org.optaplanner.examples.vehiclerouting.solver.solution.initializer.BuoyVehicleRoutingSolutionInitializer Maven / Gradle / Ivy

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OptaPlanner solves planning problems. This lightweight, embeddable planning engine implements powerful and scalable algorithms to optimize business resource scheduling and planning. This module contains the examples which demonstrate how to use it in a normal Java application.

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/*
 * Copyright 2020 Red Hat, Inc. and/or its affiliates.
 *
 * 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.optaplanner.examples.vehiclerouting.solver.solution.initializer;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Comparator;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.optaplanner.core.api.score.Score;
import org.optaplanner.core.impl.phase.custom.AbstractCustomPhaseCommand;
import org.optaplanner.core.impl.score.director.ScoreDirector;
import org.optaplanner.examples.vehiclerouting.domain.Customer;
import org.optaplanner.examples.vehiclerouting.domain.Standstill;
import org.optaplanner.examples.vehiclerouting.domain.Vehicle;
import org.optaplanner.examples.vehiclerouting.domain.VehicleRoutingSolution;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

// TODO PLANNER-380 Delete this class. Temporary implementation until BUOY_FIT is implemented as a Construction Heuristic
public class BuoyVehicleRoutingSolutionInitializer extends AbstractCustomPhaseCommand {

    protected final transient Logger logger = LoggerFactory.getLogger(getClass());

    @Override
    public void changeWorkingSolution(ScoreDirector scoreDirector) {
        VehicleRoutingSolution solution = scoreDirector.getWorkingSolution();
        List vehicleList = solution.getVehicleList();
        List customerList = solution.getCustomerList();
        List standstillList = new ArrayList<>(vehicleList.size() + customerList.size());
        standstillList.addAll(vehicleList);
        standstillList.addAll(customerList);
        logger.info("Starting sorting");
        Map nearbyMap = new HashMap<>(standstillList.size());
        for (final Standstill origin : standstillList) {
            Customer[] nearbyCustomers = customerList.toArray(new Customer[0]);
            Arrays.sort(nearbyCustomers, new Comparator() {
                @Override
                public int compare(Standstill a, Standstill b) {
                    double aDistance = origin.getLocation().getDistanceTo(a.getLocation());
                    double bDistance = origin.getLocation().getDistanceTo(b.getLocation());
                    return Double.compare(aDistance, bDistance);
                }
            });
            nearbyMap.put(origin, nearbyCustomers);
        }
        logger.info("Done sorting");

        List buoyList = new ArrayList<>(vehicleList);

        int NEARBY_LIMIT = 40;
        while (true) {
            Score stepScore = null;
            int stepBuoyIndex = -1;
            Customer stepEntity = null;
            for (int i = 0; i < buoyList.size(); i++) {
                Standstill buoy = buoyList.get(i);

                Customer[] nearbyCustomers = nearbyMap.get(buoy);
                int j = 0;
                for (Customer customer : nearbyCustomers) {
                    if (customer.getPreviousStandstill() != null) {
                        continue;
                    }
                    scoreDirector.beforeVariableChanged(customer, "previousStandstill");
                    customer.setPreviousStandstill(buoy);
                    scoreDirector.afterVariableChanged(customer, "previousStandstill");
                    scoreDirector.triggerVariableListeners();
                    Score score = scoreDirector.calculateScore();
                    scoreDirector.beforeVariableChanged(customer, "previousStandstill");
                    customer.setPreviousStandstill(null);
                    scoreDirector.afterVariableChanged(customer, "previousStandstill");
                    scoreDirector.triggerVariableListeners();
                    if (stepScore == null || score.withInitScore(0).compareTo(stepScore.withInitScore(0)) > 0) {
                        stepScore = score;
                        stepBuoyIndex = i;
                        stepEntity = customer;
                    }
                    if (j >= NEARBY_LIMIT) {
                        break;
                    }
                    j++;
                }
            }
            if (stepEntity == null) {
                break;
            }
            Standstill stepValue = buoyList.set(stepBuoyIndex, stepEntity);
            scoreDirector.beforeVariableChanged(stepEntity, "previousStandstill");
            stepEntity.setPreviousStandstill(stepValue);
            scoreDirector.afterVariableChanged(stepEntity, "previousStandstill");
            scoreDirector.triggerVariableListeners();
            logger.debug("    Score ({}), assigned customer ({}) to stepValue ({}).", stepScore, stepEntity, stepValue);
        }
    }

}