dallas_ruby_kata_8.rb

# Kata Eight: Conflicting Objectives
# by Mark, Mark, and Lance

def words
  @words ||= File.read('./wordsEn.txt').split("\r\n")
end

def six_letter_words(words)
  words.reject do |word|
    word.length != 6
  end
end

def find_less_than_six_letter_words(words)
  words.each_with_object({}) do |word, memo|
    memo[word] = true if word.length < 6
  end
end

def has_two_words?(word, word_list)
  word1_last_index_range = 1..3
  word2_last_char_index = 5

  word1_last_index_range.to_a.each do |word1_last_index|
    word1 = word[0..word1_last_index]
    word2 = word[word1_last_index+1..word2_last_char_index]
    return true if word_list[word1] and word_list[word2]
  end
  false
end

def words_containing_two_words(word_list)
  words_that_contain_two_words = []
  less_than_six_letter_words = find_less_than_six_letter_words(word_list)

  six_letter_words(word_list).each do |word|
    if has_two_words?(word, less_than_six_letter_words)
      words_that_contain_two_words << word
    end
  end
  words_that_contain_two_words
end


start_time = Time.now
num_words = words_containing_two_words(words).length
elapsed = Time.now - start_time

raise "Incorrect!" unless num_words == 3715

puts "#{num_words} found in #{elapsed*1000}ms"