{"id":27339,"date":"2018-01-20T21:14:48","date_gmt":"2018-01-20T15:44:48","guid":{"rendered":"https:\/\/www.wikitechy.com\/technology\/?p=27339"},"modified":"2018-01-20T21:14:48","modified_gmt":"2018-01-20T15:44:48","slug":"doubly-linked-list","status":"publish","type":"post","link":"https:\/\/www.wikitechy.com\/technology\/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.<\/span><\/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
\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.<\/h4>\n[ad type=”banner”]\n
Python Programming:<\/p>\n
 
 <\/div> 
# Program to delete a node in doubly linked list # for Garbage collectionimport gc # A node of the doublly linked listclass Node:         # Constructor to create a new node    def __init__(self, data):        self.data = data         self.next = None        self.prev = None class DoublyLinkedList:     # Constructor for empty Doubly Linked List    def __init__(self):        self.head = None     # Function to delete a node in a Doubly Linked List.   # head_ref --> pointer to head node pointer.   # dele --> pointer to node to be deleted     def deleteNode(self, dele):                 # Base Case        if self.head is None or dele is None:            return                 # If node to be deleted is head node        if self.head == dele:            self.head = dele.next         # Change next only if node to be deleted is NOT        # the last node        if dele.next is not None:            dele.next.prev = dele.prev             # Change prev only if node to be deleted is NOT         # the first node        if dele.prev is not None:            dele.prev.next = dele.next        # Finally, free the memory occupied by dele        # Call python garbage collector        gc.collect()      # Given a reference to the head of a list and an    # integer,inserts a new node on the front of list    def push(self, new_data):          # 1. Allocates node        # 2. Put the data in it        new_node = Node(new_data)          # 3. Make next of new node as head and        # previous as None (already None)        new_node.next = self.head          # 4. change prev of head node to new_node        if self.head is not None:            self.head.prev = new_node          # 5. move the head to point to the new node        self.head = new_node      def printList(self, node):        while(node is not None):            print node.data,            node = node.next  # Driver program to test the above functions # Start with empty listdll = DoublyLinkedList() # Let us create the doubly linked list 10<->8<->4<->2dll.push(2);dll.push(4);dll.push(8);dll.push(10); print "\\n Original Linked List",dll.printList(dll.head) # delete nodes from doubly linked listdll.deleteNode(dll.head)dll.deleteNode(dll.head.next)dll.deleteNode(dll.head.next)# Modified linked list will be NULL<-8->NULLprint "\\n Modified Linked List",dll.printList(dll.head) <\/code><\/pre> <\/div>\n
Time Complexity: O(1)
\nTime Complexity: O(1)<\/p>\n<\/div>\n
 <\/p>\n[ad type=”banner”]\n","protected":false},"excerpt":{"rendered":"
Delete a node in a Doubly Linked List – 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":[69969,79479,79476],"tags":[73376,81324,81321,81320,81323,81318,81322,81319],"class_list":["post-27339","post","type-post","status-publish","format-standard","hentry","category-algorithm","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\/27339","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=27339"}],"version-history":[{"count":0,"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/posts\/27339\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/media?parent=27339"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/categories?post=27339"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/tags?post=27339"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}