每瓶啤酒2元，2个空酒瓶或4个瓶盖可换1瓶啤酒。10元最多可喝多少瓶啤酒？ php

//根据题意设定初始变量值
//然后 一个while循环去操作
//每换得一个瓶子，换的那个减去要做相应的数目
//然后喝了啤酒后， 各数量加1
//直到不符合要求。跳出循环
 1 class Beer{

     protected $uni_gai      = 4;    //每4个瓶盖1瓶
     protected $uni_bottle   = 2;    //每两个瓶子换1瓶
     protected $uni_beer     = 2;    //每瓶2块钱
     protected $rs           = array();//存取结果
     protected $total        = 0;      //当前买了啤酒的数量
     protected $gai          = 0;      //当前有多少个啤酒
     protected $empty_bottle = 0;      //空瓶子

     public function __construct($money){
         $cur = $money / $this->uni_beer;
         $this->total        = $cur;
         $this->gai          = $cur;
         $this->empty_bottle = $cur;
     }

     public function run(){
         while($this->gai > 0 || $this->empty_bottle > 0){
             if($this->gai >= $this->uni_gai){
                 $this->deal_num('gai');
             }
             if($this->empty_bottle >= $this->uni_bottle){
                 $this->deal_num('empty_bottle');
             }

             $this->check_overflow();
         }
         return $this->rs;
     }

     public function deal_num($type){
         if($type == 'gai'){
             $this->gai -= $this->uni_gai;
         }else{
             $this->empty_bottle -= $this->uni_bottle;
         }
         $this->gai++;
         $this->empty_bottle++;
         $this->total++;
     }
     public function check_overflow(){
         if($this->gai < $this->uni_gai && $this->empty_bottle < $this->uni_bottle){
             $this->rs['gai']          = $this->gai;
             $this->rs['total']        = $this->total;
             $this->rs['empty_bottle'] = $this->empty_bottle;
             $this->gai                = 0;
             $this->empty_bottle       = 0;
         }
     }
     public function _print(){
         echo 'gai:', $this->gai;
         echo '<br>';
         echo 'empty_bottle:', $this->empty_bottle;
         echo '<br>';
         echo 'total', $this->total;
         echo '<hr>';
     }
 }

 $peer = new Beer(10);
 $rs   = $peer->run();
 print_r($rs);

打印的结果是： Array ( [gai] => 3 [empty_bottle] => 1 [total] => 15 )

盖子 3个， 空瓶子 1个， 总共喝了15瓶啤酒