53 lines
1.3 KiB
Python
53 lines
1.3 KiB
Python
#!/usr/bin/python
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# It can be seen that the number, 125874, and its double, 251748, contain exactly the same digits, but in a different order.
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#
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# Find the smallest positive integer, x, such that 2x, 3x, 4x, 5x, and 6x, contain the same digits.
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from numpy import zeros
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from timeit import default_timer
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def have_same_digits(a, b):
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digits1 = zeros(10, int)
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digits2 = zeros(10, int)
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# Get digits of a.
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while a > 0:
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digits1[a%10] = digits1[a%10] + 1
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a = a // 10
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# Get digits of b.
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while b > 0:
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digits2[b%10] = digits2[b%10] + 1
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b = b // 10
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# If they're not the same, return 0.
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for i in range(10):
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if digits1[i] != digits2[i]:
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return 0
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return 1
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def main():
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start = default_timer()
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i = 1
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# Brute force approach, try every integer number until the desired one is found.
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while True:
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if have_same_digits(i, 2*i) and have_same_digits(i, 3*i) and have_same_digits(i, 4*i) and\
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have_same_digits(i, 5*i) and have_same_digits(i, 6*i):
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break
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i = i + 1
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end = default_timer()
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print('Project Euler, Problem 52')
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print('Answer: {}'.format(i))
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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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