模拟银行叫号系统。使用基本队列操作。假设某银行有5 个服务窗口，一个统一的叫号系统。在服务时段内，每个时间单位有随机数目的顾客到来，每个新来的顾客得到一个顺序号，排入等待服务队列，等待叫号。 每个服务窗口的职员处理完一个顾客的业务后，顾客即刻离开，职员呼叫下一个顾客，窗口显示下一个顾客的服务号。被叫号的顾客随即得到服务。假定每个顾客需要的服务时间也是随机的。试设计程序模拟上述场景。-Simulated bank calling system. Use basic queue operations. Suppose a bank has five service windows, a unified calling system. In the service period, the number per unit of time with random arrival of customers, each customer to get a new sequence number, into the service queue, waiting, waiting for called. The staff of each service window treatment complete a customer　s business, the customer immediately left, the staff calls the next customer, the next window displays a customer service number. Then be called customer service number. Assume that each customer needs service hours is also random. The design process simulation test scenarios.