Remove Duplicates from Sorted List II

Given a sorted linked list, delete all nodes that have duplicate numbers, leaving only distinct numbers from the original list.

For example,
Given 1->2->3->3->4->4->5, return 1->2->5.
Given 1->1->1->2->3, return 2->3.

思路：

指针操作

代码：

 1     ListNode *deleteDuplicates(ListNode *head) {
 2         if(!head)
 3             return NULL;
 4         ListNode *result = NULL, *tail = NULL, *cur;
 5         cur = head;
 6         while(cur->next){
 7             if(cur->val == cur->next->val){
 8                 int tmp = cur->val;
 9                 while(cur){
10                     if(cur->val != tmp)
11                         break;
12                     cur = cur->next;
13                 }
14                 if(!cur)
15                     break;
16             }
17             else{
18                 if(!result){
19                     result = cur;
20                     tail = cur;
21                 }
22                 else{
23                     tail->next = cur;
24                     tail = tail->next;
25                 }
26                 cur = cur->next;
27             }
28         }
29         if(tail)
30             tail->next = cur;
31         else
32             result = cur;
33         return result;
34     }