org.sat4j.pb.constraints.pb

Class MaxWatchPb

java.lang.Object

org.sat4j.pb.constraints.pb.WatchPb

org.sat4j.pb.constraints.pb.MaxWatchPb

All Implemented Interfaces:

Serializable, Constr, Propagatable, Undoable, IWatchPb, PBConstr, IConstr

public final class MaxWatchPb
extends WatchPb

Data structure for pseudo-boolean constraint with watched literals. All literals are watched. The sum of the literals satisfied or unvalued is always memorized, to detect conflict.

Author:

anne

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static int	LIMIT_FOR_MAP

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

activity, coefs, degree, learnt, lits, sumcoefs, voc

Method Summary

Methods

Modifier and Type	Method and Description
protected void	computePropagation(UnitPropagationListener s)
protected void	computeWatches() All the literals are watched.
static MaxWatchPb	normalizedMaxWatchPbNew(UnitPropagationListener s, ILits voc, int[] lits, BigInteger[] coefs, BigInteger degree, BigInteger sumCoefs) build a pseudo boolean constraint.
static WatchPb	normalizedWatchPbNew(ILits voc, IDataStructurePB mpb) build a pseudo boolean constraint from a specific data structure.
boolean	propagate(UnitPropagationListener s, int p) Propagation of a falsified literal
void	remove(UnitPropagationListener upl) Remove a constraint from the solver
void	undo(int p) this method is called during backtrack

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

assertConstraint, assertConstraintIfNeeded, calcReason, calcReasonOnTheFly, canBePropagatedMultipleTimes, coefficientsEqualToOne, computeAnImpliedClause, computeLeftSide, computeLeftSide, equals, forwardActivity, get, getActivity, getCoef, getCoefs, getDegree, getLits, getVocabulary, hashCode, incActivity, isAssertive, isSatisfiable, learnt, locked, ppcm, register, rescaleBy, setActivity, setLearnt, simplify, size, slackConstraint, slackConstraint, sort, sort, toConstraint, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

LIMIT_FOR_MAP

public static final int LIMIT_FOR_MAP

See Also:

Constant Field Values

Method Detail

computeWatches

protected void computeWatches()
                       throws ContradictionException

All the literals are watched.

Specified by:

computeWatches in class WatchPb

Throws:

ContradictionException

See Also:

WatchPb.computeWatches()

computePropagation

protected void computePropagation(UnitPropagationListener s)
                           throws ContradictionException

Specified by:

computePropagation in class WatchPb

Throws:

ContradictionException

propagate

public boolean propagate(UnitPropagationListener s,
                int p)

Propagation of a falsified literal

Parameters:

s - the solver

p - the propagated literal (it must be falsified)

Returns:

false iff there is a conflict

remove

public void remove(UnitPropagationListener upl)

Remove a constraint from the solver

undo

public void undo(int p)

this method is called during backtrack

Parameters:

p - an unassigned literal

normalizedMaxWatchPbNew

public static MaxWatchPb normalizedMaxWatchPbNew(UnitPropagationListener s,
                                 ILits voc,
                                 int[] lits,
                                 BigInteger[] coefs,
                                 BigInteger degree,
                                 BigInteger sumCoefs)
                                          throws ContradictionException

build a pseudo boolean constraint. Coefficients are positive integers less than or equal to the degree (this is called a normalized constraint).

Parameters:

s - a unit propagation listener (usually the solver)

voc - the vocabulary

lits - the literals of the constraint

coefs - the coefficients of the constraint

degree - the degree of the constraint

Returns:

a new PB constraint or null if a trivial inconsistency is detected.

Throws:

ContradictionException

normalizedWatchPbNew

public static WatchPb normalizedWatchPbNew(ILits voc,
                           IDataStructurePB mpb)

build a pseudo boolean constraint from a specific data structure. For learnt constraints.

Parameters:

s - a unit propagation listener (usually the solver)

mpb - data structure which contains literals of the constraint, coefficients (a0, a1, ... an), and the degree of the constraint (k). The constraint is a "more than" constraint.

Returns:

a new PB constraint or null if a trivial inconsistency is detected.