Search an element in a Doubly Linked List | Java program to implement the above approach ; Structure of a node of the doubly linked list ; Stores data value of a node ; Stores pointer to next node ; Stores pointer to previous node ; Function to insert a node at the beginning of the Doubly Linked List ; Allocate memory for new node ; Insert the data ; Since node is added at the beginning , prev is always null ; Link the old list to the new node ; If pointer to head is not null ; Change the prev of head node to new node ; Move the head to point to the new node ; Function to find the position of an integer in doubly linked list ; Stores head Node ; Stores position of the integer in the doubly linked list ; Traverse the doubly linked list ; Update pos ; Update temp ; If the integer not present in the doubly linked list ; If the integer present in the doubly linked list ; Driver Code ; Create the doubly linked list 18 < -> 15 < -> 8 < -> 9 < -> 14
import java . util . * ; class GFG { static class Node { int data ; Node next ; Node prev ; } ; static Node push ( Node head_ref , int new_data ) { Node new_node = new Node ( ) ; new_node . data = new_data ; new_node . prev = null ; new_node . next = head_ref ; if ( head_ref != null ) { head_ref . prev = new_node ; } head_ref = new_node ; return head_ref ; } static int search ( Node head_ref , int x ) { Node temp = head_ref ; int pos = 0 ; while ( temp . data != x && temp . next != null ) { pos ++ ; temp = temp . next ; } if ( temp . data != x ) return - 1 ; return ( pos + 1 ) ; } public static void main ( String [ ] args ) { Node head = null ; int X = 8 ; head = push ( head , 14 ) ; head = push ( head , 9 ) ; head = push ( head , 8 ) ; head = push ( head , 15 ) ; head = push ( head , 18 ) ; System . out . print ( search ( head , X ) ) ; } }