1使用到了stl sorting 2stl find 3实现所有声明的函数。 关键方法是： virtual Listing sort(string field) 根据选择"email," "start," "close," and "quantity."来对list中的advertisements进行排序。 virtual Listing filter(string keyword) 筛选出whose name or descr iption contains

利用STL中MAP容器写的参数工具类及其使用示例：可以方便地从文件中读取参数，将参数保存到文件，在自己程序中随时随地存取参数。-Written using STL containers in the MAP parameter tools and their use example: you can easily read from the file parameter, the parameter to a file, the program anytime, anywhere access