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Open-source constraint solver.
/**
* Copyright (c) 2016, Ecole des Mines de Nantes
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the .
* 4. Neither the name of the nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY ''AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.chocosolver.solver;
import gnu.trove.map.hash.TIntIntHashMap;
import gnu.trove.map.hash.TIntObjectHashMap;
import org.chocosolver.solver.exception.SolverException;
import org.chocosolver.solver.variables.IntVar;
import org.chocosolver.solver.variables.RealVar;
import org.chocosolver.solver.variables.SetVar;
import org.chocosolver.solver.variables.Variable;
import java.util.Arrays;
/**
* Class which stores the value of each variable in a solution
*
*
* @author Jean-Guillaume Fages
* @author Charles Prud'homme
* @since 05/06/2013
*/
public class Solution implements ICause {
//***********************************************************************************
// VARIABLES
//***********************************************************************************
/** No entry value for maps */
private static final int NO_ENTRY = Integer.MAX_VALUE;
// SOLUTION
/** Set to true when this object is empty */
private boolean empty;
/** Maps of value for integer variable (id - value) */
private TIntIntHashMap intmap;
/** Maps of value for real variable (id - value) */
private TIntObjectHashMap realmap;
/** Maps of value for set variable (id - values) */
private TIntObjectHashMap setmap;
// INPUT
/** Model to store */
private Model model;
/** Variables to store; */
private Variable[] varsToStore;
//***********************************************************************************
// CONSTRUCTOR
//***********************************************************************************
/**
* Create an empty solution object
* able to store the value of each variable in varsToStore when calling record()
*
* @param model model of the solution
* @param varsToStore variables to store in this object
*/
public Solution(Model model, Variable... varsToStore) {
this.varsToStore = varsToStore;
empty = true;
this.model = model;
}
//***********************************************************************************
// METHODS
//***********************************************************************************
/**
* Records the current solution of the solver
* clears all previous recordings
* @return this object
*/
public Solution record() {
empty = false;
boolean warn = false;
if (varsToStore.length == 0) {
varsToStore = model.getSolver().getSearch().getVariables();
}
assert varsToStore.length > 0;
if (intmap != null) {
intmap.clear();
}
if (realmap != null) {
realmap.clear();
}
if (setmap != null) {
setmap.clear();
}
for (Variable var : varsToStore) {
if ((var.getTypeAndKind() & Variable.TYPE) != Variable.CSTE) {
int kind = var.getTypeAndKind() & Variable.KIND;
if (var.isInstantiated()) {
switch (kind) {
case Variable.INT:
case Variable.BOOL:
if (intmap == null) {
intmap = new TIntIntHashMap(16, .5f, Solution.NO_ENTRY, Solution.NO_ENTRY);
}
IntVar v = (IntVar) var;
intmap.put(v.getId(), v.getValue());
break;
case Variable.REAL:
if (realmap == null) {
realmap = new TIntObjectHashMap<>(16, 05f, Solution.NO_ENTRY);
}
RealVar r = (RealVar) var;
realmap.put(r.getId(), new double[]{r.getLB(), r.getUB()});
break;
case Variable.SET:
if (setmap == null) {
setmap = new TIntObjectHashMap<>(16, 05f, Solution.NO_ENTRY);
}
SetVar s = (SetVar) var;
setmap.put(s.getId(), s.getValue().toArray());
break;
default:
// do not throw exception to allow extending the solver with other variable kinds (e.g. graph)
// that should then be stored externally to this object
break;
}
} else {
warn = true;
}
}
}
if (warn && varsToStore[0].getModel().getSettings().warnUser()) {
model.getSolver().getOut().printf("Some non decision variables are not instantiated in the current solution.");
}
return this;
}
@Override
public String toString() {
if (empty) {
return "Empty solution. No solution recorded yet";
}
StringBuilder st = new StringBuilder("Solution: ");
for (Variable var : varsToStore) {
if ((var.getTypeAndKind() & Variable.TYPE) != Variable.CSTE) {
int kind = var.getTypeAndKind() & Variable.KIND;
switch (kind) {
case Variable.INT:
case Variable.BOOL:
IntVar v = (IntVar) var;
st.append(v.getName()).append("=").append(intmap.get(v.getId())).append(", ");
break;
case Variable.REAL:
RealVar r = (RealVar) var;
double[] bounds = realmap.get(r.getId());
st.append(r.getName()).append("=[").append(bounds[0]).append(",").append(bounds[1]).append("], ");
break;
case Variable.SET:
SetVar s = (SetVar) var;
st.append(s.getName()).append("=").append(Arrays.toString(setmap.get(s.getId()))).append(", ");
break;
default:
// do not throw exception to allow extending the solver with other variable kinds (e.g. graph)
// that should then be stored externally to this object
break;
}
}
}
return st.toString();
}
public Solution copySolution() {
Solution ret = new Solution(model, varsToStore);
ret.empty = empty;
ret.intmap = new TIntIntHashMap(intmap);
ret.realmap = new TIntObjectHashMap<>(realmap);
ret.setmap = new TIntObjectHashMap<>(setmap);
return ret;
}
/**
* Get the value of variable v in this solution
*
* @param v IntVar (or BoolVar)
* @return the value of variable v in this solution, or null if the variable is not instantiated in the solution
*/
public int getIntVal(IntVar v) {
if (empty) {
throw new SolverException("Cannot access value of "+v+": No solution has been recorded yet (empty solution). Make sure this.record() has been called.");
}
if (intmap.containsKey(v.getId())) {
return intmap.get(v.getId());
} else {
if ((v.getTypeAndKind() & Variable.TYPE) == Variable.CSTE) {
return v.getValue();
} else {
throw new SolverException("Cannot access value of "+v+": This variable has not been declared to be recorded in the Solution object (see Solution constructor).");
}
}
}
/**
* Get the value of variable s in this solution
*
* @param s SetVar
* @return the value of variable s in this solution, or null if the variable is not instantiated in the solution
*/
public int[] getSetVal(SetVar s) {
if (empty) {
throw new SolverException("Cannot access value of "+s+": No solution has been recorded yet (empty solution). Make sure this.record() has been called.");
}
if (setmap.containsKey(s.getId())) {
return setmap.get(s.getId());
} else if ((s.getTypeAndKind() & Variable.TYPE) == Variable.CSTE) {
return s.getValue().toArray();
} else {
throw new SolverException("Cannot access value of "+s+": This variable has not been declared to be recorded in the Solution object (see Solution constructor).");
}
}
/**
* Get the bounds of r in this solution
*
* @param r RealVar
* @return the bounds of r in this solution, or null if the variable is not instantiated in the solution
*/
public double[] getRealBounds(RealVar r) {
if (empty) {
throw new SolverException("Cannot access value of "+r+": No solution has been recorded yet (empty solution). Make sure this.record() has been called.");
}
if (realmap.containsKey(r.getId())) {
return realmap.get(r.getId());
} else {
if ((r.getTypeAndKind() & Variable.TYPE) == Variable.CSTE) {
return new double[]{r.getLB(), r.getUB()};
} else {
throw new SolverException("Cannot access value of "+r+": This variable has not been declared to be recorded in the Solution object (see Solution constructor).");
}
}
}
}