Problem

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

Input Format

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

Output Format

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

Sample Input

311    2     44     5     610    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      510

Sum across the secondary diagonal: 4 + 5 + 10 = 19

Solution

import java.io.*;import java.util.*;public class Solution {    public static void main(String[] args) {        Scanner in = new Scanner(System.in);        int n = in.nextInt();        int pSum = 0, sSum = 0;        int a[][] = new int[n][n];        for(int i = 0; i < n; i++){            for(int j = 0; j < n; j++){                a[i][j] = in.nextInt();            }        }        for(int i=0; i