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.

 

1 /** 2  * Definition for singly-linked list. 3  * public class ListNode { 4  *     public int val; 5  *     public ListNode next; 6  *     public ListNode(int x) { val = x; } 7  * } 8  */ 9 public class Solution {10     public ListNode DeleteDuplicates(ListNode head) {11         if (head == null) return null;12         13         ListNode prior = head, cur = head.next;14         15         while (cur != null)16         {17             if (cur.val != prior.val)18             {19                 cur = cur.next;20                 prior = prior.next;21             }22             else23             {24                 cur = cur.next;25                 prior.next = cur;26             }27         }28         29         return head;30     }31 }