[Lucky Algorithm] Diagonal Difference

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

Input Format

The first line contains a single integer, . The next  lines denote the matrix's rows, with each line containing space-separated integers describing the columns.

Constraints

Output Format

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

import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int a[][] = new int[n][n];
        for(int a_i=0; a_i < n; a_i++){
            for(int a_j=0; a_j < n; a_j++){
                a[a_i][a_j] = in.nextInt();
            }
        }
        
        int answer = 0;
        
        int first = 0;
        int second = 0;
        
        for (int i = 0; i < n; i++) {
			first += a[i][i];
			second += a[(n - 1) - i][i];			
		}
        
        answer = Math.abs(first-second);
        
        System.out.println(answer);
    }
}