use Data::Dumper;

use strict;
use warnings;

my @set = ('1', '2', '3');
my @strings = generate(@set);
print Dumper(\@strings);

sub generate {
	my @set = @_;
	my @strings;
	if ($#set == 0) {
		return ($set[0]);
	} else {
		for (0 .. $#set) {
			my @temp = @set;
			my $t = splice(@temp, $_, 1);
			push @strings, "$t$_" foreach (generate(@temp));
		}
		return @strings;
	}
}