Problem Definition：
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.
Solution : 值得注意的是递归解法：
1 def deleteDuplicates(head): 2 if head==None or head.next==None: 3 return head 4 head.next=self.deleteDuplicates(head.next) 5 return head.next if head.val==head.next.val else head
LeetCode#83 Remove Duplicates from Sorted List
原文：http://www.cnblogs.com/acetseng/p/4670972.html