Advanced, broken sock sorting for https://medium.com/@DawnPaladin/sorting-socks-e31e254bfa6f

advanced_sock_sort_broken.rb

def advanced(sock_pile)
  sock_book = Hash.new(Array.new)
  pairs = []
  sock_pile.each do |sock|
    if sock_book[sock].length > 0
      pairs.push([sock, sock_book[sock].pop])
    else
      sock_book[sock].push(sock)
    end
  end
  pairs
end