Submission #899213

#	Time	Username	Problem	Language	Result	Execution time	Memory
899213		MilosMilutinovic	Marriage questions (IZhO14_marriage)	C++14	66 / 100	1595 ms	4000 KiB

marriage

#include <bits/stdc++.h>

using namespace std;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n, m, k;
  cin >> n >> m >> k;
  vector<vector<int>> g(m);
  vector<vector<int>> r(n);
  for (int i = 0; i < k; i++) {
    int x, y;
    cin >> x >> y;
    --x; --y;
    g[y].push_back(x);
    r[x].push_back(y);
  }
  for (int i = 0; i < m; i++) {
    sort(g[i].begin(), g[i].end());
  }
  vector<int> f(m);
  int ptr = 0;
  auto Good = [&]() {
    vector<bool> used(m);
    vector<int> to(n, -1);
    function<bool(int)> Dfs = [&](int v) {
      if (used[v]) {
        return false;
      }
      used[v] = true;
      for (int j = f[v]; j < (int) g[v].size(); j++) {
        if (g[v][j] > ptr) {
          break;
        }
        if (to[g[v][j]] == -1 || Dfs(to[g[v][j]])) {
          to[g[v][j]] = v;
          return true;
        }
      }
      return false;
    };
    for (int i = 0; i < m; i++) {
      for (int j = 0; j < m; j++) {
        used[j] = false;
      }
      Dfs(i);
    }
    int cnt = 0;
    for (int i = 0; i < n; i++) {
      if (to[i] != -1) {
        cnt += 1;
      }
    }
    return cnt == m;
  };
  long long res = 0;
  for (int i = 0; i < n; i++) {
    while (ptr < n && (ptr - i + 1 < m || !Good())) {
      ptr += 1;
    }
    res += n - ptr;
    for (int j : r[i]) {
      f[j] += 1;
    }
  }
  cout << res << '\n';
  return 0;
}

• Subtask 1: 66 / 100