C program to find sum of diagonal elements of given matrix.

#include<stdio.h>

#include<conio.h>

#define r 3

#define c 3

void main(){

int a[r][c],sum=0,i,j;

clrscr();

printf("Enter Elements of a Matrix.\n");

for(i=0;i<r;i++){

for(j=0;j<c;j++){

printf("Enter A[%d][%d] = ",i,j);

scanf("%d",&a[i][j]);

}

}

for(i=0;i<r;i++){

for(j=0;j<c;j++){

if(i==j)

sum=sum+a[i][j];

}

}

printf("Sum of diagonal elements of given matrix is = ",sum);

getch();

}