you're right it does sound's like homework but is has passed quite some time since i last attended any real classes. so what i tried so far is through recursion catch the pattern to transform it to the nice tree : 
use strict;

open (T, "<", "file.txt")|| die "$!";
open (OUT, ">", "out.txt") || die "$!";
my $t = $ARGV[0];# $t could be 3 not 1 so that i can start from that p
+oint
my %hash;

while (<T>){
    m/^(\d+?),(\d+?)\n/g;
    my ($child, $parent) = ($2,$1);
    push @{$hash{$child}},$parent;
        }


walk($t);

sub walk {
          my $numb = shift;
             print OUT "\|->$numb\n";
             #my @walk = $numb; 
          for (@{$hash{$numb}}){
                  #push @walk, 
                  #print OUTNOD "\|->>>";
                  walk($_);
                  print OUTNOD "\|->>";
          }
         #return @walk; 
}

[download]
there are some relict's in the code but that is because i'm still trying to figure it out.

In reply to Re^2: representing a tree by baxy77bax
in thread representing a tree by baxy77bax

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