gistfile1.rb

class Suggester
  class << self

    def variants_for word
      [word.downcase, word.capitalize, word.squeeze]
    end

    def suggestions_for word
      suggestions = self.vowel_suggestions_for word
      suggestion_variants = []

      suggestions.each do |suggestion|
        variants = self.variants_for suggestion
        variants.each do |variant|
          unless suggestions.include? variant
            suggestion_variants << variant
          end
        end
      end

      suggestions + suggestion_variants
    end

    def vowel_suggestions_for word
      vowels = ['a', 'e', 'i', 'o', 'u']
      suggestions = [word]

      word.chars.each_with_index do |char, index|
        next unless vowels.include? char.downcase

        vowels.each do |vowel|
          suggestions.each do |suggestion|
            suggestion[index] = vowel
            unless suggestions.include? suggestion
              suggestions << suggestion
            end
          end
        end
      end

      suggestions
    end
  end
end