title: Merge two arrays efficiently - one sorted, another unsorted
body: <p>I am working on a problem that has a sorted array of n elements followed by an unsorted array of length</p>
  
  <ol>
  <li>O(logn)</li>
  <li>O(sqrt(n))</li>
  </ol>
  
  <p>How to sort the entire list most efficiently? Which sorting should I use in the above two cases? </p>