Chapter 13.1, Problem 3STE

Program Plan Intro

Linked list:

• Linked list denotes a linear data structure.
• The elements are not stored at contiguous locations; the elements are linked using pointers.
• It stores linear data of similar types not like arrays.
• The size of linked list can be changed based on requirement.
• It is represented by a pointer to first linked list node.
• The first node denotes a head.
• If linked list is empty, value of head is NULL.
• The node in a list has two parts, data and pointer to next node.

Given code:

//Define a structure

struct Box

{

//Declare variable

string name;

//Declare variable

int number;

//Define pointer to next

Box *next;

};

//Create an instance

BoxPtr head;

//Assign value

head = new Box;

//Assign value

head->name = "Sally";

//Assign value

head->number = 18;

//Assign value

head->next = NULL;

//Display value

cout << (*head).name << endl;

//Display value

cout << head->name << endl;

//Display value

cout << (*head).number << endl;

//Display value

cout << head->number << endl;

Explanation:

• The “Box” defines a structure with “name” and “number” as members.
• It contains a pointer to next element of list.
• The “BoxPtr head” creates an instance of structure.
• A new “Box” element is created.
• The values of “name” and “number” are been set.
• The values of “name” and “number” are been displayed.
• The member variable next to the node is been set to NULL.

Complete program:

//Include libraries

#include<iostream>

#include<string>

//Use namespace

using namespace std;

//Define a structure

struct Box

{

//Declare variable

string name;

//Declare variable

int number;

//Define pointer to next

Box *next;

};

//Define instance

typedef Box* BoxPtr;

//Define main method

void main()

{

//Create an instance

BoxPtr head;

//Assign value

head = new Box;

//Assign value

head->name = "Sally";

//Assign value

head->number = 18;

//Display value

cout << (*head).name << endl;

//Display value

cout << head->name << endl;

//Display value

cout << (*head).number << endl;

//Display value

cout << head->number << endl;

//Delete

delete head;

//Display message

cout<<"List head is been destroyed"<<endl;

//Pause console window

system("pause");

}

Explanation:

• The “Box” defines a structure with “name” and “number” as members.
• It contains a pointer to next element of list.
• Define a main method
  • The “BoxPtr head” creates an instance of structure.
  • A new “Box” element is created.
  • The values of “name” and “number” are been set.
  • The values of “name” and “number” are been displayed.
  • The member variable next to the node is been set to NULL.
  • The linked list is been destroyed using “delete” statement.