Question $3$

Consider the following linked list, where head is the reference to the beginning node.

class Node

$\{$

public String data; $//$ data in the node

public Node next; $//$ reference to the successor

public Node $($String d$)$

$\{$

data $=$ d;

next $=$ null;

$\}$

$\}$

class LinkedList

$\{$

private Node head; $//$ reference to the beginning node

public LinkedList$()$

$\{$

head $=$ null;

$\}$

public void insertAsFirstNode$($String d$)$

$\{$

$//$ your code comes here $...$

$\}$

public void insertAsLastNode$($String d$)$

$\{$

$//$ your code comes here $...$

$\}$

$\}$

Implement the following two functions. Do NOT use any other helper class$/$object such as class ReferencePair in Example$08$SortedLinkedList.

$(4$ Points$)$ Implement function insertAsFirstNode$($String d$)$ to insert a new node, whose data field is d$,$ as the beginning node of the linked list.

$(6$ Points$)$ Implement function insertAsLastNode$($String d$)$ to insert a new node, whose data field is d$,$ as the ending node of the linked list.