Following code has the start of a class creating a doubly-linked list (but NOT implementing List). You will need to complete two of the methods which are needed to add data to the list:

addBetween() -- should add a new Entry ("node") containing elem so that it appears BETWEEN prior and follower

addToFront() -- should add a new Entry ("node") containing elem so that it appears AT THE HEAD of the list

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package edu.uncp.cse122; /** * This defines a few basic methods in a doubly linked-based List. This is now much closer to being a working List * implementation. Students will be writing the code to demonstrate they understand how to add nodes to a doubly linked * list. * * @param Type of data held in this collection */ public class DoublyLinkedList { /** Reference to the first node in our linked list. This will be null if the list is empty. */ private Entry head; /** Reference to the last node in our linked list. This will be null if the list is empty. */ private Entry tail; /** * This size instance variable specifies the number of elements in the List. We could instead recompute this as * needed, but adding it costs a little space and makes our code much more efficient. This space v. time tradeoff is a * common issue in computer science. */ private int size; /** * Creates an empty list. */ public DoublyLinkedList() { reset(); } /** * This method, which is only used within the DoublyLinkedList class, returns the instance to its initial state. This * call will reset both head and tail to be null and sets the size to be 0. */ private void reset() { head = null; tail = null; size = 0; } /** * Adds a new node to the middle of the linked list. This node will need to be created and then setup so that it * appears between the specified nodes already in the list. Finally, update any instance variable so that they reflect * the newly added node. * * @param prior Node that will come before the one being created in this method. * @param elem Element we are adding to the linked list * @param follower Node that comes after the one being created in this method. */ private void addBetween(Entry prior, E elem, Entry follower) { // TODO Finish this method } /** * Adds a new node at the start of the linked list. This node will need to be created and then setup so that it comes * before the current head node. Finally, update any instance variable so that they properly reflect the addition of * this new first node. * * @param elem Element we are adding to the front of the linked list */ private void addToFront(E elem) { // TODO Finish this method } /** * Returns the number of elements currently in this list. * * @return the number of elements in the list */ public int size() { return size; } }