Rosetta Code

Gray code

Generate the 4-bit Gray code sequence with the standard reflective construction.

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Sourcerosettacode/popular/gray_code.vibe
def reverse_values(values: array<string>) -> array<string>
  reversed: array<string> = []
  index = values.length - 1

  while index >= 0
    reversed.push(values.fetch(index))
    index = index - 1
  end

  reversed
end

def prefix_all(values: array<string>, prefix: string) -> array<string>
  output: array<string> = []
  index = 0

  while index < values.length
    output.push(prefix + values.fetch(index))
    index = index + 1
  end

  output
end

def gray_code(bits: int) -> array<string>
  if bits == 0
    [""]
  else
    previous = gray_code(bits - 1)
    prefix_all(previous, "0") + prefix_all(reverse_values(previous), "1")
  end
end

def run -> array<string>
  gray_code(4)
end

Output

Click Run example to see the result.

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