Examples with LNGIntVector org.logicng.collections.LNGIntVector used on opensource projects

Example 76 with LNGIntVector

use of org.logicng.collections.LNGIntVector in project LogicNG by logic-ng.

the class MSU3 method iterative.

protected MaxSATResult iterative() {
    if (this.encoder.cardEncoding() != CardinalityEncoding.TOTALIZER) {
        throw new IllegalStateException("Error: Currently algorithm MSU3 with iterative encoding only  supports the totalizer encoding.");
    }
    this.nbInitialVariables = nVars();
    Tristate res;
    this.initRelaxation();
    this.solver = this.rebuildSolver();
    final LNGIntVector assumptions = new LNGIntVector();
    final LNGIntVector joinObjFunction = new LNGIntVector();
    final LNGIntVector currentObjFunction = new LNGIntVector();
    final LNGIntVector encodingAssumptions = new LNGIntVector();
    this.encoder.setIncremental(IncrementalStrategy.ITERATIVE);
    this.activeSoft.growTo(nSoft(), false);
    for (int i = 0; i < nSoft(); i++) {
        this.coreMapping.put(this.softClauses.get(i).assumptionVar(), i);
    }
    while (true) {
        final SATHandler satHandler = satHandler();
        res = searchSATSolver(this.solver, satHandler, assumptions);
        if (aborted(satHandler)) {
            return MaxSATResult.UNDEF;
        } else if (res == Tristate.TRUE) {
            this.nbSatisfiable++;
            final int newCost = computeCostModel(this.solver.model(), Integer.MAX_VALUE);
            saveModel(this.solver.model());
            if (this.verbosity != Verbosity.NONE) {
                this.output.println("o " + newCost);
            }
            this.ubCost = newCost;
            if (this.nbSatisfiable == 1) {
                if (!foundUpperBound(this.ubCost, null)) {
                    return MaxSATResult.UNDEF;
                }
                for (int i = 0; i < this.objFunction.size(); i++) {
                    assumptions.push(not(this.objFunction.get(i)));
                }
            } else {
                assert this.lbCost == newCost;
                return MaxSATResult.OPTIMUM;
            }
        } else {
            this.lbCost++;
            this.nbCores++;
            if (this.verbosity != Verbosity.NONE) {
                this.output.println("c LB : " + this.lbCost);
            }
            if (this.nbSatisfiable == 0) {
                return MaxSATResult.UNSATISFIABLE;
            }
            if (this.lbCost == this.ubCost) {
                assert this.nbSatisfiable > 0;
                if (this.verbosity != Verbosity.NONE) {
                    this.output.println("c LB = UB");
                }
                return MaxSATResult.OPTIMUM;
            }
            this.sumSizeCores += this.solver.conflict().size();
            if (this.solver.conflict().size() == 0) {
                return MaxSATResult.UNSATISFIABLE;
            }
            if (!foundLowerBound(this.lbCost, null)) {
                return MaxSATResult.UNDEF;
            }
            joinObjFunction.clear();
            for (int i = 0; i < this.solver.conflict().size(); i++) {
                if (this.coreMapping.containsKey(this.solver.conflict().get(i))) {
                    assert !this.activeSoft.get(this.coreMapping.get(this.solver.conflict().get(i)));
                    this.activeSoft.set(this.coreMapping.get(this.solver.conflict().get(i)), true);
                    joinObjFunction.push(this.softClauses.get(this.coreMapping.get(this.solver.conflict().get(i))).relaxationVars().get(0));
                }
            }
            currentObjFunction.clear();
            assumptions.clear();
            for (int i = 0; i < nSoft(); i++) {
                if (this.activeSoft.get(i)) {
                    currentObjFunction.push(this.softClauses.get(i).relaxationVars().get(0));
                } else {
                    assumptions.push(not(this.softClauses.get(i).assumptionVar()));
                }
            }
            if (this.verbosity != Verbosity.NONE) {
                this.output.printf("c Relaxed soft clauses %d / %d%n", currentObjFunction.size(), this.objFunction.size());
            }
            if (!this.encoder.hasCardEncoding()) {
                if (this.lbCost != currentObjFunction.size()) {
                    this.encoder.buildCardinality(this.solver, currentObjFunction, this.lbCost);
                    joinObjFunction.clear();
                    this.encoder.incUpdateCardinality(this.solver, joinObjFunction, currentObjFunction, this.lbCost, encodingAssumptions);
                }
            } else {
                this.encoder.incUpdateCardinality(this.solver, joinObjFunction, currentObjFunction, this.lbCost, encodingAssumptions);
            }
            for (int i = 0; i < encodingAssumptions.size(); i++) {
                assumptions.push(encodingAssumptions.get(i));
            }
        }
    }
}

Example 77 with LNGIntVector

use of org.logicng.collections.LNGIntVector in project LogicNG by logic-ng.

the class PBEncoder method encode.

/**
 * Builds a pseudo Boolean constraint of the form {@code c_1 * lit_1 + c_2 * lit_2 + ... + c_n * lit_n >= k}.
 * @param lits   the literals {@code lit_1 ... lit_n}
 * @param coeffs the coefficients {@code c_1 ... c_n}
 * @param rhs    the right hand side {@code k} of the constraint
 * @return the CNF encoding of the pseudo Boolean constraint
 * @throws IllegalArgumentException if the right hand side of the cardinality constraint is negative or
 *                                  larger than the number of literals
 */
protected List<Formula> encode(final Literal[] lits, final int[] coeffs, final int rhs) {
    if (rhs == Integer.MAX_VALUE) {
        throw new IllegalArgumentException("Overflow in the Encoding");
    }
    if (rhs < 0) {
        return Collections.singletonList(this.f.falsum());
    }
    final LNGVector<Literal> simplifiedLits = new LNGVector<>();
    final LNGIntVector simplifiedCoeffs = new LNGIntVector();
    final List<Formula> result = new ArrayList<>();
    if (rhs == 0) {
        for (final Literal lit : lits) {
            result.add(lit.negate());
        }
        return result;
    }
    for (int i = 0; i < lits.length; i++) {
        if (coeffs[i] <= rhs) {
            simplifiedLits.push(lits[i]);
            simplifiedCoeffs.push(coeffs[i]);
        } else {
            result.add(lits[i].negate());
        }
    }
    if (simplifiedLits.size() <= 1) {
        return result;
    }
    switch(this.config().pbEncoder) {
        case SWC:
        case BEST:
            if (this.swc == null) {
                this.swc = new PBSWC(this.f);
            }
            return this.swc.encode(simplifiedLits, simplifiedCoeffs, rhs, result);
        case BINARY_MERGE:
            return new PBBinaryMerge(this.f, this.config()).encode(simplifiedLits, simplifiedCoeffs, rhs, result);
        case ADDER_NETWORKS:
            if (this.adderNetworks == null) {
                this.adderNetworks = new PBAdderNetworks(this.f);
            }
            return this.adderNetworks.encode(simplifiedLits, simplifiedCoeffs, rhs, result);
        default:
            throw new IllegalStateException("Unknown pseudo-Boolean encoder: " + this.config().pbEncoder);
    }
}

Example 78 with LNGIntVector

use of org.logicng.collections.LNGIntVector in project LogicNG by logic-ng.

the class MaxSATSolver method addClause.

/**
 * Adds a clause to the solver.
 * @param formula the clause
 * @param weight  the weight of the clause (or -1 for a hard clause)
 */
protected void addClause(final Formula formula, final int weight) {
    this.result = UNDEF;
    final LNGIntVector clauseVec = new LNGIntVector((int) formula.numberOfAtoms());
    for (final Literal lit : formula.literals()) {
        Integer index = this.var2index.get(lit.variable());
        if (index == null) {
            index = this.solver.newLiteral(false) >> 1;
            this.var2index.put(lit.variable(), index);
            this.index2var.put(index, lit.variable());
        }
        final int litNum = lit.phase() ? index * 2 : (index * 2) ^ 1;
        clauseVec.push(litNum);
    }
    if (weight == -1) {
        this.solver.addHardClause(clauseVec);
    } else {
        this.solver.setCurrentWeight(weight);
        this.solver.updateSumWeights(weight);
        this.solver.addSoftClause(weight, clauseVec);
    }
}

Example 79 with LNGIntVector

use of org.logicng.collections.LNGIntVector in project LogicNG by logic-ng.

the class MiniSat method addClause.

@Override
protected void addClause(final Formula formula, final Proposition proposition) {
    this.result = UNDEF;
    final LNGIntVector ps = generateClauseVector(formula.literals());
    this.solver.addClause(ps, proposition);
}