说明：  解决M/M/1排队论问题，服务时间服从指数分布，队列为泊松流。系统输出为每个个体的到达时间，离开时间，等待时间，逗留时间
(M/M/1 queuing theory to solve the problem, the service time is exponentially distributed, the queue is Poisson. System output for each individual arrival time, departure time, waiting time, length of stay)