Submission #670032

#	Time	Username	Problem	Language	Result	Execution time	Memory
670032		haxorman	Arranging Shoes (IOI19_shoes)	C++14	10 / 100	1 ms	300 KiB

shoes

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

long long count_swaps(vector<int> vec) {
    map<int,vector<int>> pos;
    for (int i = 0; i < vec.size(); ++i) {
        pos[vec[i]].push_back(i);
    }
    
    int ans = 0;
    for (int i = 0; i < vec.size() - 1; ++i) {
        /*
        cout << vec[i] << "\n";
        for (auto x : pos[-vec[i]]) {
            cout << x << ' ';
        }
        cout << "\n---\n";
        */
        auto it = upper_bound(pos[-vec[i]].begin(), pos[-vec[i]].end(), i);

        ans += *it - i;
        if (vec[i] < 0) {
            --ans;
        }
    }
    return ans;
}

Compilation message (stderr)

shoes.cpp: In function 'long long int count_swaps(std::vector<int>)':
shoes.cpp:7:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    7 |     for (int i = 0; i < vec.size(); ++i) {
      |                     ~~^~~~~~~~~~~~
shoes.cpp:12:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   12 |     for (int i = 0; i < vec.size() - 1; ++i) {
      |                     ~~^~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 0 / 20
• Subtask 3: 0 / 20
• Subtask 4: 0 / 15
• Subtask 5: 0 / 20
• Subtask 6: 0 / 15