利用队列实现停车场功能，能判断停车位是够已经满，若已满，来的车进入队列，若有车离开，队列头自动进入停车，并能计算停车费用-Using Queuing parking function is enough to determine parking is full, if full, to the cars into the queue, if cars leave the queue to enter the first automatic parking, and parking fees ca