Submission #1209859

#	Time	Username	Problem	Language	Result	Execution time	Memory
1209859		Acanikolic	Marriage questions (IZhO14_marriage)	C++20	62 / 100	1595 ms	2520 KiB

marriage

#include <bits/stdc++.h>

using namespace std;

const int N = 3e4 + 10;

const int M = 2010;

bool was[N + M];
int n, m, k, mt[N + M];
vector<int> g[N + M];
vector<pair<int, int>> e;

bool kuhn(int x) {
  if(was[x]) return false;
  was[x] = true;
  for(int j : g[x]) {
    if(mt[j] == -1 || kuhn(mt[j])) {
      mt[j] = x;
      return true;
    }
  }
  return false;
}

int max_matching(int l, int r) {
  for(int i = 1; i <= n + m; i++) {
    was[i] = false;
    mt[i] = -1;
    g[i].clear();
  }
  for(auto x : e) {
    if(x.first >= l && x.first <= r) {
      g[x.second].push_back(x.first + m);
      g[x.first + m].push_back(x.second);
    }
  }
  for(int i = 1; i <= m; i++) {
    for(int j = 1; j <= m; j++) was[j] = false;
    kuhn(i);
  }
  int cnt = 0;
  for(int i = 1; i <= n + m; i++) if(mt[i] != -1) cnt++;
  return cnt;
}

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);

  cin >> n >> m >> k;
  for(int i = 1; i <= k; i++) {
    int u, v;
    cin >> u >> v;
    e.push_back({u, v});
  }
  int res = 0;
  for(int i = 1; i <= n; i++) {
    int l = 1, r = i, ans = -1;
    while(l <= r) {
      int mid = l + r >> 1;
      if(max_matching(mid, i) == m) {
        ans = mid;
        l = mid + 1;
      } else {
        r = mid - 1;
      }
    }
    if(ans == -1) continue;
    res += ans;
  }
  cout << res;
  return 0;
}

• Subtask 1: 62 / 100