【leetcode】203 - 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==NULL)return NULL;
13         ListNode* pre = head;
14         ListNode* cur = head->next;
15         while(cur != NULL)
16         {
17             if(cur->val == val)
18             {
19                 cur = cur->next;
20                 pre->next = cur;
21             }
22             else
23             {
24                 pre = cur;
25                 cur = cur->next;
26             }
27         }
28         if(head->val==val)return head->next;
29         return head;
30     }
31 };