The Stack Abstract Data Type

Stack ADT

The stack ADT is defined as a class that follows the LIFO principle for its elements. The stack should support the following operations:

1. Push(): Adds a single element at the top of the stack
2. Pop(): Removes a single element from the top of the stack.
3. Top(): Reads the value of the top element of the stack (does not remove it).
4. isEmpty(): Returns 1 if the stack is empty.
5. Size(): Returns the number of elements in the stack.