require 'digest/sha1'
 
class String
  def hash
    Digest::SHA1.hexdigest self
  end
  
  def bit
    "%0160b" % to_i(16)
  end
end
 
def distance(word1, word2)
  distance = 0
  word1.chars.zip(word2.chars) do |char1, char2|
    distance += 1 unless char1 == char2
  end
  return distance
end
 
test_phrase = "Rubinius one eight six active active record memcached exception JRuby DHH TOKYO sdfe3"
key_phrase = "I am not a big believer in fortune telling"
 
h1 = test_phrase.hash
h2 = key_phrase.hash
 
b1 = h1.bit
b2 = h2.bit
 
p distance b1, b2 # => 74