银行有n个柜员为顾客服务，顾客进入银行先去一个号码，等着叫号。当某个柜员空闲下来，就叫下一个号。使用P,V操作实现柜员和顾客同步。􄺮 􁇒 􂲴 􀨼 􂆕 􀇄 -Bank teller with n for customer service, customers enter the bank to go to a number, I called the number waiting. When a tel