Submission #289815

#	Time	Username	Problem	Language	Result	Execution time	Memory
289815		IgorI	Arranging Shoes (IOI19_shoes)	C++17	50 / 100	1091 ms	3200 KiB

shoes

#include <vector>
#include <cstdio>
#include <string>
#include <set>
#include <cstdlib>
#include <iostream>
#include <map>

using namespace std;

#define all(x) (x).begin(), (x).end()
#define forn(i, n) for (int (i) = 0; (i) < (n); (i)++)

long long count_swaps(vector<int> a)
{
    int n = a.size() / 2;
    long long ans = 0;
    for (int i = 0; i < a.size(); i += 2)
    {
        int p;
        for (int j = i; j < a.size(); j++)
        {
            if (a[j] == -a[i])
            {
                p = j;
                break;
            }
        }
        while (p != i + 1)
        {
            swap(a[p], a[p - 1]);
            p--;
            ans++;
        }
        if (a[i] > a[i + 1])
        {
            swap(a[i], a[i + 1]);
            ans++;
        }
    }
    return ans;
}

Compilation message (stderr)

shoes.cpp: In function 'long long int count_swaps(std::vector<int>)':
shoes.cpp:18:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   18 |     for (int i = 0; i < a.size(); i += 2)
      |                     ~~^~~~~~~~~~
shoes.cpp:21:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   21 |         for (int j = i; j < a.size(); j++)
      |                         ~~^~~~~~~~~~
shoes.cpp:16:9: warning: unused variable 'n' [-Wunused-variable]
   16 |     int n = a.size() / 2;
      |         ^
shoes.cpp:20:13: warning: 'p' may be used uninitialized in this function [-Wmaybe-uninitialized]
   20 |         int p;
      |             ^

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