removeDuplicatesFromArray.py

# Given a sorted array nums, remove the duplicates in-place such that each element appear only once and return the new length.

# Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memory.

# Example 1:

# Given nums = [1,1,2],

# Your function should return length = 2, with the first two elements of nums being 1 and 2 respectively.

# It doesn't matter what you leave beyond the returned length.
# Example 2:

# Given nums = [0,0,1,1,1,2,2,3,3,4],
# Given nums = [0,0,1,1,1,2,2,3,3,4],

# Your function should return length = 5, with the first five elements of nums being modified to 0, 1, 2, 3, and 4 respectively.

# It doesn't matter what values are set beyond the returned length.
# Clarification:

# Confused why the returned value is an integer but your answer is an array?

# Note that the input array is passed in by reference, which means modification to the input array will be known to the caller as well.

# Internally you can think of this:

# // nums is passed in by reference. (i.e., without making a copy)
# int len = removeDuplicates(nums);

# // any modification to nums in your function would be known by the caller.
# // using the length returned by your function, it prints the first len elements.
# for (int i = 0; i < len; i++) {
#     print(nums[i]);
# }

def removeDuplicates(nums) -> int:
    if len(nums) == 0:
        return 0
    
    running_index = 0
    previos_element = nums[0]
    index = 1
    while index < len(nums):
        if nums[index] != previos_element:
            running_index += 1
            nums[running_index] = nums[index]
            previos_element = nums[index]
        index += 1
    final_array = nums[0:running_index+1]
    print(final_array)
    return running_index+1

removeDuplicates([0,0,1,1,1,2,2,3,3,4])
removeDuplicates([0,1,2,2,3,3,4,5])