title: Creating quicksort without recursion and stack
body: <p>I have a task to write quicksort (on only posivite numbers) algorythm in Java (I can't use any imports but Scanner) but without recursion and without stack.<br>
  I have two question about it : </p>
  
  <ol>
  <li>I do understeand iterative quicksort with stack and recursive version but i cannot imagine how to do it without it. 
  I have heard about some 'in place' implementation but i dont really get it - is it solution for my problem?<br>
  I would appreciate if anyone could show me a way to do it ( dont post implementation if you can, I just want to understeand it not copy someone's code) or recommend some book where I can find it ( or some similar problem ).</li>
  <li><p>Is implementing sort by insertion for some small arrays a good idea? If so how big should be N in this code : </p>
  
  <pre><code>if (arraySize &lt; N)
      insertionSort
  else 
      quickSort
  fi
  </code></pre></li>
  </ol>