Program to find whether the given number is an Armstrong number using function

#include<iostream.h>
#include<conio.h>
int armstrong(int num)
{
int sum=0;
do
{
sum=sum+(num%10)*(num%10)*(num%10);
num=num/10;
}
while(num!=0);
return sum;
}
void main()
{
clrscr();
int a,no;
cout<<"Enter the no."<<endl;
cin>>no;
a=armstrong(no);
if(a==no)
cout<<"Amstrong"<<endl;
else
cout<<"Boo"<<endl;
getch();
}