Package org.jacop.constraints
Class Among
- 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.Among
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- All Implemented Interfaces:
SatisfiedPresent
,Stateful
,UsesQueueVariable
public class Among extends Constraint implements UsesQueueVariable, Stateful, SatisfiedPresent
Among constraint in its simplest form. It establishes the following relation. The given number N of X`s take values from the supplied set of values Kset.This constraint implements a simple and polynomial algorithm to establish GAC as presented in different research papers. There are number of improvements (iterative execution, optimization of computational load upon backtracking) to improve the constraint further.
- Version:
- 4.8
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Field Summary
Fields Modifier and Type Field Description private static boolean
debugAll
(package private) static java.util.concurrent.atomic.AtomicInteger
idNumber
IntervalDomain
kSet
It specifies a set of values which if assigned to a variable from a list makes variable counted.IntVar[]
list
It specifies the list of variables whose values are checked.private TimeStamp<java.lang.Integer>
lowerBorder
IntVar
n
It is a idNumber variable.private java.util.Map<IntVar,java.lang.Integer>
position
private TimeStamp<java.lang.Integer>
upperBorder
(package private) java.util.LinkedHashSet<IntVar>
variableQueue
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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 Among(java.util.List<IntVar> list, IntervalDomain kSet, IntVar n)
It constructs an Among constraint.Among(IntVar[] list, IntervalDomain kSet, IntVar n)
It constructs an Among constraint.
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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.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
private static final boolean debugAll
- See Also:
- Constant Field Values
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idNumber
static final java.util.concurrent.atomic.AtomicInteger idNumber
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list
public final IntVar[] list
It specifies the list of variables whose values are checked.
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kSet
public final IntervalDomain kSet
It specifies a set of values which if assigned to a variable from a list makes variable counted.
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n
public final IntVar n
It is a idNumber variable.
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lowerBorder
private TimeStamp<java.lang.Integer> lowerBorder
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upperBorder
private TimeStamp<java.lang.Integer> upperBorder
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variableQueue
java.util.LinkedHashSet<IntVar> variableQueue
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position
private java.util.Map<IntVar,java.lang.Integer> position
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Constructor Detail
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Among
public Among(IntVar[] list, IntervalDomain kSet, IntVar n)
It constructs an Among constraint.- Parameters:
list
- variables which are compared to KsetkSet
- set of integer values against which we check if variables are equal to.n
- number of possible variables equal to a value from Kset.
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Among
public Among(java.util.List<IntVar> list, IntervalDomain kSet, IntVar n)
It constructs an Among constraint.- Parameters:
list
- variables which are compared to KsetkSet
- set of integer values against which we check if variables are equal to.n
- number of possible variables equal to a value from Kset.
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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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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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