megaurav2002 has asked for the wisdom of the Perl Monks concerning the following question:

Hi Monks, I have a hash like this: 
key=>value
 1=>1
 2=>1
 3=>1
 4=>2
 5=>3
 6=>4
 7=>4
 8=>8
 9=>8

[download]
based on this hash, i want to build like levels of directory : 
1
 - 2
   - 4
     - 6
     - 7
 - 3
   - 5

8
 -9

[download]
explanation:
1=>1 therefore 1 is root. Same is with 8.
2 & 3 are sub levels of 1 as shown in diagram. Do i need recursion for this? because number of elements is not fixed.
Any hints how to do this?
Thanks!
Gaurav Talwar

Replies are listed 'Best First'.
Re: how to build directory
by greatshots (Pilgrim) on May 22, 2007 at 09:27 UTC
    I would Form a HashofList (HoL) :- 
    my %tree_Hash = (
   1=> [ 1, 2, 3 ],
   2=> [ 4 ],
   3=> [ 5 ],
   4=> [ 6, 7 ],
   8=> [ 8, 9 ],
);

    [download]
    Values are maintained as a Key and Keys become pushed as values under each key. (i,e) the level as you want.
[reply]
[d/l]

      Didn't you mean: 

      my %tree_Hash = (
   1=> {
      2 => {
         4=> {
            6 => undef,
            7 => undef,
         },
      },
      3 => {
         5 => undef,
      },
   }
   8=> {
      9 => undef,
   },
);

      [download]

      This can be build programatically from the existing hash.

      But I'm not sure what exactly the OP wants.

      s$$([},&%#}/&/]+}%&{})*;#$&&s&&$^X.($'^"%]=\&(|?*{%
      +.+=%;.#_}\&"^"-+%*).}%:##%}={~=~:.")&e&&s""`$''`"e
[reply]
[d/l]
[select]
        Yes i meant this only :). I have been trying to do this for quite sometime but no success. Can you give me some hints on how to do this?
[reply]

Back to Seekers of Perl Wisdom