mirror of
https://github.com/TheAlgorithms/Python.git
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f438440ac5
* Added doctest and more explanation about Dijkstra execution. * tests were not passing with python2 due to missing __init__.py file at number_theory folder * Removed the dot at the beginning of the imported modules names because 'python3 -m doctest -v data_structures/hashing/*.py' and 'python3 -m doctest -v data_structures/stacks/*.py' were failing not finding hash_table.py and stack.py modules. * Moved global code to main scope and added doctest for project euler problems 1 to 14. * Added test case for negative input. * Changed N variable to do not use end of line scape because in case there is a space after it the script will break making it much more error prone. * Added problems description and doctests to the ones that were missing. Limited line length to 79 and executed python black over all scripts. * Changed the way files are loaded to support pytest call. * Added __init__.py to problems to make them modules and allow pytest execution. * Added project_euler folder to test units execution * Changed 'os.path.split(os.path.realpath(__file__))' to 'os.path.dirname()' * Added Burrows-Wheeler transform algorithm. * Added changes suggested by cclauss * Fixes for issue 'Fix the LGTM issues #1024'. * Added doctest for different parameter types and negative values. * Fixed doctest issue added at last commit.
64 lines
1.5 KiB
Python
64 lines
1.5 KiB
Python
"""
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Problem:
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The prime factors of 13195 are 5,7,13 and 29. What is the largest prime factor
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of a given number N?
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e.g. for 10, largest prime factor = 5. For 17, largest prime factor = 17.
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"""
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from __future__ import print_function, division
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try:
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raw_input # Python 2
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except NameError:
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raw_input = input # Python 3
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def solution(n):
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"""Returns the largest prime factor of a given number n.
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>>> solution(13195)
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29
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>>> solution(10)
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5
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>>> solution(17)
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17
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>>> solution(3.4)
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3
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>>> solution(0)
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Traceback (most recent call last):
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...
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ValueError: Parameter n must be greater or equal to one.
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>>> solution(-17)
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Traceback (most recent call last):
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...
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ValueError: Parameter n must be greater or equal to one.
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>>> solution([])
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Traceback (most recent call last):
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...
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TypeError: Parameter n must be int or passive of cast to int.
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>>> solution("asd")
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Traceback (most recent call last):
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...
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TypeError: Parameter n must be int or passive of cast to int.
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"""
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try:
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n = int(n)
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except (TypeError, ValueError) as e:
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raise TypeError("Parameter n must be int or passive of cast to int.")
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if n <= 0:
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raise ValueError("Parameter n must be greater or equal to one.")
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prime = 1
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i = 2
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while i * i <= n:
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while n % i == 0:
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prime = i
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n //= i
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i += 1
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if n > 1:
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prime = n
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return int(prime)
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if __name__ == "__main__":
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print(solution(int(raw_input().strip())))
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