Problem C: Recycled Numbers

recycler.rb

file = File.new("input", "r")
max = file.gets
counter = 1
while (line = file.gets)

  result = 0 
  raw_range = line.split(" ")
  range = raw_range[0].to_i..raw_range[1].to_i
  computed = Hash.new

  #discard single digit range
  if range.max > 10
    range.each do |ri|
      sri = ri.to_s.split("")
     
      i = 0
      while i < sri.length - 1
        sri =  sri[sri.length-1].split + sri[0, sri.length-1] 
        sri_i = sri.join.to_i

      #no reversed 
        if sri_i != ri && range.include?(sri_i)
          key = [ri.to_s + sri_i.to_s]
	  alter_key = [sri_i.to_s + ri.to_s]
	  computed.has_key?(alter_key) ? nil : computed[key] = true	
        end
        i = i + 1	
      end
    end
  end
  
  puts "Case ##{counter}: #{computed.size}"
  counter = counter + 1
end
file.close