org.sat4j.core
Class ConstrGroup

java.lang.Object
  org.sat4j.core.ConstrGroup

All Implemented Interfaces:

IConstr

public class ConstrGroup
extends Object
implements IConstr

A utility class used to manage easily group of clauses to be deleted at some point in the solver.

Since:

2.0

Author:

dlb

Constructor Summary

ConstrGroup()
Create a ConstrGroup that cannot contain null constrs.

ConstrGroup(boolean disallowNullConstraints)
Create a new constrGroup.

Method Summary

void	add(IConstr constr)
boolean	canBePropagatedMultipleTimes() Partition constraints into the ones that can only be found once on the trail (e.g. clauses) and the ones that can be found several times (e.g.
void	clear()
int	get(int i) returns the ith literal in the constraint
double	getActivity() To obtain the activity of the constraint.
IConstr	getConstr(int i)
boolean	learnt()
void	removeFrom(ISolver solver)
int	size()
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

ConstrGroup

public ConstrGroup()

Create a ConstrGroup that cannot contain null constrs.

ConstrGroup

public ConstrGroup(boolean disallowNullConstraints)

Create a new constrGroup.

Parameters:

disallowNullConstraints - should be set to false to allow adding null constraints to the group.

Method Detail

add

public void add(IConstr constr)

clear

public void clear()

removeFrom

public void removeFrom(ISolver solver)

getConstr

public IConstr getConstr(int i)

size

public int size()

Specified by:

size in interface IConstr

Returns:

the number of literals in the constraint.

learnt

public boolean learnt()

Specified by:

learnt in interface IConstr

Returns:

true iff the clause was learnt during the search

getActivity

public double getActivity()

Description copied from interface: IConstr

To obtain the activity of the constraint.

Specified by:

getActivity in interface IConstr

Returns:

the activity of the clause.

get

public int get(int i)

Description copied from interface: IConstr

returns the ith literal in the constraint

Specified by:

get in interface IConstr

Parameters:

i - the index of the literal

Returns:

a literal

canBePropagatedMultipleTimes

public boolean canBePropagatedMultipleTimes()

Description copied from interface: IConstr

Partition constraints into the ones that can only be found once on the trail (e.g. clauses) and the ones that can be found several times (e.g. cardinality constraints and pseudo-boolean constraints).

Specified by:

canBePropagatedMultipleTimes in interface IConstr

Returns:

true if the constraint can be used several times as a reason to propagate a literal.

toString

public String toString()

Overrides:

toString in class Object