/* bc program factorial */

/* recursive calculation of n! */
define a(n){
	if(n==0)return(1)
	return(n*factorial(n-1))
}

define factorial(n){
	auto i,s
	s=1
	for(i=1;i<=n;i++)s=s*i
	return(s)
}

/* factorial_p(n,p) returns the power of prime p dividing n!. 
 * s=[n/p]+[n/p^2]+...
 */
define factorial_p(n,p){
	auto s
	s=0
	while(n){
	    n=n/p
            s=s+n
	}
	return(s)
}

define factorial1(n){
	auto s
	s=1
	while(n){
	s=s*n
	n=n-1
	}
	return(s)
}