Package org.jacop.constraints
Class AmongVar
java.lang.Object
org.jacop.constraints.DecomposedConstraint<Constraint>
org.jacop.constraints.Constraint
org.jacop.constraints.AmongVar
- All Implemented Interfaces:
SatisfiedPresent
,Stateful
,UsesQueueVariable
Among constraint in its general form. It establishes the following
relation. The given number N of X`s take values from the set
specified by Y`s.
This constraint significantly extends the algorithms presented in the literature as it does not use the decomposition into simpler constraints.
Therefore as a result, it provides stronger pruning methods without noticeable increase in the execution time. The large part of the computation is reused across following executions of the consistency function. The strength of propagation algorithm is incomporable to BC.
- Version:
- 4.8
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Field Summary
FieldsModifier and TypeFieldDescriptionstatic final boolean
It turns out printing debugging information.private MutableVar
(package private) static final AtomicInteger
Number of Among constraints created.private MutableVar
IntVar[]
List of variables x which values are checked against values of variables y.IntVar[]
It specifies what values we are counting in the list of x's.It specifies the number of x variables equal to at least one value present in the list of y.private LinkedHashSet<Integer>
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
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionvoid
consistency
(Store store) It is a (most probably incomplete) consistency function which removes the values from variables domains.void
consistencyForX
(Store store) Is called when all y are grounded and amongForSet is equivalent to simple version of Among.void
consistencyForY
(Store store) It is a function which makes Y consistent if all X's are grounded.void
consistencyWhen_LB0_EQ_UB0
(Store store) The number of x in lbsDom is equal to the number of X intersecting ubSDom.int
void
It imposes the constraint in a given store.void
queueVariable
(int level, Var var) 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
It checks if the constraint is satisfied.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, 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
Methods inherited from interface org.jacop.api.Stateful
isStateful
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Field Details
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debugAll
public static final boolean debugAllIt turns out printing debugging information.- See Also:
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idNumber
Number of Among constraints created. -
xIndex
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yIndex
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lbS
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futureLbS
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variableQueueY
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lb0TS
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ub0TS
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yGrounded
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xGrounded
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listOfX
List of variables x which values are checked against values of variables y. Each x is counted only once as equal to one of the elements of list y. -
listOfY
It specifies what values we are counting in the list of x's. -
n
It specifies the number of x variables equal to at least one value present in the list of y.
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Constructor Details
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AmongVar
It constructs an AmongVar constraint.- Parameters:
listOfX
- the list of variables whose equality to other set of variables we countlistOfY
- the list of variable to which equality is counted.n
- how many variables from list x are equal to at least one variable from list y.
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AmongVar
It constructs an AmongVar constraint.- Parameters:
listOfX
- the list of variables whose equality to other set of variables we countlistOfY
- the list of variable to which equality is counted.n
- how many variables from list x are equal to at least one variable from list y.
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Method Details
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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 interfaceStateful
- Parameters:
level
- the level which is being removed.
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consistencyForX
Is called when all y are grounded and amongForSet is equivalent to simple version of Among.- Parameters:
store
- constraint store in which context that consistency function is being executed.
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consistencyWhen_LB0_EQ_UB0
The number of x in lbsDom is equal to the number of X intersecting ubSDom.1) If there are not enough of y to cover future domain then fail 2)
- Parameters:
store
- a constraint store in which context all prunings are executed.
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consistencyForY
It is a function which makes Y consistent if all X's are grounded.- Parameters:
store
- a constraint store in which context all prunings are executed.
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consistency
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:
store
- constraint store within which the constraint consistency is being checked.
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getDefaultConsistencyPruningEvent
public int getDefaultConsistencyPruningEvent()- Specified by:
getDefaultConsistencyPruningEvent
in classConstraint
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impose
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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queueVariable
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 classConstraint
- Parameters:
level
- the level of the store at which the change has occurred.var
- variable which has changed.
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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
Description copied from class:Constraint
It produces a string representation of a constraint state.- Overrides:
toString
in classConstraint
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