Sorting

/*input
3
2
1 2
5
2 3 5 1 4
4
1 2 4 3
*/
#pragma GCC optimize ("O3")
#pragma GCC target ("avx2")
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
using namespace std;
using namespace __gnu_pbds;
template<typename T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template<typename T, typename X>
using ordered_map = tree<T, X, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template<typename T, typename X>
using fast_map = cc_hash_table<T, X>;
//using ull = __uint128_t;
using ull = unsigned long long;
using ll = long long;
using ld = long double;
mt19937_64 rng(123);
const ll mod = 1000000007;
int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	int t;
	cin >> t;
	while (t--)
	{
		int n;
		cin >> n;
		int p[n + 1];
		p[0] = 0;
		for (int i = 1; i <= n; i++)
			cin >> p[i];
		int s = 0;
		for (int i = 1; i <= n; i++)
		{
			s += max(0, p[i] - i);
			s %= 2;
		}
		if (s % 2 == 1)
			cout << "NO\n";
		else {
			if (n <= 4)
			{
				if (is_sorted(p, p + n + 1))
					cout << "YES\n";
				else
				{
					if (n == 4 && p[1] == 2 && p[2] == 1 && p[3] == 4 && p[4] == 3)
					{
						cout << "YES\n";
					}
					else
						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: WRONG ANSWER

Test 4

Group: 1, 2

Verdict: WRONG ANSWER