CS222 - Homework 7

Homework 7 - Extra Credit

Due: Wednesday March 17, 2009 at noon.
Absolutely NO late assignments will be accepted.
This assignment is worth up to 20 extra credit points in your Homework/Lab grading category.

The purpose of this assignment is to make an integer linked list and stack by inheriting from a general parent list class.

You will define three classes with the following hierarchy, plus a ListNode class for use by List.

              List
           /       \
          /         \
     Linked         Stack
     List

ListNode class

This is the basic node for the list. It holds the data and the pointer to the next node.

Private variables

A integer variable to hold the data
A ListNode pointer to the next node

Public functions

Default and copy constructors
A constructor that takes an integer and a ListNode pointer. It will create a node that holds the integer as its data and points to the ListNode pointer as the next node.
Even though this class has a pointer, there is NO destructor for the class. The List class will handle deallocation of the nodes.
Accessor and mutator functions for the data and next pointer (e.g. getNext, setNext, getData and setData)

List class

The List class is the base class from which the other two classes are derived. It has no real usable features to the main program. Its purpose is to define common functions the other two classes will use. These common functions are put in the protected section so only the derived classes can access them. It has the following features:

Protected variables

A list node for the head node

Protected functions

void front_insert(int) - insert a node at the front of the list
int front_delete() - delete the front of the list and return the value stored in it
void insert_node(ListNode *prev, int) - inserts a node into the middle of the list. The new node will contain the integer as its data.
void delete_node(ListNode *node) - delete the specified node from the list

Public functions

Default and copy constructors
Destructor - deletes all the nodes in the list
bool empty() - returns true if the list is empty
virtual void print_type() - prints "Undefined list" to standard out
void print_list() - Calls this->print_type() and then prints out the contents of the list. Prints output like the following:
```
List Type: Undefined List
Values: Empty list
```

LinkedList class

This class takes the base class and creates a fully working linked list. It will expand the base class to allow searching and deleting specific values.

Public functions

Default and copy constructors
Destructor
virtual void print_type() - prints "Linked List" to standard out
void head_insert(int) - wraps around front_insert()
void insert(ListNode *prev, int) - wraps around insert_node()
ListNode *search_forward(int) - returns the first node that contains value, or NULL if value is not in the list
void delete_first(int) - delete the first instance of value if found, wrap around delete_node()

Stack class

This will implement a stack that is derived from the base list class. It will define the push and pop functions.

Public functions

Default and copy constructors
Destructor
virtual void print_type() - prints "Stack" to standard out
void push(int) - wraps around front_insert() to add value
int pop() - wraps around delete_front() to remove the head node from the stack and return the value it contains

Menu Program

Once the classes are defined, code the following nested menu program to test that the classes work. A nested menu program has multiple menus that are selected from a main menu. When the program is first invoked, the main menu is presented. Options on the main menu give access to the sub-menus. For this assignment, use the following main menu:

   Welcome to the CS222 Homework 7 Menu
==============================================
1.  Test the linked list class
2.  Test the stack class

0.  Exit
==============================================

The submenus are defined as follows.

Linked List Menu

This menu will test the linked list class.

               Linked List Menu
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1. Insert a value at the head of the list
2. Search forwards for a value
3. Insert a value after the result of the previous search
4. Delete the first instance of a value
5. Print the list contents

0. Return to main homework menu
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Option 2 should store the result of the previous search so it is available for Option 3. If there is no prior search result available, Option 3 should print an error and return to the menu.

Stack Menu

This menu will test the stack class.

          Stack Menu
---------------------------------
1. Push a value onto the stack
2. Pop a value off of the stack
3. Print the stack contents

0. Return to main homework menu
---------------------------------