[11939] | 1 | #region License Information
|
---|
| 2 |
|
---|
| 3 | /* HeuristicLab
|
---|
[15583] | 4 | * Copyright (C) 2002-2018 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
|
---|
[11939] | 5 | *
|
---|
| 6 | * This file is part of HeuristicLab.
|
---|
| 7 | *
|
---|
| 8 | * HeuristicLab is free software: you can redistribute it and/or modify
|
---|
| 9 | * it under the terms of the GNU General Public License as published by
|
---|
| 10 | * the Free Software Foundation, either version 3 of the License, or
|
---|
| 11 | * (at your option) any later version.
|
---|
| 12 | *
|
---|
| 13 | * HeuristicLab is distributed in the hope that it will be useful,
|
---|
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
|
---|
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
---|
| 16 | * GNU General Public License for more details.
|
---|
| 17 | *
|
---|
| 18 | * You should have received a copy of the GNU General Public License
|
---|
| 19 | * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
|
---|
| 20 | */
|
---|
| 21 |
|
---|
| 22 | #endregion
|
---|
| 23 |
|
---|
[11669] | 24 | using System.Collections.Generic;
|
---|
| 25 | using HeuristicLab.Core;
|
---|
| 26 |
|
---|
[11939] | 27 | namespace HeuristicLab.Random {
|
---|
[11669] | 28 | public static class ListExtensions {
|
---|
| 29 | public static IList<T> Swap<T>(this IList<T> list, int indexA, int indexB) {
|
---|
| 30 | T tmp = list[indexA];
|
---|
| 31 | list[indexA] = list[indexB];
|
---|
| 32 | list[indexB] = tmp;
|
---|
| 33 | return list;
|
---|
| 34 | }
|
---|
| 35 |
|
---|
| 36 | public static IList<T> ShuffleInPlace<T>(this IList<T> list, IRandom random) {
|
---|
| 37 | return list.ShuffleInPlace(random, 0, list.Count - 1);
|
---|
| 38 | }
|
---|
| 39 | public static IList<T> ShuffleInPlace<T>(this IList<T> list, IRandom random, int maxIndex) {
|
---|
| 40 | return list.ShuffleInPlace(random, 0, maxIndex);
|
---|
| 41 | }
|
---|
| 42 | public static IList<T> ShuffleInPlace<T>(this IList<T> list, IRandom random, int minIndex, int maxIndex) {
|
---|
| 43 | for (int i = maxIndex; i > minIndex; i--) {
|
---|
| 44 | int swapIndex = random.Next(minIndex, i + 1);
|
---|
| 45 | list.Swap(i, swapIndex);
|
---|
| 46 | }
|
---|
| 47 | return list;
|
---|
| 48 | }
|
---|
| 49 |
|
---|
| 50 | public static IEnumerable<T> ShuffleList<T>(this IList<T> source, IRandom random) {
|
---|
| 51 | for (int i = source.Count - 1; i > 0; i--) {
|
---|
| 52 | // Swap element "i" with a random earlier element (including itself)
|
---|
| 53 | int swapIndex = random.Next(i + 1);
|
---|
| 54 | source.Swap(i, swapIndex);
|
---|
| 55 | yield return source[i];
|
---|
| 56 | }
|
---|
| 57 | yield return source[0];
|
---|
| 58 | }
|
---|
| 59 | }
|
---|
| 60 | }
|
---|