28 lines
444 B
Crystal
28 lines
444 B
Crystal
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alias NumType = Int32 | Int64 | UInt32 | UInt64
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def trial_division(n : NumType)
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factors = [] of NumType
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check = ->(p: NumType) {
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q, r = n.divmod(p)
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while r.zero?
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factors << p
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n = q
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q, r = n.divmod(p)
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end
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}
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check.call(2)
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check.call(3)
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p = 5
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while p * p <= n
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check.call(p)
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p += 2
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check.call(p)
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p += 4
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end
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factors << n if n > 1
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factors
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end
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puts trial_division(600851475143).max
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