Leetcode - List - Remove Duplicates from Sorted List

Given a sorted linked list, delete all duplicates such that each element appear only once.

For example,

Given

1->1->2

, return

1->2

.

Given

1->1->2->3->3

, return

1->2->3

.

/**
* Definition for singly-linked list.
* struct ListNode {
*     int val;
*     ListNode *next;
*     ListNode(int x) : val(x), next(NULL) {}
* };
*/
class Solution {
public:
ListNode *deleteDuplicates(ListNode *head) {
if(head==NULL)
return NULL;
ListNode *prev=head;
ListNode *cur=head->next;
while(cur!=NULL)
{
if(cur->val==prev->val)
{
prev->next=cur->next;
delete cur;
cur=prev->next;
}
else
{
prev=cur;
cur=cur->next;
}
}
return head;
}
};