Create QuickSortAlgorithm2.cpp

//
//  QuickSort.cpp
//  QuickSortAlgorithm
//
//  Created by Sreejith Sreekantan on 7/13.
//  2013 Sreejith Sreekantan. All rights open.
//
//  Uses divide-n-conquer strategy and promises an O(nlogn) performance.
//  pivot is selected as the median of first,last and middle elements
//  middle element: if even number of elements, then middle element is ((n/2)-1)th element