Submission #659024

#	Time	Username	Problem	Language	Result	Execution time	Memory
659024		evenvalue	Carnival Tickets (IOI20_tickets)	C++17	25 / 100	1774 ms	178232 KiB

tickets

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

template<typename T>
using min_heap = priority_queue<T, vector<T>, greater<T>>;
template<typename T>
using max_heap = priority_queue<T, vector<T>, less<T>>;

using int64 = long long;
using ld = long double;

constexpr int kInf = 1e9 + 10;
constexpr int64 kInf64 = 1e15 + 10;
constexpr int kMod = 1e9 + 7;

struct ticket {
  int value;
  int color;
  int index;

  bool operator<(const ticket &other) const {
    return value < other.value;
  }

  bool operator>(const ticket &other) const {
    return value > other.value;
  }
};

int64 find_maximum(const int k, const vector<vector<int>> X) {
  const int n = (int) X.size();   //number of colours
  const int m = (int) X[0].size();//number of tickets

  vector<vector<ticket>> tickets(n, vector<ticket>(m));
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < m; j++) {
      tickets[i][j].value = X[i][j];
      tickets[i][j].color = i;
      tickets[i][j].index = j;
    }
  }

  int64 ans = 0;
  max_heap<ticket> suff;
  vector<max_heap<ticket>> get_max(n);
  for (int i = 0; i < n; i++) {
    sort(tickets[i].begin(), tickets[i].end());
    for (int j = 0; j < m; j++) {
      get_max[i].push(tickets[i][j]);
    }
    for (int j = 0; j < k; j++) {
      suff.push(tickets[i][j]);
      ans -= tickets[i][j].value;
    }
  }


  const int kChoose = n * k;
  assert(suff.size() == kChoose);

  vector<ticket> positive;
  while (suff.size() > kChoose / 2) {
    const auto x = suff.top();
    suff.pop();
    const auto y = get_max[x.color].top();
    get_max[x.color].pop();

    ans += x.value + y.value;
    positive.push_back(y);
  }

  assert(suff.size() == kChoose / 2);

  vector<ticket> negative;
  while (not suff.empty()) {
    const auto x = suff.top();
    suff.pop();
    negative.push_back(x);
  }

  sort(positive.begin(), positive.end(), [&](const ticket &t1, const ticket &t2) {
    return t1.color < t2.color;
  });
  sort(negative.begin(), negative.end(), [&](const ticket &t1, const ticket &t2) {
    return t1.color < t2.color;
  });

  vector<vector<int>> allocate(n, vector<int>(m, -1));
  for (int i = 0, round = 0; i < kChoose / 2; i++, round = (round + 1) % k) {
    const ticket t1 = positive[i];
    const ticket t2 = negative[i];
    allocate[t1.color][t1.index] = round;
    allocate[t2.color][t2.index] = k - 1 - round;
  }

  allocate_tickets(allocate);
  return ans;
}

Compilation message (stderr)

In file included from /usr/include/c++/10/cassert:44,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:33,
                 from tickets.cpp:2:
tickets.cpp: In function 'int64 find_maximum(int, std::vector<std::vector<int> >)':
tickets.cpp:60:22: warning: comparison of integer expressions of different signedness: 'std::priority_queue<ticket, std::vector<ticket>, std::less<ticket> >::size_type' {aka 'long unsigned int'} and 'const int' [-Wsign-compare]
   60 |   assert(suff.size() == kChoose);
      |          ~~~~~~~~~~~~^~~~~~~~~~
tickets.cpp:63:22: warning: comparison of integer expressions of different signedness: 'std::priority_queue<ticket, std::vector<ticket>, std::less<ticket> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   63 |   while (suff.size() > kChoose / 2) {
      |          ~~~~~~~~~~~~^~~~~~~~~~~~~
In file included from /usr/include/c++/10/cassert:44,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:33,
                 from tickets.cpp:2:
tickets.cpp:73:22: warning: comparison of integer expressions of different signedness: 'std::priority_queue<ticket, std::vector<ticket>, std::less<ticket> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   73 |   assert(suff.size() == kChoose / 2);
      |          ~~~~~~~~~~~~^~~~~~~~~~~~~~

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