#include <cstdlib> #include <cctype> #include <cstring> #include <cstdio> #include <cmath> #include <algorithm> #include <vector> #include <string> #include <iostream> #include <sstream> #include <map> #include <set> #include <queue> #include <stack> #include <fstream> #include <numeric> #include <iomanip> #include <bitset> #include <list> #include <stdexcept> #include <functional> #include <utility> #include <ctime> #include <random> #include <cassert> using namespace std; typedef long long LL; typedef unsigned long long ULL; #define MEM(a,b) memset((a),(b),sizeof(a)) const LL INF = 1e9 + 7; const int N = 2e2 + 10; int a[N][N]; int main() { //freopen("input.txt", "r", stdin); //freopen("output.txt", "w", stdout); int ncase; cin >> ncase; while (ncase--) { int n; cin >> n; int flag = 1; for (int i = 1; i <= n; i++) { for (int j = 1; j <= n; j++) { cin >> a[i][j]; if (i > 1 && a[i][j] == a[i - 1][j]) flag = 0; if (j > 1 && a[i][j] == a[i][j - 1]) flag = 0; } } if (flag) puts("Yes"); else puts("No"); } return 0; }