jwutil.math
Class CombinationGenerator

java.lang.Object
  jwutil.math.CombinationGenerator

public class CombinationGenerator
extends java.lang.Object

Generates combinations.

Version:

$Id: CombinationGenerator.java 2279 2005-05-28 10:24:54Z joewhaley $

Author:

jwhaley

Constructor Summary

CombinationGenerator(int n, int r)
Create a new combination generator.

Method Summary

int[]	getCurrent() Returns the current combination.
int[]	getNext() Generate next combination (algorithm from Rosen p.
java.math.BigInteger	getNumLeft() Return number of combinations not yet generated.
java.math.BigInteger	getTotal() Return total number of combinations.
boolean	hasMore() Are there more combinations?
void	reset() Reset this combination generator back to the start.

Methods inherited from class java.lang.Object

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

Constructor Detail

CombinationGenerator

public CombinationGenerator(int n,
                            int r)

Create a new combination generator.

Parameters:

n - size of universe

r - number of elements to choose

Method Detail

reset

public void reset()

Reset this combination generator back to the start.

getNumLeft

public java.math.BigInteger getNumLeft()

Return number of combinations not yet generated.

Returns:

number of combinations not yet generated

hasMore

public boolean hasMore()

Are there more combinations?

Returns:

if there are more combinations

getTotal

public java.math.BigInteger getTotal()

Return total number of combinations.

Returns:

total number of combinations

getCurrent

public int[] getCurrent()

Returns the current combination.

Returns:

current combination

getNext

public int[] getNext()

Generate next combination (algorithm from Rosen p. 286).

Returns:

next combination