56、剑指offer--删除链表中重复的结点

 1 /*
 2 struct ListNode {
 3     int val;
 4     struct ListNode *next;
 5     ListNode(int x) :
 6         val(x), next(NULL) {
 7     }
 8 };
 9 */
10 class Solution {
11 public:
12     ListNode* deleteDuplication(ListNode* pHead)
13     {
14         if(pHead == NULL)
15             return NULL;
16         ListNode *pPreNode = NULL;
17         ListNode *pNode = pHead;
18         while(pNode != NULL)
19         {
20             ListNode *pNext = pNode->next;
21             bool needDelete = false;
22             if(pNext != NULL && pNext->val == pNode->val)
23                 needDelete = true;
24             if(!needDelete)//不等
25             {
26                 pPreNode = pNode;
27                 pNode = pNode->next;
28             }
29             else//相等该删除
30             {
31                 int value = pNode->val;
32                 ListNode *pToBeDel = pNode;
33                 while(pToBeDel != NULL && pToBeDel->val == value)
34                 {
35                     pNext = pToBeDel->next;
36                     delete pToBeDel;
37                     pToBeDel = NULL;
38                     pToBeDel = pNext;
39                 }
40                 if(pPreNode == NULL)//头结点被删除了
41                     pHead = pNext;
42                 else
43                     pPreNode->next = pNext;
44                 pNode = pNext;
45  
46             }
47         }
48         return pHead;
49     }
50 };