Determinant Calculator for 3 by 3 matrix

/**
 *
 * @author Ranajoy
 */
public class Determinant {

    static void display(int arr[][]){
        int rows = arr.length;
        int cols = arr[0].length;

        for(int i = 0; i < rows; i++){
            for(int j = 0; j < cols; j++){
                System.out.print(arr[i][j] + " ");
            }
            System.out.println("");
        }
        System.out.println("");
    }

    static int calcDeterminant(int arr[][]){
        // Expanding w.r.t first row
        int det = 0;
        int co_factors[][] = new int[2][2];
        for(int j = 0; j < 3; j++){
            // The element is arr[0][j]
            // Calculating the co-factors of
            // arr[0][j]
            int c_i = 0;
            for(int row = 1; row < 3; row++){
                int c_j = 0;
                for(int col = 0; col < 3; col++){
                    // The co-factors are present in those columns to which
                    // the element arr[0][j] does not belong
                    if(col != j){
                        co_factors[c_i][c_j] = arr[row][col];
                        c_j++;
                    }
                }
                c_i++;
            }
            System.out.println("Co-factors of " + arr[0][j] + " are");
            display(co_factors);
            // For even indexed columns the co-factors have a + sign
            // For odd indexed columns the co-factors have a - sign
            if(j % 2 == 0){
                det += arr[0][j] * ((co_factors[0][0] * co_factors[1][1]) -
                        ((co_factors[0][1] * co_factors[1][0])));
            }
            else{
                det -= arr[0][j] * ((co_factors[0][0] * co_factors[1][1]) -
                        ((co_factors[0][1] * co_factors[1][0])));
            }
        }
        return det;
    }

    public static void main(String[] args) {
        int arr[][] = {
            {1, 2, 3},
            {1, 1, 1},
            {1, 2, 3}
        };
        System.out.println("Determinant = " + calcDeterminant(arr));
    }
}