org.jacop.constraints

Class Diff

java.lang.Object

org.jacop.constraints.DecomposedConstraint<Constraint>

org.jacop.constraints.Constraint

org.jacop.constraints.Diff

All Implemented Interfaces:

SatisfiedPresent, Stateful, UsesQueueVariable

Direct Known Subclasses:

Diff2, Disjoint, DisjointConditional

public class Diff
extends Constraint
implements UsesQueueVariable, Stateful, SatisfiedPresent

Diff constraint assures that any two rectangles from a vector of rectangles does not overlap in at least one direction. It is a simple implementation which does not use sophisticated techniques for efficient backtracking.

Version:

4.9

Author:

Krzysztof Kuchcinski and Radoslaw Szymanek

Field Summary

Fields

Modifier and Type	Field and Description
protected Function<Integer,Comparator<org.jacop.constraints.IntRectangle>>	dimIthMinComparator
Rectangle[]	rectangles It specifies the list of rectangles which are of interest for this diff constraint.
protected static boolean	trace

Fields inherited from class org.jacop.constraints.Constraint

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

Fields inherited from class org.jacop.constraints.DecomposedConstraint

queueIndex

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	Diff()
	Diff(IntVar[][] rectangles) It specifies a diff constraint.
	Diff(IntVar[][] rectangles, boolean profile) It specifies a diff constraint.
	Diff(IntVar[] origin1, IntVar[] origin2, IntVar[] length1, IntVar[] length2) It constructs a diff constraint.
	Diff(IntVar[] o1, IntVar[] o2, IntVar[] l1, IntVar[] l2, boolean profile) It constructs a diff constraint.
	Diff(List<? extends IntVar> o1, List<? extends IntVar> o2, List<? extends IntVar> l1, List<? extends IntVar> l2) It constructs a diff constraint.
	Diff(List<? extends IntVar> o1, List<? extends IntVar> o2, List<? extends IntVar> l1, List<? extends IntVar> l2, boolean profile) It constructs a diff constraint.
	Diff(List<? extends List<? extends IntVar>> rectangles) It specifies a diffn constraint.
	Diff(List<? extends List<? extends IntVar>> rectangles, boolean profile) It specifies a diff constraint.
	Diff(Rectangle[] rectangles, boolean doProfile) It specifies a diff 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()
void	queueVariable(int level, Var V) This is a function called to indicate which variable in a scope of constraint has changed.
void	removeLevel(int level) This function is called in case of the backtrack, so a constraint can clear the queue of changed variables which is no longer valid.
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, 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

Methods inherited from interface org.jacop.api.Stateful

isStateful

Field Detail

trace

protected static final boolean trace

See Also:

Constant Field Values

rectangles

public Rectangle[] rectangles

It specifies the list of rectangles which are of interest for this diff constraint.

dimIthMinComparator

protected Function<Integer,Comparator<org.jacop.constraints.IntRectangle>> dimIthMinComparator

Constructor Detail

Diff

protected Diff()

Diff

public Diff(Rectangle[] rectangles,
            boolean doProfile)

It specifies a diff constraint.

Parameters:

rectangles - list of rectangles which can not overlap in at least one dimension.

doProfile - should the constraint compute and use the profile functionality.

Diff

public Diff(IntVar[][] rectangles)

It specifies a diff constraint.

Parameters:

rectangles - list of rectangles which can not overlap in at least one dimension.

Diff

public Diff(IntVar[] o1,
            IntVar[] o2,
            IntVar[] l1,
            IntVar[] l2,
            boolean profile)

It constructs a diff constraint.

Parameters:

o1 - list of variables denoting origin of the rectangle in the first dimension.

o2 - list of variables denoting origin of the rectangle in the second dimension.

l1 - list of variables denoting length of the rectangle in the first dimension.

l2 - list of variables denoting length of the rectangle in the second dimension.

profile - it specifies if the profile should be computed and used.

Diff

public Diff(IntVar[] origin1,
            IntVar[] origin2,
            IntVar[] length1,
            IntVar[] length2)

It constructs a diff constraint.

Parameters:

origin1 - list of variables denoting origin of the rectangle in the first dimension.

origin2 - list of variables denoting origin of the rectangle in the second dimension.

length1 - list of variables denoting length of the rectangle in the first dimension.

length2 - list of variables denoting length of the rectangle in the second dimension.

Diff

public Diff(List<? extends List<? extends IntVar>> rectangles)

It specifies a diffn constraint.

Parameters:

rectangles - list of rectangles which can not overlap in at least one dimension.

Diff

public Diff(List<? extends List<? extends IntVar>> rectangles,
            boolean profile)

It specifies a diff constraint.

Parameters:

profile - specifies is the profiles are used.

rectangles - list of rectangles which can not overlap in at least one dimension.

Diff

public Diff(List<? extends IntVar> o1,
            List<? extends IntVar> o2,
            List<? extends IntVar> l1,
            List<? extends IntVar> l2)

It constructs a diff constraint.

Parameters:

o1 - list of variables denoting origin of the rectangle in the first dimension.

o2 - list of variables denoting origin of the rectangle in the second dimension.

l1 - list of variables denoting length of the rectangle in the first dimension.

l2 - list of variables denoting length of the rectangle in the second dimension.

Diff

public Diff(List<? extends IntVar> o1,
            List<? extends IntVar> o2,
            List<? extends IntVar> l1,
            List<? extends IntVar> l2,
            boolean profile)

It constructs a diff constraint.

Parameters:

o1 - list of variables denoting origin of the rectangle in the first dimension.

o2 - list of variables denoting origin of the rectangle in the second dimension.

l1 - list of variables denoting length of the rectangle in the first dimension.

l2 - list of variables denoting length of the rectangle in the second dimension.

profile - it specifies if the profile should be computed and used.

Diff

public Diff(IntVar[][] rectangles,
            boolean profile)

It specifies a diff constraint.

Parameters:

profile - specifies is the profiles are used.

rectangles - list of rectangles which can not overlap in at least one dimension.

Method Detail

removeLevel

public void removeLevel(int level)

Description copied from interface: Stateful

This function is called in case of the backtrack, so a constraint can clear the queue of changed variables which is no longer valid. This function is called *before* all timestamps, variables, mutablevariables have reverted to their previous value.

Specified by:

removeLevel in interface Stateful

Parameters:

level - the level which is being removed.

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

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.

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.

toString

public String toString()

Description copied from class: Constraint

It produces a string representation of a constraint state.

Overrides:

toString in class Constraint