ADT Stack defines a set of operations to interact with its data, which

implementations must provide. It is a fundamental structure used in many computing

applications. This question concerns the data type Stack.

One Stack operation, size$(),$ returns a integral value that describes the number of

elements on the stack. Name and describe the behaviour of $4$ other operations you would

expect to find in a Stack implementation. Your descriptions should include anyinput

parameters and a retun type, if required.

Identify whether Stack is a LIFO or FIFO structure. Include a brief explanation of

both the terms FIFO and LIFO.

A simple implementation strategy for ADT Stack is to use an underlying array, where $I$

each stack element is simply stored in order, in this underlying array; e$.$g$.$ :

Assuming that Stack does not need to concern itself with creating or resizing the

underlying array, describe the implementation of the instance method size$()$ and one

other method you identified in $($a$)$ that alters data in this array.

Note: For this question, you should answer in a Java$-$like pseudo$-$code, including a

method signature$/$header for each method. This should be recognisable to a Java

programmer, but you will not be penalised for syntax errors or generics$-$related

muances, providing your code is understandable.