37 lines
731 B
Python
37 lines
731 B
Python
#!/usr/bin/python3
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import math
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from timeit import default_timer
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from projecteuler import is_prime
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def max_prime_factor(num):
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if is_prime(num):
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return num
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if num % 2 == 0:
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return max_prime_factor(num // 2)
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else:
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limit = math.floor(math.sqrt(num)) + 1
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for i in range(3, limit, 2):
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if num % i == 0:
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if is_prime(i):
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return max_prime_factor(num // i)
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def main():
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start = default_timer()
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res = max_prime_factor(600851475143)
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end = default_timer()
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print('Project Euler, Problem 3')
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print('Answer: {}'.format(res))
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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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