org.drools.planner.examples.nqueens.solver.score.NQueensSimpleScoreCalculator 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.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

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.simple.SimpleScoreCalculator;
import org.drools.planner.examples.nqueens.domain.NQueens;
import org.drools.planner.examples.nqueens.domain.Queen;

public class NQueensSimpleScoreCalculator implements SimpleScoreCalculator {

    public SimpleScore calculateScore(NQueens nQueens) {
        int n = nQueens.getN();
        List queenList = nQueens.getQueenList();
        
        int score = 0;
        for (int i = 0; i < n; i++) {
            for (int j = i + 1; j < n; j++) {
                Queen leftQueen = queenList.get(i);
                Queen rightQueen = queenList.get(j);
                if (leftQueen.getRow() != null && rightQueen.getRow() != null) {
                    if (leftQueen.getRowIndex() == rightQueen.getRowIndex()) {
                        score--;
                    }
                    if (leftQueen.getAscendingDiagonalIndex() == rightQueen.getAscendingDiagonalIndex()) {
                        score--;
                    }
                    if (leftQueen.getDescendingDiagonalIndex() == rightQueen.getDescendingDiagonalIndex()) {
                        score--;
                    }
                }
            }
        }
        return DefaultSimpleScore.valueOf(score);
    }

}