每瓶啤酒2元，2個空酒瓶或4個瓶蓋可換1瓶啤酒。10元最多可喝多少瓶啤酒？ php

//根據題意設定初始變量值
//然后 一個while循環去操作
//每換得一個瓶子，換的那個減去要做相應的數目
//然后喝了啤酒后， 各數量加1
//直到不符合要求。跳出循環
 1 class Beer{

    protected $uni_gai      = 4;    //每4個瓶蓋1瓶
    protected $uni_bottle   = 2;    //每兩個瓶子換1瓶
    protected $uni_beer     = 2;    //每瓶2塊錢
    protected $rs           = array();//存取結果
    protected $total        = 0;      //當前買了啤酒的數量
    protected $gai          = 0;      //當前有多少個啤酒
    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);

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

蓋子 3個， 空瓶子 1個， 總共喝了15瓶啤酒