source: trunk/sources/HeuristicLab.Common/3.3/ArrayExtensions.cs @ 10324

Last change on this file since 10324 was 10324, checked in by gkronber, 6 years ago

#2106: changed methods for sorting in ObservableArray and ObservableList to use a stable sort (via Enumerable.OrderBy()). This is implemented as extension methods in HeuristicLab.Common. This implementation requires additional memory O(n).
The unit tests for tabu search had to be updated as the stable sort changes the results of the sample.
(minor bug fix in TestRandom)

File size: 2.5 KB
Line 
1#region License Information
2/* HeuristicLab
3 * Copyright (C) 2002-2013 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;
25
26namespace HeuristicLab.Common {
27  public static class ArrayExtensions {
28    public static void StableSort<T>(this T[] values) {
29      values.StableSort(0, values.Length);
30    }
31
32    public static void StableSort<T>(this T[] values, int index, int count) {
33      var sortedArray = values.Skip(index).Take(count).OrderBy(x => x).ToArray();
34      Array.ConstrainedCopy(sortedArray, 0, values, index, count);
35    }
36
37    public static void StableSort<T>(this T[] values, IComparer<T> comparer) {
38      values.StableSort(0, values.Length, comparer);
39    }
40
41    public static void StableSort<T>(this T[] values, int index, int count, IComparer<T> comparer) {
42      var sortedArray = values.Skip(index).Take(count).OrderBy(x => x, comparer).ToArray();
43      Array.ConstrainedCopy(sortedArray, 0, values, index, count);
44    }
45
46    public static void StableSort<T>(this T[] values, Comparison<T> comparison) {
47      values.StableSort(0, values.Length, comparison);
48    }
49
50    public static void StableSort<T>(this T[] values, int index, int count, Comparison<T> comparison) {
51      var sortedArray = values.Skip(index).Take(count).OrderBy(x => x, new StableSortComparer<T>(comparison)).ToArray();
52      Array.ConstrainedCopy(sortedArray, 0, values, index, count);
53    }
54
55    public class StableSortComparer<T> : IComparer<T> {
56      public StableSortComparer(Comparison<T> comparison) {
57        this.comparison = comparison;
58      }
59      public int Compare(T x, T y) {
60        return comparison(x, y);
61      }
62      private readonly Comparison<T> comparison;
63    }
64  }
65}
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