题目：
题解：
class Solution:
def removeDuplicates(self, nums: List[int]) -> int:
if not nums:
return 0
n = len(nums)
fast = slow = 1
while fast < n:
if nums[fast] != nums[fast - 1]:
nums[slow] = nums[fast]
slow += 1
fast += 1
return slow
![[lesson27]二阶构造模式](https://img-blog.csdnimg.cn/direct/31a364fbd9de4b71a798d2216fc66025.png#pic_center)
