Sorting

input/code.cpp: In function 'void usaco()':
input/code.cpp:15:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
  freopen("problem.in", "r", stdin);
  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
input/code.cpp:16:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
  freopen("problem.out", "w", stdout);
  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

#include <bits/stdc++.h>
using namespace std;
void fast() {
	ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
}
void ran() {
	srand(chrono::steady_clock::now().time_since_epoch().count());
}
long long get_rand() {
	long long a = rand();
	long long b = rand();
	return a * (RAND_MAX + 1ll) + b;
}
void usaco() {
	freopen("problem.in", "r", stdin); 
	freopen("problem.out", "w", stdout);
}
template<typename T>
using min_pq = priority_queue<T, vector<T>, greater<T>>;
// #define endl '\n'
// #define double long double
// #define int long long
// const int MOD = 1000 * 1000 * 1000 + 7;
// const int MOD = 998244353;
 
void solve() {
	
	int n;
	cin >> n;
	
	int ar[n];
	for (int i=0; i<n; i++) {
		cin >> ar[i];
		ar[i]--;
	}
	
	for (int i=0; i<n-3; i++) {
		if (ar[i] == i) {
			// for (int i=0; i<n; i++) cout << ar[i] << ' '; cout << endl;
			continue;
		}
		int pos = -1;
		for (int j=i+1; j<n; j++) {
			if (ar[j] == i) pos = j;
		}
		if (pos == n-1) {
			cout << "NO" << endl;
			return;
		}
		if (pos > i+1) {
			swap(ar[i], ar[pos]);
			swap(ar[i+1], ar[pos+1]);
		}
		else {
			// pos is i+1
			if (i + 4 >= n) {
				cout << "NO" << endl;
				return;
			}
			swap(ar[i+1], ar[i+3]);
			swap(ar[i+2], ar[i+4]);
			
			swap(ar[i], ar[i+3]);
			swap(ar[i+1], ar[i+4]);
			
		}
		
		// for (int i=0; i<n; i++) cout << ar[i] << ' '; cout << endl;
		
	}
	
	for (int i=0; i<n; i++) {
		if (ar[i] != i) {
			cout << "NO" << endl;
			return;
		}
	}
	
	cout << "YES" << endl;
	
}
 
signed main() {
	
	int t;
	cin >> t;
	while (t--) solve();
 
}

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