Submission #947056

#	Time	Username	Problem	Language	Result	Execution time	Memory
947056		AkibAzmain	Carnival Tickets (IOI20_tickets)	C++17	11 / 100	1 ms	604 KiB

tickets

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

long long find_maximum(int k, std::vector<std::vector<int>> arr) {
  ll n = arr.size();
  ll m = arr[0].size();
  std::vector<std::vector<int>> ans (n, vector < int > (m, -1));
  ll sum = 0;
  if (k == 1)
    {
      vector < pair < ll, ll > > mn (n), mx (n);
      for (int i = 0; i < n; ++i)
        {
          mn[i] = { arr[i][0], i };
          mx[i] = { arr[i][m - 1], i };
        }
      sort (mn.begin (), mn.end ());
      sort (mx.begin (), mx.end ());
      reverse (mx.begin (), mx.end ());
      int i = 0, j = 0;
      vector < bool > v (n);
      for (int k = 0; k < n / 2; ++k)
        {
          while (v[mn[i].second]) ++i;
          while (v[mx[j].second]) ++j;
          if (mn[i].second != mx[j].second)
            {
              ans[mn[i].second][0] = 0;
              ans[mx[j].second][m - 1] = 0;
              sum += mx[j].first - mn[i].first;
              assert (!v[mn[i].second]);
              assert (!v[mx[j].second]);
              v[mn[i].second] = v[mx[j].second] = true;
              continue;
            }
          int ii = i + 1;
          int ji = j + 1;
          while (ii < n && v[mn[ii].second]) ++ii;
          while (ji < n && v[mx[ji].second]) ++ji;
          if (ji < n && mx[ji].first - mn[i].first > mx[j].first - mn[ii].first)
            {
              ans[mn[i].second][0] = 0;
              ans[mx[ji].second][m - 1] = 0;
              sum += mx[ji].first - mn[i].first;
              assert (!v[mn[i].second]);
              assert (!v[mx[ji].second]);
              v[mn[i].second] = v[mx[ji].second] = true;
            }
          else
            {
              ans[mn[ii].second][0] = 0;
              ans[mx[j].second][m - 1] = 0;
              sum += mx[j].first - mn[ii].first;
              assert (!v[mn[ii].second]);
              assert (!v[mx[j].second]);
              v[mn[ii].second] = v[mx[j].second] = true;
            }
        }
      for (auto x : v) assert (x);
    }
  allocate_tickets(ans);
  return sum;
}

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