#region License Information
/* HeuristicLab
* Copyright (C) 2002-2019 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
*
* This file is part of HeuristicLab.
*
* HeuristicLab is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* HeuristicLab is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with HeuristicLab. If not, see .
*/
#endregion
using System;
using System.Collections.Generic;
using System.Linq;
using HeuristicLab.Common;
using HeuristicLab.Core;
using HeuristicLab.Encodings.PermutationEncoding;
using HeuristicLab.Optimization;
using HEAL.Fossil;
namespace HeuristicLab.Problems.PTSP {
[Item("Exhaustive 2.5-MoveGenerator", "Generates all possible inversion and shift moves (2.5-opt) from a given permutation.")]
[StorableType("DF95E561-1F47-4845-A58D-CEF32B14461B")]
public sealed class ExhaustiveTwoPointFiveMoveGenerator : TwoPointFiveMoveGenerator, IExhaustiveMoveGenerator {
[StorableConstructor]
private ExhaustiveTwoPointFiveMoveGenerator(StorableConstructorFlag _) : base(_) { }
private ExhaustiveTwoPointFiveMoveGenerator(ExhaustiveTwoPointFiveMoveGenerator original, Cloner cloner) : base(original, cloner) { }
public ExhaustiveTwoPointFiveMoveGenerator() : base() { }
public override IDeepCloneable Clone(Cloner cloner) {
return new ExhaustiveTwoPointFiveMoveGenerator(this, cloner);
}
public static TwoPointFiveMove[] Apply(Permutation permutation) {
return Generate(permutation).ToArray();
}
public static IEnumerable Generate(Permutation permutation) {
int length = permutation.Length;
if (length == 1) throw new ArgumentException("Exhaustive 2.5-MoveGenerator: There cannot be a 2.5 move given a permutation of length 1.", "permutation");
int totalMoves = (length) * (length - 1) / 2;
if (permutation.PermutationType == PermutationTypes.RelativeUndirected) {
if (totalMoves - 3 > 0) {
for (int i = 0; i < length - 1; i++) {
for (int j = i + 1; j < length; j++) {
// doesn't make sense to inverse the whole permutation or the whole but one in case of relative undirected permutations
if (j - i >= length - 2) continue;
yield return new TwoPointFiveMove(i, j, true);
yield return new TwoPointFiveMove(i, j, false);
}
}
} 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
yield return new TwoPointFiveMove(0, 1, true);
}
} else {
for (int i = 0; i < length - 1; i++)
for (int j = i + 1; j < length; j++) {
yield return new TwoPointFiveMove(i, j, true);
yield return new TwoPointFiveMove(i, j, false);
}
}
}
protected override TwoPointFiveMove[] GenerateMoves(Permutation permutation) {
return Apply(permutation);
}
}
}