百分百可用随机红包算法

public function rand_red($money,$num){
        $per_money = $money/$num;
        if($per_money<0.01)
            return [false,'单个红包金额不可低于1分钱，请重填金额'];
        $pack_list=array();
        $last = $money*100-1;
        $have = 0;
        $time = $num;
        for ($i=1;$i<=$time;$i++){
            if($i==$time){
                $pack_list[] = ($money*100-$have)/100;
                break;
            }
            $per = $last/$num;
            $red = mt_rand(1,$per*2);
            $pack_list[] = $red/100;
            $last = $last-$red;
            $num--;
            $have+=$red;
        }
        return $pack_list;
}