Implement a Doubly linked list to store a set of Integer numbers (no duplicate)  • Instance variable • Constructor • Accessor and Update methods   3. Define TestDLinkedList Class a. Declare an instance of Doubly List class. b. Test all the methods of Doubly List class.

Implement a Single linked list to store a set of Integer numbers (no duplicate) • Instance variable• Constructor• Accessor and Update methods 2.) Define SLinkedList Classa. Instance Variables:     # Node head     # Node tail     # int sizeb. Constructorc. Methods     # int getSize() //Return the number of nodes of the list.     # boolean isEmpty() //Return true if the list is empty, and false otherwise.     # int getFirst() //Return the value of the first node of the list.     # int getLast()/ /Return the value of the Last node of the list.     # Node getHead()/ /Return the head     # setHead(Node h)//Set the head     # Node getTail()/ /Return the tail     # setTail(Node t)//Set the tail     # addFirst(E e) //add a new element to the front of the list     # addLast(E e) // add new element to the end of the list     # E removeFirst()//Return the value of the first node of the list     # display()/ /print out values of all the nodes of the list     # Node search(E key)//check if a given…

Assume you have a class SLNode representing a node in a singly-linked list and a variable called list referencing the first element on a list of integers, as shown below: public class SLNode { private E data; private SLNode next; public SLNode( E e){ data = e; next = null; } public SLNode getNext() { return next; } public void setNext( SLNoden){ next = n; } } SLNode list; Write a fragment of Java code that would append a new node with data value 21 at the end of the list. Assume that you don't know if the list has any elements in it or not (i.e., it may be empty). Do not write a complete method, but just show a necessary fragment of code.

Java Given main() in the ShoppingList class, define an insertAtEnd() method in the ItemNode class that adds an element to the end of a linked list. DO NOT print the dummy head node. Ex. if the input is: 4 Kale Lettuce Carrots Peanuts  where 4 is the number of items to be inserted; Kale, Lettuce, Carrots, Peanuts are the names of the items to be added at the end of the list. The output is: Kale Lettuce Carrots Peanuts  Second image is ItemNode