[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：

 /**
  * 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 *preHead = new ListNode();
         preHead->next = head;
         ListNode *cur = head, *pre = preHead;
         while(cur)
         {
             if(cur->val == val)
                 pre->next = cur->next;
             else
                 pre = pre->next;
             cur = cur->next;
         }
         return preHead->next;
     }
 };