6.To cheak whether a number is armstrong number or not

#include<stdio.h>
main()
{
int n,a,sum=0,r;
scanf("%d",&n);
while(n>0)
{
r=n%10;
a=r*r*r;
sum=sum+a;
n=n/10;
}
if(n==sum)
printf("armstrong number");
else
    printf("not armstrong number");
return 0;


}