8bb54b04ef
FYI: find ortools \( -type d -name .git -prune \) -o -type f -print0 | xargs -0 sed -i 's/\(Copyright 2010\)-2018/\1-2021/g'
127 lines
4.6 KiB
Java
127 lines
4.6 KiB
Java
// Copyright 2010-2021 Google LLC
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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// [START program]
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package com.google.ortools.constraintsolver.samples;
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// [START import]
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import static java.lang.Math.max;
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import com.google.ortools.Loader;
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import com.google.ortools.constraintsolver.Assignment;
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import com.google.ortools.constraintsolver.FirstSolutionStrategy;
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import com.google.ortools.constraintsolver.LocalSearchMetaheuristic;
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import com.google.ortools.constraintsolver.RoutingDimension;
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import com.google.ortools.constraintsolver.RoutingIndexManager;
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import com.google.ortools.constraintsolver.RoutingModel;
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import com.google.ortools.constraintsolver.RoutingSearchParameters;
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import com.google.ortools.constraintsolver.main;
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import com.google.protobuf.Duration;
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import java.util.logging.Logger;
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// [END import]
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/** Minimal VRP. */
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public final class VrpWithTimeLimit {
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private static final Logger logger = Logger.getLogger(VrpWithTimeLimit.class.getName());
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// [START solution_printer]
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/// @brief Print the solution.
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static void printSolution(
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RoutingIndexManager manager, RoutingModel routing, Assignment solution) {
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// Inspect solution.
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long maxRouteDistance = 0;
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for (int i = 0; i < manager.getNumberOfVehicles(); ++i) {
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long index = routing.start(i);
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logger.info("Route for Vehicle " + i + ":");
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long routeDistance = 0;
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String route = "";
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while (!routing.isEnd(index)) {
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route += manager.indexToNode(index) + " -> ";
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long previousIndex = index;
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index = solution.value(routing.nextVar(index));
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routeDistance += routing.getArcCostForVehicle(previousIndex, index, i);
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}
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logger.info(route + manager.indexToNode(index));
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logger.info("Distance of the route: " + routeDistance + "m");
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maxRouteDistance = max(routeDistance, maxRouteDistance);
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}
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logger.info("Maximum of the route distances: " + maxRouteDistance + "m");
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}
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// [END solution_printer]
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public static void main(String[] args) {
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Loader.loadNativeLibraries();
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// Instantiate the data problem.
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// [START data]
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final int locationNumber = 20;
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final int vehicleNumber = 5;
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final int depot = 0;
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// [END data]
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// Create Routing Index Manager
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// [START index_manager]
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RoutingIndexManager manager = new RoutingIndexManager(locationNumber, vehicleNumber, depot);
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// [END index_manager]
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// Create Routing Model.
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// [START routing_model]
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RoutingModel routing = new RoutingModel(manager);
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// [END routing_model]
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// Create and register a transit callback.
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// [START transit_callback]
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final int transitCallbackIndex =
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routing.registerTransitCallback((long fromIndex, long toIndex) -> 1);
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// [END transit_callback]
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// Define cost of each arc.
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// [START arc_cost]
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routing.setArcCostEvaluatorOfAllVehicles(transitCallbackIndex);
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// [END arc_cost]
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// Add Distance constraint.
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// [START distance_constraint]
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routing.addDimension(transitCallbackIndex,
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/*slack_max=*/0,
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/*capacity=*/3000,
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/*fix_start_cumul_to_zero=*/true, "Distance");
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RoutingDimension distanceDimension = routing.getMutableDimension("Distance");
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distanceDimension.setGlobalSpanCostCoefficient(100);
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// [END distance_constraint]
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// Setting first solution heuristic.
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// [START parameters]
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RoutingSearchParameters searchParameters =
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main.defaultRoutingSearchParameters()
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.toBuilder()
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.setFirstSolutionStrategy(FirstSolutionStrategy.Value.PATH_CHEAPEST_ARC)
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.setLocalSearchMetaheuristic(LocalSearchMetaheuristic.Value.GUIDED_LOCAL_SEARCH)
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.setLogSearch(true)
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.setTimeLimit(Duration.newBuilder().setSeconds(10).build())
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.build();
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// [END parameters]
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// Solve the problem.
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// [START solve]
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Assignment solution = routing.solveWithParameters(searchParameters);
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// [END solve]
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// Print solution on console.
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// [START print_solution]
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printSolution(manager, routing, solution);
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// [END print_solution]
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}
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private VrpWithTimeLimit() {}
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}
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// [END program]
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