{"id":9824,"date":"2025-10-22T12:52:45","date_gmt":"2025-10-22T11:52:45","guid":{"rendered":"https:\/\/solidt.eu\/site\/?p=9824"},"modified":"2025-10-22T12:52:54","modified_gmt":"2025-10-22T11:52:54","slug":"c-groupedset","status":"publish","type":"post","link":"https:\/\/solidt.eu\/site\/c-groupedset\/","title":{"rendered":"C# GroupedSet"},"content":{"rendered":"\n<div style=\"height: 250px; position:relative; margin-bottom: 50px;\" class=\"wp-block-simple-code-block-ace\"><pre class=\"wp-block-simple-code-block-ace\" style=\"position:absolute;top:0;right:0;bottom:0;left:0\" data-mode=\"csharp\" data-theme=\"monokai\" data-fontsize=\"14\" data-lines=\"Infinity\" data-showlines=\"true\" data-copy=\"false\">using System;\nusing System.Collections.Generic;\nusing System.Linq;\n\npublic class GroupedSet&lt;T>\n{\n    \/\/ Intern houdt elk element een verwijzing naar de bijbehorende groep bij\n    private readonly Dictionary&lt;T, HashSet&lt;T>> _groups = new();\n\n    \/\/\/ &lt;summary>\n    \/\/\/ Voegt een relatie toe tussen twee items. Als ze nog niet bestaan,\n    \/\/\/ worden ze aan een nieuwe groep toegevoegd. Als ze in verschillende\n    \/\/\/ groepen zitten, worden de groepen samengevoegd.\n    \/\/\/ &lt;\/summary>\n    public void AddRelation(T a, T b)\n    {\n        _groups.TryGetValue(a, out var setA);\n        _groups.TryGetValue(b, out var setB);\n\n        if (setA == null &amp;&amp; setB == null)\n        {\n            var newSet = new HashSet&lt;T> { a, b };\n            _groups[a] = newSet;\n            _groups[b] = newSet;\n        }\n        else if (setA != null &amp;&amp; setB == null)\n        {\n            setA.Add(b);\n            _groups[b] = setA;\n        }\n        else if (setA == null &amp;&amp; setB != null)\n        {\n            setB.Add(a);\n            _groups[a] = setB;\n        }\n        else if (!ReferenceEquals(setA, setB))\n        {\n            \/\/ Merge twee bestaande sets\n            setA.UnionWith(setB);\n            foreach (var item in setB)\n                _groups[item] = setA;\n        }\n    }\n\n    \/\/\/ &lt;summary>\n    \/\/\/ Haalt de groep op waarin een item zich bevindt.\n    \/\/\/ &lt;\/summary>\n    public HashSet&lt;T>? GetGroup(T item)\n    {\n        return _groups.TryGetValue(item, out var set) ? set : null;\n    }\n\n    \/\/\/ &lt;summary>\n    \/\/\/ Controleert of twee items in dezelfde groep zitten.\n    \/\/\/ &lt;\/summary>\n    public bool AreConnected(T a, T b)\n    {\n        return GetGroup(a) != null &amp;&amp; ReferenceEquals(GetGroup(a), GetGroup(b));\n    }\n\n    \/\/\/ &lt;summary>\n    \/\/\/ Geeft alle unieke groepen terug.\n    \/\/\/ &lt;\/summary>\n    public IEnumerable&lt;HashSet&lt;T>> GetAllGroups()\n    {\n        return _groups.Values.Distinct(ReferenceEqualityComparer&lt;HashSet&lt;T>>.Instance);\n    }\n\n    \/\/\/ &lt;summary>\n    \/\/\/ Verwijdert een element (en eventueel de hele groep als die leeg is).\n    \/\/\/ &lt;\/summary>\n    public void Remove(T item)\n    {\n        if (!_groups.TryGetValue(item, out var set))\n            return;\n\n        set.Remove(item);\n        _groups.Remove(item);\n\n        if (set.Count == 0)\n            return;\n\n        \/\/ Werk dictionary bij om lege verwijzingen te verwijderen\n        foreach (var i in set)\n            _groups[i] = set;\n    }\n\n    \/\/\/ &lt;summary>\n    \/\/\/ Leegt alle groepen.\n    \/\/\/ &lt;\/summary>\n    public void Clear()\n    {\n        _groups.Clear();\n    }\n}\n\n\/\/\/ &lt;summary>\n\/\/\/ Hulpfunctie om distinct op referenties te doen.\n\/\/\/ &lt;\/summary>\npublic class ReferenceEqualityComparer&lt;T> : IEqualityComparer&lt;T>\n    where T : class\n{\n    public static readonly ReferenceEqualityComparer&lt;T> Instance = new();\n    public bool Equals(T? x, T? y) => ReferenceEquals(x, y);\n    public int GetHashCode(T obj) => System.Runtime.CompilerServices.RuntimeHelpers.GetHashCode(obj);\n}\n<\/pre><\/div>\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"inline_featured_image":false,"footnotes":""},"categories":[1],"tags":[],"class_list":["post-9824","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/solidt.eu\/site\/wp-json\/wp\/v2\/posts\/9824","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/solidt.eu\/site\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/solidt.eu\/site\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/solidt.eu\/site\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/solidt.eu\/site\/wp-json\/wp\/v2\/comments?post=9824"}],"version-history":[{"count":1,"href":"https:\/\/solidt.eu\/site\/wp-json\/wp\/v2\/posts\/9824\/revisions"}],"predecessor-version":[{"id":9825,"href":"https:\/\/solidt.eu\/site\/wp-json\/wp\/v2\/posts\/9824\/revisions\/9825"}],"wp:attachment":[{"href":"https:\/\/solidt.eu\/site\/wp-json\/wp\/v2\/media?parent=9824"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/solidt.eu\/site\/wp-json\/wp\/v2\/categories?post=9824"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/solidt.eu\/site\/wp-json\/wp\/v2\/tags?post=9824"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}