title: Time complexity of reverseOrder method of Collection
body: <p>I have a list of files which I want to sort based on last access time in descending order. What's the better way out of below 2 ways:</p>
  
  <ol>
  <li><p>Write a custom comparator which has logic for comparing in reverse order</p></li>
  <li><p>Write a customer comparator which has logic for comparing in ascending order and then call <code>Comparator.reversed()</code> in caller method</p></li>
  </ol>
  
  <p>I prefer #1 because <code>reversed()</code> will again take O(n) time where n is equal to the size of list. 
  I would like to know opinions of folks here.</p>