use strict;
use warnings;

my $target = "cowboycatdog";
my @parts = qw(cow cowboy boy cat at do dog);

search ($target, [@parts], []);

##</code><code>##

sub search {
    my ($target, $parts, $used) = @_;

##</code><code>##

    unless (length $target) {
        print join ("-", @$used), "\n";
        return;
    }

##</code><code>##

    for my $part (@$parts) {

##</code><code>##

        next unless 0 == index $target, $part;

##</code><code>##

        my $remainder = substr $target, length $part;

##</code><code>##

        search ($remainder, [grep {$part ne $_} @$parts], [@$used, $part]);
    }
}