Java program to print the maximum hourglass value of the matrix

Context 
Given a  2D Array, :

1 1 1 0 0 0
0 1 0 0 0 0
1 1 1 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0

We define an hourglass in  to be a subset of values with indices falling in this pattern in 's graphical representation:

a b c
  d
e f g

There are  hourglasses in , and an hourglass sum is the sum of an hourglass' values.

Task 
Calculate the hourglass sum for every hourglass in , then print the maximum hourglass sum.

Note: If you have already solved the Java domain's Java 2D Array challenge, you may wish to skip this challenge.

Input Format

There are  lines of input, where each line contains  space-separated integers describing 2D Array ; every value in  will be in the inclusive range of  to .

Constraints

Output Format

Print the largest (maximum) hourglass sum found in .

Sample Input

1 1 1 0 0 0
0 1 0 0 0 0
1 1 1 0 0 0
0 0 2 4 4 0
0 0 0 2 0 0
0 0 1 2 4 0

Sample Output

19

Explanation

 contains the following hourglasses:

1 1 1   1 1 0   1 0 0   0 0 0
  1       0       0       0
1 1 1   1 1 0   1 0 0   0 0 0

0 1 0   1 0 0   0 0 0   0 0 0
  1       1       0       0
0 0 2   0 2 4   2 4 4   4 4 0

1 1 1   1 1 0   1 0 0   0 0 0
  0       2       4       4
0 0 0   0 0 2   0 2 0   2 0 0

0 0 2   0 2 4   2 4 4   4 4 0
  0       0       2       0
0 0 1   0 1 2   1 2 4   2 4 0

The hourglass with the maximum sum () is:

2 4 4
  2
1 2 4

Program below:

package com.rohan.test;

import java.util.Scanner;

public class HourGlassProblem {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int arr[][] = new int[6][6];
        int count = 0;
        int [] sum = new int[20];
        
        for(int arr_i=0; arr_i < 6; arr_i++) {
            for(int arr_j=0; arr_j < 6; arr_j++) {
                arr[arr_i][arr_j] = in.nextInt();
            }
        }
        int counter = 0;
        for(int i = 0; i < 6; i++) {
            for(int j = 0; j < 6; j++) {
            if(i <= 3 && j <= 3) {
            count = takeThreeByThreeMatrix(arr, i, j);
            sum[counter++] = count;
            }
            }
        }
        System.out.println(findMaxArrayElement(sum));
    }

private static int findMaxArrayElement(int[] sum) {
int max = 0;
for(int i = 0; i < sum.length; i++) {
if(max < sum[i]) {
max = sum[i];
}
}
return max;
}

private static int takeThreeByThreeMatrix(int [][] mat, int row, int column) {
int count = 0, cnt = 1;
for(int i = row; i < 3+row; i++) {
for(int j = column; j < 3+column; j++) {

if(cnt == 4 || cnt == 6) {}
else {
count += mat[i][j];
System.out.print(mat[i][j]+" ");
}
cnt++;
}
}
return count;
}
}

Sample Input:

1 1 1 0 0 0
0 1 0 0 0 0
1 1 1 0 0 0
0 9 2 -4 -4 0
0 0 0 -2 0 0
0 0 -1 -2 -4 0

Sample Output:

13
Sample Input:

1 1 1 0 0 0
0 1 0 0 0 0
1 1 1 0 0 0
0 0 2 4 4 0
0 0 0 2 0 0
0 0 1 2 4 0

Sample Output:

19