131 lines
5.2 KiB
C#
131 lines
5.2 KiB
C#
// Copyright 2018 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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// [START import]
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using System;
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using System.Collections.Generic;
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using Google.OrTools.ConstraintSolver;
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// [END import]
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/// <summary>
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/// Minimal TSP using distance matrix.
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/// </summary>
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public class TspDistanceMatrix {
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// [START data_model]
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class DataModel {
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// Constructor:
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public DataModel() {
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distancesMatrix_ = new long[,] {
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{0, 548, 776, 696, 582, 274, 502, 194, 308, 194, 536, 502, 388, 354, 468, 776, 662},
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{548, 0, 684, 308, 194, 502, 730, 354, 696, 742, 1084, 594, 480, 674, 1016, 868, 1210},
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{776, 684, 0, 992, 878, 502, 274, 810, 468, 742, 400, 1278, 1164, 1130, 788, 1552, 754},
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{696, 308, 992, 0, 114, 650, 878, 502, 844, 890, 1232, 514, 628, 822, 1164, 560, 1358},
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{582, 194, 878, 114, 0, 536, 764, 388, 730, 776, 1118, 400, 514, 708, 1050, 674, 1244},
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{274, 502, 502, 650, 536, 0, 228, 308, 194, 240, 582, 776, 662, 628, 514, 1050, 708},
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{502, 730, 274, 878, 764, 228, 0, 536, 194, 468, 354, 1004, 890, 856, 514, 1278, 480},
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{194, 354, 810, 502, 388, 308, 536, 0, 342, 388, 730, 468, 354, 320, 662, 742, 856},
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{308, 696, 468, 844, 730, 194, 194, 342, 0, 274, 388, 810, 696, 662, 320, 1084, 514},
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{194, 742, 742, 890, 776, 240, 468, 388, 274, 0, 342, 536, 422, 388, 274, 810, 468},
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{536, 1084, 400, 1232, 1118, 582, 354, 730, 388, 342, 0, 878, 764, 730, 388, 1152, 354},
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{502, 594, 1278, 514, 400, 776, 1004, 468, 810, 536, 878, 0, 114, 308, 650, 274, 844},
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{388, 480, 1164, 628, 514, 662, 890, 354, 696, 422, 764, 114, 0, 194, 536, 388, 730},
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{354, 674, 1130, 822, 708, 628, 856, 320, 662, 388, 730, 308, 194, 0, 342, 422, 536},
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{468, 1016, 788, 1164, 1050, 514, 514, 662, 320, 274, 388, 650, 536, 342, 0, 764, 194},
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{776, 868, 1552, 560, 674, 1050, 1278, 742, 1084, 810, 1152, 274, 388, 422, 764, 0, 798},
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{662, 1210, 754, 1358, 1244, 708, 480, 856, 514, 468, 354, 844, 730, 536, 194, 798, 0}
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};
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}
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public ref readonly long[,] GetDistanceMatrix() { return ref distancesMatrix_;}
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public int GetVehicleNumber() { return 1;}
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public int GetDepot() { return 0;}
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private long[,] distancesMatrix_;
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};
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// [END data_model]
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// [START solution_printer]
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/// <summary>
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/// Print the solution.
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/// </summary>
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static void PrintSolution(
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in RoutingModel routing,
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in RoutingIndexManager manager,
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in Assignment solution) {
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Console.WriteLine("Objective: {0}", solution.ObjectiveValue());
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// Inspect solution.
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Console.WriteLine("Route for Vehicle 0:");
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long routeDistance = 0;
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var index = routing.Start(0);
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while (routing.IsEnd(index) == false) {
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Console.Write("{0} -> ", manager.IndexToNode((int)index));
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var previousIndex = index;
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index = solution.Value(routing.NextVar(index));
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routeDistance += routing.GetArcCostForVehicle(previousIndex, index, 0);
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}
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Console.WriteLine("{0}", manager.IndexToNode((int)index));
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Console.WriteLine("Distance of the route: {0}m", routeDistance);
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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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// Instantiate the data problem.
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// [START data]
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DataModel data = new DataModel();
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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(
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data.GetDistanceMatrix().GetLength(0),
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data.GetVehicleNumber(),
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data.GetDepot());
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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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// Define cost of each arc.
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// [START arc_cost]
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int transitCostIndex = routing.RegisterTransitCallback(
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(long fromIndex, long toIndex) => {
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var fromNode = manager.IndexToNode(fromIndex);
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var toNode = manager.IndexToNode(toIndex);
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return data.GetDistanceMatrix()[fromNode, toNode]; }
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);
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routing.SetArcCostEvaluatorOfAllVehicles(transitCostIndex);
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// [END arc_cost]
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// Setting first solution heuristic.
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// [START parameters]
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RoutingSearchParameters searchParameters =
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operations_research_constraint_solver.DefaultRoutingSearchParameters();
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searchParameters.FirstSolutionStrategy =
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FirstSolutionStrategy.Types.Value.PathCheapestArc;
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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(routing, manager, solution);
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// [END print_solution]
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}
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}
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// [END program]
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