# Sum of diagonal of a matrix in Java …FTC

Write a program to accept a n X n matrix and print addition of diagonal elements of that matrix.

``````Input:
size of matrix nxn:  2
Enter the matrix:
1  2
3  4

Output:
Matrix:
1  2
3  4
Sum of Diagonals:  5``````
```import java.io.*;
import java.util.*;
public class temp {
public static void main(String[] args) {
int n,sum = 0;
Scanner scan = new Scanner(System.in);

System.out.println("Enter the size of matrix nxn n:  ");
n = scan.nextInt();
int[][] matrix = new int[n][n];
System.out.println("Enter the nxn matrix:  ");
for(int i=0;i<n;i++){
for(int j=0;j<n;j++){
matrix[i][j] = scan.nextInt();
if(i==j){
sum += matrix[i][j];
}
}
}

System.out.println("\nMatrix:  ");
for (int i=0; i<n; i++){
for(int j = 0;j<n;j++){
System.out.print(matrix[i][j]+" ");
}
System.out.println();
}
System.out.println("Sum of Diagonals:  "+sum);
}
}```

INPUT_1:
Enter the size of matrix nxn n:
3
Enter the nxn matrix:
1  2  3
4  5  6
7  8  9

OUTPUT:
Matrix:
1  2  3
4  5  6
7  8  9
Sum of Diagonals:  15

INPUT_2:
Enter the size of matrix nxn n:
2
Enter the nxn matrix:
1  2  3  4

OUTPUT:
Matrix:
1  2
3  4
Sum of Diagonals:  5

INPUT_3:
Enter the size of matrix nxn n:
4
Enter the nxn matrix:
1  2  3  4
4  8  9  6
2  5  4  8
1  1  1  1

OUTPUT:
Matrix:
1  2  3  4
4  8  9  6
2  5  4  8
1  1  1  1
Sum of Diagonals:  14

INPUT_4:
Enter the size of matrix nxn n:
3
Enter the nxn matrix:
2  2  2  2  2  2  2  2  2

OUTPUT:
Matrix:
2  2  2
2  2  2
2  2  2
Sum of Diagonals:  6

ILLUSTRATION