详解PHP队列的实现

<?php
/**
* php队列算法
* 
* Create On 2010-6-4
* Author Been
* QQ:281443751
* Email:binbin1129@126.com
**/
class data {
  //数据
  private $data;
  
  public function __construct($data){
    $this->data=$data;
    echo $data.":哥进队了！<br>";
  }
  
  public function getData(){
    return $this->data;
  }
  public function __destruct(){
    echo $this->data."：哥走了！<br>";
  }
}
class queue{
  protected $front;//队头
  protected $rear;//队尾
  protected $queue=array('0'=>'队尾');//存储队列
  protected $maxsize;//最大数
  
  public function __construct($size){
    $this->initQ($size);
  }
  //初始化队列
  private function initQ($size){
    $this->front=0;
    $this->rear=0;
    $this->maxsize=$size;
  }
  //判断队空
  public function QIsEmpty(){
    return $this->front==$this->rear;
  }
  //判断队满
  public function QIsFull(){
    return ($this->front-$this->rear)==$this->maxsize;
  }
  //获取队首数据
  public function getFrontDate(){
    return $this->queue[$this->front]->getData();
  }
  //入队
  public function InQ($data){
    if($this->QIsFull())echo $data.":我一来咋就满了！（队满不能入队，请等待！）<br>";
    else {
      $this->front++;
      for($i=$this->front;$i>$this->rear;$i--){
        //echo $data;
        if($this->queue[$i])unset($this->queue[$i]);
        $this->queue[$i]=$this->queue[$i-1];
      }
      $this->queue[$this->rear+1]=new data($data);
      //print_r($this->queue);
      //echo $this->front;
      echo '入队成功！<br>';
    }
  }
  //出队
  public function OutQ(){
    if($this->QIsEmpty())echo "队空不能出队！<br>";
    else{
      unset($this->queue[$this->front]);
      $this->front--;
      //print_r($this->queue);
      //echo $this->front;
      echo "出队成功！<br>";
    }
  }
}
$q=new queue(3);
$q->InQ("小苗");
$q->InQ('马帅');
$q->InQ('溜冰');
$q->InQ('张世佳');
$q->OutQ();
$q->InQ("周瑞晓");
$q->OutQ();
$q->OutQ();
$q->OutQ();
$q->OutQ();