class Solution:
    def removeDuplicates(self, nums):
    ¦   """
    ¦   :type nums: List[int]
    ¦   :rtype: int
    ¦   """
    ¦   if nums is None or len(nums) == 0:
    ¦   ¦   return 0
    ¦   idx = 0
    ¦   for item in nums:
    ¦   ¦   if item != nums[idx]:
    ¦   ¦   ¦   idx += 1
    ¦   ¦   ¦   nums[idx] = item
    ¦   ¦   ¦   print(nums)
    ¦   return idx + 1

    def removeDuplicates2(self, nums):
    ¦   if nums is None or len(nums) == 0:
    ¦   ¦   return 0
    ¦   s = set()
    ¦   for item in nums:
    ¦   ¦   s.add(item)
    ¦   return len(s)