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Diagonal Array Program - Java Programs

Define a class to accept values into an integer array of order 4 × 4 and check whether it is a diagonal array or not. An array is diagonal if the sum of the left diagonal elements equals the sum of the right diagonal elements. Print the appropriate message.

Example:
3 4 2 5
2 5 2 3
5 3 2 7
1 3 7 1

Sum of the left diagonal elements = 3 + 5 + 2 + 1 = 11
Sum of the right diagonal elements = 5 + 2 + 3 + 1 = 11

Java

import java.util.Scanner;
class Diagonal{
    public static void main(String[] args){
        Scanner in = new Scanner(System.in);
        int mat[][] = new int[4][4];
        System.out.println("Enter matrix elements:");
        int left = 0;
        int right = 0;
        for(int i = 0; i < 4; i++){
            for(int j = 0; j < 4; j++){
                mat[i][j] = Integer.parseInt(in.nextLine());
                if(i == j)
                    left += mat[i][j];
                if(i + j == 3)
                    right += mat[i][j];
            }
        }
        if(left == right)
            System.out.println("Diagonal matrix!");
        else
            System.out.println("Not a diagonal matrix.");
    }
}

Output

 
 OUTPUT : 
Enter matrix elements:
3
4
2
5
2
5
2
3
5
3
2
7
1
3
7
1
Diagonal matrix!