Stacks

There are two main operations associated with stacks:

1) Putting things on the stack which is referred to as push,

2) Taking things from the stack which is referred to as pop.

We can create a stack using linked lists if we force ourselves to insert and remove nodes only at the top of the list. One use of a stack is when you want to write a word backward. In that case, you will read the letters of the word one-by-one and as you read them will push them onto a stack. Once all letters are pushed onto the stack, then pop them back one-by-one. This will produce the letters of the word in reverse order.

- Give the definition of the member function push of the class Stack.

- Given the definition of the copy constructor for the class Stack.

Write a program that implements a stack. Your program will ask users to input a word letter-by-letter and then displays the word backward. Please note that you are working with letters to build the stack, thus when you read the word, you will push the letters onto the stack and when you write them, you will pop those letters one-by-one.