fork download
copy 
  1. <?php
  2. $arr = array(
  3. 	1=>0,
  4.     2=>1,
  5.     3=>2,
  6.     4=>1,
  7.     5=>1,
  8.     6=>3,
  9.     7=>6,
  10.     8=>7
  11. );
  12. $parents_key = array_unique(array_values($arr));
  13. $tree = array();
  14. foreach($parents_key as $p){
  15. 	foreach($arr as $k => $v){
  16. 		if($v == $p) $tree[$p][] = $k;
  17. 	}
  18. }
  19. print_r($tree);
Success #stdin #stdout 0.01s 20520KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
Array
(
    [0] => Array
        (
            [0] => 1
        )

    [1] => Array
        (
            [0] => 2
            [1] => 4
            [2] => 5
        )

    [2] => Array
        (
            [0] => 3
        )

    [3] => Array
        (
            [0] => 6
        )

    [6] => Array
        (
            [0] => 7
        )

    [7] => Array
        (
            [0] => 8
        )

)
https://ideone.com/bR4hhq
language:
PHP (php 7.3.5)
created:
9 years ago
visibility:
secret

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!