LeetCode Remove Duplicates from Sorted List II

// 60ms
 1 /**
 2  * Definition for singly-linked list.
 3  * struct ListNode {
 4  *     int val;
 5  *     ListNode *next;
 6  *     ListNode(int x) : val(x), next(NULL) {}
 7  * };
 8  */
 9 class Solution {
10 public:
11     ListNode *deleteDuplicates(ListNode *head) {
12         // Start typing your C/C++ solution below
13         // DO NOT write int main() function
14         ListNode temp(0);
15         ListNode *q,*p;
16  
17         
18         q=&temp;
19         q->next=head;             
20         p=head;
21         
22         while(p)
23         { 
24             if(p->next&&p->val==p->next->val)
25             {  
26                 while(p->next&&p->val==p->next->val)
27                 {
28                     p->next=p->next->next;
29                     q->next=p->next;
30                 }               
31             }
32             else
33             {
34                 q=p;
35             }
36             p=p->next;
37         }
38         return temp.next;
39     }
40 };