26. Remove Duplicates from Sorted Array

• 时间复杂度O(n)，空间复杂度O(1):

class Solution(object):
    def removeDuplicates(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        i = 0
        if len(nums)<1:
            return 0
        else:
            while i< len(nums)-1:
                if nums[i] == nums[i+1]:
                     nums.remove(nums[i])
                else: 
                    i += 1
            return len(nums)

• 时间复杂度O(1)，空间复杂度O(1): python自带的set函数，转化成集合类型

class Solution(object):
    def removeDuplicates(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        res = list(set(nums))
        nums[:] = sorted(res)
        return len(nums)