剑指offer 删除链表中重复的结点

 1 class Solution {
 2 public:
 3     ListNode* deleteDuplication(ListNode* pHead){
 4         if(pHead == nullptr || pHead -> next == nullptr){
 5             return pHead;
 6         }
 7         //ListNode* cur = pHead;
 8          
 9         ListNode* dummyNode = new ListNode(-1);
10         dummyNode -> next = pHead;
11         pHead = dummyNode;
12          
13         int tmp;
14           
15         while(pHead -> next != nullptr && pHead -> next -> next != nullptr){
16             if(pHead -> next -> val == pHead -> next -> next -> val){
17                 tmp = pHead -> next -> val;
18                 while(pHead -> next != nullptr && tmp == pHead -> next  -> val){
19                     pHead -> next = pHead -> next -> next;
20                 } 
21                  
22             }
23             else{               
24                 pHead  = pHead -> next;
25             }
26              
27         }
28         return dummyNode -> next;
29     }
30 };