/**
* Copyright (c) 1999-2014, 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:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * 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.
* * Neither the name of the Ecole des Mines de Nantes 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 THE REGENTS AND CONTRIBUTORS ``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
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package solver.search.solution;
import solver.exception.ContradictionException;
import solver.search.loop.monitors.IMonitorClose;
import solver.search.loop.monitors.IMonitorSolution;
import solver.variables.IntVar;
/**
* Class to store best solutions found.
* Worse solutions are removed from the solution set.
* This enables to get all optimal solutions of a problem.
*
* @author Jean-Guillaume Fages
*/
public class BestSolutionsRecorder extends AllSolutionsRecorder {
IntVar objective;
int lastValue;
public BestSolutionsRecorder(final IntVar objective){
super(objective.getSolver());
this.objective = objective;
solver.plugMonitor(new IMonitorClose() {
@Override
public void beforeClose() {
Solution last = getLastSolution();
if(last!=null){
try{
solver.getSearchLoop().restoreRootNode();
solver.getEnvironment().worldPush();
last.restore();
}catch (ContradictionException e){
throw new UnsupportedOperationException("restoring the last solution ended in a failure");
}
solver.getEngine().flush();
}
}
@Override
public void afterClose() {}
});
}
@Override
protected IMonitorSolution createRecMonitor() {
return new IMonitorSolution() {
@Override
public void onSolution() {
if(objective.getValue()!=lastValue){
lastValue = objective.getValue();
solutions.clear();
}
Solution solution = new Solution();
solution.record(solver);
solutions.add(solution);
}
};
}
}