org.sat4j.pb.constraints.pb
Class WatchPb

java.lang.Object
  org.sat4j.pb.constraints.pb.WatchPb

All Implemented Interfaces:

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

Direct Known Subclasses:

MaxWatchPb, MinWatchPb

public abstract class WatchPb
extends Object
implements IWatchPb, Propagatable, Undoable, Serializable

Abstract data structure for pseudo-boolean constraint with watched literals.

Author:

anne

See Also:

Serialized Form

Field Summary

protected double	activity constraint activity
protected BigInteger[]	coefs coefficients of the literals of the constraint
protected BigInteger	degree degree of the pseudo-boolean constraint
protected boolean	learnt true if the constraint is a learned constraint
protected int[]	lits literals of the constraint
protected BigInteger	sumcoefs
protected ILits	voc constraint's vocabulary

Method Summary

void	assertConstraint(UnitPropagationListener s)
void	calcReason(int p, IVecInt outReason) compute the reason for the assignment of a literal
boolean	canBePropagatedMultipleTimes()
boolean	coefficientsEqualToOne()
IVecInt	computeAnImpliedClause() compute an implied clause on the literals with the greater coefficients.
BigInteger	computeLeftSide() compute the sum of the coefficients of the satisfied or non-assigned literals of the current constraint (usually called poss)
BigInteger	computeLeftSide(BigInteger[] theCoefs) compute the sum of the coefficients of the satisfied or non-assigned literals of a described constraint (usually called poss)
protected abstract void	computePropagation(UnitPropagationListener s)
protected abstract void	computeWatches()
boolean	equals(Object pb)
void	forwardActivity(double claInc)
int	get(int i) to obtain the i-th literal of the constraint
double	getActivity() to obtain the activity value of the constraint
BigInteger	getCoef(int i) to obtain the coefficient of the i-th literal of the constraint
BigInteger[]	getCoefs() to obtain the coefficients of the constraint.
BigInteger	getDegree()
int[]	getLits() to obtain the literals of the constraint.
ILits	getVocabulary()
int	hashCode()
void	incActivity(double claInc) increase activity value of the constraint
boolean	isAssertive(int dl) This predicate tests wether the constraint is assertive at decision level dl
protected boolean	isSatisfiable() tests if the constraint is still satisfiable.
boolean	learnt() is the constraint a learnt constraint ?
boolean	locked() The constraint is the reason of a unit propagation.
protected static BigInteger	ppcm(BigInteger a, BigInteger b) ppcm : least common multiple for two integers (plus petit commun multiple)
void	register()
void	rescaleBy(double d) to re-scale the activity of the constraint
void	setActivity(double d)
void	setLearnt() the constraint is learnt
boolean	simplify() simplify the constraint (if it is satisfied)
int	size()
BigInteger	slackConstraint() compute the slack of the current constraint slack = poss - degree of the constraint
BigInteger	slackConstraint(BigInteger[] theCoefs, BigInteger theDegree) compute the slack of a described constraint slack = poss - degree of the constraint
protected void	sort() sort coefficient and literal arrays
protected void	sort(int from, int to) sort partially coefficient and literal arrays
Constr	toConstraint()
String	toString()

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.sat4j.minisat.core.Constr

remove

Methods inherited from interface org.sat4j.minisat.core.Propagatable

propagate

Methods inherited from interface org.sat4j.minisat.core.Undoable

undo

Field Detail

activity

protected double activity

constraint activity

coefs

protected BigInteger[] coefs

coefficients of the literals of the constraint

sumcoefs

protected BigInteger sumcoefs

degree

protected BigInteger degree

degree of the pseudo-boolean constraint

lits

protected int[] lits

literals of the constraint

learnt

protected boolean learnt

true if the constraint is a learned constraint

voc

protected ILits voc

constraint's vocabulary

Method Detail

isAssertive

public boolean isAssertive(int dl)

This predicate tests wether the constraint is assertive at decision level dl

Parameters:

dl -

Returns:

true iff the constraint is assertive at decision level dl.

calcReason

public void calcReason(int p,
                       IVecInt outReason)

compute the reason for the assignment of a literal

Specified by:

calcReason in interface Constr

Parameters:

p - a falsified literal (or Lit.UNDEFINED)

outReason - list of falsified literals for which the negation is the reason of the assignment

See Also:

Constr.calcReason(int, IVecInt)

computeWatches

protected abstract void computeWatches()
                                throws ContradictionException

Throws:

ContradictionException

computePropagation

protected abstract void computePropagation(UnitPropagationListener s)
                                    throws ContradictionException

Throws:

ContradictionException

get

public int get(int i)

to obtain the i-th literal of the constraint

Specified by:

get in interface IConstr

Parameters:

i - index of the literal

Returns:

the literal

getCoef

public BigInteger getCoef(int i)

to obtain the coefficient of the i-th literal of the constraint

Specified by:

getCoef in interface PBConstr

Parameters:

i - index of the literal

Returns:

coefficient of the literal

getActivity

public double getActivity()

to obtain the activity value of the constraint

Specified by:

getActivity in interface IConstr

Returns:

activity value of the constraint

See Also:

IConstr.getActivity()

incActivity

public void incActivity(double claInc)

increase activity value of the constraint

Specified by:

incActivity in interface Constr

See Also:

Constr.incActivity(double)

setActivity

public void setActivity(double d)

Specified by:

setActivity in interface Constr

slackConstraint

public BigInteger slackConstraint()

compute the slack of the current constraint slack = poss - degree of the constraint

Returns:

la marge

slackConstraint

public BigInteger slackConstraint(BigInteger[] theCoefs,
                                  BigInteger theDegree)

compute the slack of a described constraint slack = poss - degree of the constraint

Specified by:

slackConstraint in interface IWatchPb

Parameters:

theCoefs - coefficients of the constraint

theDegree - degree of the constraint

Returns:

slack of the constraint

computeLeftSide

public BigInteger computeLeftSide(BigInteger[] theCoefs)

compute the sum of the coefficients of the satisfied or non-assigned literals of a described constraint (usually called poss)

Parameters:

coefs - coefficients of the constraint

Returns:

poss

computeLeftSide

public BigInteger computeLeftSide()

compute the sum of the coefficients of the satisfied or non-assigned literals of the current constraint (usually called poss)

Returns:

poss

isSatisfiable

protected boolean isSatisfiable()

tests if the constraint is still satisfiable. this method is only called in assertions.

Returns:

the constraint is satisfiable

learnt

public boolean learnt()

is the constraint a learnt constraint ?

Specified by:

learnt in interface IConstr

Returns:

true if the constraint is learnt, else false

See Also:

IConstr.learnt()

locked

public boolean locked()

The constraint is the reason of a unit propagation.

Specified by:

locked in interface Constr

Returns:

true

ppcm

protected static BigInteger ppcm(BigInteger a,
                                 BigInteger b)

ppcm : least common multiple for two integers (plus petit commun multiple)

Parameters:

a - one integer

b - the other integer

Returns:

the least common multiple of a and b

rescaleBy

public void rescaleBy(double d)

to re-scale the activity of the constraint

Specified by:

rescaleBy in interface Constr

Parameters:

d - adjusting factor

setLearnt

public void setLearnt()

the constraint is learnt

Specified by:

setLearnt in interface Constr

simplify

public boolean simplify()

simplify the constraint (if it is satisfied)

Specified by:

simplify in interface Constr

Returns:

true if the constraint is satisfied, else false

size

public final int size()

Specified by:

size in interface IConstr

sort

protected final void sort()

sort coefficient and literal arrays

sort

protected final void sort(int from,
                          int to)

sort partially coefficient and literal arrays

Parameters:

from - index for the beginning of the sort

to - index for the end of the sort

toString

public String toString()

Overrides:

toString in class Object

assertConstraint

public void assertConstraint(UnitPropagationListener s)

Specified by:

assertConstraint in interface Constr

getDegree

public BigInteger getDegree()

Specified by:

getDegree in interface PBConstr

Returns:

Returns the degree.

register

public void register()

Specified by:

register in interface Constr

getCoefs

public BigInteger[] getCoefs()

to obtain the coefficients of the constraint.

Specified by:

getCoefs in interface PBConstr

Returns:

a copy of the array of the coefficients

getLits

public int[] getLits()

to obtain the literals of the constraint.

Specified by:

getLits in interface PBConstr

Returns:

a copy of the array of the literals

getVocabulary

public ILits getVocabulary()

Specified by:

getVocabulary in interface PBConstr

computeAnImpliedClause

public IVecInt computeAnImpliedClause()

compute an implied clause on the literals with the greater coefficients.

Specified by:

computeAnImpliedClause in interface PBConstr

Returns:

a vector containing the literals for this clause.

coefficientsEqualToOne

public boolean coefficientsEqualToOne()

equals

public boolean equals(Object pb)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

forwardActivity

public void forwardActivity(double claInc)

Specified by:

forwardActivity in interface Constr

canBePropagatedMultipleTimes

public boolean canBePropagatedMultipleTimes()

Specified by:

canBePropagatedMultipleTimes in interface IConstr

toConstraint

public Constr toConstraint()

Specified by:

toConstraint in interface Propagatable