A Small HashSet Class<\/p>\n\n\n\n
using System;\nusing System.Collections.Generic;\nusing System.Diagnostics;\nusing System.Linq;\n[DebuggerTypeProxy(typeof(HashSetDebugView<>))]\n[DebuggerDisplay(\"Count = {\" + nameof(Count) + \"}\")]\n[Serializable]\npublic class TinySet<T>\n{\n private int[] _hashBuckets;\n private SizeHelper<T> _newSize = new SizeHelper<T>();\n internal IEqualityComparer<T> Comparer;\n public int Position;\n internal Slot[] Slots;\n public TinySet() : this(101, EqualityComparer<T>.Default)\n {\n }\n public TinySet(int size) : this(size, EqualityComparer<T>.Default)\n {\n }\n public TinySet(IEqualityComparer<T> comparer) : this(101, comparer)\n {\n }\n public TinySet(int size, IEqualityComparer<T> comparer)\n {\n if (comparer == null)\n comparer = EqualityComparer<T>.Default;\n Comparer = comparer;\n _hashBuckets = new int[size];\n Slots = new Slot[size];\n Count = 0;\n Position = -1;\n }\n public TinySet(IEnumerable<T> collection, IEqualityComparer<T> comparer)\n {\n if (comparer == null)\n comparer = EqualityComparer<T>.Default;\n Comparer = comparer;\n if (!(collection is ICollection<T> coll))\n return;\n var size = coll.Count;\n _hashBuckets = new int[size];\n Slots = new Slot[size];\n UnionWith(coll);\n }\n public int Count\n {\n get;\n private set;\n }\n public T[] ToArray()\n {\n var newArray = new T[Count];\n var copied = 0;\n for (var i = 0; i < Count && copied < Count; i++)\n if (Slots[i].HashCode > 0)\n newArray[copied++] = Slots[i].Value;\n return newArray;\n }\n public void Create(int size, IEqualityComparer<T> comparer)\n {\n if (comparer == null)\n comparer = EqualityComparer<T>.Default;\n Comparer = comparer;\n _hashBuckets = new int[size];\n Slots = new Slot[size];\n Count = 0;\n Position = -1;\n }\n public void Clear()\n {\n var size = Slots.Length;\n _hashBuckets = new int[size];\n Slots = new Slot[size];\n Count = 0;\n Position = -1;\n }\n public bool Add(T item)\n {\n return Insert(item, true);\n }\n public bool Contains(T item)\n {\n return Insert(item, false);\n }\n internal bool Insert(T item, bool add)\n {\n var hashCode = Comparer.GetHashCode(item) & int.MaxValue;\n if (FindEntry(item, hashCode) != -1)\n return true;\n if (add)\n {\n if (Count >= Slots.Length)\n SetSizeAndOrForceNewHashCodes(_newSize.GetNewSize(_hashBuckets.Length));\n var hashPos = hashCode % _hashBuckets.Length;\n Slots[Count].Next = _hashBuckets[hashPos] - 1;\n Slots[Count].Value = item;\n Slots[Count].HashCode = hashCode;\n _hashBuckets[hashPos] = Count + 1;\n Position = Count;\n ++Count;\n }\n return false;\n }\n public void ForceNewHashCodes()\n {\n SetSizeAndOrForceNewHashCodes();\n }\n private void SetSizeAndOrForceNewHashCodes(int Size = 0)\n {\n if (Count == 0) return;\n var newSize = Size == 0 ? Count : Size;\n var newSlots = new Slot[newSize];\n var newHashBuckets = new int[newSize];\n if (Slots != null)\n Array.Copy(Slots, 0, newSlots, 0, Count);\n for (var i = 0; i < newSize; ++i)\n if (newSlots[i].HashCode > 0 && newSlots[i].Value != null)\n newSlots[i].HashCode = Comparer.GetHashCode(newSlots[i].Value) & int.MaxValue;\n for (var i = 0; i < newSize; ++i)\n {\n var pos = newSlots[i].HashCode % newSize;\n newSlots[i].Next = newHashBuckets[pos] - 1;\n newHashBuckets[pos] = i + 1;\n }\n Slots = newSlots;\n _hashBuckets = newHashBuckets;\n }\n public void TrimExcess()\n {\n var newHashBuckets = new int[Count];\n var newSlots = new Slot[Count];\n Array.Copy(Slots, newSlots, Count);\n for (var i = 0; i < Count; i++)\n {\n var pos = newSlots[i].HashCode % Count;\n newSlots[i].Next = newHashBuckets[pos] - 1;\n newHashBuckets[pos] = i + 1;\n }\n _hashBuckets = newHashBuckets;\n Slots = newSlots;\n }\n public bool Remove(T item)\n {\n if (Count != 0)\n {\n var hashCode = Comparer.GetHashCode(item) & int.MaxValue;\n var iPos = hashCode % _hashBuckets.Length;\n var tPos = -1;\n for (var sPos = _hashBuckets[iPos] - 1; sPos >= 0; sPos = Slots[sPos].Next)\n {\n if (Slots[sPos].HashCode == hashCode && Comparer.Equals(Slots[sPos].Value, item))\n {\n if (tPos < 0)\n _hashBuckets[iPos] = Slots[sPos].Next + 1;\n else\n Slots[tPos].Next = Slots[sPos].Next;\n Slots[sPos].HashCode = -1;\n Slots[sPos].Value = default;\n Slots[sPos].Next = 0;\n --Count;\n return true;\n }\n tPos = sPos;\n }\n }\n return false;\n }\n private int FindEntry(T item, int hashCode)\n {\n for (var position = _hashBuckets[hashCode % _hashBuckets.Length] - 1; position >= 0; position = Slots[position].Next)\n if (Slots[position].HashCode == hashCode && Comparer.Equals(Slots[position].Value, item))\n {\n Position = position;\n return position;\n }\n return -1;\n }\n public int FindEntry(T item)\n {\n return FindEntry(item, Comparer.GetHashCode(item) & int.MaxValue);\n }\n public void ExceptWith(IEnumerable<T> other)\n {\n if (other == null)\n throw new Exception(\"The other set must not be null.\");\n if (Count == 0)\n return;\n if (Equals(other, this))\n Clear();\n else\n foreach (var obj in other)\n Remove(obj);\n }\n public void UnionWith(IEnumerable<T> other)\n {\n if (other == null)\n throw new Exception(\"The other set must not be null.\");\n foreach (var obj in other)\n Add(obj);\n }\n public bool Overlaps(IEnumerable<T> other)\n {\n if (other == null)\n throw new Exception(\"The other set must not be null.\");\n return Count != 0 && other.Any(Contains);\n }\n public bool ContainsAllElements(IEnumerable<T> other)\n {\n return other.All(Contains);\n }\n public int RemoveWhere(Predicate<T> pred)\n {\n if (pred == null)\n throw new Exception(\"The Predicate cannot be null.\");\n var matches = 0;\n for (var i = 0; i < Count; ++i)\n if (Slots[i].HashCode >= 0)\n {\n var obj = Slots[i].Value;\n if (pred(obj) && Remove(obj))\n ++matches;\n }\n return matches;\n }\n internal struct Slot\n {\n public int HashCode;\n public int Next;\n public T Value;\n }\n}<\/pre>\n","protected":false},"excerpt":{"rendered":"A Small HashSet Class<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[2],"tags":[58,57,56],"_links":{"self":[{"href":"https:\/\/michaeljohnsteiner.com\/index.php\/wp-json\/wp\/v2\/posts\/122"}],"collection":[{"href":"https:\/\/michaeljohnsteiner.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/michaeljohnsteiner.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/michaeljohnsteiner.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/michaeljohnsteiner.com\/index.php\/wp-json\/wp\/v2\/comments?post=122"}],"version-history":[{"count":1,"href":"https:\/\/michaeljohnsteiner.com\/index.php\/wp-json\/wp\/v2\/posts\/122\/revisions"}],"predecessor-version":[{"id":123,"href":"https:\/\/michaeljohnsteiner.com\/index.php\/wp-json\/wp\/v2\/posts\/122\/revisions\/123"}],"wp:attachment":[{"href":"https:\/\/michaeljohnsteiner.com\/index.php\/wp-json\/wp\/v2\/media?parent=122"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/michaeljohnsteiner.com\/index.php\/wp-json\/wp\/v2\/categories?post=122"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/michaeljohnsteiner.com\/index.php\/wp-json\/wp\/v2\/tags?post=122"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}