C++ Program to determine the Armstrong Number

# include <iostream.h>
   # include <conio.h>
   # include <math.h>
   void main ()
   {
     clrscr();
     int a,b=0,sum=0;
     long int n;
     cout<<"Enter the NO. : ";
     cin>>n;
     for(;n>0;)
     //counts the digits
     {
       a=n%10;
       n=n/10;
       b++;
     }
     for(;n>0;)
     {
       a=n%10;
       sum=sum+pow(a,b);
       n=n/10;
     }
     if(sum==n)
     {
       cout<<"IT IS AN ARMSTRONG NUMBER...";
       getch();
     }
     else
     {
       cout<<"IT IS NOT AN ARMSTRONG NUMBER...";
       getch();
     }
   }