barber

代码说明：

  一个理发店，只有一个理发师，只有n张可供顾客等待理发的椅子，如果没有顾客，则理发师睡觉；如果有一顾客进入理发店发现理发师在睡觉，则把他叫醒，写一个程序协调理发师和顾客之间的关系。(A barber shop, there is only one barber, only the n Zhang barber' s chair waiting for customers, without customers, the barber to sleep if there is a customer into the barber shop barber was found sleeping, others view him wake up, write a program Coordination between barber and customer relations.)