关于数组重组

Question

有这样一个数组：

[
     1 => [ 'k' => 0 ],
     2 => [ 'k' => 1 ],
     3 => [ 'k' => 1 ],
     4 => [ 'k' => 2 ],
     5 => [ 'k' => 4 ],
     6 => [ 'k' => 3 ],
     7 => [ 'k' => 0 ],
     8 => [ 'k' => 6 ]
]

根据数组中存的k的值，在数组中找自己的父级，然后把自己添加到父级的children下，数组重组成如下的结构：

[
    1 => [
      'k' => 0,
      'children' => [
          2 => [
            'k' => 1,
            'children' => [
                4 => [
                    'k' => 2
                    'children' => [
                        5 => ['k' => 4]
                    ]
                ]
            ]
          ],
          3 => [
              'k' => 1,
              'children' => [
                  6 => [
                  'k' => 3,
                  'children' => [
                      8 => ['k' => 6]
                  ]
              ]
          ]
      ]
    ],
    7 => [ 'k' => 0 ]
]

Answer 1

直接贴代码了

$array = [
     1 => [ 'k' => 0 ],
     2 => [ 'k' => 1 ],
     3 => [ 'k' => 1 ],
     4 => [ 'k' => 2 ],
     5 => [ 'k' => 4 ],
     6 => [ 'k' => 3 ],
     7 => [ 'k' => 0 ],
     8 => [ 'k' => 6 ]
];


$tree  = [];
$refer = $array;

foreach($array as $key => $val) {
    if (isset($refer[$val['k']])) {
        $refer[$val['k']]['children'][$key] = &$refer[$key];
    } else {
        $tree[$key] = &$refer[$key];
    }
}

print_r($tree);