Package org.jacop.constraints
Class ElementVariable
- 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.ElementVariable
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- All Implemented Interfaces:
SatisfiedPresent
,Stateful
,UsesQueueVariable
public class ElementVariable extends Constraint implements UsesQueueVariable, Stateful, SatisfiedPresent
ElementVariable constraint defines a relation list[index - indexOffset] = value.The first element of the list corresponds to index - indexOffset = 1. By default indexOffset is equal 0 so first value within a list corresponds to index equal 1.
If index has a domain from 0 to list.length-1 then indexOffset has to be equal -1 to make addressing of list array starting from 1.
- Version:
- 4.8
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Field Summary
Fields Modifier and Type Field Description (package private) java.util.Map<IntVar,java.util.List<java.lang.Integer>>
duplicates
(package private) boolean
firstConsistencyCheck
(package private) int
firstConsistencyLevel
(package private) java.util.Random
generator
(package private) static java.util.concurrent.atomic.AtomicInteger
idNumber
IntVar
index
It specifies variable index within an element constraint list[index - indexOffset] = value.(package private) boolean
indexHasChanged
int
indexOffset
It specifies indexOffset within an element constraint list[index - indexOffset] = value.(package private) IntDomain
indexRange
IntVar[]
list
It specifies list of variables within an element constraint list[index - indexOffset] = value.(package private) java.util.Map<IntVar,java.lang.Integer>
mapping
(package private) IntDomain[]
supports
IntVar
value
It specifies variable value within an element constraint list[index - indexOffset] = value.private boolean
valueHasChanged
(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 ElementVariable(IntVar index, java.util.List<? extends IntVar> list, IntVar value)
It constructs an element constraint.ElementVariable(IntVar index, java.util.List<? extends IntVar> list, IntVar value, int indexOffset)
It constructs an element constraint.ElementVariable(IntVar index, IntVar[] list, IntVar value)
It constructs an element constraint.ElementVariable(IntVar index, IntVar[] list, IntVar value, int indexOffset)
It constructs an element 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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idNumber
static java.util.concurrent.atomic.AtomicInteger idNumber
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firstConsistencyCheck
boolean firstConsistencyCheck
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firstConsistencyLevel
int firstConsistencyLevel
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index
public IntVar index
It specifies variable index within an element constraint list[index - indexOffset] = value.
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value
public IntVar value
It specifies variable value within an element constraint list[index - indexOffset] = value.
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indexOffset
public final int indexOffset
It specifies indexOffset within an element constraint list[index - indexOffset] = value.
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list
public IntVar[] list
It specifies list of variables within an element constraint list[index - indexOffset] = value. The list is addressed by positive integers (>=1
) if indexOffset is equal to 0.
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indexHasChanged
boolean indexHasChanged
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indexRange
IntDomain indexRange
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variableQueue
java.util.LinkedHashSet<IntVar> variableQueue
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mapping
java.util.Map<IntVar,java.lang.Integer> mapping
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duplicates
java.util.Map<IntVar,java.util.List<java.lang.Integer>> duplicates
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supports
IntDomain[] supports
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valueHasChanged
private boolean valueHasChanged
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generator
java.util.Random generator
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Constructor Detail
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ElementVariable
public ElementVariable(IntVar index, IntVar[] list, IntVar value, int indexOffset)
It constructs an element constraint.- Parameters:
index
- variable indexlist
- list of variables from which an index-th element is takenvalue
- a value of the index-th element from listindexOffset
- shift applied to index variable.
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ElementVariable
public ElementVariable(IntVar index, java.util.List<? extends IntVar> list, IntVar value)
It constructs an element constraint.- Parameters:
index
- variable indexlist
- list of variables from which an index-th element is takenvalue
- a value of the index-th element from list
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ElementVariable
public ElementVariable(IntVar index, java.util.List<? extends IntVar> list, IntVar value, int indexOffset)
It constructs an element constraint.- Parameters:
index
- variable indexlist
- list of variables from which an index-th element is takenvalue
- a value of the index-th element from listindexOffset
- shift applied to index variable.
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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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