Description

Overview

In this lab, we will explore a new useful data structure: Stacks.  Stacks are usually referred to as a LIFO (Last In First Out) structure, where the last element inserted into the data structure is the first one to be removed from it.  Stacks can be implemented with any type of container (e.g. arrays, linked lists, etc.).  In this lab, you will implement the Stacks with your implementation of the Linked Lists in Lab#8.  In fact, you can think of Stacks as Linked Lists, with the LIFO constraints:  you will implement them using inheritance, by inheriting from a Linked List class.

Getting started

Create a new directory in your main development directory (probably on Desktop/CSE30) called Lab_9.  Try to use the terminal on your own, without getting help from the TA to setup the new directories (try to learn/remember the terminal commands).

The g++ syntax to compile classes is slightly dierent than for a single program comprised of a main (and potential functions):

g++ class1.h class1.cpp class2.h class2.cpp mainSource.cpp -o executable

where:

• g++ is the compiler (installed on your Linux system) of C++ source files,
• cpp is the source file for your main program (main function),
• h is the class declaration for your 1st class,
• cpp is your 1st class definition,
• h is the class declaration for your 2nd class,
• cpp is your 2nd class definition (and so on…),
• -o tells the compiler that you want to give the executable its own name, and  executable is the name you want to give your program.

As an example, if we have a main source file called Exercise1.cpp, the class declaration called LinkedList.h, the class definition called LinkedList.cpp, and want to create an executable called aTestProgram, you would type:

g++ LinkedList.h LinkedList.cpp Exercise1.cpp -o aTestProgram

Assuming that your program compiled successfully (i.e. no errors were found), you can run your program as you normally would by typing “./aTestProgram” in the terminal/console.

Good coding practices (worth 2 points!)

Writing code that is understandable by humans is as important as being correct for compilers.  Writing good code will help you complete the code, debug it and … get good grades.   It is very important to learn as soon as possible, because bad habits are hard to get rid of and good habits become effortless.   Someone (guess who) reads your code will be in a better mood if it is easy to understand … leading to better grades!   This lab will include 2 points (10% for code quality):

• Explanations with comments
• Meaningful names
• Indenting of blocks { }  and nesting …
• Proper use of spaces, parentheses, etc. to
• Visible, clear logic
• One / simple statements per line
• Anything that keeps your style consistent

(Exercise 1)

In this part of the lab, you will be implementing your own Stack class, comprised of a class declaration (Stack.h) and class definition (Stack.cpp).  You will also create a simple main program to test your stack class (Exercise1.cpp).  This part of the Lab will use int as the type for elements in the Stack (Linked List nodes). In order to make the Stack implementation as easy as possible, your stack class will inherit the LinkedList class so that any functions available inside the LinkedList class can be used by the Stack class.  Take a look at the Inheritance_example_files from lecture to see how to use inheritance.  As you will see when you implement the Stack class, inheriting the LinkedList class will make this part of the lab very simple.  Your Stack class will be comprised of the following functions, which you need to implement (note that the Stack class does not need any variables, since those from the inherited LinkedList are all you need):

• Default Constructor (Stack()): does nothing
• Destructor (~Stack()): does nothing
• void push(int value): inserts a new element (value) at the front of the stack, by calling the appropriate LinkedList function.
• int pop(): removes the first element of the Stack, by calling the appropriate LinkedList function. It also returns the value of the element that has been popped.
• int& top(): returns a reference to the top element of the Stack.

You also need to create your own main program (Exercise1.cpp) to test the various Stack functions:

• Create a stack of at least 10 elements in your main program and call various member functions to manipulate the stack (as you have seen in your HW2 problem).
• Call push to insert integer to the stack
• Call top to return to the top of the stack
• Check the size of the stack by calling a function inherited from Linked List.
• Check if the stack is empty by calling a function inherited from Linked List.
• Print the content of the stack by calling a function inherited from Linked List and verify if the member functions work correctly.

Note:

• You do not need to create exceptions, so create a main program that does not call top or pop when the stack is empty.
• Your Stack implementation should be very simple and short. Most, if not all, functions can be implemented using a single line of code. Remember that since you are inheriting the LinkedList class, you can call any functions/variables that were defined inside the LinkedList class.

 (Exercise 2)

In this part of the lab, you will make the following changes to the code developed in Exercise 1:

• Change your Stack and Linked List classes so that they use char type instead of int. Name them Stack_char.h/Stack_char.cpp and LinkedList_char.h/ cpp to avoid the confusion between the classes created in Exercise 1.
• Create a main program (Exercise2.cpp) to produce the following output similar to what was illustrated in the lecture.
• You do not need to produce the table lines, but need to use tabs in between columns and newlines for each row. Columns do not need to be aligned between rows.