top_twenty_frequent_words

top_twenty_frequent_words.rb

# Download this file - The Adventures of Sherlock Holmes
# http://www.gutenberg.org/cache/epub/1661/pg1661.txt
# 
# Write a program to print the 20 most frequent words in the document, in
# descending order,
# with counts.  Output format looks like:
# 
# 9213  the
# 3223  i
def top_twenty_frequent_words(text)
  words_count = {}

  words = text.split(/\W+/)

  words_count = words.inject({}) do |count, word|
    normalized_word = word.downcase

    count[normalized_word] = 0 if count[normalized_word].nil?
    count[normalized_word] += 1

    count
  end

  top_twenty = words_count.sort_by(&:last).reverse[0..19]

  top_twenty.each_with_index do |(word, count), i|
    puts "#{count}\t#{word}"
  end
end

sherlock_holmes = File.readlines("./pg1661.txt").join
top_twenty_frequent_words(sherlock_holmes)