#!perl -w
use strict;
my @set = qw(a b c);
my @tuples = mk_tuples(3, \@set);
for (@tuples) {
print "(", join(", ", @$_), ")\n";
}
sub mk_tuples {
my $n = shift;
my $setr = shift;
my $len = 0;
my @result = ();
my @hold = ();
mk_tuples_r($n, $setr, \@hold, \@result);
return @result;
}
sub mk_tuples_r {
my ($n, $setr, $holdr, $resultr) = @_;
my $len = 1 + @$holdr;
for my $e (@$setr) {
push @$holdr, $e;
if ($len == $n) {
push @$resultr, [ @$holdr ];
} else {
mk_tuples_r($n, $setr, $holdr, $resultr);
}
pop @$holdr;
}
}