Package org.jacop.constraints
Class ExtensionalSupportMDD
- java.lang.Object
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- org.jacop.constraints.DecomposedConstraint<Constraint>
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- org.jacop.constraints.Constraint
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- org.jacop.constraints.ExtensionalSupportMDD
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- All Implemented Interfaces:
SatisfiedPresent
public class ExtensionalSupportMDD extends Constraint implements SatisfiedPresent
Extensional constraint assures that one of the tuples is enforced in the relation.This implementation uses technique developed/improved by Roland Yap and his student. Paper presented at CP2008. We would like to thank Roland for answering our detailed questions about the implementation. It is a slightly improved version to what was presented at the conference.
This constraint uses a lot of memory, despite using an MDD. However, if the constraint is imposed multiple times (50+) its overall usage of memory maybe advantageous. Always test against STR version.
- Version:
- 4.7
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Field Summary
Fields Modifier and Type Field Description static boolean
debugAll
It specifies if the debugging information is printed.(package private) SparseSet
G_no
(package private) TimeStamp<java.lang.Integer>
G_no_size
(package private) SparseSet
G_yes
(package private) static java.util.concurrent.atomic.AtomicInteger
idNumber
MDD
mdd
It specifies a multiple value decision diagram used by this constraint.(package private) IndexDomainView[]
views
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Fields inherited from class org.jacop.constraints.Constraint
afcWeight, atomicExecution, consistencyPruningEvents, constraintScope, earlyTerminationOK, increaseWeight, numberId, scope, trace, watchedVariableGrounded
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Fields inherited from class org.jacop.constraints.DecomposedConstraint
queueIndex
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Constructor Summary
Constructors Constructor Description ExtensionalSupportMDD(IntVar[] vars, int[][] table)
It constructs extensional support constraint.ExtensionalSupportMDD(MDD diagram)
It creates an extensional constraint.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
consistency(Store s)
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
satisfied()
It checks if the constraint is satisfied.boolean
seekSupport(int nodeId, int level)
It checks if the node at a given level of MDD has a support.java.lang.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, queueVariable, removeConstraint, requiresMonotonicity, setConsistencyPruningEvent, setConstraintScope, setScope, setScope, setScope, setScope, setScope, setWatchedVariableGrounded, supplyGuideFeedback, toInt, toInt, updateAFC, watchedVariableGrounded
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Methods inherited from class org.jacop.constraints.DecomposedConstraint
auxiliaryVariables, checkInput, checkInput, checkInputForDuplication, checkInputForDuplicationSkipSingletons, checkInputForNullness, checkInputForNullness, checkInputForNullness, derivative, getDubletonsSkipSingletons, imposeDecomposition
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Field Detail
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debugAll
public static final boolean debugAll
It specifies if the debugging information is printed.- See Also:
- Constant Field Values
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idNumber
static java.util.concurrent.atomic.AtomicInteger idNumber
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G_no_size
TimeStamp<java.lang.Integer> G_no_size
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G_no
SparseSet G_no
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mdd
public MDD mdd
It specifies a multiple value decision diagram used by this constraint.
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G_yes
SparseSet G_yes
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views
IndexDomainView[] views
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Constructor Detail
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ExtensionalSupportMDD
public ExtensionalSupportMDD(MDD diagram)
It creates an extensional constraint.- Parameters:
diagram
- multiple-valued decision diagram describing allowed tuples.
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ExtensionalSupportMDD
public ExtensionalSupportMDD(IntVar[] vars, int[][] table)
It constructs extensional support constraint. Please note that parameters will be stored internally as references until the impose of the constraint takes place. Changing parameters after constructing the constraint and before its imposition will change the constraint too.- Parameters:
vars
- the variables in the scope of the constraint.table
- list of tuples which are allowed.
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Method Detail
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impose
public void impose(Store store)
Description copied from class:Constraint
It imposes the constraint in a given store.- Overrides:
impose
in classConstraint
- Parameters:
store
- the constraint store to which the constraint is imposed to.
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consistency
public void consistency(Store s)
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 classConstraint
- Parameters:
s
- constraint store within which the constraint consistency is being checked.
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seekSupport
public boolean seekSupport(int nodeId, int level)
It checks if the node at a given level of MDD has a support.- Parameters:
nodeId
- the position of the node in the MDD.level
- number of variable associated with the node.- Returns:
- true if node is supported by current domains of variables.
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getDefaultConsistencyPruningEvent
public int getDefaultConsistencyPruningEvent()
- Specified by:
getDefaultConsistencyPruningEvent
in classConstraint
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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 interfaceSatisfiedPresent
- Returns:
- true if constraint is possible to verify that it is satisfied.
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toString
public java.lang.String toString()
Description copied from class:Constraint
It produces a string representation of a constraint state.- Overrides:
toString
in classConstraint
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