Sorting

#include <bits/stdc++.h>

using namespace std;

#define rep(i, a, b) for (int i = a; i < (b); ++i)
#define per(i, a, b) for (int i = a - 1; i >= (b); --i)
#define trav(a, x) for (auto &a : x)

#define all(x) x.begin(), x.end()
#define sz(x) x.size()
#define pb push_back

#define umap unordered_map
#define uset unordered_set
#define INF 1000000000

typedef pair<int, int> ii;
typedef pair<int, ii> iii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef long long ll;


int main() {
    ios::sync_with_stdio(0);
    cin.tie(NULL);

    int tc, n;
    cin >> tc;
    while (tc--) {
        cin >> n;
        int num, m3 = 0;
        rep(i, 0, n) {
            cin >> num;
            m3 += abs(i - num) / 2;
        }
        if (m3%2)cout<<"NO"<<endl;
        else cout<<"YES"<<endl;
    }
    return 0;
}

Test 1

Group: 1, 2

Verdict: WRONG ANSWER

Test 2

Group: 2

Verdict: WRONG ANSWER

Test 3

Group: 1, 2

Verdict: WRONG ANSWER

Test 4

Group: 1, 2

Verdict: WRONG ANSWER