Leetcode 203. 移除链表元素

 1 class Solution {
 2 public:
 3     ListNode* removeElements(ListNode* head, int val) {
 4         ListNode *prehead = new ListNode(-1);
 5         ListNode *p = prehead;
 6         p->next = head;
 7         while(p != NULL && p->next != NULL){
 8             if(p->next->val  == val) 
 9                 p->next = p->next->next;
10             else 
11                 p = p->next;
12 
13         } 
14         return prehead->next;
15     }
16 };