Package org.jacop.constraints
Class AmongVar
- 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.AmongVar
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- All Implemented Interfaces:
SatisfiedPresent
,Stateful
,UsesQueueVariable
public class AmongVar extends Constraint implements UsesQueueVariable, Stateful, SatisfiedPresent
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:
- 4.7
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Field Summary
Fields Modifier and Type Field Description static boolean
debugAll
It turns out printing debugging information.private MutableVar
futureLbS
(package private) static java.util.concurrent.atomic.AtomicInteger
idNumber
Number of Among constraints created.private TimeStamp<java.lang.Integer>
lb0TS
private MutableVar
lbS
IntVar[]
listOfX
List of variables x which values are checked against values of variables y.IntVar[]
listOfY
It specifies what values we are counting in the list of x's.IntVar
n
It specifies the number of x variables equal to at least one value present in the list of y.private TimeStamp<java.lang.Integer>
ub0TS
private java.util.LinkedHashSet<java.lang.Integer>
variableQueueY
private TimeStamp<java.lang.Integer>
xGrounded
private java.util.Map<IntVar,java.lang.Integer>
xIndex
private TimeStamp<java.lang.Integer>
yGrounded
private java.util.Map<IntVar,java.lang.Integer>
yIndex
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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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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
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
getDefaultConsistencyPruningEvent()
void
impose(Store store)
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
satisfied()
It checks if the constraint is satisfied.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, 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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Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
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Methods inherited from interface org.jacop.api.Stateful
isStateful
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Field Detail
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debugAll
public static final boolean debugAll
It turns out printing debugging information.- See Also:
- Constant Field Values
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idNumber
static final java.util.concurrent.atomic.AtomicInteger idNumber
Number of Among constraints created.
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xIndex
private java.util.Map<IntVar,java.lang.Integer> xIndex
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yIndex
private java.util.Map<IntVar,java.lang.Integer> yIndex
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lbS
private MutableVar lbS
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futureLbS
private MutableVar futureLbS
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variableQueueY
private java.util.LinkedHashSet<java.lang.Integer> variableQueueY
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lb0TS
private TimeStamp<java.lang.Integer> lb0TS
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ub0TS
private TimeStamp<java.lang.Integer> ub0TS
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yGrounded
private TimeStamp<java.lang.Integer> yGrounded
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xGrounded
private TimeStamp<java.lang.Integer> xGrounded
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listOfX
public IntVar[] 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.
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listOfY
public IntVar[] listOfY
It specifies what values we are counting in the list of x's.
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n
public IntVar 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 Detail
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AmongVar
public AmongVar(IntVar[] listOfX, IntVar[] listOfY, IntVar n)
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
public AmongVar(java.util.List<IntVar> listOfX, java.util.List<IntVar> listOfY, IntVar n)
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 Detail
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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
public void consistencyForX(Store store)
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
public void consistencyWhen_LB0_EQ_UB0(Store store)
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
public void consistencyForY(Store store)
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
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 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
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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queueVariable
public void queueVariable(int level, Var var)
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
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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