问查找一组数组的所有子集(perl)

EN

use strict;
use warnings;

use List::PowerSet 'powerset_lazy';

my @arr = (
        [1,2],
        [2,3,4],
);
my %hash;
for my $v (@arr) {
    my $ps = powerset_lazy(@$v);
    while (my $set = $ps->()) {
        my $str = join ",", @$set;
        next if $hash{$str}++;
        print "($str)\n";
    }
}

(1,2)
(2)
(1)
()
(2,3,4)
(3,4)
(2,4)
(4)
(2,3)
(3)