gov.nasa.jpf.util

Class UniqueRandomPermGenerator

java.lang.Object

gov.nasa.jpf.util.PermutationGenerator

gov.nasa.jpf.util.RandomPermutationGenerator

gov.nasa.jpf.util.UniqueRandomPermGenerator

public class UniqueRandomPermGenerator
extends RandomPermutationGenerator

a RandomPermutationGenerator that keeps track of previously produced values to avoid duplicates. Note this only makes sense for relatively small sample sizes, but then again that is what RandomPermutationGenerators are used for (to avoid N!)

Field Summary

Fields

Modifier and Type	Field and Description
protected SortedArrayIntSet	visited

Fields inherited from class gov.nasa.jpf.util.RandomPermutationGenerator

orig, rand, seed

Fields inherited from class gov.nasa.jpf.util.PermutationGenerator

nElements, nGenerated, nPermutations, permutation

Constructor Summary

Constructors

Constructor and Description
UniqueRandomPermGenerator(int nElements, int nPermutations, int seed)

Method Summary

Modifier and Type	Method and Description
int[]	next() return the next permutation or throw a NoSuchElementException if there is none.
void	reset()

Methods inherited from class gov.nasa.jpf.util.RandomPermutationGenerator

computeNumberOfPermutations

Methods inherited from class gov.nasa.jpf.util.PermutationGenerator

getNumberOfGeneratedPermutations, getNumberOfPermutations, hasNext, initPermutations, printOn, printOn

Methods inherited from class java.lang.Object

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

Field Detail

visited

protected SortedArrayIntSet visited

Constructor Detail

UniqueRandomPermGenerator

public UniqueRandomPermGenerator(int nElements,
                                 int nPermutations,
                                 int seed)

Method Detail

reset

public void reset()

Overrides:

reset in class RandomPermutationGenerator

next

public int[] next()

Description copied from class: PermutationGenerator

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

Overrides:

next in class RandomPermutationGenerator