org.sat4j.pb.constraints.pb
Class WatchPb

java.lang.Object
  extended by 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


Copyright © 2012 Centre de Recherche en Informatique de Lens (CRIL). All Rights Reserved.