Interview Questions -- 3

intervew_3.rb

# My solution here was kinda meh. I should never do an interview
# before lunch. I stay up too late. I'm not awake yet.
#
# My original solution got lost in copy/paste, so I've tidied it up
# a bit here so you're not seeing all my flaws (though my solution
# worked and was built within the hour, while chatting, which is
# what counts). So this is sort of a tidy refactoring of my answer
# with maybe an extra 20-30 mins to clean it up added. The basic
# shape of the solution is the same though. I just moved around
# downcasing, and used select instead of .map.conmpact - that kind
# of thing.

#---

# Write a program with the following inputs:

# * A search string
# * A list of results matching that search string

# Sort those results according to the following order:

# 1. First exact matches
# 2. Results where one of the words is an exact match
# 3. Results that start with the search string
# 4. The rest-, alphabetically sorted-

# For example, given the search string "word" a correct ordering would be 
# "Word", "Microsoft Word", "Wordpress", "1Password", "Google AdWords".


class OrderedSearch
  attr_reader :search, :ordered_results, :results

  def initialize(search, results)
    @ordered_results = []
    @results = results || []
    @search = search.downcase
  end

  def print_ordered_results
    build_ordered_results
    puts ordered_results
  end


  private

  def build_ordered_results
    extend_ordered_results(matches_exact)
    extend_ordered_results(matches_one_word)
    extend_ordered_results(matches_start)
    extend_ordered_results(remaining_results)
  end

  def extend_ordered_results(matches)
    ordered_results.tap { |ord_res| ord_res << matches - ord_res }.flatten!
  end

  def matches_exact
    @exact_matches ||= results.select {|r| r.downcase == search }
  end

  def matches_one_word
    @owm ||= results.select { |r| r.split.map(&:downcase).include?(search) }
  end

  def matches_start
    @sm ||= results.select { |r| r.split.map(&:downcase).any? { |word| word.start_with?(search) } }
  end

  def remaining_results
    results - ordered_results
  end
end


# $ sample_input = ["1Password", "Google AdWords", "Microsoft Word", "Wordpress", "Word"]
# $ sample_search = "word"

# $ filter = OrderedSearch.new(sample_search, sample_input)
# $ filter.print_ordered_results
# => Word
#    Microsoft Word
#    Wordpress
#    1Password
#    Google AdWords

# $ correct_output = ["Word", "Microsoft Word", "Wordpress", "1Password", "Google AdWords"]
# $ filter.ordered_results == correct_output
# => true