26. Remove Duplicates from Sorted Array (python)

Given a sorted array, remove the duplicates in place such that each element appear only once and return the new length.
Do not allocate extra space for another array, you must do this in place with constant memory.
For example,
Given input array nums = [1,1,2],
Your function should return length = 2, with the first two elements of nums being 1 and 2 respectively.
It doesn’t matter what you leave beyond the new length.
题意：去除重复元素，每个元素只出现一次，要求不增加新的数组空间实现，且新数组后面的部分不影响
返回值为新数组的长度
思路：采用两指针，一个指针i指向原数组需要判断的元素，一个指针j指向新数组新加入的元素。
由于是有序数组，因此只要判断原数组中的元素不同于新数组新加入的元素，就将原数组的元素和新数组后一元素交换位置即可，没有重复元素就是和自身交换位置。

class Solution(object):    def removeDuplicates(self, nums):        if len(nums)==0:            return 0        j=0        for i in range(1,len(nums)):            if nums[i]!=nums[j]:                nums[j+1]=nums[i]                j=j+1        return  j+1