Create QuickSortAlgorithm3.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.
//  Pivote element is always the last element of the array