2019-09-12 10:33:56 -07:00
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proc modInv(a0, b0: int): int =
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2016-12-05 23:44:36 +01:00
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var (a, b, x0) = (a0, b0, 0)
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result = 1
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if b == 1: return
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while a > 1:
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2019-09-12 10:33:56 -07:00
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result = result - (a div b) * x0
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2016-12-05 23:44:36 +01:00
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a = a mod b
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swap a, b
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swap x0, result
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if result < 0: result += b0
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2019-09-12 10:33:56 -07:00
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echo modInv(42, 2017)
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