In this chapter, two different implementations were developed for a stack: class Stack and class LLStack. The names of methods in both classes suggest that the same data structure is meant; however, a...

In this chapter, two different implementations were developed for a stack: class Stack and class LLStack. The names of methods in both classes suggest that the same data structure is meant; however, a tighter connection between these two classes can be established. Define an abstract base class for a stack and derive from it both class Stack and class LLStack.