Submission #1049365

#	Time	Username	Problem	Language	Result	Execution time	Memory
1049365		duckindog	Joker (BOI20_joker)	C++17	0 / 100	1 ms	600 KiB

Joker

#include <bits/stdc++.h>

using namespace std;

const int N = 5'000 + 10;
int n, m, q;
pair<int, int> edge[N];

int id[N], cnt;
int root(int u) { return id[u] < 0 ? u : id[u] = root(id[u]); }
void add(int u, int v) { 
  u = root(u); v = root(v);
  if (u == v) { 
    cnt += 1;
    return;
  }
  id[u] += id[v];
  id[v] = u;
}

int32_t main() { 
  cin.tie(0)->sync_with_stdio(0);

  cin >> n >> m >> q;
  for (int i = 1; i <= m; ++i) cin >> edge[i].first >> edge[i].second;

  while (q--) { 
    memset(id, -1, sizeof id);
    cnt = 0;

    int l, r; cin >> l >> r;
    for (int i = 1; i < l; ++i) add(edge[i].first, edge[i].second);
    for (int i = m; i > r; --i) add(edge[i].first, edge[i].second);
    
    cout << (cnt ? "YES" : "NO") << "\n";
  }

}

• Subtask 1: 0 / 6
• Subtask 2: 0 / 8
• Subtask 3: 0 / 25
• Subtask 4: 0 / 10
• Subtask 5: 0 / 22
• Subtask 6: 0 / 29