親に応じて配列をソートする。 1次元配列のツリー

Question

すべての子をそれぞれの親の後に並べ替えるにはどうすればよいですか？私は1次元配列の内部に木を格納しようとしていると思います。私はusortを使ってこれを理解しようとしましたが、それがその仕事のための適切なツールではないと思います。

例入力配列：

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',)) 

出力例：

Answer 1

スタート実際のツリーを構築することにより、そのツリーを平坦化：

$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); 

?> 

回答は次のようになります

アレイ （ [0] =>配列 （ [ID] => 1 [親] => 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 
    ) 

）

並べ替え後

アレイ （ [0] =>アレイ （ [ID] => 1 [親] => 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 
    ) 

）