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  1. /*
  2. *       author :  3hmed_124M
  3. */
  4. #include <bits/stdc++.h>
  5. #include <string>
  6. using namespace std;
  7. #define ll     long long
  8. #define int    long long
  9. #define el     '\n'
  10. #define all(v) v.begin(), v.end()
  11. const int mod = 1e9 + 7, OO = 0x3f3f3f3f;
  12. const int dx[] = {1, -1, 0, 0, 1, 1, -1, -1};
  13. const int dy[] = {0, 0, 1, -1, 1, -1, 1, -1};
  14. const char di[] = {'U', 'R', 'L', 'D'};
  15.  
  16. void solve() {
  17.     int n, m;
  18.     cin >> n >> m;
  19.     vector<vector<int> > graph(n + 1);
  20.     for (int i = 0; i < m; ++i) {
  21.         int x, y;
  22.         cin >> x >> y;
  23.         graph[y].push_back(x);
  24.     }
  25.     vector<bool> visited(n + 1, false);
  26.     int q;
  27.     cin >> q;
  28.     while (q--) {
  29.         int x, y;
  30.         cin >> x >> y;
  31.         if (x == 1) {
  32.             if (visited[y]) continue;
  33.             queue<int> q;
  34.             visited[y] = true;
  35.             q.push(y);
  36.             while (!q.empty()) {
  37.                 int u = q.front();
  38.                 q.pop();
  39.                 for (auto v: graph[u]) {
  40.                     if (!visited[v]) {
  41.                         visited[v] = true;
  42.                         q.push(v);
  43.                     }
  44.                 }
  45.             }
  46.         } else if (x == 2) {
  47.             if (visited[y]) {
  48.                 cout << "YES" << el;
  49.             } else {
  50.                 cout << "NO" << el;
  51.             }
  52.         }
  53.     }
  54. }
  55.  
  56. int32_t main() {
  57.     ios_base::sync_with_stdio(false);
  58.     cout.tie(nullptr), cin.tie(nullptr);
  59.  
  60.     // if(fopen("in.txt", "r")){
  61.     //     freopen("in.txt", "r", stdin);
  62.     //     freopen("out.txt", "w", stdout);
  63.     // }
  64.  
  65.     int tt = 1;
  66.     //cin >> tt;
  67.     while (tt--) {
  68.         solve();
  69.     }
  70.  
  71.     return 0;
  72. }
  73.  
Success #stdin #stdout 0s 5320KB
comments (?)
stdin 
Standard input is empty
stdout 
Standard output is empty
https://ideone.com/Zv7waS
language:
C++ (gcc 8.3)
created:
2 days ago
visibility:
public

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