Submission #387479

#	Time	Username	Problem	Language	Result	Execution time	Memory
387479		WLZ	Carnival Tickets (IOI20_tickets)	C++14	100 / 100	841 ms	76396 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);
  priority_queue< pair<int, int> > pq;
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < k; j++) ans -= x[i][j];
    pq.push({x[i][ptr1[i]] + x[i][ptr2[i] - 1], i});    
  }
  for (int i = 0; i < k * n / 2; i++) {
    ans += pq.top().first;
    int idx = pq.top().second;
    pq.pop();
    ptr1[idx]--; ptr2[idx]--;
    if (ptr1[idx] >= 0) pq.push({x[idx][ptr1[idx]] + x[idx][ptr2[idx] - 1], idx});
  }
  vector< vector<int> > s(n, vector<int>(m, -1));
  vector<int> v(n);
  iota(v.begin(), v.end(), 0);
  for (int i = 0; i < k; i++) {
    sort(v.begin(), v.end(), [&](int a, int b) {
      return ptr1[a] > ptr1[b];
    });
    for (int j = 0; j < n / 2; j++) {
      s[v[j]][ptr1[v[j]]--] = i;
    }
    for (int j = n / 2; j < n; j++) {
      s[v[j]][ptr2[v[j]]++] = i;
    }
  }
  allocate_tickets(s);
  return ans;
}

• 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