Minkowski question-mark function: Difference between revisions

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=={{header|Julia}}==

{{trans|FreeBasic}}

<lang julia>function minkowski(x, maxiter=151)

p = Int(floor(x))

(x > 1 || x < 0) && return p + minkowski(x - p, maxiter)

q, r, s, m, n = 1, p + 1, 1, 0, 0

d, y = 1.0, Float64(p)

while true

d /= 2.0

y + d == y && break

m = p + r

(m < 0 || p < 0) && break

n = q + s

n < 0 && break

if x < (m / n)

r, s = m, n

else

y, p, q = y + d, m, n

end

end

return y + d

end

function minkowski_inv(x, maxiter=151)

p = Int(floor(x))

(x > 1 || x < 0) && return p + minkowski_inv(x - p, maxiter)

(x == 1 || x == 0) && return x

contfrac = [0]

curr, coun, i = 0, 1, 0

while true

x *= 2

if curr == 0

if x < 1

coun += 1

else

i += 1

append!(contfrac, fill(0, i - length(contfrac) + 1))

contfrac[i] = coun

coun = 1

curr = 1

x -= 1

end

else

if x > 1

coun += 1

x -= 1

else

i += 1

append!(contfrac, fill(0, i - length(contfrac) + 1))

contfrac[i] = coun

coun = 1

curr = 0

end

end

if x == Int(floor(x))

contfrac[i + 1] = coun

break

end

i == maxiter && break

end

ret = 1.0 / contfrac[i + 1]

for j in i:-1:1

ret = contfrac[j] + 1.0 / ret

end

return 1.0 / ret

end

println(" ", minkowski((1 + sqrt(5)) / 2), " ", 5 / 3)

println(minkowski_inv(-5/9), " ", (sqrt(13) - 7) / 6)

println(" ", minkowski(minkowski_inv(0.718281828)), " ",

minkowski_inv(minkowski(0.1213141516171819)))

</lang>{{out}}

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1.6666666666696983 1.6666666666666667

-0.5657414540893351-0.5657414540893352

0.7182818280000092 0.12131415161718191