分别基于线性表、二叉排序树或哈希表不同的检索策略，实现一个列车信息检索系统（列车信息保存在train.txt中），能根据输入的“车次”检索出对应的列车详细信息，并计算不同检索策略的平均查找长度ASL。-Respectively, based on the linear table, binary sort tree or hash table different search strategies to achieve a train Information Retri　System (train information stored in train.txt), corresponding to the train details can be entered in accordance with the " trips"　search, and calculate the different search strategies of the average length of ASL.