31 lines
553 B
Text
31 lines
553 B
Text
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require "big"
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def pi
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q, r, t, k, n, l = [1, 0, 1, 1, 3, 3].map { |n| BigInt.new(n) }
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dot_written = false
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loop do
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if 4*q + r - t < n*t
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yield n
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unless dot_written
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yield '.'
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dot_written = true
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end
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nr = 10*(r - n*t)
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n = ((10*(3*q + r)) / t) - 10*n
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q *= 10
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r = nr
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else
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nr = (2*q + r) * l
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nn = (q*(7*k + 2) + r*l) / (t*l)
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q *= k
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t *= l
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l += 2
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k += 1
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n = nn
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r = nr
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end
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end
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end
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pi { |digit_or_dot| print digit_or_dot; STDOUT.flush }
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