{"id":27334,"date":"2018-01-20T20:59:16","date_gmt":"2018-01-20T15:29:16","guid":{"rendered":"https:\/\/www.wikitechy.com\/technology\/?p=27334"},"modified":"2018-01-20T20:59:41","modified_gmt":"2018-01-20T15:29:41","slug":"delete-a-node-in-a-doubly-linked-list-doubly-linked-list","status":"publish","type":"post","link":"https:\/\/www.wikitechy.com\/technology\/delete-a-node-in-a-doubly-linked-list-doubly-linked-list\/","title":{"rendered":"Delete a node in a Doubly Linked List"},"content":{"rendered":"

Write a function to delete a given node in a doubly linked list<\/p>\n

     (a) Original Doubly Linked List<\/pre>\n
\"Delete<\/p>\n
     (a) After deletion of head node<\/pre>\n
\"Delete<\/p>\n
 (a) After deletion of middle node<\/pre>\n
\"Delete<\/p>\n
     (a) After deletion of last node<\/pre>\n
\"Delete<\/p>\n
Algorithm
\nLet the node to be deleted is del<\/em>.
\n1) If node to be deleted is head node, then change the head pointer to next current head.
\n2) Set next <\/em>of previous to del<\/em>, if previous to del<\/em> exixts.
\n3) Set prev <\/em>of next to del<\/em>, if next to del<\/em> exixts.<\/p>\n[ad type=”banner”]\n
Java Programming:<\/p>\n
 
 <\/div> 
\/\/ Java program to delete a node from doubly linked list class LinkedList {     static Node head = null;     class Node {         int data;        Node next, prev;         Node(int d) {            data = d;            next = prev = null;        }    }     \/*Function to delete a node in a Doubly Linked List.    head_ref --> pointer to head node pointer.    del  -->  pointer to node to be deleted. *\/    void deleteNode(Node head_ref, Node del) {         \/* base case *\/        if (head == null || del == null) {            return;        }         \/* If node to be deleted is head node *\/        if (head == del) {            head = del.next;        }         \/* Change next only if node to be deleted is NOT the last node *\/        if (del.next != null) {            del.next.prev = del.prev;        }         \/* Change prev only if node to be deleted is NOT the first node *\/        if (del.prev != null) {            del.prev.next = del.next;        }         \/* Finally, free the memory occupied by del*\/        return;    }     \/* UTILITY FUNCTIONS *\/    \/* Function to insert a node at the beginning of the Doubly Linked List *\/    void push(Node head_ref, int new_data) {         \/* allocate node *\/        Node new_node = new Node(new_data);         \/* since we are adding at the begining,         prev is always NULL *\/        new_node.prev = null;         \/* link the old list off the new node *\/        new_node.next = (head);         \/* change prev of head node to new node *\/        if ((head) != null) {            (head).prev = new_node;        }         \/* move the head to point to the new node *\/        (head) = new_node;    }      \/*Function to print nodes in a given doubly linked list     This function is same as printList() of singly linked lsit *\/    void printList(Node node) {        while (node != null) {            System.out.print(node.data + " ");            node = node.next;        }    }     public static void main(String[] args) {        LinkedList list = new LinkedList();         \/* Let us create the doubly linked list 10<->8<->4<->2 *\/        list.push(head, 2);        list.push(head, 4);        list.push(head, 8);        list.push(head, 10);         System.out.println("Original Linked list ");        list.printList(head);         \/* delete nodes from the doubly linked list *\/        list.deleteNode(head, head);  \/*delete first node*\/         list.deleteNode(head, head.next);  \/*delete middle node*\/         list.deleteNode(head, head.next);  \/*delete last node*\/        System.out.println("");         \/* Modified linked list will be NULL<-8->NULL *\/        System.out.println("Modified Linked List");        list.printList(head);    }}<\/code><\/pre> <\/div>\n
Time Complexity: O(1)
\nTime Complexity: O(1)<\/p>\n
\u00a0[ad type=”banner”]<\/div>\n","protected":false},"excerpt":{"rendered":"
Delete a node in a Doubly Linked List – If node to be deleted is head node, then change the head pointer to next current head.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[79479,79476],"tags":[73376,81324,81321,81320,81323,81318,81322,81319],"class_list":["post-27334","post","type-post","status-publish","format-standard","hentry","category-doubly-linked-list","category-linked-list","tag-algorithm-for-insertion-and-deletion-in-doubly-linked-list","tag-delete-all-nodes-in-doubly-linked-list","tag-delete-last-node-in-doubly-linked-list-in-c","tag-delete-node-from-doubly-linked-list-java","tag-doubly-linked-list-c-examples","tag-insertion-and-deletion-in-doubly-linked-list-in-c","tag-insertion-and-deletion-in-doubly-linked-list-in-data-structure","tag-write-a-function-to-delete-a-node-from-doubly-linked-list"],"_links":{"self":[{"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/posts\/27334","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/comments?post=27334"}],"version-history":[{"count":0,"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/posts\/27334\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/media?parent=27334"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/categories?post=27334"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/tags?post=27334"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}