Merging Two Doubly Linked Lists

This Project on Merging Two Doubly Linked Lists is submitted by Shikhar(CGC Landran)

#include<iostream>
using namespace std;
class Node
{
public:
int data;
Node *next;
Node *prev;
Node()
{
data=0;
next=prev=NULL;
}
};
class Node1
{
public:
int data;
Node1 *next;
Node1 *prev;
Node1()
{
data=0;
next=prev=NULL;
}
};
class Node2
{
public:
int data;
Node2 *next;
Node2 *prev;
Node2()
{
data=0;
next=prev=NULL;
}
};
class DoublyLinkedList
{
private:
Node *headNode, *tailnode;
Node1 *headNode1, *tailNode1;
Node2 *headNode2, *tailNode2;
public:
DoublyLinkedList()
{
headNode=tailNode=NULL;
headNode1=tailNode1=NULL;
headNode2=tailNode2=NULL;
}
void Insert();//Insert data into the two lists
void Merge() ;//Merging two lists into one
void Display();//Display only the merged list
};
void DoublyLinkedList::Insert()
{
char option;
//This section inserts elements into the nodes of the first list
do
{
Node *newnode = new Node();
cin>>newnode->data;
newnode->next=NULL;
newnode->prev=NULL;
if(headNode==NULL)
{
headNode= tailNode=newnode;
}
else
{
Node *curr = headNode;
while(curr->next!=NULL)
{
curr=curr->next;
}
curr->next=tailNode=newnode;
newnode->prev=curr;
}
cout<<”Enter y to continue adding data into the first list :”;
cin>>option;
}
while(option==’y'||option==’Y');

//The section inserts the elements into the nodes of the second
list
do
{
Node1 *newnode = new Node1();
cin>>newnode->data;
newnode->next=NULL;
newnode->prev=NULL;
if(headNode1==NULL)
{
headNode1=tailNode1=newnode;
}
else
{
Node1 *curr = headNode1;
while(curr->next!=NULL)
{
curr=curr->next;
}
curr->next= tailNode1=newnode;
newnode->prev=curr;
}
cout<<”Enter y to continue adding data into the second list :”;
cin>>option;
}
while(option==’y'||option==’Y');
}
void DoublyLinkedList::Merge()
{
Node *currentNode=headNode;
Node1 *currentNode1=headNode1;
//This section of code copies all the data from list 1 into the new
list
while(currentNode!=NULL)
{
Node2 *newnode = new Node2();
newnode->data = currentNode->data;
newnode->next = NULL;
newnode->prev = NULL;
if(headNode2==NULL)
{
headNode2=tailNode2=newnode;
}
else
{
Node2 *temp = headNode2;
while(temp->next!=NULL)
{
temp=temp->next;
}
temp->next=tailNode2=newnode;
newnode->prev=temp;
}
currentNode=currentNode->next;
}

//This section of code appends the new list with data from the
second
list
while(currentNode1!=NULL)
{
Node2 *newnode = new Node2();
newnode->data = currentNode1->data;
newnode->next = newnode->prev=NULL;
if(tailNode2->next==NULL)
{
tailNode2->next=newnode;
newnode->prev = tailNode2;
tailNode2=newnode;
}
currentNode1= currentNode1->next;
}
}
void DoublyLinkedList::Display()
{
Node2 *currentNode2 = headNode2;
while(currentNode2!=NULL)
{
cout<<currentNode2->data<<” “;
currentNode2=currentNode2->next;
}
cout<<endl;
}

void main()
{
DoublyLinkedList DLL;
DLL.Insert();
DLL.Merge();
DLL.Display();
}