org.oscim.utils

Class TimSort<T>

java.lang.Object

org.oscim.utils.TimSort<T>

Direct Known Subclasses:

TileDistanceSort

public class TimSort<T>
extends java.lang.Object

A stable, adaptive, iterative mergesort that requires far fewer than n lg(n) comparisons when running on partially sorted arrays, while offering performance comparable to a traditional mergesort when run on random arrays. Like all proper mergesorts, this sort is stable and runs O(n log n) time (worst case). In the worst case, this sort requires temporary storage space for n/2 object references; in the best case, it requires only a small constant amount of space.

This implementation was adapted from Tim Peters's list sort for Python, which is described in detail here:

http://svn.python.org/projects/python/trunk/Objects/listsort.txt

Tim's C code may be found here:

http://svn.python.org/projects/python/trunk/Objects/listobject.c

The underlying techniques are described in this paper (and may have even earlier origins):

"Optimistic Sorting and Information Theoretic Complexity" Peter McIlroy SODA (Fourth Annual ACM-SIAM Symposium on Discrete Algorithms), pp 467-474, Austin, Texas, 25-27 January 1993.

While the API to this class consists solely of static methods, it is (privately) instantiable; a TimSort instance holds the state of an ongoing sort, assuming the input array is large enough to warrant the full-blown TimSort. Small arrays are sorted in place, using a binary insertion sort.

Constructor Summary

Constructors

Constructor and Description
TimSort()

Method Summary

Modifier and Type	Method and Description
void	doSort(T[] a, java.util.Comparator<T> c, int lo, int hi)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TimSort

public TimSort()

Method Detail

doSort

public void doSort(T[] a,
                   java.util.Comparator<T> c,
                   int lo,
                   int hi)