Rosetta Code

Find palindromic numbers in both binary and ternary bases

Search for numbers whose binary and ternary representations are both palindromes.

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Sourcerosettacode/popular/find_palindromic_numbers_in_both_binary_and_ternary_bases.vibe
def digits_in_base(number: int, base: int) -> string
  if number == 0
    return "0"
  end

  digits = ""
  current = number

  while current > 0
    digits = "#{current % base}#{digits}"
    current = current // base
  end

  digits
end

def palindrome?(text: string) -> bool
  text == text.reverse
end

def first_shared_palindromes(count: int) -> array<int>
  values: array<int> = []
  candidate = 1

  while values.length < count
    if palindrome?(digits_in_base(candidate, 2)) && palindrome?(digits_in_base(candidate, 3))
      values << candidate
    end
    candidate = candidate + 1
  end

  values
end

def run -> array<{ binary: string, ternary: string, value: int }>
  [1, 6643].map { |value|
    {
      value:,
      binary: digits_in_base(value, 2),
      ternary: digits_in_base(value, 3)
    }
  }
end

Output

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