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30 lines
575 B
Ruby
30 lines
575 B
Ruby
# https://en.wikipedia.org/wiki/Extended_Euclidean_algorithm
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def extended_euclidean_gcd(a, b)
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x0 = a
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x1 = b
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s = 1
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t = 0
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until x1.zero?
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q, x2 = x0.divmod(x1)
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x0 = x1
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x1 = x2
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s, t = t, s - q * t
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end
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x0
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end
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puts 'GCD(3, 5) = ' + extended_euclidean_gcd(3, 5).to_s
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# GCD(3, 5) = 1
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puts 'GCD(3, 6) = ' + extended_euclidean_gcd(3, 6).to_s
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# GCD(3, 6) = 3
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puts 'GCD(6, 3) = ' + extended_euclidean_gcd(6, 3).to_s
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# GCD(6, 3) = 3
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#
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# Dynamic driver code:
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#
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# a = gets.to_i
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# b = gets.to_i
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# puts "GCD (#{a}, #{b} ) = #{extended_euclidean_gcd(a, b)}"
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#
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