Re^2: Puzzle: What is the largest integer whose digits are all different (and do not include 0) that is divisible by each of its individual digits?

[inman]

I used Math::Combinatorics for both parts and a slight modification of the original test to get the answer (9867312) in less time than it takes to make a coffee...

use strict;
use warnings;

use Math::Combinatorics;
my @n = qw(1 2 3 4 6 7 8 9);

my $found;
foreach my $count (reverse (1..@n))
{
    my $combinat = Math::Combinatorics->new(count => $count, data => [
+@n],);
    my @comb;
    while (@comb = $combinat->next_combination())
    {
        my @permu;
        my $permute = Math::Combinatorics->new(data => [@comb]);
        while (@permu = $permute->next_permutation())
        {
            if (passes(@permu))
            {
                print "@permu\n";
                $found++;
            }
        }
    }
    
    exit if $found;
}

sub passes {
    my $test_number = join '', @_;
    for ( @_ ) {
        return 0 unless $test_number % $_ == 0 ;
    }
    return 1;
}

update I have modified my original code taking the 5 out of the possible numbers and paring down the test as much as possible. This now runs much faster.