Submission #711615

#	Time	Username	Problem	Language	Result	Execution time	Memory
711615		Sam_a17	Marriage questions (IZhO14_marriage)	C++17	100 / 100	367 ms	3288 KiB

marriage

#define _CRT_SECURE_NO_WARNINGS
#include <bits/stdc++.h>
//#include "temp.cpp"
#include <cstdio>
using namespace std;

#ifndef ONLINE_JUDGE
#define dbg(x) cerr << #x <<" "; print(x); cerr << endl;
#else
#define dbg(x)
#endif

#define sz(x) (int((x).size()))
#define len(x) (int)x.length()
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define clr(x) (x).clear()
#define uniq(x) x.resize(unique(all(x)) - x.begin());
#define blt(x) __builtin_popcount(x)

#define pb push_back
#define popf pop_front
#define popb pop_back

void print(long long t) {cerr << t;}
void print(int t) {cerr << t;}
void print(string t) {cerr << t;}
void print(char t) {cerr << t;}
void print(double t) {cerr << t;}
void print(long double t) {cerr << t;}
void print(unsigned long long t) {cerr << t;}

template <class T, class V> void print(pair <T, V> p);
template <class T> void print(vector <T> v);
template <class T> void print(set <T> v);
template <class T, class V> void print(map <T, V> v);
template <class T> void print(multiset <T> v);
template <class T, class V> void print(T v[],V n) {cerr << "["; for(int i = 0; i < n; i++) {print(v[i]); cerr << " "; } cerr << "]";}
template <class T, class V> void print(pair <T, V> p) {cerr << "{"; print(p.first); cerr << ","; print(p.second); cerr << "}";}
template <class T> void print(vector <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T> void print(set <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T> void print(multiset <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T, class V> void print(map <T, V> v) {cerr << "[ "; for (auto i : v) {print(i); cerr << " ";} cerr << "]";}

#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
#define nl '\n'

// for grid problems
int dx[8] = {-1,0,1,0,1,-1,1,-1};
int dy[8] = {0,1,0,-1,1,1,-1,-1};

// lowest / (1 << 17) >= 1e5 / (1 << 18) >= 2e5 / (1 << 21) >= 1e6
void fastIO() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr); cout.tie(nullptr);
}
// file in/out
void setIO(string str = "") {
  fastIO();

  if (str != "") {
    freopen((str + ".in").c_str(), "r", stdin);
    freopen((str + ".out").c_str(), "w", stdout);
  }
}
// Indexed Set
template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
const int N = 5e4 + 10;
vector<int> adj[N];
int n, m, k, mt[N];
bool used[N];

int khun(int node, int lim_down, int lim_up) {
  if(used[node]) {
    return false;
  }
  used[node] = true;
  for(auto i: adj[node]) {
    
    if(i > lim_up) {
      break;
    }
    
    if(i < lim_down) {
      continue;
    }

    if(mt[i] == -1 || khun(mt[i], lim_down, lim_up)) {
      mt[i] = node;
      return true;
    }
  }
  return false;
}

void solve_() {
  cin >> n >> m >> k;

  for(int i = 1; i <= k; i++) {
    int a, b; cin >> a >> b;
    a += m;
    adj[a].push_back(b);
    adj[b].push_back(a);
  }

  for(int i = 1; i <= m; i++) {
    sort(all(adj[i]));
  }

  int ina = m, inb = n, ans = -1;
  while(ina <= inb) {
    int mid = (ina + inb) / 2;
    
    int cnt = 0;
    for(int i = 1; i <= mid; i++) {
      mt[i + m] = -1;
    }

    for(int i = 1; i <= m; i++) {
      for(int j = 1; j <= m; j++) {
        used[j] = false;
      }
      cnt += khun(i, 0, mid + m);
    }

    if(cnt == m) {
      ans = mid;
      inb = mid - 1;
    } else {
      ina = mid + 1;
    }
  }

  if(ans == -1) {
    cout << 0 << endl;
    return;
  }


  {
    for(int i = 1; i <= n; i++) {
      mt[i + m] = -1;
    }

    for(int i = 1; i <= m; i++) {
      for(int j = 1; j <= m; j++) {
        used[j] = false;
      }
      khun(i, 0, ans + m);
    }
  }

  int answ = n - ans + 1;

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

    int who = mt[i + m];
    while(r <= n) {
      for(int j = 1; j <= m; j++) {
        used[j] = false;
      }
      int c = khun(who, i + m + 1, r + m);
      if(c) break;
      r++;
    }

    //
    if(r <= n) {
      answ += n - r + 1;
    } else {
      break;
    }
  }

  cout << answ << endl;
}

int main() {
  setIO();

  auto solve = [&](int test_case)-> void {
    while(test_case--) {
      solve_();
    }
  };

  int test_cases = 1;
  // cin >> test_cases;
  solve(test_cases);

  return 0;
}

Compilation message (stderr)

marriage.cpp: In function 'void setIO(std::string)':
marriage.cpp:63:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   63 |     freopen((str + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
marriage.cpp:64:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   64 |     freopen((str + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 100 / 100