# C Program to Find Sum of Opposite Diagonal Elements of a Matrix

Howdy readers, today you will learn how to write a program to find the sum of opposite diagonal elements of a matrix using C Programming language.

The minor or opposite diagonal elements are the ones that occur from top right of matrix to bottom left corner. It is also known as secondary diagonal.

```A = 4 8 2
7 5 1
2 9 5```

We will find the sum of opposite diagonal elements of a matrix using a for loop statement.

So, without any delay, letâ€™s begin this tutorial.

## C Program to Find Sum of Opposite Diagonal Elements of a Matrix

C Program

```// C Program to Find Sum of Opposite Diagonal Elements of a Matrix
#include <stdio.h>
int main(){
int i, j, row, col, sum = 0;
int arr[25][25];

printf("Enter the no. of rows: ");
scanf("%d", &row);
printf("Enter the no. of columns: ");
scanf("%d", &col);

// Enter the elements
printf("Enter the elements of the matrix: \n");
for (i = 0; i < row; i++){
for (j = 0; j < col; j++){
scanf("%d", &arr[i][j]);
}
}

// Calculating sum of opposite diagonal elements
for (i = 0; i < row; i++){
sum = sum + arr[i][row - i - 1];
}

// Displaying output
printf("Sum of Opposite Diagonal Elements of a Matrix: %d", sum);

return 0;
}
```

Output

```Enter the no. of rows: 3
Enter the no. of columns: 3
Enter the elements of the matrix:
2 4 6
1 3 5
7 5 9
Sum of Opposite Diagonal Elements of a Matrix: 16
```

Explanation

```    int i, j, row, col, sum = 0;
int arr[25][25];
```

In this program, we have declared five int data type variables and one array named arr.

```    // Asking for input
printf("Enter the no. of rows: ");
scanf("%d", &row);
printf("Enter the no. of columns: ");
scanf("%d", &col);

// Enter the elements
printf("Enter the elements of the matrix: \n");
for (i = 0; i < row; i++){
for (j = 0; j < col; j++){
scanf("%d", &arr[i][j]);
}
}
```

Then, the user is asked to enter the no. of rows and columns of the matrix. After that, the user has to enter each element of the matrix.

```    // Calculating sum of opposite diagonal elements
for (i = 0; i < row; i++){
sum = sum + arr[i][row - i - 1];
}```

Suppose, we have a matrix A = {(2, 4, 6), (1, 3, 5), (7, 5, 9)}, then:

```    // Displaying output
printf("Sum of Opposite Diagonal Elements of a Matrix: %d", sum);
```

Finally, the sum of opposite diagonal elements of the matrix is printed on the screen using printf() function.

## C Program to Find Sum of Opposite Diagonals Elements

C Program

```// C Program to Find Sum of Opposite Diagonal Elements of a Matrix
#include <stdio.h>
int main(){
int i, j, row, col, sum = 0;
int arr[25][25];

printf("Enter the no. of rows: ");
scanf("%d", &row);
printf("Enter the no. of columns: ");
scanf("%d", &col);

// Enter the elements
printf("Enter the elements of the matrix: \n");
for (i = 0; i < row; i++){
for (j = 0; j < col; j++){
scanf("%d", &arr[i][j]);
}
}

// Calculating sum of opposite diagonal elements
for (i = 0; i < row; i++){
for (j = 0; j < col; j++){
if (i + j == (row + 1) - 2)
sum = sum + arr[i][j];
}
}
// Displaying output
printf("Sum of Opposite Diagonal Elements of a Matrix: %d", sum);

return 0;
}
```

Output

```Enter the no. of rows: 3
Enter the no. of columns: 3
Enter the elements of the matrix:
8 6 4
2 5 3
1 8 9
Sum of Opposite Diagonal Elements of a Matrix: 10
```

## Conclusion

I hope after reading this tutorial, you will understand how to write a program to find the sum of opposite diagonal elements of a matrix using C Programming language.

If you face any difficulty while understanding this tutorial, then let us know in the comment section. We will be glad to solve your doubts.