Remove Linked List Elements

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

Example
Given: 1 --> 2 --> 6 --> 3 --> 4 --> 5 --> 6, val = 6
Return: 1 --> 2 --> 3 --> 4 --> 5

 /**
  * Definition for singly-linked list.
  * struct ListNode {
  *     int val;
  *     ListNode *next;
  *     ListNode(int x) : val(x), next(NULL) {}
  * };
  */
 class Solution {
 public:
     ListNode* removeElements(ListNode* head, int val) {

         ListNode node(-);
         node.next=head;
         ListNode *pre=&node;
         while(head!=NULL)
         {
             if(head->val==val)
             {
                 pre->next=head->next;
                 delete head;
                 head=pre->next;
             }
             else
             {
                 pre=pre->next;
                 head=head->next;
             }

         }
         return node.next;
     }
 };