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source: branches/2434_crossvalidation/HeuristicLab.Problems.PTSP/3.3/Moves/TwoPointFiveOpt/ExhaustiveTwoPointFiveMoveGenerator.cs

Last change on this file was 13412, checked in by abeham, 9 years ago

#2221:

  • Completely refactored PTSP branch
    • Added two sets of problem instances based on TSPLIB: homogeneous and heterogeneous
    • Implemented missing EvaluateByCoordinates for 1-shift moves
    • Made it clear that move evaluators are for estimated PTSP only
    • Changed parameter realization from a rather strange list of list of ints to a list of bool arrays
    • Reusing code of the 2-opt and 1-shift move evaluators in 2.5 move evaluator
    • Introducing distance calculators to properly handle the case when no distance matrix is given (previous code only worked with distance matrix and without only with euclidean distance in some settings)
    • Fixed several smaller code issues: protected, static, method parameters, copy & paste, interfaces, naming, parameters, serialization hooks, license headers, doc comments, data types
File size: 3.5 KB
Line 
1#region License Information
2/* HeuristicLab
3 * Copyright (C) 2002-2015 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.Encodings.PermutationEncoding;
28using HeuristicLab.Optimization;
29using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
30
31namespace HeuristicLab.Problems.PTSP {
32  [Item("Exhaustive 2.5-MoveGenerator", "Generates all possible inversion and shift moves (2.5-opt) from a given permutation.")]
33  [StorableClass]
34  public sealed class ExhaustiveTwoPointFiveMoveGenerator : TwoPointFiveMoveGenerator, IExhaustiveMoveGenerator {
35
36    [StorableConstructor]
37    private ExhaustiveTwoPointFiveMoveGenerator(bool deserializing) : base(deserializing) { }
38    private ExhaustiveTwoPointFiveMoveGenerator(ExhaustiveTwoPointFiveMoveGenerator original, Cloner cloner) : base(original, cloner) { }
39    public ExhaustiveTwoPointFiveMoveGenerator() : base() { }
40
41    public override IDeepCloneable Clone(Cloner cloner) {
42      return new ExhaustiveTwoPointFiveMoveGenerator(this, cloner);
43    }
44
45    public static TwoPointFiveMove[] Apply(Permutation permutation) {
46      return Generate(permutation).ToArray();
47    }
48
49    public static IEnumerable<TwoPointFiveMove> Generate(Permutation permutation) {
50      int length = permutation.Length;
51      if (length == 1) throw new ArgumentException("Exhaustive 2.5-MoveGenerator: There cannot be a 2.5 move given a permutation of length 1.", "permutation");
52      int totalMoves = (length) * (length - 1) / 2;
53
54      if (permutation.PermutationType == PermutationTypes.RelativeUndirected) {
55        if (totalMoves - 3 > 0) {
56          for (int i = 0; i < length - 1; i++) {
57            for (int j = i + 1; j < length; j++) {
58              // doesn't make sense to inverse the whole permutation or the whole but one in case of relative undirected permutations
59              if (j - i >= length - 2) continue;
60              yield return new TwoPointFiveMove(i, j, true);
61              yield return new TwoPointFiveMove(i, j, false);
62            }
63          }
64        } 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
65          yield return new TwoPointFiveMove(0, 1, true);
66        }
67      } else {
68        for (int i = 0; i < length - 1; i++)
69          for (int j = i + 1; j < length; j++) {
70            yield return new TwoPointFiveMove(i, j, true);
71            yield return new TwoPointFiveMove(i, j, false);
72          }
73      }
74    }
75
76    protected override TwoPointFiveMove[] GenerateMoves(Permutation permutation) {
77      return Apply(permutation);
78    }
79  }
80}
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