org.jacop.constraints

Class Count

java.lang.Object

org.jacop.constraints.DecomposedConstraint<Constraint>

org.jacop.constraints.Constraint

org.jacop.constraints.PrimitiveConstraint

org.jacop.constraints.Count

All Implemented Interfaces:

SatisfiedPresent, StoreAware

public class Count
extends PrimitiveConstraint

Count constraint implements the counting over number of occurrences of a given value in a list of variables. The number of occurrences is specified by variable counter.

Version:

4.9

Author:

Krzysztof Kuchcinski and Radoslaw Szymanek

Field Summary

Fields

Modifier and Type	Field and Description
IntVar	counter It specifies variable idNumber to count the number of occurences of the specified value in a list.
IntVar[]	list The list of variables which are checked and counted if equal to specified value.
int	value The value to which is any variable is equal to makes the constraint count it.

Fields inherited from class org.jacop.constraints.PrimitiveConstraint

notConsistencyPruningEvents

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

Constructor and Description
Count(IntVar[] list, IntVar counter, int value) It constructs a Count constraint.
Count(List<? extends IntVar> list, IntVar counter, int value) It constructs a Count constraint.

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()
protected int	getDefaultNotConsistencyPruningEvent()
void	impose(Store store) It imposes the constraint in a given store.
void	include(Store store) It provide store for constraints that are not imposed but called from other constraints.
void	notConsistency(Store store) It makes pruning in such a way that constraint is notConsistent.
boolean	notSatisfied() It checks if constraint would be always not satisfied.
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.PrimitiveConstraint

getDefaultNestedConsistencyPruningEvent, getDefaultNestedNotConsistencyPruningEvent, getNestedPruningEvent, getNotConsistencyPruningEvent, setNotConsistencyPruningEvent

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, queueVariable, 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

counter

public final IntVar counter

It specifies variable idNumber to count the number of occurences of the specified value in a list.

list

public final IntVar[] list

The list of variables which are checked and counted if equal to specified value.

value

public final int value

The value to which is any variable is equal to makes the constraint count it.

Constructor Detail

Count

public Count(IntVar[] list,
             IntVar counter,
             int value)

It constructs a Count constraint.

Parameters:

value - value which is counted

list - variables which equality to val is counted.

counter - number of variables equal to val.

Count

public Count(List<? extends IntVar> list,
             IntVar counter,
             int value)

It constructs a Count constraint.

Parameters:

value - value which is counted

list - variables which equality to val is counted.

counter - number of variables equal to val.

Method Detail

impose

public void impose(Store store)

Description copied from class: Constraint

It imposes the constraint in a given store.

Overrides:

impose in class PrimitiveConstraint

Parameters:

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

include

public void include(Store store)

Description copied from interface: StoreAware

It provide store for constraints that are not imposed but called from other constraints.

Specified by:

include in interface StoreAware

Overrides:

include in class PrimitiveConstraint

Parameters:

store - the constraint store in which context the constraint is executed.

getDefaultConsistencyPruningEvent

public int getDefaultConsistencyPruningEvent()

Specified by:

getDefaultConsistencyPruningEvent in class Constraint

getDefaultNotConsistencyPruningEvent

protected int getDefaultNotConsistencyPruningEvent()

Specified by:

getDefaultNotConsistencyPruningEvent in class PrimitiveConstraint

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.

notConsistency

public void notConsistency(Store store)

Description copied from class: PrimitiveConstraint

It makes pruning in such a way that constraint is notConsistent. It removes values which always belong to a solution.

Specified by:

notConsistency in class PrimitiveConstraint

Parameters:

store - the constraint store in which context the notConsistency technique is evaluated.

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.

Returns:

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

notSatisfied

public boolean notSatisfied()

Description copied from class: PrimitiveConstraint

It checks if constraint would be always not satisfied.

Specified by:

notSatisfied in class PrimitiveConstraint

Returns:

true if constraint must be notSatisfied, false otherwise.

toString

public String toString()

Description copied from class: Constraint

It produces a string representation of a constraint state.

Overrides:

toString in class Constraint