说明：  银行业务模拟问题描述：客户业务分为两种：第一种是申请从银行得到一笔资金，即取款或借款。第二种是向银行投入一笔资金，即存款或还款。银行有两个服务窗口，相应的有两个队列。客户到达银行后先排第一个队。处理每个客户业务时，如果属于第一种，且申请额超出银行现存资金总额而得不到满足，则立即排入第二队等候，直至满足时才离开银行，否则业务处理完后立即离开银行。每接待完一个第二种业务的客户，则顺序检查和处理（如果可能）第二个队列的客户，对能满足的申请者予以满足，不能满足者重新排到第二个队列的队尾。通过模拟方法求出客户在银行内逗留的平均时间。
(Banking simulation description of the problem: the client s business is divided into two: the first one is the application to get funds from the bank, that withdrawal or borrowing. The second is to invest a sum of money to the bank deposits or repayment. The bank has two service windows, the corresponding two queues. Customers arrived at the bank after the first row of the first team. Handle each customer s business, if they are the first, and applicants exceeds the total capital of banks existing and can not be met immediately discharged into the second team to wait until meet only left the bank, otherwise the business dealt with immediately leave Bank. Per reception finished a second business customers, sequence checking and handling (if possible) a second queue of customers, to meet the applicant be met, can not meet the re-routed to the second queue the tail. By simulation method calculated the average time customers stay in the bank.)