php 算法 双向链表

<?php
/**双向链表 -- 水浒传英雄排行版*/
class hero{
    public $name = '';
    public $no ='';
    public $cname = '';
    public $next = '';
    public $pre = '';
    public function __construct($no = '',$name='',$cname=''){
        $this->no = $no;
        $this->name = $name;
        $this->cname = $cname;
    }
    //显示英雄链表
    public static function showHero($head){
        $cur = $head;
        while($cur->next != null){
            echo '英雄编号:'.$cur->next->no.'  ';
            echo '英雄姓名:'.$cur->next->name.'  ';
            echo '英雄昵称:'.$cur->next->cname.'  ';
            echo '<br />';
            $cur  = $cur->next;
        }
        echo '<hr />';
    }
    //英雄按排序加入
    public static function addHero($head,$hero){
        $cur = $head;
        $isExits = false;
        while($cur->next != null){
            if($cur->next->no > $hero->no){
                break;
            }elseif($cur->next->no == $hero->no){
                $isExits = true;
            }
            $cur = $cur->next;
        }
        if(!$isExits){
            if($cur->next != null){
                $hero->next  = $cur->next;
            }
            $hero->pre = $cur;
            if($cur->next != null){
                $cur->next->pre = $hero;
            }
            $cur->next  = $hero;
        }
    }
    //修改英雄
    public static function editHero($head,$hero){
        $cur = $head;
        while($cur->next != null){
            if($cur->next == $hero){
                break;
            }
            $cur = $cur->next;
        }
        $cur->next->name  = $hero->name;
        $cur->next->cname  = $hero->cname;
    }
    //删除英雄
    public static function delHero($head,$hero){
        $cur = $head;
        if($cur == null){
            return false;
        }
        while($cur->next != null){
            if($cur  == $hero){
                break;
            }
            $cur = $cur->next;
        }
        if($cur->next != null){
            $cur->next->pre  = $cur->pre;
        }
        $cur->pre->next  = $cur->next;
    }
}

$head = new hero();
$songjiang = new hero(1,'宋江','及时雨');
$lujunyi     = new hero(2,'卢俊义','玉麒麟');
$linchong   = new hero(6,'林冲','豹子头');
$wuyong   = new hero(3,'吴用','智多星');
hero::addHero($head,$songjiang);
hero::addHero($head,$lujunyi);
hero::addHero($head,$linchong);
hero::addHero($head,$wuyong);
hero::showHero($head);
$wuyong->name = '吴用2';
hero::editHero($head,$wuyong);
hero::showHero($head);
hero::delHero($head,$wuyong);
hero::showHero($head);
?>
</body>
</html>

　　双向链表的知识讲解：http://blog.csdn.net/wenximalong/article/details/8308881