Permutation demo
//----------------------------------------------------------------------- // <copyright file="Permutation.cs" // project="SteelGame" // assembly="SteelGame" // solution="Steel" // company="Opuno"> // Copyright (c) Opuno. All rights reserved. // </copyright> // <author id="">Andreas Brekken</author> // <summary></summary> //----------------------------------------------------------------------- using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace Opuno.Steel.Utils { public static class Permutation { public static IEnumerable<List<int>> WaysToMake(int components, int highestNumber) { var distinct = false; var componentN = components - 1; var current = new List<int>(); for (int i = 0; i < components; i++) { current.Add(1); } while (true) { yield return current.ToList(); while (componentN > 0 && current[componentN] == (distinct ? current[componentN - 1] : highestNumber)) { componentN--; } if (componentN == 0 && current[0] == highestNumber) { yield break; } current[componentN] += 1; for (int i = componentN + 1; i < components; i++) { current[i] = 1; } componentN = components - 1; } } public class ListEqualityComparer : IEqualityComparer<List<int>> { public static readonly ListEqualityComparer Instance = new ListEqualityComparer(); public bool Equals(List<int> x, List<int> y) { if (x.Count != y.Count) { return false; } if (x == y) { return true; } for (int i = 0; i < x.Count; i++) { if (!x[i].Equals(y[i])) { return false; } } return true; } public int GetHashCode(List<int> obj) { var result = 0; for (int i = 0; i < obj.Count; i++) { result ^= obj[i]; } return result; } } public static IEnumerable<List<int>> DisregardOrder(IEnumerable<List<int>> combinations) { return combinations.Select(combination => combination.OrderBy(k => k).ToList()).Distinct(ListEqualityComparer.Instance); } } }
