title: Minimum number of comparisons needed to use merge sort algorithm?
body: <p>For those of you familiar with merge sort, I'm trying to figure out the minimum number of comparisons needed to merge two subarrays of size n/2, where n is the number of items in the original unsorted array. </p>
  
  <p>I know the average- and worst-case time complexity of the algorithm is O(nlogn), but I can't figure out the exact <strong>minimum</strong> number of comparisons needed (in terms of n).</p>