http://www.perlmonks.org?node_id=250924


in reply to Creating tuples based on sets

Here is my solution. This is not a great example, as I didn't have time to really think this out, but...

use strict; my @set = qw(A B C); mk_tuples(2, 0, \@set, []); # put the number of tuples first print join "\n", map join(' ', @$_), get_tuples(); { my @full_builds; sub mk_tuples { my ($depth, $previous_depth, $set, $built) = @_; push(@full_builds, $built) if $depth == $previous_depth; for my $current_depth ($previous_depth..$depth) { for (@$set) { mk_tuples($depth, $previous_depth+1, $set, [@$built, $_]); } } } sub get_tuples { die "none made\n" unless @full_builds; return @full_builds; } }

Hope that helps.

Update: As you can see, mine requires 4 arguments: 1) the depth to stop at, 2) the depth we are at currently, 3) the full set of possibles to iterate over, and 4) the partial_builds to be passed recursively. I know this isn't exactly what you want... Sorry.