Package org.jacop.constraints
Class ElementInteger
- 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.ElementInteger
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- All Implemented Interfaces:
SatisfiedPresent
,Stateful
,UsesQueueVariable
public class ElementInteger extends Constraint implements UsesQueueVariable, Stateful, SatisfiedPresent
ElementInteger 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 boolean
checkDuplicates
It specifies whether duplicate values should be treated specially (combined to a single check).(package private) java.util.List<IntDomain>
duplicates
It holds information about the positions within list array that are equal.(package private) IntDomain
duplicatesIndexes
(package private) boolean
firstConsistencyCheck
(package private) int
firstConsistencyLevel
(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
It specifies for each value what are the possible values of the index variable (it takes into account indexOffset.int
indexOffset
It specifies indexOffset within an element constraint list[index-indexOffset] = value.(package private) static int
limitForDomainPruning
It specifies the maximal size of index domain when the constraint will apply domain consistency for value.int[]
list
It specifies list of variables within an element constraint list[index-indexOffset] = value.(package private) static int
minDuplicatesSize
It specifies the minimal size of number of duplicated values on the list that are consodered together..IntVar
value
It specifies variable value within an element constraint list[index-indexOffset] = value.(package private) boolean
valueHasChanged
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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 ElementInteger(IntVar index, int[] list, IntVar value)
It constructs an element constraint with indexOffset by default set to 0.ElementInteger(IntVar index, int[] list, IntVar value, int indexOffset)
It constructs an element constraint.ElementInteger(IntVar index, int[] list, IntVar value, int indexOffset, boolean checkDuplicates)
It constructs an element constraint.ElementInteger(IntVar index, java.util.List<java.lang.Integer> list, IntVar value)
It constructs an element constraint with default indexOffset equal 0.ElementInteger(IntVar index, java.util.List<java.lang.Integer> list, IntVar value, int indexOffset)
It constructs an element constraint.ElementInteger(IntVar index, java.util.List<java.lang.Integer> list, IntVar value, int indexOffset, boolean checkDuplicates)
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.(package private) boolean
disjoint(IntDomain v1, int v2)
int
getDefaultConsistencyPruningEvent()
void
impose(Store store)
It imposes the constraint in a given store.boolean
isStateful()
This function can be overriden by any constraint to specify dynamic conditions (based on the domain of variables at imposition level to decide if it is a stateful constraint.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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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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limitForDomainPruning
static final int limitForDomainPruning
It specifies the maximal size of index domain when the constraint will apply domain consistency for value. Otherwise bound consistency is applied. This limit applies to both duplicates and index.- See Also:
- Constant Field Values
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minDuplicatesSize
static final int minDuplicatesSize
It specifies the minimal size of number of duplicated values on the list that are consodered together.. Otherwise they are processed one by one.- See Also:
- Constant Field Values
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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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checkDuplicates
public final boolean checkDuplicates
It specifies whether duplicate values should be treated specially (combined to a single check). In general a good idea but when lists are long it makes the process slower instead of faster.
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list
public int[] 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
It specifies for each value what are the possible values of the index variable (it takes into account indexOffset.
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valueHasChanged
boolean valueHasChanged
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duplicates
java.util.List<IntDomain> duplicates
It holds information about the positions within list array that are equal. It allows to safely skip duplicates when enumerating index domain. duplicatesIndexes is a domain having indexes of all indexes for duplicates.
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duplicatesIndexes
IntDomain duplicatesIndexes
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Constructor Detail
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ElementInteger
public ElementInteger(IntVar index, int[] list, IntVar value, int indexOffset)
It constructs an element constraint.- Parameters:
index
- variable indexlist
- list of integers 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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ElementInteger
public ElementInteger(IntVar index, int[] list, IntVar value, int indexOffset, boolean checkDuplicates)
It constructs an element constraint.- Parameters:
index
- variable indexlist
- list of integers from which an index-th element is takenvalue
- a value of the index-th element from listindexOffset
- shift applied to index variable.checkDuplicates
- informs whether to create duplicates list for values from list (default = true).
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ElementInteger
public ElementInteger(IntVar index, java.util.List<java.lang.Integer> list, IntVar value)
It constructs an element constraint with default indexOffset equal 0.- Parameters:
index
- index variable.list
- list containing variables which one pointed out by index variable is made equal to value variable.value
- a value variable equal to the specified element from the list.
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ElementInteger
public ElementInteger(IntVar index, java.util.List<java.lang.Integer> list, IntVar value, int indexOffset)
It constructs an element constraint.- Parameters:
index
- variable indexlist
- list of integers 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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ElementInteger
public ElementInteger(IntVar index, java.util.List<java.lang.Integer> list, IntVar value, int indexOffset, boolean checkDuplicates)
It constructs an element constraint.- Parameters:
index
- variable indexlist
- list of integers from which an index-th element is takenvalue
- a value of the index-th element from listindexOffset
- shift applied to index variable.checkDuplicates
- informs whether to create duplicates list for values from list (default = true).
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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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disjoint
boolean disjoint(IntDomain v1, int v2)
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getDefaultConsistencyPruningEvent
public int getDefaultConsistencyPruningEvent()
- Specified by:
getDefaultConsistencyPruningEvent
in classConstraint
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isStateful
public boolean isStateful()
Description copied from interface:Stateful
This function can be overriden by any constraint to specify dynamic conditions (based on the domain of variables at imposition level to decide if it is a stateful constraint.- Specified by:
isStateful
in interfaceStateful
- Returns:
- true if constraint is stateful.
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impose
public void impose(Store store)
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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