37 lines
974 B
Python
37 lines
974 B
Python
#coding: utf-8
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''' mbinary
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#######################################################################
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# File : euler.py
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# Author: mbinary
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# Mail: zhuheqin1@gmail.com
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# Blog: https://mbinary.xyz
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# Github: https://github.com/mbinary
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# Created Time: 2018-12-16 10:53
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# Description:
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euler function: phi(n)
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perfect num: \sigma (n) = 2n, \sigma (n) is the sum of all factors of n
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eg \sigma (9) = 3+3+9 = 15
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#######################################################################
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'''
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from factor import factor
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from collections import Counter
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from functools import reduce
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from operator import mul
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def phi(n):
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st = set(factor(n))
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return round(reduce(mul, (1-1/p for p in st), n))
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def sigma(n):
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ct = Counter(factor(n))
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return reduce(mul, (round((p**(ct[p]+1)-1)/(p-1)) for p in ct), 1)
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if __name__ == '__main__':
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while 1:
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n = int(input('n: '))
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print('phi(n):', phi(n))
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print('sigma(n):', sigma(n))
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