gov.nasa.jpf.util

Class PermutationGenerator

java.lang.Object

gov.nasa.jpf.util.PermutationGenerator

Direct Known Subclasses:

PairPermutationGenerator, RandomPermutationGenerator, TotalPermutationGenerator

public abstract class PermutationGenerator
extends java.lang.Object

base type for permutation generators

Field Summary

Fields

Modifier and Type	Field and Description
protected int	nElements
protected long	nGenerated
protected long	nPermutations
protected int[]	permutation

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	PermutationGenerator(int nElements)

Method Summary

Modifier and Type	Method and Description
protected abstract long	computeNumberOfPermutations()
long	getNumberOfGeneratedPermutations()
long	getNumberOfPermutations()
boolean	hasNext()
protected void	initPermutations()
abstract int[]	next() return the next permutation or throw a NoSuchElementException if there is none.
void	printOn(java.io.PrintStream ps) for debugging purposes
static void	printOn(java.io.PrintStream ps, long nGenerated, int[] perm)
abstract void	reset()

Methods inherited from class java.lang.Object

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

Field Detail

nElements

protected final int nElements

permutation

protected int[] permutation

nPermutations

protected long nPermutations

nGenerated

protected long nGenerated

Constructor Detail

PermutationGenerator

protected PermutationGenerator(int nElements)

Method Detail

initPermutations

protected void initPermutations()

computeNumberOfPermutations

protected abstract long computeNumberOfPermutations()

reset

public abstract void reset()

getNumberOfPermutations

public long getNumberOfPermutations()

getNumberOfGeneratedPermutations

public long getNumberOfGeneratedPermutations()

printOn

public void printOn(java.io.PrintStream ps)

for debugging purposes

printOn

public static void printOn(java.io.PrintStream ps,
                           long nGenerated,
                           int[] perm)

hasNext

public boolean hasNext()

next

public abstract int[] next()

return the next permutation or throw a NoSuchElementException if there is none. NOTE - this does not guarantee to return a different object on each call, i.e. the caller has to clone if the result is stored directly