Linked List

In this lab, you will write a program that manipulates Linked List. 

· The execution of the finished program should look what is shown below (User input is shown in bold).

Author:      Hong Wang

Lab:         Thursday 2pm

Program:     Lab 13: Linked List

Available commands:

  insert <CHARACTER> <FREQUENCY>

  undo

  exit

Current linked list:

$ insert a 123

Current linked list:

[a/123]

$ insert b 2345

Current linked list:

[b/2345] -> [a/123]

$ insert x 777

Current linked list:

[x/777] -> [b/2345] -> [a/123]

$ undo

Current linked list:

[b/2345] -> [a/123]

$ undo

Current linked list:

[a/123]

$ insert x 999

Current linked list:

[x/999] -> [a/123]

$ exit

· The skeleton code is provided here:  Lab13.cpp , you need to implement three functions. 

· DO NOT change any code within 'main' function. 

· Stage 1 (1 point):

· Implement function void displayList(Node* pHead), which display the entries in the list.

Example:

[x/777] -> [b/2345] -> [a/123]

· Stage 2 (1 point):

· Implement function Node* addNode(Node* pHead, char c, int count), which 

· Creates a new node using given values

· Inserts the new node at the beginning of linked list

· Returns the new head pointer