Insert value in sorted way in a sorted doubly linked list - GeeksforGeeks

27 Oct, 2021
Given a sorted doubly linked list and a value to insert, write a function to insert the value in sorted way.Initial doubly linked list 
Doubly Linked List after insertion of 9 
Algorithm: Let input doubly linked list is sorted in increasing order. New node passed to the function contains data in the data part and previous and next link are set to NULL.
sortedInsert(head_ref, newNode)
      if (head_ref == NULL)
      head_ref = newNode
        
      else if head_ref->data >= newNode->data
          newNode->next = head_ref
      newNode->next->prev = newNode
      head_ref = newNode    
        
      else
      Initialize current = head_ref
      while (current->next != NULL and
               current->next->data < newNode->data)
        current = current->next
        
      newNode->next = current->next
      if current->next != NULL
        newNode->next->prev = newNode
            
          current->next = newNode
      newNode->prev = current
C++
Java
Python3
C#
Javascript
// C++ implementation to insert value in sorted way// in a sorted doubly linked list#include <bits/stdc++.h> using namespace std; // Node of a doubly linked liststruct Node {    int data;    struct Node* prev, *next;}; // function to create and return a new node// of a doubly linked liststruct Node* getNode(int data){    // allocate node    struct Node* newNode =        (struct Node*)malloc(sizeof(struct Node));     // put in the data    newNode->data = data;    newNode->prev = newNode->next = NULL;    return newNode;} // function to insert a new node in sorted way in// a sorted doubly linked listvoid sortedInsert(struct Node** head_ref, struct Node* newNode){    struct Node* current;     // if list is empty    if (*head_ref == NULL)        *head_ref = newNode;     // if the node is to be inserted at the beginning    // of the doubly linked list    else if ((*head_ref)->data >= newNode->data) {        newNode->next = *head_ref;        newNode->next->prev = newNode;        *head_ref = newNode;    }     else {        current = *head_ref;         // locate the node after which the new node        // is to be inserted        while (current->next != NULL &&               current->next->data < newNode->data)            current = current->next;         /* Make the appropriate links */        newNode->next = current->next;         // if the new node is not inserted        // at the end of the list        if (current->next != NULL)            newNode->next->prev = newNode;         current->next = newNode;        newNode->prev = current;    }} // function to print the doubly linked listvoid printList(struct Node* head){    while (head != NULL) {        cout << head->data << " ";        head = head->next;    }} // Driver program to test aboveint main(){    /* start with the empty doubly linked list */    struct Node* head = NULL;     // insert the following nodes in sorted way    struct Node* new_node = getNode(8);    sortedInsert(&head, new_node);    new_node = getNode(5);    sortedInsert(&head, new_node);    new_node = getNode(3);    sortedInsert(&head, new_node);    new_node = getNode(10);    sortedInsert(&head, new_node);    new_node = getNode(12);    sortedInsert(&head, new_node);    new_node = getNode(9);    sortedInsert(&head, new_node);     cout << "Created Doubly Linked Listn";    printList(head);    return 0;}
// Java implementation to insert value in sorted way// in a sorted doubly linked listimport java.io.*;import java.util.*; // Node of a doubly linked listclass Node{    int data;    Node next, prev;} class GFG{     // function to create and return a new node    // of a doubly linked list    static Node getNode(int data)    {            // allocate node            Node newNode = new Node();             // put in the data            newNode.data = data;            newNode.prev = newNode.next = null;            return newNode;     }     // function to insert a new node in sorted way in    // a sorted doubly linked list    static Node sortedInsert(Node head, Node newNode)    {            Node current;             // if list is empty            if (head == null)                head = newNode;             // if the node is to be inserted at the beginning            // of the doubly linked list            else if (head.data >= newNode.data)            {                newNode.next = head;                newNode.next.prev = newNode;                head = newNode;            }             else            {                current = head;                 // locate the node after which the new node                // is to be inserted                while (current.next != null &&                        current.next.data < newNode.data)                    current = current.next;                 /* Make the appropriate links */                newNode.next = current.next;                 // if the new node is not inserted                // at the end of the list                if (current.next != null)                    newNode.next.prev = newNode;                 current.next = newNode;                newNode.prev = current;                         }            return head;    }     // function to print the doubly linked list    static void printList(Node head)    {            while (head != null)            {                    System.out.print(head.data + " ");                    head = head.next;            }     }     // Driver code    public static void main(String args[])    {            /* start with the empty doubly linked list */            Node head = null;             // insert the following nodes in sorted way            Node new_node = getNode(8);            head = sortedInsert(head, new_node);            new_node = getNode(5);            head = sortedInsert(head, new_node);            new_node = getNode(3);            head = sortedInsert(head, new_node);            new_node = getNode(10);            head = sortedInsert(head, new_node);            new_node = getNode(12);            head = sortedInsert(head, new_node);            new_node = getNode(9);            head = sortedInsert(head, new_node);             System.out.println("Created Doubly Linked List");            printList(head);    }} // This code is contributed by rachana soma
# Python3 implementation to insert# value in sorted way in a sorted# doubly linked list # Node of a doubly linked listclass Node:     # Constructor to initialize    # the node object    def __init__(self, data):                 self.data = data        self.next = None        self.prev = None class DoublyLinkedList:     # Function to initialize head    def __init__(self):                 self.head = None     # Function to create and return a    # new node of a doubly linked list    def getNode(self, data):                 return Node(data)     # Function to insert a new node in    # sorted way in a sorted doubly linked list    def sortedInsert(self, data):                 new_node = self.getNode(data)         # If the list is empty        if self.head is None:            self.head = new_node                 # If the node is to be inserted at         # the beginning of the doubly linked list        elif self.head.data >= new_node.data:            new_node.next = self.head            new_node.next.prev = new_node            self.head = new_node        else:            current = self.head             # Locate the node after which            # the new node  is to be inserted            while ((current.next is not None) and                   (current.next.data < new_node.data)):                current = current.next                 # Make the appropriate links            new_node.next = current.next             # If the new node is not inserted            # at the end of the list            if current.next is not None:                new_node.next.prev = new_node             current.next = new_node            new_node.prev = current         # Function to print the doubly linked list    def printList(self):         node = self.head        while node:            print(str(node.data), end = " ")            node = node.next # Driver codeif __name__ == '__main__':     # Insert the following nodes    # in sorted way    llist = DoublyLinkedList()    llist.sortedInsert(8)    llist.sortedInsert(5)    llist.sortedInsert(3)    llist.sortedInsert(10)    llist.sortedInsert(12)    llist.sortedInsert(9)         print("Created Doubly Linked List")    llist.printList() # This code is contributed by Siddhartha Pramanik
// C# implementation to insert value in sorted way// in a sorted doubly linked listusing System; // Node of a doubly linked listpublic class Node{    public int data;    public Node next, prev;} class GFG{     // function to create and return a new node    // of a doubly linked list    static Node getNode(int data)    {        // allocate node        Node newNode = new Node();         // put in the data        newNode.data = data;        newNode.prev = newNode.next = null;        return newNode;     }     // function to insert a new node in sorted way in    // a sorted doubly linked list    static Node sortedInsert(Node head, Node newNode)    {        Node current;         // if list is empty        if (head == null)            head = newNode;         // if the node is to be inserted at the beginning        // of the doubly linked list        else if (head.data >= newNode.data)        {            newNode.next = head;            newNode.next.prev = newNode;            head = newNode;        }         else        {            current = head;             // locate the node after which the new node            // is to be inserted            while (current.next != null &&                    current.next.data < newNode.data)                current = current.next;             /* Make the appropriate links */            newNode.next = current.next;             // if the new node is not inserted            // at the end of the list            if (current.next != null)                newNode.next.prev = newNode;             current.next = newNode;            newNode.prev = current;                 }        return head;    }     // function to print the doubly linked list    static void printList(Node head)    {        while (head != null)        {                Console.Write(head.data + " ");                head = head.next;        }     }     // Driver code    public static void Main(String []args)    {        /* start with the empty doubly linked list */        Node head = null;         // insert the following nodes in sorted way        Node new_node = getNode(8);        head = sortedInsert(head, new_node);        new_node = getNode(5);        head = sortedInsert(head, new_node);        new_node = getNode(3);        head = sortedInsert(head, new_node);        new_node = getNode(10);        head = sortedInsert(head, new_node);        new_node = getNode(12);        head = sortedInsert(head, new_node);        new_node = getNode(9);        head = sortedInsert(head, new_node);         Console.WriteLine("Created Doubly Linked List");        printList(head);    }} // This code is contributed by Arnab Kundu
<script>// javascript implementation to insert value in sorted way// in a sorted doubly linked list// Node of a doubly linked listclass Node{constructor(){     this.data = 0;     this.next = null, this.prev = null;     }}    // function to create and return a new node    // of a doubly linked list    function getNode(data)    {             // allocate node         newNode = new Node();         // put in the data        newNode.data = data;        newNode.prev = newNode.next = null;        return newNode;     }     // function to insert a new node in sorted way in    // a sorted doubly linked list    function sortedInsert( head,  newNode)    {        var current;         // if list is empty        if (head == null)            head = newNode;         // if the node is to be inserted at the beginning        // of the doubly linked list        else if (head.data >= newNode.data)        {            newNode.next = head;            newNode.next.prev = newNode;            head = newNode;        }         else {            current = head;             // locate the node after which the new node            // is to be inserted            while (current.next != null && current.next.data < newNode.data)                current = current.next;             /* Make the appropriate links */            newNode.next = current.next;             // if the new node is not inserted            // at the end of the list            if (current.next != null)                newNode.next.prev = newNode;             current.next = newNode;            newNode.prev = current;         }        return head;    }     // function to print the doubly linked list    function printList( head) {        while (head != null) {            document.write(head.data + " ");            head = head.next;        }    }     // Driver code             /* start with the empty doubly linked list */         head = null;         // insert the following nodes in sorted way         new_node = getNode(8);        head = sortedInsert(head, new_node);        new_node = getNode(5);        head = sortedInsert(head, new_node);        new_node = getNode(3);        head = sortedInsert(head, new_node);        new_node = getNode(10);        head = sortedInsert(head, new_node);        new_node = getNode(12);        head = sortedInsert(head, new_node);        new_node = getNode(9);        head = sortedInsert(head, new_node);         document.write("Created Doubly Linked List<br/>");        printList(head); // This code is contributed by umadevi9616</script>
Output:
Created Doubly Linked List
3 5 8 9 10 12
Time Complexity: O(n)This article is contributed by Ayush Jauhari. If you like GeeksforGeeks and would like to contribute, you can also write an article using write.geeksforgeeks.org or mail your article to review-team@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above. 
rachana soma
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