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.

从链表中删除重复结点，这题非常类似于 Remove Duplicates from Array，只是链表操作中还需要重新定义指向问题。维护一个prev为重复元素的开始元素，cur为当前处理的元素。当前为重复元素时，就令prev.next＝cur.next。否则更新prev,代码如下：

class Solution(object):
    def removeDuplicates(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        length=len(nums)
        if length<3:
            return length
        end = 1
        for i in xrange(2,length):
            temp = nums[i]
            if temp != nums[end-1] :
                end+=1
                nums[end]=temp

        return end+1

时间复杂度O(n),空间复杂度O(1).