Submission #540658

#	Time	Username	Problem	Language	Result	Execution time	Memory
540658		MilosMilutinovic	Carnival Tickets (IOI20_tickets)	C++14	100 / 100	1002 ms	175604 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] = (i + j) % k;
    }                       
    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]);
    who[i].push_back();
    ans[i][j] = nxt;
    if ((id + 1) % (
  }*/   
  sum = 0;
  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 sz = vec.size();
  vector<vector<bool>> L(n, vector<bool>(m, false));
  vector<vector<bool>> R(n, vector<bool>(m, false));
  for (int i = 0; i < sz; i++) {
    if (i < sz / 2) {
      sum -= get<0>(vec[i]);
      L[get<1>(vec[i])][get<2>(vec[i])] = true;
    } else {
      sum += get<0>(vec[i]);
      R[get<1>(vec[i])][get<2>(vec[i])] = true;
    }
  }
  int nxt = 0;    
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < m; j++) {
      if (L[i][j]) {
        ans[i][j] = nxt;
        nxt = (nxt + 1) % k;
      }
    }
  }
  for (int i = 0; i < n; i++) {
    vector<bool> was(k);       
    for (int j = 0; j < m; j++) {
      if (L[i][j]) {
        was[ans[i][j]] = true;
      }
    }              
    vector<int> vec;
    for (int j = 0; j < k; j++) {
      if (!was[j]) {
        vec.push_back(j);
      }
    }
    for (int j = 0; j < m; j++) {
      if (R[i][j]) {
        assert(vec.size() > 0);
        ans[i][j] = vec.back();
        vec.pop_back();
      }
    }
  }
  /*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;
}

• 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