Submission #540646

#	Time	Username	Problem	Language	Result	Execution time	Memory
540646		MilosMilutinovic	카니발 티켓 (IOI20_tickets)	C++14	27 / 100	468 ms	51540 KiB

tickets

#include "tickets.h"
#include <bits/stdc++.h>

using namespace std;

/*
at every round we choose n / 2 mins and n / 2 maxs
value of round is sum_of_maxs - sum_of_mins
mx[i] + mn[i] > mx[j] + mn[j]
    ^ wrong
   
just image taking k mins and then find diffs next max - last min
sort everything and take greedy
works?
*/

long long find_maximum(int k, vector<vector<int>> x) {
  int n = x.size(), m = x[0].size();
  vector<vector<int>> ans(n, vector<int>(m, -1));
  long long sum = 0;      
  vector<tuple<long long, int, int, int>> ops;
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < k; j++) {
      sum -= x[i][j];
      ans[i][j] = j;
    }                       
    for (int j = k - 1; j >= 0; j--) {
      ops.emplace_back(x[i][j] + x[i][m - (k - j)], i, j, m - (k - j));
    }
  }
  int take = (n / 2) * k;
  sort(ops.rbegin(), ops.rend());
  for (int id = 0; id < take; id++) {
    sum += get<0>(ops[id]);
    int i = get<1>(ops[id]);
    int jx = get<2>(ops[id]);
    int jy = get<3>(ops[id]);
    swap(ans[i][jx], ans[i][jy]);
  }
  vector<tuple<int, int, int>> vec;
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < m; j++) {
      if (ans[i][j] != -1) {
        vec.emplace_back(x[i][j], i, j);
      }
    }
  }
  sort(vec.begin(), vec.end());
  int nxt = 0;
  for (int id = 0; id < vec.size(); id++) {
    int i = get<1>(vec[id]);
    int j = get<2>(vec[id]);
    ans[i][j] = nxt;
    nxt = (nxt + 1) % k;
  }   
  sum = 0;                  
  vector<vector<int>> vals(k);
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < m; j++) {
      if (ans[i][j] == -1) {
        continue;
      }
      vals[ans[i][j]].push_back(x[i][j]);
    }
  }
  for (int i = 0; i < k; i++) {
    sort(vals[i].begin(), vals[i].end());
    for (int j = 0; j < n; j++) {
      if (j < n / 2) {
        sum -= vals[i][j];
      } else {
        sum += vals[i][j];
      }
    }
  }
  allocate_tickets(ans);
  return sum;
}

Compilation message (stderr)

tickets.cpp: In function 'long long int find_maximum(int, std::vector<std::vector<int> >)':
tickets.cpp:50:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::tuple<int, int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   50 |   for (int id = 0; id < vec.size(); id++) {
      |                    ~~~^~~~~~~~~~~~

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