Write a Doubly Linked List program in Java
A Double linked list is a linked data structure, it built like set of nodes and each node contain three portions (one Data portion & two Node Reference portions).All Node References portion may connected to another node if it really had neighbor node or otherwise Reference portion marked as NULL.Obibsily head node and tail node sigle Reference portion which marked as NULL.DoublyLinkedList.java
1 import java.util.Scanner;
2
3 class DLLNode {
4 DLLNode parentNode;
5 int nodeValue;
6 DLLNode childNode;
7
8 public DLLNode(int nodeValue) {
9 parentNode = null;
10 this.nodeValue = nodeValue;
11 childNode = null;
12 }
13 }
14
15 class DLLCompute {
16 private static DLLNode newNode;
17 private static DLLNode headNode = null;
18 private static DLLNode tailNode = null;
19 private static DLLNode tempNode;
20
21 public static void add(int nodeValue) {
22 newNode = new DLLNode(nodeValue);
23 if(headNode != null) {
24 tailNode.childNode = newNode;
25 newNode.parentNode = tailNode;
26 tailNode = newNode;
27 }
28 else
29 {
30 headNode = newNode;
31 tailNode = newNode;
32 }
33 }
34
35 public static void displayFromHead() {
36 tempNode = headNode;
37 if(tempNode != null) {
38 while(tempNode.childNode != null) {
39 System.out.print(tempNode.nodeValue+" ");
40 tempNode = tempNode.childNode;
41 }
42 System.out.println(tempNode.nodeValue);
43 }
44 }
45
46 public static void displayFromTail() {
47 tempNode = tailNode;
48 if(tempNode != null) {
49 while(tempNode.parentNode != null) {
50 System.out.print(tempNode.nodeValue+" ");
51 tempNode = tempNode.parentNode;
52 }
53 System.out.println(tempNode.nodeValue);
54 }
55 }
56 }
57
58 public class DoublyLinkedList {
59 public static void main(String[] args) {
60 try(Scanner scan = new ScannerSystem.in) {
61 System.out.print("Enter the number of elements to insert:");
62 int numberOfElements = scan.nextInt();
63 int count = 1;
64 for(;count<=numberOfElements;count++) {
65 System.out.print("Enter the "+count+" element value:");
66 DLLCompute.add(scan.nextInt);
67 }
68 scan.close();
69 }
70 System.out.print("Show data's from Head Postition:");
71 DLLCompute.displayFromHead();
72 System.out.print("Show data's from Tail Postition:");
73 DLLCompute.displayFromTail();
74 }
75 }