83 lines
1.5 KiB
Python
83 lines
1.5 KiB
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 (need to support abs, comparison, * and %)
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:param b: second number (need to support abs, comparison, * and %)
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:returns: the gcd
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>>> gcd(3, 15)
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3
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>>> gcd(15, 3)
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3
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>>> gcd(-3, -15)
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-3
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>>> gcd(5, 12)
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1
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>>> gcd(4, 14)
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2
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"""
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try:
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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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except TypeError:
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_a = a
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_b = b
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gcd_sgn = 1
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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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def lcm(a, b):
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"""Compute lcm(a,b)
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:param a: first number (need to support abs, comparison, *, % and //)
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:param b: second number (need to support abs, comparison, *, % and //)
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:returns: the lcm
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>>> lcm(3, 15)
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15
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>>> lcm(15, 3)
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15
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>>> lcm(-3, -15)
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-15
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>>> lcm(5, 12)
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60
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>>> lcm(4, 14)
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28
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"""
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return (a * b) // gcd(a, b)
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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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