codewar.rb

def find_missing_number(sequence)
  numbers = sequence.split.sort
  
  prev = 0
  numbers.each do |number|
    puts number.inspect
    if number.to_i.to_s != number
      return 1
    end
    if number.to_i != prev + 1
      return prev + 1
    end
    
    prev = prev + 1
  end
  return 0
end