A couple of things. First and foremost you once you have read everything out of <DATA> you would not be able to call the routine again to reload the data. (a simple example should show what i mean):
use strict;
use warnings;
get_data();
get_data();

sub get_data    
{
   while ( <DATA> ) {
     print $_;
   }
}   ##get_data


__DATA__
A
B
C
D

[download]
Second, instead of popping things off of the array (in the hash) and thus changing the data in the structure, I would use a construct like the following,so that the data structure stays intact and thus there would be no reason to rebuild it. What I mean is that, instead of this:
while(1){
         last unless my $immed = pop @{$immed_child{$root}};
        get_descends($immed);
        $all_descends{$immed}++;
    }

[download]
I would do something like this instead:
    foreach my $immed ( @{$immed_child{$root}} )  {
        get_descends($immed);
        $all_descends{$immed}++;
    }

[download]
Anyhow, I hope this helps.

-enlil

In reply to Re: recursive difficulty by Enlil
in thread recursive difficulty by jjohhn

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.