PHP实现转盘抽奖算法分享

/**
     * @Description: 获取九宫格抽奖结果
     * @Author: zxy
     * @param {type} 
     * @return {type} 
     */
    public function turntable()
    {
        //拼装奖项数组 
        // 奖项id，奖品，概率
        $prize_arr = array(
            '0' => array('id' => 1, 'prize' => '平板电脑', 'v' => 0),
            '1' => array('id' => 2, 'prize' => '数码相机', 'v' => 0),
            '2' => array('id' => 3, 'prize' => '音箱设备', 'v' => 0),
            '3' => array('id' => 4, 'prize' => '4G优盘', 'v' => 5),
            '4' => array('id' => 5, 'prize' => '10Q币', 'v' => 0),
            '5' => array('id' => 6, 'prize' => '空奖', 'v' => 5),
        );
        foreach ($prize_arr as $key => $val) {
            $arr[$val['id']] = $val['v']; //概率数组 
        }
        $rid = $this->get_rand($arr); //根据概率获取奖项id 
        $res['yes'] = $prize_arr[$rid - 1]['prize']; //中奖项 
        unset($prize_arr[$rid - 1]); //将中奖项从数组中剔除，剩下未中奖项 
        shuffle($prize_arr); //打乱数组顺序 
        for ($i = 0; $i < count($prize_arr); $i++) {
            $pr[] = $prize_arr[$i]['prize']; //未中奖项数组 
        }
        $res['no'] = $pr;
        // var_dump($res);


        if ($res['yes'] != '空奖') {
            $result['status'] = 1;
            $result['name'] = $res['yes'];
        } else {
            $result['status'] = -1;
            $result['msg'] = $res['yes'];
        }
        //return $result; 
        var_dump($result);
    }

    //计算中奖概率
    function get_rand($proArr)
    {
        $result = '';
        //概率数组的总概率精度 
        $proSum = array_sum($proArr);
        // var_dump($proSum);
        //概率数组循环 
        foreach ($proArr as $key => $proCur) {
            $randNum = mt_rand(1, $proSum); //返回随机整数 

            if ($randNum <= $proCur) {
                $result = $key;
                break;
            } else {
                $proSum -= $proCur;
            }
        }
        unset($proArr);
        return $result;
    }