org.expasy.jpl.commons.base.math
Class CombinationFactory

java.lang.Object
  org.expasy.jpl.commons.base.math.CombinationFactory

All Implemented Interfaces:

org.apache.commons.collections15.Transformer<int[],List<int[]>>

public final class CombinationFactory
extends Object
implements org.apache.commons.collections15.Transformer<int[],List<int[]>>

Generate all combinations of p things among n.

Version:

1.0

Author:

nikitin

Constructor Summary

CombinationFactory()

Method Summary

static long	computeCombNumber(int p, int n) Compute the number of all the combinations of p elements among n.
static CombinationFactory	newInstance()
List<int[]>	process(int p, int n) Generate all combinations of p elements among n.
static String	toString(List<int[]> combinations)
List<int[]>	transform(int[] param)

Methods inherited from class java.lang.Object

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

Constructor Detail

CombinationFactory

public CombinationFactory()

Method Detail

newInstance

public static CombinationFactory newInstance()

transform

public List<int[]> transform(int[] param)

Specified by:

transform in interface org.apache.commons.collections15.Transformer<int[],List<int[]>>

Throws:

IllegalArgumentException - if invalid parameters.

process

public List<int[]> process(int p,
                           int n)

Generate all combinations of p elements among n.

Parameters:

p - p.

n - n.

Returns:

a list of combinations.

Throws:

IllegalArgumentException - if invalid parameters.

computeCombNumber

public static long computeCombNumber(int p,
                                     int n)

Compute the number of all the combinations of p elements among n.

Parameters:

p - p.

n - n.

Returns:

the total number of C(n, p).

toString

public static String toString(List<int[]> combinations)