org.drools.planner.examples.nqueens.solver.score.NQueensAdvancedIncrementalScoreCalculator Maven / Gradle / Ivy
/*
* Copyright 2012 JBoss Inc
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.drools.planner.examples.nqueens.solver.score;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.drools.planner.core.score.buildin.simple.DefaultSimpleScore;
import org.drools.planner.core.score.buildin.simple.SimpleScore;
import org.drools.planner.core.score.director.incremental.AbstractIncrementalScoreCalculator;
import org.drools.planner.examples.nqueens.domain.NQueens;
import org.drools.planner.examples.nqueens.domain.Queen;
import org.drools.planner.examples.nqueens.domain.Row;
public class NQueensAdvancedIncrementalScoreCalculator extends AbstractIncrementalScoreCalculator {
private Map> rowIndexMap;
private Map> ascendingDiagonalIndexMap;
private Map> descendingDiagonalIndexMap;
private int score;
public void resetWorkingSolution(NQueens nQueens) {
int n = nQueens.getN();
rowIndexMap = new HashMap>(n);
ascendingDiagonalIndexMap = new HashMap>(n * 2);
descendingDiagonalIndexMap = new HashMap>(n * 2);
for (int i = 0; i < n; i++) {
rowIndexMap.put(i, new ArrayList(n));
ascendingDiagonalIndexMap.put(i, new ArrayList(n));
descendingDiagonalIndexMap.put(i, new ArrayList(n));
if (i != 0) {
ascendingDiagonalIndexMap.put(n - 1 + i, new ArrayList(n));
descendingDiagonalIndexMap.put((-i), new ArrayList(n));
}
}
score = 0;
for (Queen queen : nQueens.getQueenList()) {
insert(queen);
}
}
public void beforeEntityAdded(Object entity) {
// Do nothing
}
public void afterEntityAdded(Object entity) {
insert((Queen) entity);
}
public void beforeAllVariablesChanged(Object entity) {
retract((Queen) entity);
}
public void afterAllVariablesChanged(Object entity) {
insert((Queen) entity);
}
public void beforeVariableChanged(Object entity, String variableName) {
retract((Queen) entity);
}
public void afterVariableChanged(Object entity, String variableName) {
insert((Queen) entity);
}
public void beforeEntityRemoved(Object entity) {
retract((Queen) entity);
}
public void afterEntityRemoved(Object entity) {
// Do nothing
}
private void insert(Queen queen) {
Row row = queen.getRow();
if (row != null) {
int rowIndex = queen.getRowIndex();
List rowIndexList = rowIndexMap.get(rowIndex);
score -= rowIndexList.size();
rowIndexList.add(queen);
List ascendingDiagonalIndexList = ascendingDiagonalIndexMap.get(queen.getAscendingDiagonalIndex());
score -= ascendingDiagonalIndexList.size();
ascendingDiagonalIndexList.add(queen);
List descendingDiagonalIndexList = descendingDiagonalIndexMap.get(queen.getDescendingDiagonalIndex());
score -= descendingDiagonalIndexList.size();
descendingDiagonalIndexList.add(queen);
}
}
private void retract(Queen queen) {
Row row = queen.getRow();
if (row != null) {
List rowIndexList = rowIndexMap.get(queen.getRowIndex());
rowIndexList.remove(queen);
score += rowIndexList.size();
List ascendingDiagonalIndexList = ascendingDiagonalIndexMap.get(queen.getAscendingDiagonalIndex());
ascendingDiagonalIndexList.remove(queen);
score += ascendingDiagonalIndexList.size();
List descendingDiagonalIndexList = descendingDiagonalIndexMap.get(queen.getDescendingDiagonalIndex());
descendingDiagonalIndexList.remove(queen);
score += descendingDiagonalIndexList.size();
}
}
public SimpleScore calculateScore() {
return DefaultSimpleScore.valueOf(score);
}
}