fouriest.rb

module Fouriest
	def to_base(x)
		raise ArgumentError, "the base must be a positive > 1 number" if x < 2 ||  x != (x.to_i)
		num = self
		new_string = ""
		loop do
			new_string += (num % x).represent_number
			num = num / x
			break if num == 0
		end
		new_string.reverse!
	end

	def represent_number
		self < 10 ? self.to_s : 'x'
	end

	def fouriest
		fours = -1
		fouriest = self.to_s
		base = 2
		best_base = 0
		loop do
			new_num = self.to_base(base)
			new_fours = new_num.count("4")
			if new_fours > fours
				fouriest = new_num
				fours = new_fours
				best_base = base
			end
			break if new_num == 'x' || new_num.length <= fours || (self<10 && base >=10)
			base+=1
		end
		"#{self} is the fouriest (#{fouriest}) on base #{best_base}"
	end
end

Bignum.include(Fouriest)
Fixnum.include(Fouriest)
10000.times do |i|
	puts i.fouriest
end