Submission #971768

#	Time	Username	Problem	Language	Result	Execution time	Memory
971768		opPO	Arranging Shoes (IOI19_shoes)	C++14	65 / 100	18 ms	1884 KiB

shoes

#include "shoes.h"
#include <bits/stdc++.h>

#define sz(x) (int)x.size()

using namespace std;

long long count_swaps(vector<int> s) {
    int n = sz(s) / 2;
    if (n <= 10000) {
        long long swaps = 0;

        for (int i = 0; i < 2 * n; i += 2) {
            int pos = -1;
            for (int j = i + 1; j < 2 * n; j++) {
                if (s[j] == -s[i]) {
                    pos = j;
                    break;
                }
            }
            assert(pos != -1);

            if (s[i] < 0) {
                while (pos > i + 1) {
                    swaps++;
                    swap(s[pos - 1], s[pos]);
                    pos--;
                }
            } else {
                while (pos > i) {
                    swaps++;
                    swap(s[pos - 1], s[pos]);
                    pos--;
                }
            }
        }

        return swaps;
    }

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

/*
g++ -std=gnu++14 -O2 -Wall -pipe -static -o "shoes" "grader.cpp" "shoes.cpp"
*/

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