Q:

What is the Best Input Array for Quick Sort

I am working to find the best performing input array for quicksort.   My array is to be 100 elements long consisting of integers 1 thru 100.   I am choosing the last element as the pivot value. 
I know I want the last element to be 50 so that I get two subarrays of equal length.   I then know I want element 49 to be 25 so that I get another event split. 
I am a little confused as to where to put that original 25 so that after the first split it is in position 49.   Can anyone help me understand the algorithm a little better? 
I am not necessarily looking for an example, but an explanation on how to achieve the positions.   I would like the answer for 10,100,1000... length array. 

A:

The best case for Quicksort using last element as pivot is the post-order traversal of the balanced binary search tree.  For example:
     5
   /   \
  3      7
 / \    / \
1   4  6   8

The post-order traversal of this binary tree is
1 4 3 6 8 7 5

