TOP K WORDS

top_k_word.rb

def top_k_words(str, n)
  return [] if n < 0

  str = str.downcase.scan(/[\w']+/)

  occurances = Hash.new

  str.each do |word|
    if occurances[word]
      occurances[word] += 1
    else
      occurances[word] = 1
    end
  end

  p occurances

  occurances.sort.sort_by { |word, occurence| [-occurence, -word] }[0..n-1].map {|x| x[0]}.join(" ")
end