问题描述：
Given a sorted linked list, delete all nodes that have duplicate numbers, leaving only distinct numbers from the original list.
For example,
Given 1->2->3->3->4->4->5, return 1->2->5.
Given 1->1->1->2->3, return 2->3.
解题笔记：
[leetcode笔记] Remove Duplicates from Sorted List II,布布扣,bubuko.com
[leetcode笔记] Remove Duplicates from Sorted List II
原文：http://www.cnblogs.com/lequ/p/3885935.html