Q:

Program to insert a new node at the end of doubly linked list

belongs to collection: Doubly Linked List Programs

robaa
Save to bookmark
|
2022-11-10
|
  254 
0

Explanation

In this program, we will create a doubly linked list and insert every new node at the end of the list. If the list is empty, then head and tail will point to newly added node. If list is not empty then, insert the new node at the end of the list such that tail's next will point to new node. Make new node as new tail of the list and its next will point to null.

In above example, node 4 was the tail of the list. Now, the new node will be inserted at the end of the list such that node 4's next will point to new node. Make new node as the tail of the list, and its next will point to null.

Algorithm

  1. Define a Node class which represents a node in the list. It will have three properties: data, previous which will point to the previous node and next which will point to the next node.
  2. Define another class for creating a doubly linked list, and it has two nodes: head and tail. Initially, head and tail will point to null.
  3. addAtEnd() will add node to the list:
    1. It first checks whether the head is null, then it will insert the node as the head.
    2. Both head and tail will point to a newly added node.
    3. Head's previous pointer will point to null and tail's next pointer will point to null.
    4. If the head is not null, the new node will be inserted at the end of the list such that new node's previous pointer will point to tail.
    5. The new node will become the new tail. Tail's next pointer will point to null.
  4. display() will show all the nodes present in the list.
    1. Define a new node 'current' that will point to the head.
    2. Print current.data till current points to null.
    3. Current will point to the next node in the list in each iteration.

Input:

 

#Adding 1 to the list  

dList.addAtEnd(1);  

#Adding 2 to the list  

dList.addAtEnd(2);  

#Adding 3 to the list  

dList.addAtEnd(3);   

#Adding 4 to the list  

dList.addAtEnd(4);  

#Adding 5 to the list  

dList.addAtEnd(5);  

Output:

Adding a node to the end of the list: 1 
Adding a node to the end of the list: 1 2 
Adding a node to the end of the list: 1 2 3 
Adding a node to the end of the list: 1 2 3 4 
Adding a node to the end of the list: 1 2 3 4 5
Python programming, Php programming, Java programming, C programming, c# programming, examples, Python programming examples, Php programming examples, Java programming examples, C programming examples, c# programming examples,
login and add your own answer to this question

All Answers

robaa
2022-11-10
need an explanation for this answer? contact us directly to get an explanation for this answer

Python

#Represent a node of doubly linked list  
class Node:  
    def __init__(self,data):  
        self.data = data;  
        self.previous = None;  
        self.next = None;  
          
class InsertEnd:  
    #Represent the head and tail of the doubly linked list  
    def __init__(self):  
        self.head = None;  
        self.tail = None;  
          
    #addAtEnd() will add a node to the end of the list  
    def addAtEnd(self, data):  
        #Create a new node  
        newNode = Node(data);  
          
        #If list is empty  
        if(self.head == None):  
            #Both head and tail will point to newNode  
            self.head = self.tail = newNode;  
            #head's previous will point to None  
            self.head.previous = None;  
            #tail's next will point to None, as it is the last node of the list  
            self.tail.next = None;  
        #Add newNode as new tail of the list  
        else:  
            #newNode will be added after tail such that tail's next will point to newNode  
            self.tail.next = newNode;  
            #newNode's previous will point to tail  
            newNode.previous = self.tail;  
            #newNode will become new tail  
            self.tail = newNode;  
            #As it is last node, tail's next will point to None  
            self.tail.next = None;  
              
    #display() will print out the nodes of the list  
    def display(self):  
        #Node current will point to head  
        current = self.head;  
        if(self.head == None):  
            print("List is empty");  
            return;  
        print("Adding a node to the end of the list: ");  
        while(current != None):  
            #Prints each node by incrementing pointer.  
            print(current.data),  
            current = current.next;  
              
        print();  
          
dList = InsertEnd();  
   
#Adding 1 to the list  
dList.addAtEnd(1);  
dList.display();  
#Adding 2 to the list  
dList.addAtEnd(2);  
dList.display();  
#Adding 3 to the list  
dList.addAtEnd(3);  
dList.display();  
#Adding 4 to the list  
dList.addAtEnd(4);  
dList.display();  
#Adding 5 to the list  
dList.addAtEnd(5);  
dList.display();

 

Output:

Adding a node to the end of the list: 
1 
Adding a node to the end of the list: 
1 2 
Adding a node to the end of the list: 
1 2 3 
Adding a node to the end of the list: 
1 2 3 4 
Adding a node to the end of the list: 
1 2 3 4 5

 

C

#include <stdio.h>  
   
//Represent a node of the doubly linked list  
  
struct node{  
    int data;  
    struct node *previous;  
    struct node *next;  
};      
   
//Represent the head and tail of the doubly linked list  
struct node *head, *tail = NULL;  
   
//addAtEnd() will add a node to the end of the list  
void addAtEnd(int data) {  
    //Create a new node  
    struct node *newNode = (struct node*)malloc(sizeof(struct node));  
    newNode->data = data;  
      
    //If list is empty  
    if(head == NULL) {  
        //Both head and tail will point to newNode  
        head = tail = newNode;  
        //head's previous will point to NULL  
        head->previous = NULL;  
        //tail's next will point to NULL, as it is the last node of the list  
        tail->next = NULL;  
    }  
    //Add newNode as new tail of the list  
    else {  
        //newNode will be added after tail such that tail's next will point to newNode  
        tail->next = newNode;  
        //newNode's previous will point to tail  
        newNode->previous = tail;  
        //newNode will become new tail  
        tail = newNode;  
        //As it is last node, tail's next will point to NULL  
        tail->next = NULL;  
    }  
}  
   
//display() will print out the nodes of the list  
void display() {  
    //Node current will point to head  
    struct node *current = head;  
    if(head == NULL) {  
        printf("List is empty\n");  
        return;  
    }  
    printf("Adding a node to the end of the list: \n");  
    while(current != NULL) {  
        //Prints each node by incrementing pointer.  
        printf("%d ", current->data);  
        current = current->next;  
    }  
    printf("\n");  
}  
      
int main()  
{  
    //Adding 1 to the list  
    addAtEnd(1);  
    display();  
    //Adding 2 to the list  
    addAtEnd(2);  
    display();  
    //Adding 3 to the list  
    addAtEnd(3);  
    display();  
    //Adding 4 to the list  
    addAtEnd(4);  
    display();  
    //Adding 5 to the list  
    addAtEnd(5);  
    display();  
   
    return 0;  
}

 

Output:

Adding a node to the end of the list: 
1 
Adding a node to the end of the list: 
1 2 
Adding a node to the end of the list: 
1 2 3 
Adding a node to the end of the list: 
1 2 3 4 
Adding a node to the end of the list: 
1 2 3 4 5

 

JAVA

public class InsertEnd {  
      
    //Represent a node of the doubly linked list  
  
    class Node{  
        int data;  
        Node previous;  
        Node next;  
          
        public Node(int data) {  
            this.data = data;  
        }  
    }  
      
    //Represent the head and tail of the doubly linked list  
    Node head, tail = null;  
      
    //addAtEnd() will add a node to the end of the list  
    public void addAtEnd(int data) {  
        //Create a new node  
        Node newNode = new Node(data);  
          
        //If list is empty  
        if(head == null) {  
            //Both head and tail will point to newNode  
            head = tail = newNode;  
            //head's previous will point to null  
            head.previous = null;  
            //tail's next will point to null, as it is the last node of the list  
            tail.next = null;  
        }  
        //Add newNode as new tail of the list  
        else {  
            //newNode will be added after tail such that tail's next will point to newNode  
            tail.next = newNode;  
            //newNode's previous will point to tail  
            newNode.previous = tail;  
            //newNode will become new tail  
            tail = newNode;  
            //As it is last node, tail's next will point to null  
            tail.next = null;  
        }  
    }  
      
    //display() will print out the nodes of the list  
    public void display() {  
        //Node current will point to head  
        Node current = head;  
        if(head == null) {  
            System.out.println("List is empty");  
            return;  
        }  
        System.out.println("Adding a node to the end of the list: ");  
        while(current != null) {  
            //Prints each node by incrementing the pointer.  
  
            System.out.print(current.data + " ");  
            current = current.next;  
        }  
        System.out.println();  
    }  
      
    public static void main(String[] args) {  
          
        InsertEnd dList = new InsertEnd();  
          
        //Adding 1 to the list  
        dList.addAtEnd(1);  
        dList.display();  
        //Adding 2 to the list  
        dList.addAtEnd(2);  
        dList.display();  
        //Adding 3 to the list  
        dList.addAtEnd(3);  
        dList.display();  
        //Adding 4 to the list  
        dList.addAtEnd(4);  
        dList.display();  
        //Adding 5 to the list  
        dList.addAtEnd(5);  
        dList.display();  
    }  
}

 

Output:

Adding a node to the end of the list: 
1 
Adding a node to the end of the list: 
1 2 
Adding a node to the end of the list: 
1 2 3 
Adding a node to the end of the list: 
1 2 3 4 
Adding a node to the end of the list: 
1 2 3 4 5

 

C#

using System;   
namespace DoublyLinkedList   
{                       
    public class Program  
    {  
        //Represent a node of the doubly linked list  
  
        public class Node<T>{  
            public T data;  
            public Node<T> previous;  
            public Node<T> next;  
              
            public Node(T value) {  
                data = value;  
            }  
        }  
          
        public class InsertEnd<T>{  
            //Represent the head and tail of the doubly linked list  
            protected Node<T> head = null;               
             protected Node<T> tail = null;  
              
            //addAtEnd() will add a node to the end of the list  
            public void addAtEnd(T data) {  
                //Create a new node  
                Node<T> newNode = new Node<T>(data);  
   
                //If list is empty  
                if(head == null) {  
                    //Both head and tail will point to newNode  
                    head = tail = newNode;  
                    //head's previous will point to null  
                    head.previous = null;  
                    //tail's next will point to null, as it is the last node of the list  
                    tail.next = null;  
                }  
                //Add newNode as new tail of the list  
                else {  
                    //newNode will be added after tail such that tail's next will point to newNode  
                    tail.next = newNode;  
                    //newNode's previous will point to tail  
                    newNode.previous = tail;  
                    //newNode will become new tail  
                    tail = newNode;  
                    //As it is last node, tail's next will point to null  
                    tail.next = null;  
                }  
            }  
      
            //display() will print out the nodes of the list  
            public void display() {  
                //Node current will point to head  
                Node<T> current = head;  
                if(head == null) {  
                    Console.WriteLine("List is empty");  
                    return;  
                }  
                Console.WriteLine("Adding a node to the end of the list: ");  
                while(current != null) {  
                    //Prints each node by incrementing the pointer.  
  
                    Console.Write(current.data + " ");  
                    current = current.next;  
                }  
                Console.WriteLine();  
            }  
        }  
          
        public static void Main()  
        {  
            InsertEnd<int> dList = new InsertEnd<int>();  
   
            //Adding 1 to the list  
            dList.addAtEnd(1);  
            dList.display();  
            //Adding 2 to the list  
            dList.addAtEnd(2);  
            dList.display();  
            //Adding 3 to the list  
            dList.addAtEnd(3);  
            dList.display();  
            //Adding 4 to the list  
            dList.addAtEnd(4);  
            dList.display();  
            //Adding 5 to the list  
            dList.addAtEnd(5);  
            dList.display();  
        }      
    }  
}

 

Output:

Adding a node to the end of the list: 
1 
Adding a node to the end of the list: 
1 2 
Adding a node to the end of the list: 
1 2 3 
Adding a node to the end of the list: 
1 2 3 4 
Adding a node to the end of the list: 
1 2 3 4 5

 

PHP

<!DOCTYPE html>  
<html>  
<body>  
<?php  
//Represent a node of doubly linked list  
class Node{  
    public $data;  
    public $previous;  
    public $next;  
      
    function __construct($data){  
        $this->data = $data;  
    }  
}  
class InsertEnd{  
    //Represent the head and tail of the doubly linked list  
    public $head;  
    public $tail;  
    function __construct(){  
        $this->head = NULL;  
        $this->tail = NULL;  
    }  
      
    //addAtEnd() will add a node to the end of the list  
    function addAtEnd($data) {  
        //Create a new node  
        $newNode = new Node($data);  
          
        //If list is empty  
        if($this->head == NULL) {  
            //Both head and tail will point to newNode  
            $this->head = $this->tail = $newNode;  
            //head's previous will point to NULL  
            $this->head->previous = NULL;  
            //tail's next will point to NULL, as it is the last node of the list  
            $this->tail->next = NULL;  
        }  
        //Add newNode as new tail of the list  
        else {  
            //newNode will be added after tail such that tail's next will point to newNode  
            $this->tail->next = $newNode;  
            //newNode's previous will point to tail  
            $newNode->previous = $this->tail;  
            //newNode will become new tail  
            $this->tail = $newNode;  
            //As it is last node, tail's next will point to NULL  
            $this->tail->next = NULL;  
        }  
    }  
      
    //display() will print out the nodes of the list  
    function display() {  
        //Node current will point to head  
        $current = $this->head;  
        if($this->head == NULL) {  
            print("List is empty <br>");  
            return;  
        }  
        print("Adding a node to the end of the list: <br>");  
        while($current != NULL) {  
            //Prints each node by incrementing pointer.  
            print($current->data . " ");  
            $current = $current->next;  
        }  
        print("<br>");  
    }  
}  
      
$dList = new InsertEnd();  
   
//Adding 1 to the list  
$dList->addAtEnd(1);  
$dList->display();  
//Adding 2 to the list  
$dList->addAtEnd(2);  
$dList->display();  
//Adding 3 to the list  
$dList->addAtEnd(3);  
$dList->display();  
//Adding 4 to the list  
$dList->addAtEnd(4);  
$dList->display();  
//Adding 5 to the list  
$dList->addAtEnd(5);  
$dList->display();  
?>  
</body>  
</html>

 

Output:

Adding a node to the end of the list: 
1 
Adding a node to the end of the list: 
1 2 
Adding a node to the end of the list: 
1 2 3 
Adding a node to the end of the list: 
1 2 3 4 
Adding a node to the end of the list: 
1 2 3 4 5

need an explanation for this answer? contact us directly to get an explanation for this answer

total answers (1)

Doubly Linked List Programs
This question belongs to these collections

Similar questions

need a help?

find thousands of online teachers now
Program to insert a new node at the middle of doub... >>
<< Program to insert a new node at the beginning of t...