How to efficiently find the missing number in a large array with duplicates in Python?
I'm working on a personal project and I'm having trouble with I'm stuck on something that should probably be simple... I'm trying to implement I'm relatively new to this, so bear with me. I'm trying to find the missing number in a large array of integers where some numbers might be duplicated, and the array is not sorted. I've tried using a set to track seen numbers, but I'm concerned about performance since the array can be quite large (up to 10^6 elements). Here's what I've tried so far: ```python # Sample array with duplicates and a missing number arr = [1, 2, 3, 4, 5, 5, 7, 8, 9, 10] # Let's say the number '6' is missing ``` I attempted to use the following approach, which gives me the expected result but is not optimal: ```python def find_missing(arr): seen = set(arr) for num in range(1, 11): # As I know the range is 1 to 10 if num not in seen: return num return None missing_number = find_missing(arr) print(missing_number) # Output: 6 ``` This works, but I wonder if there’s a more efficient way to achieve the same result while maintaining good performance. Could I leverage the properties of the array to reduce the time complexity? Additionally, I’d like to avoid using additional space if possible. Any advice or best practices would be greatly appreciated! My development environment is Windows 10. I'm open to any suggestions. This is part of a larger service I'm building. My development environment is Ubuntu 20.04. Has anyone else encountered this?