Java Program to find Diagonal difference

 Problem Statement :

Given a square matrix, calculate the absolute difference between the sums of its diagonals.

For example, the square matrix  is shown below:

1 2 3
4 5 6
9 8 9  

The left-to-right diagonal = . The right to left diagonal = . Their absolute difference is .

Return

• int: the absolute diagonal difference

Input Format

The first line contains a single integer, , the number of rows and columns in the square matrix .
Each of the next  lines describes a row, , and consists of  space-separated integers .

Output Format

Return the absolute difference between the sums of the matrix's two diagonals as a single integer.

Sample Input

11 2 4
4 5 6
10 8 -12

Sample Output

15

Explanation

The primary diagonal is:

11
   5
     -12

Sum across the primary diagonal: 11 + 5 - 12 = 4

The secondary diagonal is:

     4
   5
10

Sum across the secondary diagonal: 4 + 5 + 10 = 19
Difference: |4 - 19| = 15

Program :

public class DiagonalDifference {

public static void main(String[] args) {

int[][] matrix = { { 11, 2, 4 }, { 4, 5, 6 }, { 10, 8, -12 } };

int leftSum = 0;

int rightSum = 0;

for (int i = 0; i < matrix.length; i++) {

for (int j = 0; j < matrix.length; j++) {

if (i == j) {

leftSum += matrix[i][j];

}

if (i == matrix.length - 1 - j) {

rightSum += matrix[i][j];

}

}

}

System.out.println(Math.abs(leftSum - rightSum));

}

}