Sum of diagonal elements of a matrix

C program to find sum of diagonal elements of a matrix

#include<stdio.h>

int main(){

int a[10][10],i,j,sum=0,m,n;

printf("\nEnter the row and column of matrix: ");

scanf("%d %d",&m,&n);

printf("\nEnter the elements of matrix: ");

for(i=0;i<m;i++)

for(j=0;j<n;j++)

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

printf("\nThe matrix is\n");

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

printf("\n");

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

printf("%d\t",a[i][j]);

}

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

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

if(i==j)

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

}

printf("\n\nSum of the diagonal elements of a matrix is: %d",sum);

return 0;

}