code5.rudi

/*----------------------------   CUT HERE --------------------------------------*/

/* This file test nest of subroutine */
program
decs [
	integer fact		/* factorial result 			*/
	integer n		/* input factorial term		*/
]	
begin
	print "Enter the factorial term:"
	input n
	print n
	print "! = "
	fact = n
	factorial ( fact ) 
	print fact
end

subroutine factorial ( fact )
decs [
	integer temp
]

begin
	/* Safety check to make sure value is > 0 */
	if ( fact :lt: 0 ) then
	[
		fact = fact * -1
	]
	
	/* Set local value to temp and then use recursion to generate factorial */
	temp = fact
	if ( fact :eq: 0 ) then 
	[
		fact = 1
	]
	else
	[
		temp = fact - 1
		factorial ( temp )
		fact = fact * temp
	]
return