module SimilarityChecker

# File lib/similarity_checker.rb, line 4
def self.get_similarity_index string_one, string_two
      string_one.downcase!
              string_two.downcase!
      pairs_one = (0..string_one.length-2).collect {|i| string_one[i,2]}.reject { |pair| pair.include? " " }
      pairs_two = (0..string_two.length-2).collect {|i| string_two[i,2]}.reject { |pair| pair.include? " " }
      union = pairs_one.size + pairs_two.size
              intersection = 0
              pairs_one.each do |p1| 
                0.upto(pairs_two.size-1) do |i|
                  if p1 == pairs_two[i]
                    intersection += 1
                    pairs_two.slice!(i)
                    break
                  end
                end
              end
              (2.0 * intersection) / union * 100
end