Submission #387477

#	Time	Username	Problem	Language	Result	Execution time	Memory
387477		WLZ	Carnival Tickets (IOI20_tickets)	C++14	76 / 100	3060 ms	178284 KiB

tickets

#include "tickets.h"
#include <bits/stdc++.h>
using namespace std;

long long find_maximum(int k, vector< vector<int> > x) {
  int n = (int) x.size(), m = (int) x[0].size();
  long long ans = 0;
  vector<int> ptr1(n, k - 1), ptr2(n, m - 1);
  vector< vector< pair<int, int> > > sorted(n);
  for (int i = 0; i < n; i++) for (int j = 0; j < m; j++) sorted[i].push_back({x[i][j], j});
  priority_queue< pair<int, int> > pq;
  vector< set<int> > plus(n), minus(n);
  for (int i = 0; i < n; i++) {
    sort(sorted[i].begin(), sorted[i].end());
    for (int j = 0; j < k; j++) ans -= sorted[i][j].first, minus[i].insert(sorted[i][j].second);
    pq.push({sorted[i][ptr1[i]].first + sorted[i][ptr2[i]].first, i});
  }
  for (int i = 0; i < k * n / 2; i++) {
    ans += pq.top().first;
    int idx = pq.top().second;
    pq.pop();
    minus[idx].erase(sorted[idx][ptr1[idx]].second); plus[idx].insert(sorted[idx][ptr2[idx]].second);
    ptr1[idx]--; ptr2[idx]--;
    if (ptr1[idx] >= 0) pq.push({sorted[idx][ptr1[idx]].first + sorted[idx][ptr2[idx]].first, idx});
  }
  vector< vector<int> > s(n, vector<int>(m, -1));
  for (int i = 0; i < k; i++) {
    vector<int> v(n);
    iota(v.begin(), v.end(), 0);
    sort(v.begin(), v.end(), [&](int a, int b) {
      return (int) plus[a].size() > (int) plus[b].size();
    });
    for (int j = 0; j < n / 2; j++) {
      s[v[j]][*plus[v[j]].begin()] = i;
      plus[v[j]].erase(plus[v[j]].begin());
    }
    for (int j = n / 2; j < n; j++) {
      s[v[j]][*minus[v[j]].begin()] = i;
      minus[v[j]].erase(minus[v[j]].begin());
    }
  }
  allocate_tickets(s);
  return ans;
}

• Subtask 1: 11 / 11
• Subtask 2: 16 / 16
• Subtask 3: 14 / 14
• Subtask 4: 0 / 14
• Subtask 5: 12 / 12
• Subtask 6: 23 / 23
• Subtask 7: 0 / 10