银行有n个柜员负责为顾客服务，顾客进入银行先取一个号码，然后等着叫号。当某个柜员空闲下来，就叫下一个号。 编程实现该问题，用P、V操作实现柜员和顾客的同步。 -Bank tellers have n responsible for customer service, the customer enters the bank to take a number and wait for call number. When a teller idle down, and called the