euler35

euler35.rb

#!/usr/bin/env ruby
require 'prime'
require 'mathn'

def shifts(arr)
  res = []
  tmp = arr.dup
  (0..arr.length-1).each do |a| 
    tmp << tmp.shift
    res << tmp.dup
  end 
  res 
end

no_zeros = Prime.each(1000000).select do |num| 
                                  ! num.to_s.split("").include?("0")
                                end 
res = no_zeros.select do |num| 
        shifts(num.to_s.split("")).all? do |n| 
          n.join.to_i.prime?
        end 
      end 

p res.size