摘要：
这题还是接着Exercise1和Exercise2来的，没什么难的，照着它给的头文件补充好函数就可以了本题给了两个头文件 Category.h和Categories.h看一下题目给的提示Class CategoryClass Category models a category. This class contains private data members for the category name, identification number, and parent identification number. A vector<int> stores the unique 阅读全文