org.sat4j.pb.constraints.pb

Class ConflictMap

java.lang.Object

org.sat4j.pb.constraints.pb.MapPb

org.sat4j.pb.constraints.pb.ConflictMap

All Implemented Interfaces:

IConflict, IDataStructurePB

Direct Known Subclasses:

ConflictMapClause, ConflictMapDivideByPivot, ConflictMapMinimizeWeakening, ConflictMapReduceByGCD, ConflictMapReduceByPowersOf2, ConflictMapReduceToCard, ConflictMapReduceToClause, ConflictMapRounding, ConflictMapSwitchToClause, ConflictMapWeakenReason, ConflictMapWeakenToClash

public class ConflictMap
extends MapPb
implements IConflict

Author:

parrain TODO To change the template for this generated type comment go to Window - Preferences - Java - Code Style - Code Templates

Field Summary

Fields

Modifier and Type	Field and Description
protected VecInt[]	byLevel allows to access directly to all variables belonging to a particular level At index 0, unassigned literals are stored (usually level -1); so there is always a step between index and levels.
protected BigInteger	coefMult
protected BigInteger	coefMultCons
protected int	currentLevel
protected BigInteger	currentSlack to store the slack of the current resolvant
protected boolean	hasBeenReduced
protected long	numberOfReductions
protected IPreProcess	preProcess
protected BigInteger	sumAllCoefs

Fields inherited from class org.sat4j.pb.constraints.pb.MapPb

assertiveLiteral, autoDivisionStrategy, degree, weightedLits

Fields inherited from interface org.sat4j.pb.constraints.pb.IDataStructurePB

TAUTOLOGY

Method Summary

Modifier and Type	Method and Description
static IConflict	createConflict(PBConstr cpb, int level, boolean noRemove, SkipStrategy skip, IPreProcess preProcessing, IPostProcess postProcessing, IWeakeningStrategy weakeningStrategy, AutoDivisionStrategy autoDivisionStrategy, PBSolverStats stats) constructs the data structure needed to perform cutting planes
static IConflictFactory	factory()
int	getBacktrackLevel(int maxLevel) computes the level for the backtrack : the highest decision level for which the conflict is assertive.
long	getNumberOfReductions()
boolean	hasBeenReduced()
boolean	isAssertive(int dl) change the currentLevel of the conflict to a new decision level and tests if the conflict is assertive (allows to imply a literal) at this new decision level
boolean	isUnsat() tests if the conflict is unsatisfiable
int	oldGetBacktrackLevel(int maxLevel)
boolean	oldIsAssertive(int dl)
protected BigInteger	possConstraint(IWatchPb wpb, BigInteger[] theCoefs)
void	postProcess(int dl)
protected BigInteger	ppcm(BigInteger a, BigInteger b) computes the least common factor of two integers (Plus Petit Commun Multiple in french)
void	preProcess()
BigInteger	reduceInConstraint(IWatchPb wpb, BigInteger[] coefsBis, int indLitImplied, BigInteger degreeBis, BigInteger slackResolve) constraint reduction : removes a literal of the constraint.
protected BigInteger	reduceUntilConflict(int litImplied, int ind, BigInteger[] reducedCoefs, BigInteger degreeReduced, IWatchPb wpb)
BigInteger	resolve(PBConstr cpb, int litImplied, VarActivityListener val) computes a cutting plane with a pseudo-boolean constraint. this method updates the current instance (of ConflictMap).
protected BigInteger	saturation(BigInteger[] coefs, BigInteger degree, IWatchPb wpb)
void	setDecisionLevel(int dl)
BigInteger	slackConflict() computes the slack of the current instance
boolean	slackIsCorrect(int dl)
String	toString()
void	undoOne(int lit)
void	updateSlack(int level)

Methods inherited from class org.sat4j.pb.constraints.pb.MapPb

buildConstraintFromConflict, buildConstraintFromMapPb, cuttingPlane, cuttingPlane, cuttingPlane, cuttingPlane, getAssertiveLiteral, getCardDegree, getDegree, getNumberOfCuttingPlanesCardinalities, isCardinality, isLongSufficient, reduceCoeffsByGCD, reduceCoeffsByPower2, saturation, size

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.sat4j.pb.constraints.pb.IDataStructurePB

buildConstraintFromConflict, buildConstraintFromMapPb, cuttingPlane, cuttingPlane, cuttingPlane, cuttingPlane, getAssertiveLiteral, getCardDegree, getDegree, isCardinality, isLongSufficient, reduceCoeffsByPower2, saturation, size

Field Detail

hasBeenReduced

protected boolean hasBeenReduced

numberOfReductions

protected long numberOfReductions

currentSlack

protected BigInteger currentSlack

to store the slack of the current resolvant

sumAllCoefs

protected BigInteger sumAllCoefs

currentLevel

protected int currentLevel

preProcess

protected IPreProcess preProcess

byLevel

protected VecInt[] byLevel

allows to access directly to all variables belonging to a particular level At index 0, unassigned literals are stored (usually level -1); so there is always a step between index and levels.

coefMult

protected BigInteger coefMult

coefMultCons

protected BigInteger coefMultCons

Method Detail

createConflict

public static IConflict createConflict(PBConstr cpb,
                                       int level,
                                       boolean noRemove,
                                       SkipStrategy skip,
                                       IPreProcess preProcessing,
                                       IPostProcess postProcessing,
                                       IWeakeningStrategy weakeningStrategy,
                                       AutoDivisionStrategy autoDivisionStrategy,
                                       PBSolverStats stats)

constructs the data structure needed to perform cutting planes

Parameters:

cpb - pseudo-boolean constraint which raised the conflict

level - current decision level

Returns:

a conflict on which cutting plane can be performed.

factory

public static IConflictFactory factory()

postProcess

public void postProcess(int dl)

Specified by:

postProcess in interface IConflict

resolve

public BigInteger resolve(PBConstr cpb,
                          int litImplied,
                          VarActivityListener val)

computes a cutting plane with a pseudo-boolean constraint. this method updates the current instance (of ConflictMap).

Specified by:

resolve in interface IConflict

Parameters:

cpb - constraint to compute with the cutting plane

litImplied - literal that must be resolved by the cutting plane

val - TODO

Returns:

an update of the degree of the current instance

preProcess

public void preProcess()

reduceUntilConflict

protected BigInteger reduceUntilConflict(int litImplied,
                                         int ind,
                                         BigInteger[] reducedCoefs,
                                         BigInteger degreeReduced,
                                         IWatchPb wpb)

possConstraint

protected BigInteger possConstraint(IWatchPb wpb,
                                    BigInteger[] theCoefs)

slackConflict

public BigInteger slackConflict()

computes the slack of the current instance

Specified by:

slackConflict in interface IConflict

oldIsAssertive

public boolean oldIsAssertive(int dl)

isAssertive

public boolean isAssertive(int dl)

change the currentLevel of the conflict to a new decision level and tests if the conflict is assertive (allows to imply a literal) at this new decision level

Specified by:

isAssertive in interface IConflict

Parameters:

dl - the decision level

Returns:

true if the conflict is assertive at the decision level

setDecisionLevel

public void setDecisionLevel(int dl)

Specified by:

setDecisionLevel in interface IConflict

isUnsat

public boolean isUnsat()

tests if the conflict is unsatisfiable

Specified by:

isUnsat in interface IConflict

Returns:

true if the conflict is unsatisfiable

ppcm

protected BigInteger ppcm(BigInteger a,
                          BigInteger b)

computes the least common factor of two integers (Plus Petit Commun Multiple in french)

Parameters:

a - first integer

b - second integer

Returns:

the least common factor

reduceInConstraint

public BigInteger reduceInConstraint(IWatchPb wpb,
                                     BigInteger[] coefsBis,
                                     int indLitImplied,
                                     BigInteger degreeBis,
                                     BigInteger slackResolve)

constraint reduction : removes a literal of the constraint. The literal should be either unassigned or satisfied. The literal can not be the literal that should be resolved.

Specified by:

reduceInConstraint in interface IConflict

Parameters:

wpb - the initial constraint to reduce

coefsBis - the coefficients of the constraint wrt which the reduction will be proposed

indLitImplied - index in wpb of the literal that should be resolved

degreeBis - the degree of the constraint wrt which the reduction will be proposed

Returns:

new degree of the reduced constraint

saturation

protected BigInteger saturation(BigInteger[] coefs,
                                BigInteger degree,
                                IWatchPb wpb)

getBacktrackLevel

public int getBacktrackLevel(int maxLevel)

computes the level for the backtrack : the highest decision level for which the conflict is assertive.

Specified by:

getBacktrackLevel in interface IConflict

Parameters:

maxLevel - the lowest level for which the conflict is assertive

Returns:

the highest level (smaller int) for which the constraint is assertive.

oldGetBacktrackLevel

public int oldGetBacktrackLevel(int maxLevel)

updateSlack

public void updateSlack(int level)

Specified by:

updateSlack in interface IConflict

slackIsCorrect

public boolean slackIsCorrect(int dl)

Specified by:

slackIsCorrect in interface IConflict

toString

public String toString()

Overrides:

toString in class MapPb

hasBeenReduced

public boolean hasBeenReduced()

getNumberOfReductions

public long getNumberOfReductions()

undoOne

public void undoOne(int lit)

Specified by:

undoOne in interface IConflict