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54401387a8
* Fix typehints in project_euler/problem01
Squashed commit of the following:
commit 6801d073b31bf702814861cd3b07b634ca295bfa
Author: Archaengel <god11341258@gmail.com>
Date: Mon Oct 5 16:40:10 2020 -0700
Fix typehints in project_euler/problem01
commit 29afc3af114abd1b99dc3f7c8fc99128229db131
Author: Archaengel <god11341258@gmail.com>
Date: Mon Oct 5 15:06:34 2020 -0700
Add typehints and default argument for project_euler/problem_01
* Add default args, typehints, and expand variable names for PE prob 02
* Add style improvements for first solution of PE Problem 02
* Add default arg and typehints for second solution of PE Problem 02
* Add default arg for third solution of PE Problem 02
* Add style improvements for 1st soln of PE problem 03
* Add default arg and typehints for 2nd soln of PE problem 03
* Add default arg for 3rd soln of PE problem 03
* Remove unnecessary newlines
* Remove unnecessary newlines
* Fix end of file for 2nd soln in PE problem 03
95 lines
2.4 KiB
Python
95 lines
2.4 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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import math
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def isprime(num: int) -> bool:
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"""Returns boolean representing primality of given number num.
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>>> isprime(2)
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True
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>>> isprime(3)
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True
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>>> isprime(27)
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False
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>>> isprime(2999)
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True
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>>> isprime(0)
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Traceback (most recent call last):
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...
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ValueError: Parameter num must be greater or equal to two.
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>>> isprime(1)
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Traceback (most recent call last):
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...
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ValueError: Parameter num must be greater or equal to two.
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"""
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if num <= 1:
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raise ValueError("Parameter num must be greater or equal to two.")
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if num == 2:
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return True
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elif num % 2 == 0:
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return False
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for i in range(3, int(math.sqrt(num)) + 1, 2):
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if num % i == 0:
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return False
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return True
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def solution(n: int = 600851475143) -> int:
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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):
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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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max_number = 0
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if isprime(n):
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return n
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while n % 2 == 0:
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n //= 2
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if isprime(n):
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return n
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for i in range(3, int(math.sqrt(n)) + 1, 2):
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if n % i == 0:
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if isprime(n / i):
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max_number = n / i
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break
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elif isprime(i):
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max_number = i
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return max_number
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if __name__ == "__main__":
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print(solution(int(input().strip())))
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