Find the sum of main diagonal of a square matrix of size n.
For example for the following matrix output will be like this:
Sum of main diagonal = 14
#include <stdio.h>
int main()
{
int i, j, n;
int matrix[10][10];
int sumD;
printf("Enter size of matrix : ");
scanf("%d", &n);
/* Input data in matrix */
for (i = 0; i < n; i++)
{
for (j = 0; j < n; j++)
{
printf("Enter data in [%d][%d]: ", i, j);
scanf("%d", &matrix[i][j]);
}
}
printf("\n");
/* Display the matrix */
for (i = 0; i < n; i++)
{
for (j = 0; j < n; j++)
{
printf("%d\t", matrix[i][j]);
}
printf("\n");
}
/* Find the diagonal sum of matrix */
sumD = 0;
for (i = 0; i < n; i++)
{
sumD += matrix[i][i];
}
printf("\nSum of main diagonal = %d", sumD);
return 0;
}
Enter size of matrix : 3
Enter data in [0][0]: 11
Enter data in [0][1]: 10
Enter data in [0][2]: 20
Enter data in [1][0]: 30
Enter data in [1][1]: 10
Enter data in [1][2]: 15
Enter data in [2][0]: 25
Enter data in [2][1]: 30
Enter data in [2][2]: 35
11 10 20
30 10 15
25 30 35
Sum of main diagonal = 56