Sortowanie macierzy w zależności od rodzica; drzewo w jednowymiarowej tablicy

Question

Jak mogę posortować tablicę ze wszystkimi dziećmi po ich rodzicach? Chyba próbuję przechowywać drzewo wewnątrz jednowymiarowej tablicy. Próbowałem to zrozumieć za pomocą usort, ale nie sądzę, że jest to właściwe narzędzie do pracy.

przykład tablicy wkład:

array (0 => array ('id' => '1', 'parent' => '0',), 
1 => array ('id' => '2', 'parent' => '1',), 
2 => array ('id' => '3', 'parent' => '0',), 
3 => array ('id' => '5', 'parent' => '0',), 
4 => array ('id' => '17', 'parent' => '3',), 
5 => array ('id' => '31', 'parent' => '2',), 
6 => array ('id' => '32', 'parent' => '2',)) 

Przykład Wydajność:

Answer 1

start budując rzeczywistego drzewa, a następnie spłaszcza że drzewa:

$array = array (0 => array ('id' => '1', 'parent' => '0',), 
       1 => array ('id' => '2', 'parent' => '1',), 
       2 => array ('id' => '3', 'parent' => '0',), 
       3 => array ('id' => '5', 'parent' => '0',), 
       4 => array ('id' => '17', 'parent' => '3',), 
       5 => array ('id' => '31', 'parent' => '2',), 
       6 => array ('id' => '32', 'parent' => '2',)); 

/* Building a tree. We also save a map of references to avoid         
    searching the tree for nodes */ 

//Helper to create nodes                  
$tree_node = function($id, $parent) { 
    return array('id' => $id, 'parent' => $parent, 'children' => array()); 
}; 

$tree = $tree_node(0, null); //root node              
$map = array(0 => &$tree); 
foreach($array as $cur) { 
    $id = (int) $cur['id']; 
    $parentId = (int) $cur['parent']; 
    $map[$id] =& $map[$parentId]['children'][]; 
    $map[$id] = $tree_node($id, $parentId); 
} 

//Now recursively flatten the tree:               
function flatter($node) { 
    //Create an array element of the node            
    $array_element = array('id' => (string) $node['id'], 
         'parent' => (string) $node['parent']); 
    //Add all children after me                 
    $result = array($array_element); 
    foreach($node['children'] as $child) { 
    $result = array_merge($result, flatter($child)); 
    } 
    return $result; 
} 

$array = flatter($tree); 
array_shift($array); //Remove the root node, which was only added as a helper     

print_r($array); 

Answer 2

<?php 

/** 
* @author Prasath A.R 
* @copyright 2012 
* @Date 2012-8-31 17:14 
*/ 

$array = array (0 => array ('id' => '1', 'parent' => '0',), 
       1 => array ('id' => '2', 'parent' => '1',), 
       2 => array ('id' => '3', 'parent' => '0',), 
       3 => array ('id' => '5', 'parent' => '0',), 
       4 => array ('id' => '17', 'parent' => '3',), 
       5 => array ('id' => '31', 'parent' => '2',), 
       6 => array ('id' => '32', 'parent' => '2',)); 

print_r($array); 
echo "<br />"; 

for($i=0;$i<count($array);$i++) 
{ 
for($j=$i;$j<count($array);$j++) 
{ 
     if($array[$i]['parent']>$array[$j]['parent']) 
     { 
      $temp=$array[$i]; 
      $array[$i]=$array[$j]; 
      $array[$j]=$temp; 
     } 
    } 
} 

echo "<h2>After Sorting</h2><br />"; 
print_r($array); 

?> 

odpowiedź będzie:

Tablica ( [0] => Array ( [id] => 1 [przodek] => 0 )

[1] => Array 
    (
     [id] => 2 
     [parent] => 1 
    ) 

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

[3] => Array 
    (
     [id] => 5 
     [parent] => 0 
    ) 

[4] => Array 
    (
     [id] => 17 
     [parent] => 3 
    ) 

[5] => Array 
    (
     [id] => 31 
     [parent] => 2 
    ) 

[6] => Array 
    (
     [id] => 32 
     [parent] => 2 
    ) 

)

Po sortowaniu

Array ( [0] => Array ( [id] => 1 [przodek] => 0 )

[1] => Array 
    (
     [id] => 3 
     [parent] => 0 
    ) 

[2] => Array 
    (
     [id] => 5 
     [parent] => 0 
    ) 

[3] => Array 
    (
     [id] => 2 
     [parent] => 1 
    ) 

[4] => Array 
    (
     [id] => 31 
     [parent] => 2 
    ) 

[5] => Array 
    (
     [id] => 32 
     [parent] => 2 
    ) 

[6] => Array 
    (
     [id] => 17 
     [parent] => 3 
    ) 

)