[LeetCode]Remove Linked List Elements

 1 /**
 2  * Definition for singly-linked list.
 3  * struct ListNode {
 4  *     int val;
 5  *     ListNode *next;
 6  *     ListNode(int x) : val(x), next(NULL) {}
 7  * };
 8  */
 9 class Solution {
10 public:
11     ListNode* removeElements(ListNode* head, int val) {
12         if (!head) {
13             return head;
14         }
15         
16         ListNode dummy(-1);
17         dummy.next = head;
18         ListNode *prev = &dummy;
19         ListNode *cur = prev->next;
20         while (cur != nullptr) {
21             if (cur->val == val) {
22                 ListNode *tmpNode = cur;
23                 prev->next = cur->next;
24                 cur = prev->next;
25             } else {
26                 prev = cur;
27                 cur = cur->next;
28             }
29         }
30         
31         return dummy.next;
32     }
33 };