Lintcode-easy-remove Linked List Elements

Remove all elements from a linked list of integers, that has value val .

Example

Given 1->2->3->3->4->5->3 , val = 3, you should return the list as1->2->4->5

It seems that the problem is not difficult, but there are some places to pay attention, it is said that the interview to do Bug-free

p = p.next; after execution, p is likely to be null, so check whether P is null in the loop condition.

In fact, before accessing a member of an object, it is important to check whether the object is null or else an exception will occur.

/*** Definition for singly-linked list. * public class ListNode {* int val; * ListNode Next; * ListNode (int X) {val = x;}}*/ Public classSolution {/**     * @paramhead a ListNode *@paramval an integer *@returna ListNode*/     PublicListNode removeelements (ListNode head,intval) {        //Write Your code here        if(Head = =NULL)            returnHead; ListNode Fakehead=NewListNode (0); Fakehead.next=Head; ListNode P=Fakehead;  while(p!=NULL&& P.next! =NULL){             while(P.next! =NULL&& P.next.val = =val) {P.next=P.next.next; } P=P.next; }                returnFakehead.next; }}

Lintcode-easy-remove Linked List Elements