quicksort

Algorithms like Timsort, Quicksort & Mergesort dominate the " real world " sorting methods. The case for these comparison sorts is quite practical — they've been shown to be the most performant, stable, multipurpose sorting algorithms in a wide variety of environments. However, it seems like nearly everything that we would sort on a computer are countable / partially ordered. Numbers, characters, strings, even functions are amenable to some meaningful non-comparison sorting method. A candidate here is Radix sort. In general it will behave faster than O(n*log(n)), beating the theoretical

I'm learning sorting algorithms and as next step, I'm trying to get my implementation perform close to the std::sort() . I'm pretty far, so far.. :-) I have 3 implementations of quicksort: standard quicksort (using temp arrays). quicksort with following optimizations: median3 used to select median tail-recursion quicksort applied only upto partition sizes < 16. For smaller partitions insertion sort is used. insertion sort applied to the whole array at once instead of applying to each partition, left unsorted by quicksort. quicksort with all optimizations listed above + in-place partitioning

Possible Duplicate: Quick Sort with random pivot in Java The below written code of the Quicksort uses the first element of the array as the pivot and then sorts the array. Now I want to randomly pick up the pivot instead of first one and then sort the array and I am stuck please tell me what changes I can make in the below code to get the perfect results. import java.util.*; import javax.swing.JOptionPane; public class Quicksort { public static void main(String[] args) { String arraylength = JOptionPane.showInputDialog("Enter the length of the array."); int a = Integer.parseInt(arraylength);

I have a question that could seem very basic, but it is in a context where "every CPU tick counts" (this is a part of a larger algorithm that will be used on supercomputers). The problem is quite simple : what is the fastest way to sort a list of unsigned long long int numbers and their original indexes ? (At the beginning, the unsigned long long int numbers are in a completely random order.) Example : Before Numbers: 32 91 11 72 Indexes: 0 1 2 3 After Numbers: 11 32 72 91 Indexes: 2 0 3 1 By "fastest way", I mean : what algorithm to use : std::sort, C qsort, or another sorting algorithm