#include using namespace std; int n; int mat[22][22]; long long dp[1<<20]; long long rec(int visited) { if(__builtin_popcount(visited) == n) { return 1; } if(dp[visited] != -1) { return dp[visited]; } int at = __builtin_popcount(visited); long long combinations = 0; for(int j = 0; j< n ; j++) { if(mat[at][j] == 1) { if((visited & (1 << j)) == 0) { int new_mask = (visited | (1 << j)); combinations += rec(new_mask); } } } return dp[visited] = combinations; } int main() { int t; cin >> t; while(t--) { cin >> n; for(int i = 0; i < n; i++) { for(int j = 0; j < n; j++) { cin >> mat[i][j]; } } memset(dp, -1, sizeof dp); cout << rec(0) << endl; } return 0; }