Números cachipulis

cachipulis.rb

#!/usr/bin/env ruby
param = ARGV.first

class Fixnum

  def is_cachipulis?
    length = self.to_s.length
    digits = self.to_s.split('').map(&:to_i)

    return false if digits.inject(&:+) != length

    digits.each_with_index do |d, i|
      unless digits.count(i) == d
        return false
      end
    end

    true
  end

  def self.cachipulis
    min, max = 1000, 2000
    while min < 1_000_000_000
      n = min.to_s.split('').map(&:to_i)
      unless n.inject(&:+) > n.length
        (min..max).each do |i|
          yield i if i.is_cachipulis?
        end
      end
      min, max = max + 1, max + 1000
    end
  end

end

if param == "lista"
  Fixnum.cachipulis do |number|
    puts number
  end
else
  if param.to_i.is_cachipulis?
    puts 'Si'
  else
    puts 'No'
  end
end