Submission #219761

#	Time	Username	Problem	Language	Result	Execution time	Memory
219761		VEGAnn	Arranging Shoes (IOI19_shoes)	C++14	65 / 100	36 ms	2296 KiB

shoes

#include <bits/stdc++.h>
#include "shoes.h"
#define all(x) x.begin(),x.end()
#define PB push_back
#define sz(x) ((int)x.size())
using namespace std;
typedef long long ll;
const int N = 100100;

long long count_swaps(std::vector<int> s) {
	if (sz(s) <= 2000) {
        int n = sz(s) / 2;
        ll ans = 0;

        for (int i = 0; i < n; i++){
            int loc = i + i;
            int pos = -1;

            for (int j = loc + 1; j < sz(s); j++)
                if (s[j] == -s[loc]){
                    pos = j;
                    break;
                }

            assert(pos >= 0);

            while (pos > loc + 1){
                swap(s[pos], s[pos - 1]);
                pos--;
                ans++;
            }

            if (s[loc] > 0)
                ans++;
        }

        return ans;
	} else {
        ll n = sz(s) / 2;

        return n * (n - 1ll) / 2ll;
	}
}

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