PHP ツリー - 再帰は必要ありません、PHP ツリーは再帰的です

<span>/*</span><span>*
 * 创建父节点树形数组
 * 参数
 * $ar 数组，邻接列表方式组织的数据
 * $id 数组中作为主键的下标或关联键名
 * $pid 数组中作为父键的下标或关联键名
 * 返回 多维数组
 *</span><span>*/</span>
<span>function</span> find_parent(<span>$ar</span>, <span>$id</span>='id', <span>$pid</span>='pid'<span>) {
  </span><span>foreach</span>(<span>$ar</span> <span>as</span> <span>$v</span>) <span>$t</span>[<span>$v</span>[<span>$id</span>]] = <span>$v</span><span>;
  </span><span>foreach</span> (<span>$t</span> <span>as</span> <span>$k</span> => <span>$item</span><span>){
    </span><span>if</span>( <span>$item</span>[<span>$pid</span><span>] ){
      </span><span>if</span>( ! <span>isset</span>(<span>$t</span>[<span>$item</span>[<span>$pid</span>]]['parent'][<span>$item</span>[<span>$pid</span><span>]]) )
         </span><span>$t</span>[<span>$item</span>[<span>$id</span>]]['parent'][<span>$item</span>[<span>$pid</span>]] =& <span>$t</span>[<span>$item</span>[<span>$pid</span><span>]];
    }
  }
  </span><span>return</span> <span>$t</span><span>;
}


</span><span>/*</span><span>*
 * 创建子节点树形数组
 * 参数
 * $ar 数组，邻接列表方式组织的数据
 * $id 数组中作为主键的下标或关联键名
 * $pid 数组中作为父键的下标或关联键名
 * 返回 多维数组
 *</span><span>*/</span>
<span>function</span> find_child(<span>$ar</span>, <span>$id</span>='id', <span>$pid</span>='pid'<span>) {
  </span><span>foreach</span>(<span>$ar</span> <span>as</span> <span>$v</span>) <span>$t</span>[<span>$v</span>[<span>$id</span>]] = <span>$v</span><span>;
  </span><span>foreach</span> (<span>$t</span> <span>as</span> <span>$k</span> => <span>$item</span><span>){
    </span><span>if</span>( <span>$item</span>[<span>$pid</span><span>] ) {
      </span><span>$t</span>[<span>$item</span>[<span>$pid</span>]]['child'][<span>$item</span>[<span>$id</span>]] =& <span>$t</span>[<span>$k</span><span>];
    }
  }
  </span><span>return</span> <span>$t</span><span>;
}

    </span><span>$data</span> = <span>array</span><span>(
      </span><span>array</span>('ID'=>1, 'PARENT'=>0, 'NAME'=>'祖父'),
      <span>array</span>('ID'=>2, 'PARENT'=>1, 'NAME'=>'父亲'),
      <span>array</span>('ID'=>3, 'PARENT'=>1, 'NAME'=>'叔伯'),
      <span>array</span>('ID'=>4, 'PARENT'=>2, 'NAME'=>'自己'),
      <span>array</span>('ID'=>5, 'PARENT'=>4, 'NAME'=>'儿子'),<span>
    );

    </span><span>$p</span> = find_parent(<span>$data</span>, 'ID', 'PARENT'<span>);
    </span><span>$c</span> = find_child(<span>$data</span>, 'ID', 'PARENT'<span>);
    </span><span>Print_r</span> (<span>$c</span>);