Sorting

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;
 
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define fbo find_by_order
#define ook order_of_key
 
typedef long long ll;
typedef pair<int,int> ii;
typedef vector<int> vi;
typedef long double ld; 
typedef pair<ld,ld> state;
typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> pbds;

void solve()
{
	int n; cin>>n;
	vi a(n);
	for(int i=0;i<n;i++) cin>>a[i];
	for(int i=0;i<n;i++) a[i]--;
	int cnt=0;
	int lul=0;
	for(int i=0;i<n;i+=2)
	{
		lul++;
		if(a[i]%2==0) cnt++;
	}
	if(cnt%2==lul%2) cout<<"YES\n";
	else cout<<"NO\n";
}

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