#!/usr/bin/env python3

# encoding: utf-8

# Author: Pyclearl

# 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 by modifying the input array in-place with O(1) extra memory.

# Example:

# Given 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.

class Solution:

def removeDuplicates(self, nums):

"""

:type nums: List[int]

:rtype: int

"""

if len(nums) < 2:

return len(nums)

cursor = 0

for i in range(1,len(nums)):

if nums[i] != nums[cursor]:

cursor += 1

# 如果后面的都是重复的那么游标会停下来，直到遇到不重复的

#利用不重复的覆盖掉重复的值，所以要cursor + 1

nums[cursor]=nums[i]

# 最后停下来的游标就是去重后的最后一位

# 所以要curosr+1去除后面因为前移了,导致有重复的

# 之所以不能直接在循环里del是因为会有游标和i重叠这种情况

del nums[cursor+1:]

return len(nums)