PHP无限分类的代码谁有？？？

Question

广告: http://hi.baidu.com/zjstandup/blog/item/040d2b468ec18c0c6a63e5ce.html

Answer 1

<?php
class Array2Tree
{
private $_arr;

private $_tree;

public function __construct($arr) {
$this->_arr = $arr;
}

private function _getdata($id) {
$data = array();
foreach ($this->_arr as $key => $row) {
if ($row["bid"] == $id)
$data[] = $row;
}
return $data;
}

private function _load($id) {
$set = $this->_getdata($id);
if (0 == count($set)) {
return $set;
} else {
foreach ($set as $row) {
$sub = array($row["name"]);
$sub['sub'] = $this->_load($row["id"]);
$tree[] = $sub;
}
}
return $tree;
}

public function load($id = 0) {
$this->_tree = $this->_load($id);
return $this;
}

public function gettree() {
return $this->_tree;
}
}
$arr = array(
array("id"=>1, "bid"=>0, "name"=>"足球"),
array("id"=>2, "bid"=>0, "name"=>"篮球"),
array("id"=>3, "bid"=>1, "name"=>"巴西"),
array("id"=>4, "bid"=>1, "name"=>"中国"),
array("id"=>5, "bid"=>3, "name"=>"罗纳尔多"),
array("id"=>6, "bid"=>4, "name"=>"米卢"),
);
?>
简单写了一个，效率稍微有点问题，可以修改一下递归部分，把搜寻父节点的任务在递归中完成，那就不需要用_getdata函数遍历整个数组了
下面是输出结果：$a2t = new Array2Tree($arr);
$zero = $a2t->load()->gettree(); //默认输出整颗树
print_r($zero);
结果：
Array
(
    [0] => Array
        (
            [0] => 足球
            [sub] => Array
                (
                    [0] => Array
                        (
                            [0] => 巴西
                            [sub] => Array
                                (
                                    [0] => Array
                                        (
                                            [0] => 罗纳尔多
                                            [sub] => Array
                                                (
                                                )                                        )                                )                        )                    [1] => Array
                        (
                            [0] => 中国
                            [sub] => Array
                                (
                                    [0] => Array
                                        (
                                            [0] => 米卢
                                            [sub] => Array
                                                (
                                                )                                        )                                )                        )                )        )    [1] => Array
        (
            [0] => 篮球
            [sub] => Array
                (
                )        ))$one = $a2t->load(1)->gettree(); //load()方法接受树的节点号，输出该节点下的所有子节点
print_r($one);
结果：
Array
(
    [0] => Array
        (
            [0] => 巴西
            [sub] => Array
                (
                    [0] => Array
                        (
                            [0] => 罗纳尔多
                            [sub] => Array
                                (
                                )                        )                )        )    [1] => Array
        (
            [0] => 中国
            [sub] => Array
                (
                    [0] => Array
                        (
                            [0] => 米卢
                            [sub] => Array
                                (
                                )                        )                )        ))

Answer 2

joomla里面有串好代码,很简单很强大./*
id     bid    name
1      0      足球 
2      0      篮球 
3      1      巴西 
4      1      中国 
5      3      罗纳尔多 
6      4      米卢 
*/   
$array[0] = array("id"=>1,"bid"=>0,"name"=>"足球");
$array[1] = array("id"=>2,"bid"=>0,"name"=>"篮球");
$array[2] = array("id"=>3,"bid"=>1,"name"=>"巴西");
$array[3] = array("id"=>4,"bid"=>1,"name"=>"中国");
$array[4] = array("id"=>5,"bid"=>3,"name"=>"罗纳尔多");
$array[5] = array("id"=>6,"bid"=>4,"name"=>"米卢");//tree array -- copy some codes from joomla
$tree = array();
if( $array ){
foreach ( $array as $v ){
$pt  = $v['bid'];
$list = @$tree[$pt] ? $tree[$pt] : array();
array_push( $list, $v );
$tree[$pt] = $list;
}
}//foreach root node
foreach($tree[0] as $k=>$v)
{
echo $v['name']."<br/>";
if($tree[$v['id']]) drawTree($tree[$v['id']],$tree,0);

}
//foreach child node
function drawTree($arr,$tree,$level)
{
$level++;
$prefix = str_pad("|",$level+1,'-',STR_PAD_RIGHT);
foreach($arr as $k2=>$v2)
{
echo $prefix.$v2['name']."<br/>";
  if($tree[$v2['id']]) drawTree($tree[$v2['id']],$tree,$level);

}
}
exit;