org.jacop.constraints

Class Alldifferent

java.lang.Object

org.jacop.constraints.DecomposedConstraint<Constraint>

org.jacop.constraints.Constraint

org.jacop.constraints.Alldifferent

All Implemented Interfaces:

SatisfiedPresent, UsesQueueVariable

Direct Known Subclasses:

Alldiff

public class Alldifferent
extends Constraint
implements UsesQueueVariable, SatisfiedPresent

Alldifferent constraint assures that all FDVs has differnet values. It uses partial consistency technique.

Version:

4.9

Author:

Krzysztof Kuchcinski and Radoslaw Szymanek

Field Summary

Fields

Modifier and Type	Field and Description
protected TimeStamp<Integer>	grounded
IntVar[]	list It specifies a list of variables which must take different values.
protected Map<IntVar,Integer>	positionMapping

Fields inherited from class org.jacop.constraints.Constraint

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

Fields inherited from class org.jacop.constraints.DecomposedConstraint

queueIndex

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	Alldifferent()
	Alldifferent(IntVar[] list) It constructs the alldifferent constraint for the supplied variable.
	Alldifferent(List<? extends IntVar> variables) It constructs the alldifferent constraint for the supplied variable.

Method Summary

Modifier and Type	Method and 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.
boolean	notSatisfied() Check whether the constraint is not satisfied based on bipartite graph matching.
void	queueVariable(int level, Var V) This is a function called to indicate which variable in a scope of constraint has changed.
boolean	satisfied() It checks if the constraint is satisfied.
String	toString() It produces a string representation of a constraint state.

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, 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 Detail

list

public IntVar[] list

It specifies a list of variables which must take different values.

positionMapping

protected Map<IntVar,Integer> positionMapping

grounded

protected TimeStamp<Integer> grounded

Constructor Detail

Alldifferent

protected Alldifferent()

Alldifferent

public Alldifferent(IntVar[] list)

It constructs the alldifferent constraint for the supplied variable.

Parameters:

list - variables which are constrained to take different values.

Alldifferent

public Alldifferent(List<? extends IntVar> variables)

It constructs the alldifferent constraint for the supplied variable.

Parameters:

variables - variables which are constrained to take different values.

Method Detail

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.

Specified by:

consistency in class Constraint

Parameters:

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

getDefaultConsistencyPruningEvent

public int getDefaultConsistencyPruningEvent()

Specified by:

getDefaultConsistencyPruningEvent in class Constraint

satisfied

public boolean satisfied()

Description copied from interface: SatisfiedPresent

It checks if the constraint is satisfied. It can return false even if constraint is satisfied but not all variables in its scope are grounded. It needs to return true if all variables in its scope are grounded and constraint is satisfied.

Implementations of this interface for constraints that are not PrimitiveConstraint may require constraint imposition and consistency check as a requirement to work correctly.

Specified by:

satisfied in interface SatisfiedPresent

Returns:

true if constraint is possible to verify that it is satisfied.

notSatisfied

public boolean notSatisfied()

Check whether the constraint is not satisfied based on bipartite graph matching.

Returns:

true if constraint is not satisfied

impose

public void impose(Store store)

Description copied from class: Constraint

It imposes the constraint in a given store.

Overrides:

impose in class Constraint

Parameters:

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

queueVariable

public void queueVariable(int level,
                          Var V)

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 Constraint

Parameters:

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

V - variable which has changed.

toString

public String toString()

Description copied from class: Constraint

It produces a string representation of a constraint state.

Overrides:

toString in class Constraint