[LeetCode]Remove Linked List Elements

题目描述：(链接)

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

解题思路：

/**
* 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) {
if (!head) {
return head;
}

ListNode dummy(-1);
dummy.next = head;
ListNode *prev = &dummy;
ListNode *cur = prev->next;
while (cur != nullptr) {
if (cur->val == val) {
ListNode *tmpNode = cur;
prev->next = cur->next;
cur = prev->next;
} else {
prev = cur;
cur = cur->next;
}
}

return dummy.next;
}
};