Sorting

#include <bits/stdc++.h>
using namespace std;
#define int long long
int t, n, ok = 0,  a[8];

void solve(int b[8], int count){
    if(count>6) return;
    int good = 1;
    for(int i=0; i<n; ++i) good &= (b[i]==i+1);
    ok |= good;
    for(int i=0; i+1<n; ++i){
        for(int j=i+2; j+1<n; ++j){
            swap(b[i], b[j]);
            swap(b[i+1], b[j+1]);
            solve(b, count+1);
            swap(b[i], b[j]);
            swap(b[i+1], b[j+1]);
        }
    }
}

signed main(){
    ios_base::sync_with_stdio(false); cin.tie(nullptr);
    cin >> t;
    while(t--) {
        cin >> n; ok = 0;
        for (int i = 0; i < n; ++i) cin >> a[i];
        solve(a, 0);
        cout << (ok ? "YES\n" : "NO\n");
    }
}

Test 1

Group: 1, 2

Verdict: ACCEPTED

Test 2

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 3

Group: 1, 2

Verdict: TIME LIMIT EXCEEDED

Test 4

Group: 1, 2

Verdict: TIME LIMIT EXCEEDED