LeetCode OJ---203. 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

Code:

/**
 * 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 dummy(0);
        ListNode *prev = &dummy;
        while(head)
        {
            if(head->val != val)
            {
                prev->next = head;
                prev = head;
            }
            head = head->next;
        }
        prev->next == NULL;
        return dummy.next;
    }
};