Submission #988296

#	Time	Username	Problem	Language	Result	Execution time	Memory
988296		kachim2	Arranging Shoes (IOI19_shoes)	C++17	100 / 100	445 ms	281804 KiB

shoes

#include "shoes.h"
#include <climits>
#include <queue>
#include <vector>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
long long count_swaps(std::vector<int> s) {
  std::vector<int> pos(s.size(), INT_MIN);
  auto qm = new std::queue<int>[s.size()+1];
  auto qp = new std::queue<int>[s.size()+1];

  for (int i = 0; i < s.size(); i++) {
    if (s[i] < 0) {
      if (qp[-s[i]].empty()) {
        qm[-s[i]].push(i);
      } else {
        auto x = qp[-s[i]].front();
        qp[-s[i]].pop();
        pos[i] = x;
      }
    } else {
      if (qm[s[i]].empty()) {
        qp[s[i]].push(i);
      } else {
        auto x = qm[s[i]].front();
        qm[s[i]].pop();
        pos[i] = x;
      }
    }
  }
  long count = 0;
  tree<int, null_type, std::less<int>, rb_tree_tag,
       tree_order_statistics_node_update>
      B;
  for (int i = 0; i < s.size(); i++) {
    B.insert(i * 3 + 1);
  }
  for (int i = 0; i < s.size(); i++) {
    if (pos[i] >= 0) {
      if (s[i] > 0) {
        count += B.order_of_key(i * 3 + 1) - B.order_of_key(pos[i] * 3 + 1) - 1;
        B.erase(i * 3 + 1);
        B.insert(pos[i] * 3 + 2);
      } else {
        count += B.order_of_key(i * 3 + 1) - B.order_of_key(pos[i] * 3 + 1);
        B.erase(i * 3 + 1);
        B.insert(pos[i] * 3);
      }
    }
  }
  delete[] qm;
  delete[] qp;
  return count;
}

Compilation message (stderr)

shoes.cpp: In function 'long long int count_swaps(std::vector<int>)':
shoes.cpp:13:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   13 |   for (int i = 0; i < s.size(); i++) {
      |                   ~~^~~~~~~~~~
shoes.cpp:36:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   36 |   for (int i = 0; i < s.size(); i++) {
      |                   ~~^~~~~~~~~~
shoes.cpp:39:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   39 |   for (int i = 0; i < s.size(); i++) {
      |                   ~~^~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 20 / 20
• Subtask 3: 20 / 20
• Subtask 4: 15 / 15
• Subtask 5: 20 / 20
• Subtask 6: 15 / 15