LeetCode OJ：Remove Duplicates from Sorted List （排好序的链表去重）

Given a sorted linked list, delete all duplicates such that each element appear only once.

For example,
Given 1->1->2, return 1->2.
Given 1->1->2->3->3, return 1->2->3.

简单的链表去重而已啊，遍历一边就实现了：

 1 class Solution {
 2 public:
 3     ListNode* deleteDuplicates(ListNode* head) {
 4         ListNode * p = head;
 5         if(p == NULL || p->next == NULL)
 6             return p;
 7         ListNode * prev = p;
 8         p = p->next;
 9         while(p!=NULL){
10             if(p->val == prev->val){
11                 prev->next = p->next;
12             }else{
13                 prev = p;
14             }
15             p = p->next;
16         }
17         return head;
18     }
19 };