Chapter 18, Problem 15PC

Program Plan Intro

Pop( ) and push( ) Member functions

Program Plan:

“IntList.h”:

• Include the required specifications into the program.
• Define a class named “IntList”.
  • Declare the member variables “value” and “*next” in structure named “ListNode”.
  • Declare a variable named “size” in type of integer and initialize the variable as “0” in the constructor.
  • Define the constructor, destructor, and member functions in the class.
  • Declare the functions prototypes of  “pop_back()”, “pop_front()”, “push_back()”, and “push_front()”.

“IntList.cpp”:

• Include the required header files into the program.
• Define a function named “appendNode()” to insert the node at end of the list.
  • Declare the structure pointer variables “newNode” and “dataPtr” for the structure named “ListNode”.
  • Assign the “newNode” value into received variable “num” and assign the “newNode” address into null.
  • Using “if…else” condition check whether the list is empty or not, if the “head” is empty then make a new node into “head” pointer. Otherwise, make a loop to find last node in the loop.
  • Assign the value of “dataPtr” into the variable “newNode”.
  • Increment the value of the variable “size” by “1”.
• Define a function named “display()” to print the values in the list.
  • Declare the structure pointer “dataPtr” for the structure named “ListNode”.
  • Initialize the variable “dataPtr” with the “head” pointer.
  • Make a loop “while” to display the values of the list.
• Define a function named “insertNode()” to insert a value into the list.
  • Declare the structure pointer variables “newNode”, “dataPtr”, and “prev” for the structure named “ListNode”.
  • Make a “newNode” value into the received variable value “num”.
  • Use “if…else” condition to check whether the list is empty or not.
    • If the list is empty then initialize “head” pointer with the value of “newNode” variable.
    • Otherwise, make a “while” loop to test whether the “num” value is less than the list values or not.
    • Use “if…else” condition to initialize the value into list.
  • Increment the value of the variable “size” by “1”.
• Define a function named “deleteNode()” to delete a value from the list.
  • Declare the structure pointer variables “dataPtr”, and “prev” for the structure named “ListNode”.
  • Use “if…else” condition to check whether the “head” value is equal to “num” or not.
    • Initialize the variable “dataPtr” with the value of the variable “head”.
    • Remove the value using “delete” operator and reassign the “head” value into the “dataPtr”.
    • If the “num” value not equal to the “head” value, then define the “while” loop to assign the “dataPtr” into “prev”.
    • Use “if” condition to delete the “prev” pointer.
  • Decrement the value of the variable “size” by “1”.
• Define the function named “getSize()” to return the current value of the “size”.
• Define the destructor to destroy the list values from the memory.
  • Declare the structure pointer variables “dataPtr”, and “nextNode” for the structure named “ListNode”.
  • Initialize the “head” value into the “dataPtr”.
  • Define a “while” loop to make the links of node into “nextNode” and remove the node using “delete” operator.
• Define the function named “pop_back()”  to insert a value at end of the list.
  • Declare the pointer variables for structure named “ListNode” and assign null to the “previousNode”.
  • Using “if” condition check whether the list is empty or not.
    • If the list is empty then throw a message on the screen.
  • Using “while” loop to traverse the list.
    • Initialize the variable “previousNode” with the value of the variable “node”.
    • Assign null to the address of “previousNode”.
  • Delete the value of “node” using “delete” operator.
  • Return the value of “temp” to the calling function.
• Define the function named “pop_front()”  to insert a value at front of the list.
  • Declare the pointer variable “node” for a structure “ListNode”.
  • Using “if” condition check whether the list is empty or not.
    • If the list is empty then throw a message on the screen.
  • Using “while” loop to traverse the list.
    • Initialize the variable “temp” with the value of the variable “head”.
    • Assign null to the address of “head”.
  • Delete the value of “node” using “delete” operator.
  • Return the value of “temp” to the calling function.
• Define the function named “push_back()” to insert the value at end of the list.
  • Make a call to the “appendNode()” function to insert the received value of variable “value” at end of the list.
• Define the function named “push_front()” to insert the value at front of the list.
  • Declare a pointer variable “newNode” for the structure.
  • Initialize the variable “newNode” with the value of received variable “value”.
  • Using “if…else” condition check the list is empty.
    • If the list is empty then add a value into “head” pointer.
    • Otherwise, add a value into address of “newNode”.
  • Increment the “size” variable by “1”.

“main.cpp”:

• Include the required header files into the program.
• Declare an object named “obj” for the class “IntList”.
• Make a call to functions for append and display operations.
• Make a call to function “pop_back()”, “pop_front()”, “push_front()”, and “push_back()” and display the values using a function “display()”.