gistfile1.rb

SMALL_WORDS = %w{a an and as at but by en for if in of on or the to v v. via vs vs.}

def titleize( sentence )
  capped_words = sentence.downcase.split(" ").map do |word|
    SMALL_WORDS.include?(word) ? word : word.capitalize
  end

  capped_words[0] = capped_words[0].capitalize unless capped_words.empty?

  capped_words.join(" ")
end

puts titleize("The quick brown fox jumps over the lazy dog")
puts titleize("the quick brown fox jumps over a lazy dog")
puts titleize("a quick brown fox jumps over the lazy dog")
puts titleize("A QUICK BROWN FOX JUMPS OVER THE LAZY DOG")