HackerRank | Diagonal Difference | Java

Diagonal Difference

 public static int diagonalDifference(List<List<Integer>> arr) {
    // Write your code here
        int sumA = 0;
        int sumB = 0;
        
        for(int i=0;i<arr.size();i++){
            sumA+=arr.get(i).get(i);
            sumB+=arr.get(i).get(arr.size()-1-i);
        }
        
        int elem = Math.abs(sumA-sumB);
        return elem;

    }

import java.util.*;

public class Solution{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int num = sc.nextInt();
        
        int[][] arr = new int [num][num];
        
        for(int i=0;i<num;i++){
            for(int j=0;j<num;j++){
                arr[i][j]=sc.nextInt();
            }
        }
        
        int sumA = 0;
        int sumB = 0;
        
        for(int i=0;i<num;i++){
            for(int j=0;j<num;j++){
                if(i==j){
                    sumA+=arr[i][j];
                }
                if(j==num-i-1){
                    sumB+=arr[i][j];
                }
            }
        }
        
        int elem = Math.abs(sumA-sumB);
        System.out.println(elem);
    }
}