Here is the code:
...
} else {
return factors($q, @f);
}
...
Return the values during recursive calls too.
Output:
[2 2 5]
2
2
5
Simon Proctor @ 2022-06-16 19:07 +01:
> I think, and I don't have my computer to hand to double check but I
> think you want a return before your recursive.call to factors passing
> in @f.
>
> When dealing with recursive functions you need to make sure what
> you're returning back up the stack.
>
> On Thu, 16 Jun 2022, 18:10 Rick Bychowski, <r...@hiranyaloka.com>
> wrote:
>
> Hi Everyone,
>
> I've been lurking quite a while, this will be my first post to
> perl6
> users. I've written a lot of short scripts in perl5 for system
> admin
> type stuff at home and work. Lately I'm playing with Raku, which
> is a
> lot of fun. Error reporting is excellent, as is the online
> documentation.
>
> To the point. I recently started the perl weekly challenge. Lots
> of
> math/primes stuff. I wrote an algorithm to list all the prime
> factors of
> an integer, using a recursive subroutine. I'm able to print the
> result
> from the subroutine, but it always returns Nil. What am I missing?
>
> #!/usr/bin/env raku
>
> sub MAIN($n = 20) {
> .say for factors($n); # Nil
> }
>
> sub factors($n, @factors?) {
> my @f = @factors.elems ?? @factors !! ();
> my $q;
> for 2 ..^ $n -> $i {
> if $n %% $i {
> $q = Int($n / $i);
> @f.push($i);
> if $q.is-prime {
> @f.push($q);
> say @f; # [2 2 5]
> return @f;
> } else {
> factors($q, @f);
> }
> last;
> }
> }
> }
>
> Returns
> [2 2 5]
> Nil
>
> --
> Rick Bychowski
>
> The information in this email is confidential and may be legally
> privileged. It is intended solely for the addressee(s). Access to
> this
> e-mail by anyone else is unauthorized.
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