45 lines
887 B
Python
45 lines
887 B
Python
#!/usr/bin/env python
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# encoding: utf-8
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__all__ = ['gcd']
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def gcd(a, b):
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"""Compute gcd(a,b)
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:param a: first number
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:param b: second number
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:returns: the gcd
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"""
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pos_a, _a = (a >= 0), abs(a)
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pos_b, _b = (b >= 0), abs(b)
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gcd_sgn = (-1 + 2*(pos_a or pos_b))
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if _a > _b:
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c = _a % _b
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else:
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c = _b % _a
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if c == 0:
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return gcd_sgn * min(_a,_b)
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elif _a == 1:
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return gcd_sgn * _b
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elif _b == 1:
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return gcd_sgn * _a
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else:
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return gcd_sgn * gcd(min(_a,_b), c)
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if __name__ == '__main__':
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print(gcd(3, 15))
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print(gcd(3, 15))
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print(gcd(-15, -3))
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print(gcd(-3, -12))
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# -----------------------------
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# Reglages pour 'vim'
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# vim:set autoindent expandtab tabstop=4 shiftwidth=4:
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# cursor: 16 del
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