title: multipath two-phase natural balanced merge
body: <p>I have a problem. I need implement multipath two-phase natural balanced merge using java. I saw merger sort example here <a href="http://www.vogella.de/articles/JavaAlgorithmsMergesort/article.html" rel="nofollow">http://www.vogella.de/articles/JavaAlgorithmsMergesort/article.html</a>
  I understand how it works, but I do not know how implement two-phase merge. One function divide array for indices and the second is to arrange a merger. Also it should be implemented for array and files (instead array used files). Who knows how to do it ? </p>