1797B - Li Hua and Pattern - CodeForces Solution

#include<bits/stdc++.h>
#define endl '\n'
#define ll long long

using namespace std;

signed main() {
	int T;
	cin >> T;
	while (T--) {
		int n, k;
		cin >> n >> k;
		vector<vector<int>> a(n, vector<int>(n));
		for (int i = 0; i < n; ++i)
			for (int j = 0; j < n; ++j)
				cin >> a[i][j];
		int cnt = 0;
		for (int i = 0; i < n >> 1; ++i)
			for (int j = 0; j < n; ++j)
				if (a[i][j] != a[n - i - 1][n - j - 1])
					++cnt;
		if (n & 1) {
			int t = n >> 1;
			for (int i = 0; i < n >> 1; ++i)
				if (a[t][i] != a[t][n - i - 1])
					++cnt;
		}
		cout << (cnt <= k && (n & 1 || !((k - cnt) & 1)) ? "YES" : "NO") << endl;
	}
}/*
1
5 0
0 0 0 0 0
1 1 1 1 1
0 1 0 0 0
1 1 1 1 1
0 0 0 0 0
*/