Submission #442158

#	Time	Username	Problem	Language	Result	Execution time	Memory
442158		elazarkoren	Xor Sort (eJOI20_xorsort)	C++17	25 / 100	169 ms	12440 KiB

xorsort

#include <iostream>
#include <vector>
#include <algorithm>
#define x first
#define y second
using namespace std;
typedef vector<int> vi;
typedef pair<int, int> pii;
typedef vector<pii> vii;

vi a;
vii ans;

void Xor(int i, int j) {
    a[i] ^= a[j];
    ans.push_back({i, j});
}

void Swap(int i, int j) {
    Xor(j, i);
    Xor(i, j);
    Xor(j, i);
//    ans.push_back({j, i});
//    ans.push_back({i, j});
//    ans.push_back({j, i});
//    swap(a[i], a[j]);
}

int main() {
    int n, s;
    cin >> n >> s;
    a.resize(n + 1);
    for (int i = 1; i <= n; i++) cin >> a[i];
    while (true) {
        bool is_new = false;
        for (int i = 1; i < n; i++) {
            if (a[i] > a[i + 1]) {
                Swap(i, i + 1);
                is_new = true;
            }
        }
        if (!is_new) break;
    }
    cout << ans.size() << '\n';
    for (int i = 0; i < ans.size(); i++) {
        cout << ans[i].x << ' ' << ans[i].y << '\n';
    }
}

Compilation message (stderr)

xorsort.cpp: In function 'int main()':
xorsort.cpp:45:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   45 |     for (int i = 0; i < ans.size(); i++) {
      |                     ~~^~~~~~~~~~~~

• Subtask 1: 25 / 25
• Subtask 2: 0 / 35
• Subtask 3: 0 / 40