Sorting

#include <bits/stdc++.h>
using namespace std;
//#define int long long
int a[100], pos[100], n, ok, t;

void exchange(int i, int j){
    swap(a[i], a[j]);
    pos[a[i]] = i;
    pos[a[j]] = j;
    ++i; ++j;
    swap(a[i], a[j]);
    pos[a[i]] = i;
    pos[a[j]] = j;
}

signed main(){
    ios_base::sync_with_stdio(false); cin.tie(nullptr);
    cin >> t;
    while(t--){
        cin >> n;
        ok=1;
        for(int i=0; i<n; ++i) cin >> a[i];
        for(int i=0; i<n; ++i) --a[i];
        int sum=0;
        for(int i=0; i<n; ++i){
            for(int j=0; j<i; ++j){
                sum += a[j]>a[i];
            }
//            for(int j=i+1; j<n; ++j){
//                sum += a[j]<a[i];
//            }
        }
        if(sum&1) cout << "NO\n";
        else cout << "YES\n";
    }

}

Test 1

Group: 1, 2

Verdict: WRONG ANSWER

Test 2

Group: 2

Verdict: WRONG ANSWER

Test 3

Group: 1, 2

Verdict: ACCEPTED

Test 4

Group: 1, 2

Verdict: ACCEPTED