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source: branches/VRP/HeuristicLab.Problems.VehicleRouting/3.4/Encodings/Potvin/Manipulators/PotvinTwoLevelExchangeManipulator.cs @ 6796

Last change on this file since 6796 was 6796, checked in by svonolfe, 13 years ago

Fixed issue related to incremental evaluation (#1177)

File size: 3.9 KB
Line 
1#region License Information
2/* HeuristicLab
3 * Copyright (C) 2002-2010 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
4 *
5 * This file is part of HeuristicLab.
6 *
7 * HeuristicLab is free software: you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation, either version 3 of the License, or
10 * (at your option) any later version.
11 *
12 * HeuristicLab is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
19 */
20#endregion
21
22using HeuristicLab.Core;
23using HeuristicLab.Encodings.PermutationEncoding;
24using HeuristicLab.Parameters;
25using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
26using HeuristicLab.Data;
27using System.Collections.Generic;
28using HeuristicLab.Common;
29
30namespace HeuristicLab.Problems.VehicleRouting.Encodings.Potvin {
31  [Item("PotvinTwoLevelExchangeManipulator", "The 2M operator which manipulates a VRP representation.  It is implemented as described in Potvin, J.-Y. and Bengio, S. (1996). The Vehicle Routing Problem with Time Windows - Part II: Genetic Search. INFORMS Journal of Computing, 8:165–172.")]
32  [StorableClass]
33  public sealed class PotvinTwoLevelExchangeManipulator : PotvinManipulator {
34    [StorableConstructor]
35    private PotvinTwoLevelExchangeManipulator(bool deserializing) : base(deserializing) { }
36
37    public PotvinTwoLevelExchangeManipulator() : base() { }
38
39    public override IDeepCloneable Clone(Cloner cloner) {
40      return new PotvinTwoLevelExchangeManipulator(this, cloner);
41    }
42
43    private PotvinTwoLevelExchangeManipulator(PotvinTwoLevelExchangeManipulator original, Cloner cloner)
44      : base(original, cloner) {
45    }
46
47    protected override void Manipulate(IRandom random, PotvinEncoding individual) {
48      bool allowInfeasible = AllowInfeasibleSolutions.Value.Value;
49     
50      int selectedIndex = SelectRandomTourBiasedByLength(random, individual);
51      Tour route1 = individual.Tours[selectedIndex];
52
53      bool performed = false;
54      int customer1Position = 0;
55      while (customer1Position < route1.Stops.Count) {
56        performed = false;
57
58        foreach (Tour tour in individual.Tours) {
59          if (tour != route1) {
60            for (int customer2Position = 0; customer2Position < tour.Stops.Count; customer2Position++) {
61              int customer1 = route1.Stops[customer1Position];
62              int customer2 = tour.Stops[customer2Position];
63
64              //customer1 can be feasibly inserted at the location of customer2
65              tour.Stops[customer2Position] = customer1;
66              route1.Stops.RemoveAt(customer1Position);
67
68              if (ProblemInstance.Feasible(tour)) {
69                int routeIdx, place;
70                if (FindInsertionPlace(individual,
71                  customer2, selectedIndex, allowInfeasible, out routeIdx, out place)) {
72                  individual.Tours[routeIdx].Stops.Insert(place, customer2);
73
74                  //two-level exchange has been performed
75                  performed = true;
76                  break;
77                } else {
78                  tour.Stops[customer2Position] = customer2;
79                  route1.Stops.Insert(customer1Position, customer1);
80                }
81              } else {
82                tour.Stops[customer2Position] = customer2;
83                route1.Stops.Insert(customer1Position, customer1);
84              }
85            }
86          }
87
88          if (performed)
89            break;
90        }
91
92        if (!performed)
93          customer1Position++;
94      }
95    }
96  }
97}
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