#!/usr/bin/perl 

use strict;
use warnings;

print "iterFac_for:\t", iterFac_for(6), "\n";
print "recFac:\t\t",   	recFac(6),      "\n";
print "iterFac:\t",   	iterFac(6),     "\n";
exit;

sub iterFac_for {			# straight iterativ (perl-style)
	my ($max, $val) = (shift, 1);
	$val *= $_ for (1..$max);
	return $val;
}

sub recFac {				# linear recursive
	my $n = shift;
	return 1 if $n == 1;
	$n *= recFac($n-1);
}

sub iterFac {				# linear iterativ but recursive defined?!
	my $max = shift;
	my $val = shift || 1;
	my $cnt = shift || 1;

	return $val if $cnt > $max;
	iterFac( $max, $val*$cnt, ++$cnt );
}