[LeetCode203]Remove Linked List Elements

题目：

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

删除一个单链表中的元素

代码：

 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         ListNode *preHead = new ListNode(0);
13         preHead->next = head;
14         ListNode *cur = head, *pre = preHead;
15         while(cur)
16         {
17             if(cur->val == val)
18                 pre->next = cur->next;
19             else
20                 pre = pre->next;
21             cur = cur->next;
22         }
23         return preHead->next;
24     }
25 };