PHP实现链式队列

<?php
header("Content-Type:text/html;charset=utf-8");
/**
 * 链式队列
 */
class node{
  public $nickname;
  public $next;
}
class queue
{
  public $front;//头部
  public $tail;//尾部
  public $maxSize;//容量
  public $next;//指针
  public $len=0;//长度
  public function __construct($size)
  {
    $this->init($size);
  }
  public function init($size)
  {
    $this->front = $this;
    $this->tail = $this;
    $this->maxSize = $size;
  }
  //入队操作
  public function inQ($nickname)
  {
    $node = new node();
    $node->nickname = $nickname;
    if ($this->len==$this->maxSize)
    {
      echo '队满了</br>';
    } else {
      $this->tail = $node;
      $this->tail->next = $node;
      $this->len++;
      echo $node->nickname.'入队成功</br>';
    }
  }
  //出队操作
  public function outQ()
  {
    if ($this->len==0)
    {
      echo '队空了</br>';
    } else {
      $p = $this->front->next;
      $this->front->next = $p->next;
      $this->len--;
      echo $p->nickname.'出队成功</br>';
    }
  }
  //打印队
  public function show()
  {
    for ($i=$this->len;$i>0;$i--)
    {
      $this->outQ();
    }
  }
}
echo "**********入队操作******************</br>";
$q = new queue(5);
$q->inQ('入云龙');
$q->inQ('花和尚');
$q->inQ('青面兽');
$q->inQ('行者');
$q->inQ('玉麒麟');
$q->inQ('母夜叉');
echo "**********出队队操作******************</br>";
$q->outQ();
$q->outQ();
$q->outQ();
$q->outQ();
$q->inQ('操刀鬼');
$q->inQ('截江鬼');
$q->inQ('赤发鬼');
$q->outQ();
?>