source: branches/2520_PersistenceReintegration/HeuristicLab.Encodings.PermutationEncoding/3.3/Moves/TwoOpt/ExhaustiveInversionMoveGenerator.cs @ 16453

Last change on this file since 16453 was 16453, checked in by jkarder, 10 months ago

#2520: updated year of copyrights

File size: 3.2 KB
Line 
1#region License Information
2/* HeuristicLab
3 * Copyright (C) 2002-2019 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 System;
23using System.Collections.Generic;
24using System.Linq;
25using HeuristicLab.Common;
26using HeuristicLab.Core;
27using HeuristicLab.Optimization;
28using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
29
30namespace HeuristicLab.Encodings.PermutationEncoding {
31  [Item("ExhaustiveInversionMoveGenerator", "Generates all possible inversion moves (2-opt) from a given permutation.")]
32  [StorableClass]
33  public class ExhaustiveInversionMoveGenerator : InversionMoveGenerator, IExhaustiveMoveGenerator {
34    [StorableConstructor]
35    protected ExhaustiveInversionMoveGenerator(bool deserializing) : base(deserializing) { }
36    protected ExhaustiveInversionMoveGenerator(ExhaustiveInversionMoveGenerator original, Cloner cloner) : base(original, cloner) { }
37    public ExhaustiveInversionMoveGenerator() : base() { }
38
39    public override IDeepCloneable Clone(Cloner cloner) {
40      return new ExhaustiveInversionMoveGenerator(this, cloner);
41    }
42
43    public static InversionMove[] Apply(Permutation permutation) {
44      return Generate(permutation).ToArray();
45    }
46
47    public static IEnumerable<InversionMove> Generate(Permutation permutation) {
48      int length = permutation.Length;
49      if (length == 1) throw new ArgumentException("ExhaustiveInversionMoveGenerator: There cannot be an inversion move given a permutation of length 1.", "permutation");
50      int totalMoves = (length) * (length - 1) / 2;
51
52      if (permutation.PermutationType == PermutationTypes.RelativeUndirected) {
53        if (totalMoves - 3 > 0) {
54          for (int i = 0; i < length - 1; i++) {
55            for (int j = i + 1; j < length; j++) {
56              // doesn't make sense to inverse the whole permutation or the whole but one in case of relative undirected permutations
57              if (j - i >= length - 2) continue;
58              yield return new InversionMove(i, j);
59            }
60          }
61        } else { // when length is 3 or less, there's actually no difference, but for the sake of not crashing the algorithm create a dummy move
62          yield return new InversionMove(0, 1);
63        }
64      } else {
65        for (int i = 0; i < length - 1; i++)
66          for (int j = i + 1; j < length; j++) {
67            yield return new InversionMove(i, j);
68          }
69      }
70    }
71
72    protected override InversionMove[] GenerateMoves(Permutation permutation) {
73      return Apply(permutation);
74    }
75  }
76}
Note: See TracBrowser for help on using the repository browser.