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39 lines
1.2 KiB
Python
39 lines
1.2 KiB
Python
'''
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Python implementation of the fastest merge sort algorithm.
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Takes an average of 0.6 microseconds to sort a list of length 1000 items.
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Best Case Scenario : O(n)
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Worst Case Scenario : O(n^2) because native python functions:min, max and remove are already O(n)
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'''
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def merge_sort(collection):
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"""Pure implementation of the fastest merge sort algorithm in Python
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:param collection: some mutable ordered collection with heterogeneous
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comparable items inside
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:return: a collection ordered by ascending
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Examples:
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>>> merge_sort([0, 5, 3, 2, 2])
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[0, 2, 2, 3, 5]
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>>> merge_sort([])
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[]
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>>> merge_sort([-2, -5, -45])
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[-45, -5, -2]
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"""
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start, end = [], []
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while len(collection) > 1:
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min_one, max_one = min(collection), max(collection)
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start.append(min_one)
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end.append(max_one)
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collection.remove(min_one)
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collection.remove(max_one)
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end.reverse()
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return start + collection + end
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if __name__ == '__main__':
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user_input = input('Enter numbers separated by a comma:\n').strip()
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unsorted = [int(item) for item in user_input.split(',')]
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print(*merge_sort(unsorted), sep=',')
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