02-Remove Duplicates from Sorted Array.py

'''
Example 1:

Input: nums = [1,1,2]
Output: 2, nums = [1,2,_]
Explanation: Your function should return k = 2, with the first two elements of nums being 1 and 2 respectively.
It does not matter what you leave beyond the returned k (hence they are underscores).

Example 2:

Input: nums = [0,0,1,1,1,2,2,3,3,4]
Output: 5, nums = [0,1,2,3,4,_,_,_,_,_]
Explanation: Your function should return k = 5, with the first five elements of nums being 0, 1, 2, 3, and 4 respectively.
It does not matter what you leave beyond the returned k (hence they are underscores).
'''

def removeDuplicates(nums):
    if not nums:
        return 0
    a, b = 0, 1
    while b != len(nums):
        if nums[a] != nums[b]:
            nums[a+1] = nums[b]
            a += 1
        b += 1
    return a+1

nums = [1, 1, 2]
print(removeDuplicates(nums))

nums = [0,0,1,1,1,2,2,3,3,4]
print(removeDuplicates(nums))

nums = []
print(removeDuplicates(nums))