Package org.jacop.constraints

Class Alldiff

java.lang.Object

org.jacop.constraints.DecomposedConstraint<Constraint>

org.jacop.constraints.Constraint

org.jacop.constraints.Alldifferent

org.jacop.constraints.Alldiff

All Implemented Interfaces:

SatisfiedPresent, UsesQueueVariable

Direct Known Subclasses:

Circuit, Subcircuit

public class Alldiff
extends Alldifferent

Alldiff constraint assures that all FDVs has different values. It uses bounds consistency technique as described in the paper by Alejandro Lopez-Ortiz, Claude-Guy Quimper, John Tromp, Peter van Beek, "A fast and simple algorithm for bounds consistency of the alldifferent constraint", Proceedings of the 18th international joint conference on Artificial intelligence (IJCAI'03), Pages 245-250. Before using bounds consistency it calls consistency method for ground variables.

It extends basic functionality of Alldifferent constraint.

Version:

4.10

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static class	Alldiff.Element

Field Summary

Fields

Modifier and Type	Field	Description
private int[]	bounds
private int[]	d
private int[]	h
(package private) static AtomicInteger	idNumber
private Alldiff.Element[]	maxsorted
private Comparator<Alldiff.Element>	maxVariable
private Alldiff.Element[]	minsorted
private Comparator<Alldiff.Element>	minVariable
private int	nb
(package private) Store	store
private int[]	t

Fields inherited from class org.jacop.constraints.Alldifferent

grounded, list, positionMapping, variableQueue

Fields inherited from class org.jacop.constraints.Constraint

afcWeight, atomicExecution, consistencyPruningEvents, constraintScope, earlyTerminationOK, increaseWeight, numberId, scope, trace, watchedVariableGrounded

Fields inherited from class org.jacop.constraints.DecomposedConstraint

queueIndex

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	Alldiff()
	Alldiff(List<? extends IntVar> variables)	It constructs the alldiff constraint for the supplied variable.
	Alldiff(IntVar[] variables)	It constructs the alldiff constraint for the supplied variable.

Method Summary

Modifier and Type	Method	Description
void	consistency(Store store)	It is a (most probably incomplete) consistency function which removes the values from variables domains.
int	getDefaultConsistencyPruningEvent()
void	impose(Store store)	It imposes the constraint in a given store.
private void	init()
private int	pathmax(int[] v, int i)
private int	pathmin(int[] v, int i)
private void	pathset(int[] v, int start, int end, int to)
void	queueVariable(int level, Var var)	This is a function called to indicate which variable in a scope of constraint has changed.
String	toString()	It produces a string representation of a constraint state.
private void	updateLB()
private void	updateUB()

Methods inherited from class org.jacop.constraints.Alldifferent

notSatisfied, satisfied

Methods inherited from class org.jacop.constraints.Constraint

afc, arguments, cleanAfterFailure, decompose, getConsistencyPruningEvent, getGuideConstraint, getGuideValue, getGuideVariable, grounded, grounded, id, impose, imposeDecomposition, increaseWeight, intArrayToString, long2int, numberArgs, removeConstraint, requiresMonotonicity, setConsistencyPruningEvent, setConstraintScope, setScope, setScope, setScope, setScope, setScope, setWatchedVariableGrounded, supplyGuideFeedback, toInt, toInt, updateAFC, watchedVariableGrounded

Methods inherited from class org.jacop.constraints.DecomposedConstraint

auxiliaryVariables, checkInput, checkInput, checkInputForDuplication, checkInputForDuplicationSkipSingletons, checkInputForNullness, checkInputForNullness, checkInputForNullness, derivative, getDubletonsSkipSingletons, imposeDecomposition

Methods inherited from class java.lang.Object

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

Field Details

idNumber

static AtomicInteger idNumber

store

Store store

maxVariable

private Comparator<Alldiff.Element> maxVariable

minVariable

private Comparator<Alldiff.Element> minVariable

t

private int[] t

d

private int[] d

h

private int[] h

bounds

private int[] bounds

nb

private int nb

minsorted

private Alldiff.Element[] minsorted

maxsorted

private Alldiff.Element[] maxsorted

Constructor Details

Alldiff

protected Alldiff()

Alldiff

public Alldiff(IntVar[] variables)

It constructs the alldiff constraint for the supplied variable.

Parameters:

variables - variables which are constrained to take different values.

Alldiff

public Alldiff(List<? extends IntVar> variables)

It constructs the alldiff constraint for the supplied variable.

Parameters:

variables - variables which are constrained to take different values.

Method Details

getDefaultConsistencyPruningEvent

public int getDefaultConsistencyPruningEvent()

Overrides:

getDefaultConsistencyPruningEvent in class Alldifferent

impose

public void impose(Store store)

Description copied from class: Constraint

It imposes the constraint in a given store.

Overrides:

impose in class Alldifferent

Parameters:

store - the constraint store to which the constraint is imposed to.

consistency

public void consistency(Store store)

Description copied from class: Constraint

It is a (most probably incomplete) consistency function which removes the values from variables domains. Only values which do not have any support in a solution space are removed.

Overrides:

consistency in class Alldifferent

Parameters:

store - constraint store within which the constraint consistency is being checked.

init

private void init()

updateLB

private void updateLB()

updateUB

private void updateUB()

pathset

private void pathset(int[] v,
 int start,
 int end,
 int to)

pathmin

private int pathmin(int[] v,
 int i)

pathmax

private int pathmax(int[] v,
 int i)

toString

public String toString()

Description copied from class: Constraint

It produces a string representation of a constraint state.

Overrides:

toString in class Alldifferent

queueVariable

public void queueVariable(int level,
 Var var)

Description copied from class: Constraint

This is a function called to indicate which variable in a scope of constraint has changed. It also indicates a store level at which the change has occurred.

Overrides:

queueVariable in class Alldifferent

Parameters:

level - the level of the store at which the change has occurred.

var - variable which has changed.