Submission #713374

#	Time	Username	Problem	Language	Result	Execution time	Memory
713374		YENGOYAN	Marriage questions (IZhO14_marriage)	C++17	100 / 100	853 ms	3036 KiB

marriage

/*
                                    //\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\\
                                    \\                                    //
                                    //  271828___182845__904523__53602__  \\
                                    \\  87___47____13______52____66__24_  //
                                    //  97___75____72______47____09___36  \\
                                    \\  999595_____74______96____69___67  //
                                    //  62___77____24______07____66__30_  \\
                                    \\  35___35____47______59____45713__  //
                                    //                                    \\
                                    \\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\//
*/
#include <iostream>
#include <vector>
#include <set>
#include <map>
#include <unordered_map>
#include <unordered_set>
#include <cmath>
#include <climits>
#include <algorithm>
#include <random>
#include <queue>
#include <deque>
#include <iomanip>
#include <string>
#include <tuple>
#include <bitset>
#include <chrono>
#include <ctime>
#include <fstream>
#include <stack>
#include <cstdio>
#include <functional>

using namespace std;
using LL = long long;
const int N = 1e3 + 5;
const LL mod = 998244353, inf = 1e18;

vector<int> dx = { 1, 0, -1, 0, 1, -1, 1, -1 };
vector<int> dy = { 0, -1, 0, 1, -1, 1, 1, -1 };

void solve() {
  int n, m, k; cin >> n >> m >> k;
  vector<vector<int>> gp(n + m);
  for (int i = 0; i < k; ++i) {
    int u, v; cin >> u >> v;
    u += m;
    gp[--u].push_back(--v);
    gp[v].push_back(u);
  }

  int ans = 0;

  vector<int> mt(n + m, -1);
  vector<bool> vis(n + m);

  function<bool(int, int, int)> kuhn = [&](int u, int l, int r) {
    if (vis[u]) return 0;
    vis[u] = 1;
    for (int& v : gp[u]) {
      if (v < l || v > r) continue;
      if (mt[v] == -1 || kuhn(mt[v], l, r)) {
        mt[v] = u;
        return 1;
      }
    }
    return 0;
  };

  int l = m - 5, r = n + 5, idx = -1;
  while (l + 1 < r) {
    int mid = (l + r) / 2;
    
    mt = vector<int>(n + m, -1);

    int cnt = 0;
    for (int i = 0; i < m; ++i) {
      vis = vector<bool>(n + m);
      cnt += kuhn(i, 0, m + mid);
    }
    if(cnt == m){
      r = mid;
      idx = mid;
    }
    else {
      l = mid;
    }
  }

  if (idx == -1) {
    cout << "0\n";
    return;
  }

  ans += n - idx;

  mt = vector<int>(n + m, -1);
  
  for (int i = 0; i < m; ++i) {
    vis = vector<bool>(n + m);
    kuhn(i, m, idx + m);
  }

  for (int i = 0; i < n; ++i) {
    if (mt[i + m] == -1) {
      ans += n - idx;
      continue;
    }

    int u = mt[i + m];
    while (idx < n) {
      vis = vector<bool>(n + m);
      if (kuhn(u, i + 1 + m, idx + m)) break;
      ++idx;
    }
    if (idx == n) break;
    ans += n - idx;
  }

  cout << ans << "\n";
}

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  //int t; cin >> t; while (t--)
  solve();
}

• Subtask 1: 100 / 100