Post_14.3.rb

 def smart_move(cells)
    comp_spaces = comp_location(cells)
    wins_left = delete_from_array(cells)

    comp_spaces.map!(&:to_i)

    options = []

    if comp_spaces.empty?
      return [5]
    else
      @comp_winning_combos.each do |sub_array|
        intersect = sub_array & comp_spaces
        if intersect.any?
          difference = sub_array - comp_spaces
          options << difference
        end
      end
    end
    options.uniq!
    options
  end