## Challenge

Given a sorted integer array, remove duplicate in place that elements appears at most twice.

Constraints:

- The relative order of the elements should be kept the same.
- Do not allocate extra space for another array. Modify the input array in-place with O(1) extra memory.

Don’t change the length of the array return the index of the last element after your operations.

## Solution 1

```
class Solution:
def removeDuplicates(self, nums: List[int]) -> int:
i = 0
ct = 1
diff = 0
my_end = len(nums)
while i < my_end:
j = i
ct = 1
while j < my_end-1:
if nums[j] == nums[j+1]:
ct += 1
else:
break
j += 1
if ct > 2:
# overwrite
start = i + 2
end = i + ct
my_end -= end - start
z = 0
while end + z < len(nums):
nums[start+z] = nums[end+z]
z += 1
i += 1
return my_end
```