Remove Duplicates from Sorted List

 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         
13         ListNode *p = head;
14         while(p != NULL && p->next != NULL)
15         {
16             if(p->val == p->next->val)
17             {
18                 ListNode *del = p->next;
19                 p->next = p->next->next;
20                 delete del;
21             }
22             else
23                 p = p->next;
24         }
25         
26         return head;
27     }
28 };