Diagonal Difference | Solved | Java

                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 .

Function description

Complete the  function with the following parameter:

• : a 2-D array of integers

Return

• : the absolute difference in sums along the diagonals

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 .

Solution:

  public static int diagonalDifference(List<List<Integer>> arr) {

// Write your code here

int sum = 0;

int sum1 = 0;

int m = arr.size() - 1;

for (List<Integer> i : arr) {

int k = 0;

for (Integer j : i) {

if (k == arr.get(0).size() - 1 - m) {

sum = sum + i.get(k);

}

if (m == arr.get(0).size() - 1 - k) {

sum1 = sum1 + i.get(m);

}

k++;

}

m--;

}

return Math.abs(sum1 - sum);

}