314 lines
12 KiB
Java
314 lines
12 KiB
Java
//
|
|
// Copyright 2012 Google
|
|
//
|
|
// 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.
|
|
import com.google.ortools.constraintsolver.Assignment;
|
|
import com.google.ortools.constraintsolver.FirstSolutionStrategy;
|
|
import com.google.ortools.constraintsolver.LongLongToLong;
|
|
import com.google.ortools.constraintsolver.LongToLong;
|
|
import com.google.ortools.constraintsolver.IntVar;
|
|
import com.google.ortools.constraintsolver.RoutingDimension;
|
|
import com.google.ortools.constraintsolver.RoutingIndexManager;
|
|
import com.google.ortools.constraintsolver.RoutingModel;
|
|
import com.google.ortools.constraintsolver.RoutingSearchParameters;
|
|
import com.google.ortools.constraintsolver.main;
|
|
import java.util.ArrayList;
|
|
import java.util.List;
|
|
import java.util.Random;
|
|
import java.util.logging.Logger;
|
|
|
|
// A pair class
|
|
|
|
class Pair<K, V> {
|
|
final K first;
|
|
final V second;
|
|
|
|
public static <K, V> Pair<K, V> of(K element0, V element1) {
|
|
return new Pair<K, V>(element0, element1);
|
|
}
|
|
|
|
public Pair(K element0, V element1) {
|
|
this.first = element0;
|
|
this.second = element1;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Sample showing how to model and solve a capacitated vehicle routing problem with time windows
|
|
* using the swig-wrapped version of the vehicle routing library in src/constraint_solver.
|
|
*/
|
|
public class CapacitatedVehicleRoutingProblemWithTimeWindows {
|
|
|
|
static {
|
|
System.loadLibrary("jniortools");
|
|
}
|
|
|
|
private static Logger logger =
|
|
Logger.getLogger(CapacitatedVehicleRoutingProblemWithTimeWindows.class.getName());
|
|
|
|
// Locations representing either an order location or a vehicle route
|
|
// start/end.
|
|
private List<Pair<Integer, Integer>> locations = new ArrayList();
|
|
|
|
// Quantity to be picked up for each order.
|
|
private List<Integer> orderDemands = new ArrayList();
|
|
// Time window in which each order must be performed.
|
|
private List<Pair<Integer, Integer>> orderTimeWindows = new ArrayList();
|
|
// Penalty cost "paid" for dropping an order.
|
|
private List<Integer> orderPenalties = new ArrayList();
|
|
|
|
// Capacity of the vehicles.
|
|
private int vehicleCapacity = 0;
|
|
// Latest time at which each vehicle must end its tour.
|
|
private List<Integer> vehicleEndTime = new ArrayList();
|
|
// Cost per unit of distance of each vehicle.
|
|
private List<Integer> vehicleCostCoefficients = new ArrayList();
|
|
// Vehicle start and end indices. They have to be implemented as int[] due
|
|
// to the available SWIG-ed interface.
|
|
private int vehicleStarts[];
|
|
private int vehicleEnds[];
|
|
|
|
// Random number generator to produce data.
|
|
private final Random randomGenerator = new Random(0xBEEF);
|
|
|
|
/**
|
|
* Creates a Manhattan Distance evaluator with 'costCoefficient'.
|
|
*
|
|
* @param manager Node Index Manager.
|
|
* @param costCoefficient The coefficient to apply to the evaluator.
|
|
*/
|
|
private LongLongToLong buildManhattanCallback(RoutingIndexManager manager, int costCoefficient) {
|
|
return new LongLongToLong() {
|
|
@Override
|
|
public long run(long firstIndex, long secondIndex) {
|
|
try {
|
|
int firstNode = manager.indexToNode(firstIndex);
|
|
int secondNode = manager.indexToNode(secondIndex);
|
|
Pair<Integer, Integer> firstLocation = locations.get(firstNode);
|
|
Pair<Integer, Integer> secondLocation = locations.get(secondNode);
|
|
return (long) costCoefficient
|
|
* (Math.abs(firstLocation.first - secondLocation.first)
|
|
+ Math.abs(firstLocation.second - secondLocation.second));
|
|
} catch (Throwable throwed) {
|
|
logger.warning(throwed.getMessage());
|
|
return 0;
|
|
}
|
|
}
|
|
};
|
|
}
|
|
|
|
/**
|
|
* Creates order data. Location of the order is random, as well as its demand (quantity), time
|
|
* window and penalty.
|
|
*
|
|
* @param numberOfOrders number of orders to build.
|
|
* @param xMax maximum x coordinate in which orders are located.
|
|
* @param yMax maximum y coordinate in which orders are located.
|
|
* @param demandMax maximum quantity of a demand.
|
|
* @param timeWindowMax maximum starting time of the order time window.
|
|
* @param timeWindowWidth duration of the order time window.
|
|
* @param penaltyMin minimum pernalty cost if order is dropped.
|
|
* @param penaltyMax maximum pernalty cost if order is dropped.
|
|
*/
|
|
private void buildOrders(
|
|
int numberOfOrders,
|
|
int xMax,
|
|
int yMax,
|
|
int demandMax,
|
|
int timeWindowMax,
|
|
int timeWindowWidth,
|
|
int penaltyMin,
|
|
int penaltyMax) {
|
|
logger.info("Building orders.");
|
|
for (int order = 0; order < numberOfOrders; ++order) {
|
|
locations.add(Pair.of(randomGenerator.nextInt(xMax + 1), randomGenerator.nextInt(yMax + 1)));
|
|
orderDemands.add(randomGenerator.nextInt(demandMax + 1));
|
|
int timeWindowStart = randomGenerator.nextInt(timeWindowMax + 1);
|
|
orderTimeWindows.add(Pair.of(timeWindowStart, timeWindowStart + timeWindowWidth));
|
|
orderPenalties.add(randomGenerator.nextInt(penaltyMax - penaltyMin + 1) + penaltyMin);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Creates fleet data. Vehicle starting and ending locations are random, as well as vehicle costs
|
|
* per distance unit.
|
|
*
|
|
* @param numberOfVehicles
|
|
* @param xMax maximum x coordinate in which orders are located.
|
|
* @param yMax maximum y coordinate in which orders are located.
|
|
* @param endTime latest end time of a tour of a vehicle.
|
|
* @param capacity capacity of a vehicle.
|
|
* @param costCoefficientMax maximum cost per distance unit of a vehicle (mimimum is 1),
|
|
*/
|
|
private void buildFleet(
|
|
int numberOfVehicles, int xMax, int yMax, int endTime, int capacity, int costCoefficientMax) {
|
|
logger.info("Building fleet.");
|
|
vehicleCapacity = capacity;
|
|
vehicleStarts = new int[numberOfVehicles];
|
|
vehicleEnds = new int[numberOfVehicles];
|
|
for (int vehicle = 0; vehicle < numberOfVehicles; ++vehicle) {
|
|
vehicleStarts[vehicle] = locations.size();
|
|
locations.add(Pair.of(randomGenerator.nextInt(xMax + 1), randomGenerator.nextInt(yMax + 1)));
|
|
vehicleEnds[vehicle] = locations.size();
|
|
locations.add(Pair.of(randomGenerator.nextInt(xMax + 1), randomGenerator.nextInt(yMax + 1)));
|
|
vehicleEndTime.add(endTime);
|
|
vehicleCostCoefficients.add(randomGenerator.nextInt(costCoefficientMax) + 1);
|
|
}
|
|
}
|
|
|
|
/** Solves the current routing problem. */
|
|
private void solve(final int numberOfOrders, final int numberOfVehicles) {
|
|
logger.info(
|
|
"Creating model with " + numberOfOrders + " orders and " + numberOfVehicles + " vehicles.");
|
|
// Finalizing model
|
|
final int numberOfLocations = locations.size();
|
|
|
|
RoutingIndexManager manager =
|
|
new RoutingIndexManager(numberOfLocations, numberOfVehicles, vehicleStarts, vehicleEnds);
|
|
RoutingModel model = new RoutingModel(manager);
|
|
|
|
// Setting up dimensions
|
|
final int bigNumber = 100000;
|
|
final LongLongToLong callback = buildManhattanCallback(manager, 1);
|
|
final String timeStr = "time";
|
|
model.addDimension(
|
|
model.registerTransitCallback(callback), bigNumber, bigNumber, false, timeStr);
|
|
RoutingDimension timeDimension = model.getMutableDimension(timeStr);
|
|
|
|
LongToLong demandCallback =
|
|
new LongToLong() {
|
|
@Override
|
|
public long run(long index) {
|
|
try {
|
|
int node = manager.indexToNode(index);
|
|
if (node < numberOfOrders) {
|
|
return orderDemands.get(node);
|
|
}
|
|
return 0;
|
|
} catch (Throwable throwed) {
|
|
logger.warning(throwed.getMessage());
|
|
return 0;
|
|
}
|
|
}
|
|
};
|
|
final String capacityStr = "capacity";
|
|
model.addDimension(
|
|
model.registerUnaryTransitCallback(demandCallback), 0, vehicleCapacity, true, capacityStr);
|
|
RoutingDimension capacityDimension = model.getMutableDimension(capacityStr);
|
|
|
|
// Setting up vehicles
|
|
LongLongToLong[] callbacks = new LongLongToLong[numberOfVehicles];
|
|
for (int vehicle = 0; vehicle < numberOfVehicles; ++vehicle) {
|
|
final int costCoefficient = vehicleCostCoefficients.get(vehicle);
|
|
callbacks[vehicle] = buildManhattanCallback(manager, costCoefficient);
|
|
final int vehicleCost = model.registerTransitCallback(callbacks[vehicle]);
|
|
model.setArcCostEvaluatorOfVehicle(vehicleCost, vehicle);
|
|
timeDimension.cumulVar(model.end(vehicle)).setMax(vehicleEndTime.get(vehicle));
|
|
}
|
|
|
|
// Setting up orders
|
|
for (int order = 0; order < numberOfOrders; ++order) {
|
|
timeDimension
|
|
.cumulVar(order)
|
|
.setRange(orderTimeWindows.get(order).first, orderTimeWindows.get(order).second);
|
|
long[] orderIndices = {manager.nodeToIndex(order)};
|
|
model.addDisjunction(orderIndices, orderPenalties.get(order));
|
|
}
|
|
|
|
// Solving
|
|
RoutingSearchParameters parameters =
|
|
main.defaultRoutingSearchParameters()
|
|
.toBuilder()
|
|
.setFirstSolutionStrategy(FirstSolutionStrategy.Value.ALL_UNPERFORMED)
|
|
.build();
|
|
|
|
logger.info("Search");
|
|
Assignment solution = model.solveWithParameters(parameters);
|
|
|
|
if (solution != null) {
|
|
String output = "Total cost: " + solution.objectiveValue() + "\n";
|
|
// Dropped orders
|
|
String dropped = "";
|
|
for (int order = 0; order < numberOfOrders; ++order) {
|
|
if (solution.value(model.nextVar(order)) == order) {
|
|
dropped += " " + order;
|
|
}
|
|
}
|
|
if (dropped.length() > 0) {
|
|
output += "Dropped orders:" + dropped + "\n";
|
|
}
|
|
// Routes
|
|
for (int vehicle = 0; vehicle < numberOfVehicles; ++vehicle) {
|
|
String route = "Vehicle " + vehicle + ": ";
|
|
long order = model.start(vehicle);
|
|
// Empty route has a minimum of two nodes: Start => End
|
|
if (model.isEnd(solution.value(model.nextVar(order)))) {
|
|
route += "Empty";
|
|
} else {
|
|
for (; !model.isEnd(order); order = solution.value(model.nextVar(order))) {
|
|
IntVar load = capacityDimension.cumulVar(order);
|
|
IntVar time = timeDimension.cumulVar(order);
|
|
route +=
|
|
order
|
|
+ " Load("
|
|
+ solution.value(load)
|
|
+ ") "
|
|
+ "Time("
|
|
+ solution.min(time)
|
|
+ ", "
|
|
+ solution.max(time)
|
|
+ ") -> ";
|
|
}
|
|
IntVar load = capacityDimension.cumulVar(order);
|
|
IntVar time = timeDimension.cumulVar(order);
|
|
route +=
|
|
order
|
|
+ " Load("
|
|
+ solution.value(load)
|
|
+ ") "
|
|
+ "Time("
|
|
+ solution.min(time)
|
|
+ ", "
|
|
+ solution.max(time)
|
|
+ ")";
|
|
}
|
|
output += route + "\n";
|
|
}
|
|
logger.info(output);
|
|
}
|
|
}
|
|
|
|
public static void main(String[] args) throws Exception {
|
|
CapacitatedVehicleRoutingProblemWithTimeWindows problem =
|
|
new CapacitatedVehicleRoutingProblemWithTimeWindows();
|
|
final int xMax = 20;
|
|
final int yMax = 20;
|
|
final int demandMax = 3;
|
|
final int timeWindowMax = 24 * 60;
|
|
final int timeWindowWidth = 4 * 60;
|
|
final int penaltyMin = 50;
|
|
final int penaltyMax = 100;
|
|
final int endTime = 24 * 60;
|
|
final int costCoefficientMax = 3;
|
|
|
|
final int orders = 100;
|
|
final int vehicles = 20;
|
|
final int capacity = 50;
|
|
|
|
problem.buildOrders(
|
|
orders, xMax, yMax, demandMax, timeWindowMax, timeWindowWidth, penaltyMin, penaltyMax);
|
|
problem.buildFleet(vehicles, xMax, yMax, endTime, capacity, costCoefficientMax);
|
|
problem.solve(orders, vehicles);
|
|
}
|
|
}
|