Re: Using Tree::Simple with while loop and input file.

You really don't need Tree::Simple to do that. A simple approach could be:

Read the file in a hash in the form child => parent
Get all the leaves: keys of the hash that are not used also as values (keys, grep)
For each leaf
- Generate an array with its "genealogy" searchin in the hash till you get a value that's not a key (a root)
- reverse the array
- join
- print

All considered it should be no more than 20 lines of code.

Update: make it 22...

#!/usr/bin/perl 
use strict;
use warnings;

open my $f,"<","x.txt";
my %tree;
while (<$f>) {
  chomp;
  my ($c,$p)=split(/:/,$_);
  $tree{$c}=$p;
}
my %eert = reverse %tree;
foreach my $l (keys %tree) {
  if (!defined($eert{$l})) {
    my @g=($l);
    while($l) {
      $l=$tree{$l};
      push(@g,$l) if defined($l);
    }
    print join(':',@g),"\n";
  }
}
[download]

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Comment on Re: Using Tree::Simple with while loop and input file. Download Code

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Re^2: Using Tree::Simple with while loop and input file. by ikegami (Patriarch) on Jun 30, 2009 at 22:30 UTC
You can cut the bottom loop by half (11 ⇒ 5) without making it more complex `for (grep $tree{$_}, keys %tree) { my @g = $_; push @g, $_ while $_=$tree{$_}; print(join(':', @g), "\n"); }` [download] And why bother with an array? `for (grep $tree{$_}, keys %tree) { my $g = $_; $g .= ":$_" while $_=$tree{$_}; print("$g\n"); }` [download]	[reply] [d/l] [select]