Envío 3213

Código

n1 = gets.chomp

def sum_one number
  accumulator = 0
  size = number.length
  one = "1".rjust(size, "0")
  answer = "0" * size

  (size - 1).downto(0).each do |index|
    current_digit = number[index].to_i + one[index].to_i
    current_digit = current_digit + accumulator
    answer[index] = (current_digit % 10).to_s

    accumulator = current_digit / 10
  end

  if accumulator != 0
    answer = accumulator.to_s + answer
  end

  answer
end

puts sum_one n1