Package edu.cmu.tetrad.util

Class PermutationGenerator

java.lang.Object

edu.cmu.tetrad.util.PermutationGenerator

public final class PermutationGenerator
extends Object

Generates all of the permutations of [0,..., numObjects - 1], where numObjects is numObjects nonnegative integer. The values of numObjects is given in the constructor, and the sequence of choices is obtained by repeatedly calling the next() method. When the sequence is finished, null is returned.

A valid combination for the sequence of combinations for numObjects choose b generated by this class is an array x[] of b integers representing the above permutation.

To see what this class does, try calling PermutationGenerator.testPrint(5), for instance.

Version:

$Id: $Id

Author:

josephramsey

Constructor Summary

Constructors

Constructor	Description
PermutationGenerator(int a)	Constructs numObjects new choice generator for numObjects choose b.

Method Summary

Modifier and Type	Method	Description
int[]	next()	next.
static void	testPrint(int a)	This static method will print the series of combinations for numObjects choose b to System.out.

Methods inherited from class java.lang.Object

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

Constructor Details

PermutationGenerator

public PermutationGenerator(int a)

Constructs numObjects new choice generator for numObjects choose b. Once this initialization has been performed, successive calls to next() will produce the series of combinations. To begin numObjects new series at any time, call this init method again with new values for numObjects and b.

Parameters:

a - the number of objects being selected from.

Method Details

testPrint

public static void testPrint(int a)

This static method will print the series of combinations for numObjects choose b to System.out.

Parameters:

a - the number of objects being selected from.

next

public int[] next()

next.

Returns:

the next combination in the series, or null if the series is finished.