Submission #1078633

#	Time	Username	Problem	Language	Result	Execution time	Memory
1078633		juicy	Carnival Tickets (IOI20_tickets)	C++17	100 / 100	620 ms	92840 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(), m = x[0].size();
  long long res = 0;
  vector<array<int, 3>> cands;
  for (int i = 0; i < n; ++i) {
    for (int j = 0; j < k; ++j) {
      cands.push_back({x[i][j] + x[i][m - k + j], i, -j});
      res -= x[i][j];
    }
  }
  sort(cands.rbegin(), cands.rend());
  vector<int> cnt(n), ptr(n);
  for (int i = 0; i < n * k / 2; ++i) {
    auto [v, r, c] = cands[i];
    ++cnt[r];
    res += v;
  }
  vector a(n, vector<int>(m, -1));
  vector<int> ord(n); iota(ord.begin(), ord.end(), 0);
  for (int t = 0; t < k; ++t) {
    sort(ord.begin(), ord.end(), [&](int u, int v) {
      return cnt[u] > cnt[v];
    });
    for (int i = 0; i < n / 2; ++i) {
      int u = ord[i];
      a[u][m - cnt[u]--] = t;
    }
    for (int i = n / 2; i < n; ++i) {
      int u = ord[i];
      a[u][ptr[u]++] = t;
    }
  }
  allocate_tickets(a);
  return res;
}

• 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