Submission #886397

#	Time	Username	Problem	Language	Result	Execution time	Memory
886397		NeroZein	Carnival Tickets (IOI20_tickets)	C++17	100 / 100	543 ms	76376 KiB

tickets

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

long long find_maximum(int k, vector<vector<int>> x) {
  int n = x.size();
  int m = x[0].size();
  long long ret = 0; 
  priority_queue<pair<int, int>> pq;  
  for (int i = 0; i < n; ++i) {
    for (int j = m - 1; j >= m - k; --j) {
      ret += x[i][j]; 
    }
    pq.emplace(-x[i][0] - x[i][m - k], i);
  }
  int cnt = 0; 
  vector<int> t(n); 
  while (cnt < n * k / 2) {
    auto [val, ind] = pq.top();
    pq.pop();
    cnt++;
    ret += val;
    t[ind]++; 
    if (t[ind] < k) {
      pq.emplace(-x[ind][t[ind]] - x[ind][m - k + t[ind]], ind);       
    }
  }
  while (!pq.empty()) pq.pop(); 
  vector<int> c(n), c2(n); 
  for (int i = 0; i < n; ++i) {
    c2[i] = m - k + t[i];
  }
  vector<vector<int>> answer(n, vector<int> (m, -1));
  for (int round = 0; round < k; ++round) {
    vector<int> ord(n);
    iota(ord.begin(), ord.end(), 0); 
    sort(ord.begin(), ord.end(), [&](int i, int j) {
      return t[i] - c[i] > t[j] - c[j]; 
    });
    for (int j = 0, taken = 0; j < (int) ord.size(); ++j) {
      if (taken < n / 2) {
        answer[ord[j]][c[ord[j]]] = round;
        c[ord[j]]++; 
        taken++; 
      } else {
        answer[ord[j]][c2[ord[j]]] = round;
        c2[ord[j]]++; 
      }
    }
  }
  allocate_tickets(answer);
  return ret;
}

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