Mar 25, 2009 · Quick sort is typically faster than merge sort when the data is stored in memory. However, when the data set is huge and is stored on external devices such as a hard drive, merge sort is the clear winner in terms of speed.

Quicksort is slightly sensitive to input that happens to be in the right order, in which case it can skip some swaps. Mergesort doesn't have any such optimizations, which also makes Quicksort a bit faster compared to Mergesort. Why Quick sort is better than Merge sort

Apr 26, 2011 · Of course, @greybeard whenever possible I recommend developers to re-use the STL qsort. My answer is for those trying to learn how quick-sorting works

Oct 3, 2008 · Quick sort's complexity varies greatly with the selection of pivot value. for example if you always choose first element as an pivot, algorithm's complexity becomes as worst as O (n^2). here is an smart method to choose pivot element- 1. …

The worst case running time depends on the partition method within quick-sort. That has two aspects: selecting the pivot how to partition around the pivot Good strategies to select the pivot have been outlinied in previous posts (median of medians, or median of three or randomization).

May 3, 2012 · Is anybody able to give a 'plain english' intuitive, yet formal, explanation of what makes QuickSort n log n? From my understanding it has to make a pass over n items, and it does this log n times....

Sep 17, 2012 · Take into account that insertion sort will behave badly if your array is sorted reversely (worst case). As regards to the recursion stuff, you only need to modify the stop case of the quick-sort recursion -> array size <= 10 stop recursion and sort the all the array (which is much smaller in this recursion step) using insertion sort.

Feb 26, 2014 · So the space efficiency of Quicksort is O (log (n)). This is the space required to maintain the call stack. Now, according to the Wikipedia page on Quicksort, this qualifies as an in-place algorithm, as the algorithm is just swapping elements within the input data structure.

My understanding of quick sort is Choose a pivot element (in this case I am choosing middle element as pivot) Initialize left and right pointers at extremes. Find the first element to the left of ...

Dec 2, 2015 · I was studying Quick sort, I found the algorithm explained here best to my understanding, but I have a question at one of the step. Could someone explained me properly what would be the steps til...