Untitled

import java.util.Scanner;

public class ColorCombinationBacktracking {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int T = sc.nextInt();
        for (int t = 1; t <= T; t++) {
            int n = sc.nextInt();
            int[][] matrix = new int[n][n];
            for (int i = 0; i < n; i++) {
                for (int j = 0; j < n; j++) {
                    matrix[i][j] = sc.nextInt();
                }
            }

            int count = 0;
            int[] color = new int[n * n];
            backtrack(matrix, color, 0);
            System.out.println("Case #" + t);
            System.out.println(count);
        }
    }

    private static void backtrack(int[][] matrix, int[] color, int i) {
        if (i == matrix.length * matrix.length) {
            count++;
            return;
        }

        for (int c = 0; c < 4; c++) {
            if (isSafe(matrix, color, i, c)) {
                color[i] = c;
                backtrack(matrix, color, i + 1);
            }
        }
    }

    private static boolean isSafe(int[][] matrix, int[] color, int i, int c) {
        int row = i / matrix.length;
        int col = i % matrix.length;

        for (int j = 0; j < matrix.length; j++) {
            if (matrix[row][j] == 1 && color[j * matrix.length + c] == c) {
                return false;
            }
            if (matrix[j][col] == 1 && color[i + j * matrix.length] == c) {
                return false;
            }
        }

        return true;
    }
}