多处最优服务次序问题，设有N个顾客同时等待一项服务。顾客i需要的服务时间为ti，共有s处可以提供此项服务，应如何安排n个顾客的服务次序才能使平均等待时间达到最小。-Optimal order of multiple services, with N of customers waiting for a service at the same time. I need to service customers time ti, a total of s Office can provide the