[0], min(p[1], x[1]), p[2]});         }       }     }     cout << ans.size() <<   n ;     sort(ans.begin(), ans.end());     for (auto x : ans) {       for (auto y : x) cout << y <<    ;       cout <<   n ;     }   }   