41 lines
740 B
Python
41 lines
740 B
Python
#!/usr/bin/python3
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from math import floor, sqrt
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from timeit import default_timer
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def sum_of_divisors(n):
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limit = floor(sqrt(n)) + 1
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sum_ = 1
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for i in range(2, limit):
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if n % i == 0:
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sum_ = sum_ + i
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if n != i * i:
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sum_ = sum_ + n // i
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return sum_
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def main():
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start = default_timer()
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sum_ = 0
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for i in range(2, 10000):
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n = sum_of_divisors(i)
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if i != n and sum_of_divisors(n) == i:
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sum_ = sum_ + i + n
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sum_ = sum_ // 2
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end = default_timer()
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print('Project Euler, Problem 21')
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print('Answer: {}'.format(sum_))
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print('Elapsed time: {:.9f} seconds'.format(end - start))
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if __name__ == '__main__':
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main()
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