建立一个继承结构，以栈、队列、优先级队列作为派生类，建立它们的抽象基类Bag。统一命名派生类的插入操作Add，删除操作Remove，存取操作Get和Put，初始化操作MakeEmpty，判空操作isEmpty，判满操作isFull，计数操作Length。-Establish an inheritance structure to stacks, queues, priority queues as a derived class, to establish their abstract base class Bag. Uniform Naming derived class insert Add, delete Remove, access operations Get and Put, initialization MakeEmpty, sentenced to air operations isEmpty, sentenced to full operation isFull, counting operation Length.