org.sat4j.tools

Class OptToSatAdapter

java.lang.Object

org.sat4j.tools.SolverDecorator<ISolver>

org.sat4j.tools.OptToSatAdapter

All Implemented Interfaces:

Serializable, IProblem, ISolver, RandomAccessModel

public class OptToSatAdapter
extends SolverDecorator<ISolver>

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
OptToSatAdapter(IOptimizationProblem problem)
OptToSatAdapter(IOptimizationProblem problem, SolutionFoundListener sfl)

Method Summary

Methods

Modifier and Type	Method and Description
int[]	findModel() Look for a model satisfying all the clauses available in the problem.
int[]	findModel(IVecInt assumps) Look for a model satisfying all the clauses available in the problem.
boolean	isOptimal() Allow to easily check is the solution returned by isSatisfiable is optimal or not.
boolean	isSatisfiable() Check the satisfiability of the set of constraints contained inside the solver.
boolean	isSatisfiable(boolean global) Check the satisfiability of the set of constraints contained inside the solver.
boolean	isSatisfiable(IVecInt myAssumps) Check the satisfiability of the set of constraints contained inside the solver.
boolean	isSatisfiable(IVecInt myAssumps, boolean global) Check the satisfiability of the set of constraints contained inside the solver.
int[]	model() Provide a model (if any) for a satisfiable formula.
boolean	model(int var) Provide the truth value of a specific variable in the model.
int[]	modelWithInternalVariables() That method is designed to be used to retrieve the real model of the current set of constraints, i.e. to provide the truth value of boolean variables used internally in the solver (for encoding purposes for instance).
void	reset() Clean up the internal state of the solver.
String	toString(String prefix) Display a textual representation of the solver configuration.

Methods inherited from class org.sat4j.tools.SolverDecorator

addAllClauses, addAtLeast, addAtMost, addBlockingClause, addClause, addExactly, clearDecorated, clearLearntClauses, decorated, expireTimeout, getLogPrefix, getSearchListener, getSolvingEngine, getStat, getTimeout, getTimeoutMs, isDBSimplificationAllowed, isSolverKeptHot, isVerbose, nConstraints, newVar, newVar, nextFreeVarId, nVars, primeImplicant, primeImplicant, printInfos, printInfos, printStat, printStat, printStat, realNumberOfVariables, registerLiteral, removeConstr, removeSubsumedConstr, setDBSimplificationAllowed, setExpectedNumberOfClauses, setKeepSolverHot, setLogPrefix, setSearchListener, setTimeout, setTimeoutMs, setTimeoutOnConflicts, setUnitClauseProvider, setVerbose, toString, unsatExplanation

Methods inherited from class java.lang.Object

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

Constructor Detail

OptToSatAdapter

public OptToSatAdapter(IOptimizationProblem problem)

OptToSatAdapter

public OptToSatAdapter(IOptimizationProblem problem,
               SolutionFoundListener sfl)

Method Detail

reset

public void reset()

Description copied from interface: ISolver

Clean up the internal state of the solver. Note that such method should also be called when you no longer need the solver because the state of the solver may prevent the GC to proceed. There is a known issue for instance where failing to call reset() on a solver will keep timer threads alive and exhausts memory.

Specified by:

reset in interface ISolver

Overrides:

reset in class SolverDecorator<ISolver>

isSatisfiable

public boolean isSatisfiable()
                      throws TimeoutException

Description copied from interface: IProblem

Check the satisfiability of the set of constraints contained inside the solver.

Specified by:

isSatisfiable in interface IProblem

Overrides:

isSatisfiable in class SolverDecorator<ISolver>

Returns:

true if the set of constraints is satisfiable, else false.

Throws:

TimeoutException

isSatisfiable

public boolean isSatisfiable(boolean global)
                      throws TimeoutException

Description copied from interface: IProblem

Check the satisfiability of the set of constraints contained inside the solver.

Specified by:

isSatisfiable in interface IProblem

Overrides:

isSatisfiable in class SolverDecorator<ISolver>

Parameters:

global - whether that call is part of a global process (i.e. optimization) or not. if (global), the timeout will not be reset between each call.

Returns:

true if the set of constraints is satisfiable, else false.

Throws:

TimeoutException

isSatisfiable

public boolean isSatisfiable(IVecInt myAssumps,
                    boolean global)
                      throws TimeoutException

Description copied from interface: IProblem

Check the satisfiability of the set of constraints contained inside the solver.

Specified by:

isSatisfiable in interface IProblem

Overrides:

isSatisfiable in class SolverDecorator<ISolver>

Parameters:

myAssumps - a set of literals (represented by usual non null integers in Dimacs format).

global - whether that call is part of a global process (i.e. optimization) or not. if (global), the timeout will not be reset between each call.

Returns:

true if the set of constraints is satisfiable when literals are satisfied, else false.

Throws:

TimeoutException

isSatisfiable

public boolean isSatisfiable(IVecInt myAssumps)
                      throws TimeoutException

Description copied from interface: IProblem

Check the satisfiability of the set of constraints contained inside the solver.

Specified by:

isSatisfiable in interface IProblem

Overrides:

isSatisfiable in class SolverDecorator<ISolver>

Parameters:

myAssumps - a set of literals (represented by usual non null integers in Dimacs format).

Returns:

true if the set of constraints is satisfiable when literals are satisfied, else false.

Throws:

TimeoutException

model

public int[] model()

Description copied from interface: IProblem

Provide a model (if any) for a satisfiable formula. That method should be called AFTER isSatisfiable() or isSatisfiable(IVecInt) if the formula is satisfiable. Else an exception UnsupportedOperationException is launched.

Specified by:

model in interface IProblem

Overrides:

model in class SolverDecorator<ISolver>

Returns:

a model of the formula as an array of literals to satisfy.

See Also:

IProblem.isSatisfiable(), IProblem.isSatisfiable(IVecInt)

model

public boolean model(int var)

Description copied from interface: RandomAccessModel

Provide the truth value of a specific variable in the model. That method should be called AFTER isSatisfiable() if the formula is satisfiable. Else an exception UnsupportedOperationException is launched.

Specified by:

model in interface RandomAccessModel

Overrides:

model in class SolverDecorator<ISolver>

Parameters:

var - the variable id in Dimacs format

Returns:

the truth value of that variable in the model

See Also:

#model()

modelWithInternalVariables

public int[] modelWithInternalVariables()

Description copied from interface: ISolver

That method is designed to be used to retrieve the real model of the current set of constraints, i.e. to provide the truth value of boolean variables used internally in the solver (for encoding purposes for instance). If no variables are added in the solver, then Arrays.equals(model(),modelWithInternalVariables()). In case new variables are added to the solver, then the number of models returned by that method is greater of equal to the number of models returned by model() when using a ModelIterator.

Specified by:

modelWithInternalVariables in interface ISolver

Overrides:

modelWithInternalVariables in class SolverDecorator<ISolver>

Returns:

an array of literals, in Dimacs format, corresponding to a model of the formula over all the variables declared in the solver.

See Also:

IProblem.model(), ModelIterator

findModel

public int[] findModel()
                throws TimeoutException

Description copied from interface: IProblem

Look for a model satisfying all the clauses available in the problem. It is an alternative to isSatisfiable() and model() methods, as shown in the pseudo-code: if (isSatisfiable()) { return model(); } return null;

Specified by:

findModel in interface IProblem

Overrides:

findModel in class SolverDecorator<ISolver>

Returns:

a model of the formula as an array of literals to satisfy, or null if no model is found

Throws:

TimeoutException - if a model cannot be found within the given timeout.

findModel

public int[] findModel(IVecInt assumps)
                throws TimeoutException

Description copied from interface: IProblem

Look for a model satisfying all the clauses available in the problem. It is an alternative to isSatisfiable(IVecInt) and model() methods, as shown in the pseudo-code: if (isSatisfiable(assumpt)) { return model(); } return null;

Specified by:

findModel in interface IProblem

Overrides:

findModel in class SolverDecorator<ISolver>

Returns:

a model of the formula as an array of literals to satisfy, or null if no model is found

Throws:

TimeoutException - if a model cannot be found within the given timeout.

toString

public String toString(String prefix)

Description copied from interface: ISolver

Display a textual representation of the solver configuration.

Specified by:

toString in interface ISolver

Overrides:

toString in class SolverDecorator<ISolver>

Parameters:

prefix - the prefix to use on each line.

Returns:

a textual description of the solver internals.

isOptimal

public boolean isOptimal()

Allow to easily check is the solution returned by isSatisfiable is optimal or not.

Returns:

true is the solution found is indeed optimal.