Bidirectional 1 to 1 Dictionary in C#
我在C(2)中寻找一个通用的、双向的1到1字典类,即
这个问题的答案中有一个bidictionary,但它不是针对唯一元素(也不实现removebyfirst(t t)或removebysecond(s))。
谢谢!
好的,这是我的尝试(建立在Jon的基础上-谢谢),存档在这里并打开进行改进:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 | /// <summary> /// This is a dictionary guaranteed to have only one of each value and key. /// It may be searched either by TFirst or by TSecond, giving a unique answer because it is 1 to 1. /// </summary> /// <typeparam name="TFirst">The type of the"key"</typeparam> /// <typeparam name="TSecond">The type of the"value"</typeparam> public class BiDictionaryOneToOne<TFirst, TSecond> { IDictionary<TFirst, TSecond> firstToSecond = new Dictionary<TFirst, TSecond>(); IDictionary<TSecond, TFirst> secondToFirst = new Dictionary<TSecond, TFirst>(); #region Exception throwing methods /// <summary> /// Tries to add the pair to the dictionary. /// Throws an exception if either element is already in the dictionary /// </summary> /// <param name="first"></param> /// <param name="second"></param> public void Add(TFirst first, TSecond second) { if (firstToSecond.ContainsKey(first) || secondToFirst.ContainsKey(second)) throw new ArgumentException("Duplicate first or second"); firstToSecond.Add(first, second); secondToFirst.Add(second, first); } /// <summary> /// Find the TSecond corresponding to the TFirst first /// Throws an exception if first is not in the dictionary. /// </summary> /// <param name="first">the key to search for</param> /// <returns>the value corresponding to first</returns> public TSecond GetByFirst(TFirst first) { TSecond second; if (!firstToSecond.TryGetValue(first, out second)) throw new ArgumentException("first"); return second; } /// <summary> /// Find the TFirst corresponing to the Second second. /// Throws an exception if second is not in the dictionary. /// </summary> /// <param name="second">the key to search for</param> /// <returns>the value corresponding to second</returns> public TFirst GetBySecond(TSecond second) { TFirst first; if (!secondToFirst.TryGetValue(second, out first)) throw new ArgumentException("second"); return first; } /// <summary> /// Remove the record containing first. /// If first is not in the dictionary, throws an Exception. /// </summary> /// <param name="first">the key of the record to delete</param> public void RemoveByFirst(TFirst first) { TSecond second; if (!firstToSecond.TryGetValue(first, out second)) throw new ArgumentException("first"); firstToSecond.Remove(first); secondToFirst.Remove(second); } /// <summary> /// Remove the record containing second. /// If second is not in the dictionary, throws an Exception. /// </summary> /// <param name="second">the key of the record to delete</param> public void RemoveBySecond(TSecond second) { TFirst first; if (!secondToFirst.TryGetValue(second, out first)) throw new ArgumentException("second"); secondToFirst.Remove(second); firstToSecond.Remove(first); } #endregion #region Try methods /// <summary> /// Tries to add the pair to the dictionary. /// Returns false if either element is already in the dictionary /// </summary> /// <param name="first"></param> /// <param name="second"></param> /// <returns>true if successfully added, false if either element are already in the dictionary</returns> public Boolean TryAdd(TFirst first, TSecond second) { if (firstToSecond.ContainsKey(first) || secondToFirst.ContainsKey(second)) return false; firstToSecond.Add(first, second); secondToFirst.Add(second, first); return true; } /// <summary> /// Find the TSecond corresponding to the TFirst first. /// Returns false if first is not in the dictionary. /// </summary> /// <param name="first">the key to search for</param> /// <param name="second">the corresponding value</param> /// <returns>true if first is in the dictionary, false otherwise</returns> public Boolean TryGetByFirst(TFirst first, out TSecond second) { return firstToSecond.TryGetValue(first, out second); } /// <summary> /// Find the TFirst corresponding to the TSecond second. /// Returns false if second is not in the dictionary. /// </summary> /// <param name="second">the key to search for</param> /// <param name="first">the corresponding value</param> /// <returns>true if second is in the dictionary, false otherwise</returns> public Boolean TryGetBySecond(TSecond second, out TFirst first) { return secondToFirst.TryGetValue(second, out first); } /// <summary> /// Remove the record containing first, if there is one. /// </summary> /// <param name="first"></param> /// <returns> If first is not in the dictionary, returns false, otherwise true</returns> public Boolean TryRemoveByFirst(TFirst first) { TSecond second; if (!firstToSecond.TryGetValue(first, out second)) return false; firstToSecond.Remove(first); secondToFirst.Remove(second); return true; } /// <summary> /// Remove the record containing second, if there is one. /// </summary> /// <param name="second"></param> /// <returns> If second is not in the dictionary, returns false, otherwise true</returns> public Boolean TryRemoveBySecond(TSecond second) { TFirst first; if (!secondToFirst.TryGetValue(second, out first)) return false; secondToFirst.Remove(second); firstToSecond.Remove(first); return true; } #endregion /// <summary> /// The number of pairs stored in the dictionary /// </summary> public Int32 Count { get { return firstToSecond.Count; } } /// <summary> /// Removes all items from the dictionary. /// </summary> public void Clear() { firstToSecond.Clear(); secondToFirst.Clear(); } } |
更完整的双向字典实现:
- 几乎支持原始
Dictionary 的所有接口(基础设施接口除外):IDictionary IReadOnlyDictionary IDictionary ICollection (本界面及以下为上述界面的基础界面)> ICollection IReadOnlyCollection > IEnumerable > IEnumerable
- 使用
SerializableAttribute 进行序列化。 - 使用
DebuggerDisplayAttribute 和DebuggerTypeProxyAttribute 调试视图(用于在手表中显示键值对)。 - Reverse Dictionary作为
IDictionary 属性提供,也实现了上面提到的所有接口。任何一个字典上的所有操作都会同时修改这两个字典。Reverse
用途:
1 2 3 4 5 6 | var dic = new BiDictionary<int, string>(); dic.Add(1,"1"); dic[2] ="2"; dic.Reverse.Add("3", 3); dic.Reverse["4"] = 4; dic.Clear(); |
代码在我的Github私有框架中提供:bidictionary(tfirst,tsecond).cs(permalink,search)。
复印件:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 | [Serializable] [DebuggerDisplay ("Count = {Count}"), DebuggerTypeProxy (typeof(DictionaryDebugView<,>))] public class BiDictionary<TFirst, TSecond> : IDictionary<TFirst, TSecond>, IReadOnlyDictionary<TFirst, TSecond>, IDictionary { private readonly IDictionary<TFirst, TSecond> _firstToSecond = new Dictionary<TFirst, TSecond>(); [NonSerialized] private readonly IDictionary<TSecond, TFirst> _secondToFirst = new Dictionary<TSecond, TFirst>(); [NonSerialized] private readonly ReverseDictionary _reverseDictionary; public BiDictionary () { _reverseDictionary = new ReverseDictionary(this); } public IDictionary<TSecond, TFirst> Reverse { get { return _reverseDictionary; } } public int Count { get { return _firstToSecond.Count; } } object ICollection.SyncRoot { get { return ((ICollection)_firstToSecond).SyncRoot; } } bool ICollection.IsSynchronized { get { return ((ICollection)_firstToSecond).IsSynchronized; } } bool IDictionary.IsFixedSize { get { return ((IDictionary)_firstToSecond).IsFixedSize; } } public bool IsReadOnly { get { return _firstToSecond.IsReadOnly || _secondToFirst.IsReadOnly; } } public TSecond this [TFirst key] { get { return _firstToSecond[key]; } set { _firstToSecond[key] = value; _secondToFirst[value] = key; } } object IDictionary.this [object key] { get { return ((IDictionary)_firstToSecond)[key]; } set { ((IDictionary)_firstToSecond)[key] = value; ((IDictionary)_secondToFirst)[value] = key; } } public ICollection<TFirst> Keys { get { return _firstToSecond.Keys; } } ICollection IDictionary.Keys { get { return ((IDictionary)_firstToSecond).Keys; } } IEnumerable<TFirst> IReadOnlyDictionary<TFirst, TSecond>.Keys { get { return ((IReadOnlyDictionary<TFirst, TSecond>)_firstToSecond).Keys; } } public ICollection<TSecond> Values { get { return _firstToSecond.Values; } } ICollection IDictionary.Values { get { return ((IDictionary)_firstToSecond).Values; } } IEnumerable<TSecond> IReadOnlyDictionary<TFirst, TSecond>.Values { get { return ((IReadOnlyDictionary<TFirst, TSecond>)_firstToSecond).Values; } } public IEnumerator<KeyValuePair<TFirst, TSecond>> GetEnumerator () { return _firstToSecond.GetEnumerator(); } IEnumerator IEnumerable.GetEnumerator () { return GetEnumerator(); } IDictionaryEnumerator IDictionary.GetEnumerator () { return ((IDictionary)_firstToSecond).GetEnumerator(); } public void Add (TFirst key, TSecond value) { _firstToSecond.Add(key, value); _secondToFirst.Add(value, key); } void IDictionary.Add (object key, object value) { ((IDictionary)_firstToSecond).Add(key, value); ((IDictionary)_secondToFirst).Add(value, key); } public void Add (KeyValuePair<TFirst, TSecond> item) { _firstToSecond.Add(item); _secondToFirst.Add(item.Reverse()); } public bool ContainsKey (TFirst key) { return _firstToSecond.ContainsKey(key); } public bool Contains (KeyValuePair<TFirst, TSecond> item) { return _firstToSecond.Contains(item); } public bool TryGetValue (TFirst key, out TSecond value) { return _firstToSecond.TryGetValue(key, out value); } public bool Remove (TFirst key) { TSecond value; if (_firstToSecond.TryGetValue(key, out value)) { _firstToSecond.Remove(key); _secondToFirst.Remove(value); return true; } else return false; } void IDictionary.Remove (object key) { var firstToSecond = (IDictionary)_firstToSecond; if (!firstToSecond.Contains(key)) return; var value = firstToSecond[key]; firstToSecond.Remove(key); ((IDictionary)_secondToFirst).Remove(value); } public bool Remove (KeyValuePair<TFirst, TSecond> item) { return _firstToSecond.Remove(item); } public bool Contains (object key) { return ((IDictionary)_firstToSecond).Contains(key); } public void Clear () { _firstToSecond.Clear(); _secondToFirst.Clear(); } public void CopyTo (KeyValuePair<TFirst, TSecond>[] array, int arrayIndex) { _firstToSecond.CopyTo(array, arrayIndex); } void ICollection.CopyTo (Array array, int index) { ((IDictionary)_firstToSecond).CopyTo(array, index); } [OnDeserialized] internal void OnDeserialized (StreamingContext context) { _secondToFirst.Clear(); foreach (var item in _firstToSecond) _secondToFirst.Add(item.Value, item.Key); } private class ReverseDictionary : IDictionary<TSecond, TFirst>, IReadOnlyDictionary<TSecond, TFirst>, IDictionary { private readonly BiDictionary<TFirst, TSecond> _owner; public ReverseDictionary (BiDictionary<TFirst, TSecond> owner) { _owner = owner; } public int Count { get { return _owner._secondToFirst.Count; } } object ICollection.SyncRoot { get { return ((ICollection)_owner._secondToFirst).SyncRoot; } } bool ICollection.IsSynchronized { get { return ((ICollection)_owner._secondToFirst).IsSynchronized; } } bool IDictionary.IsFixedSize { get { return ((IDictionary)_owner._secondToFirst).IsFixedSize; } } public bool IsReadOnly { get { return _owner._secondToFirst.IsReadOnly || _owner._firstToSecond.IsReadOnly; } } public TFirst this [TSecond key] { get { return _owner._secondToFirst[key]; } set { _owner._secondToFirst[key] = value; _owner._firstToSecond[value] = key; } } object IDictionary.this [object key] { get { return ((IDictionary)_owner._secondToFirst)[key]; } set { ((IDictionary)_owner._secondToFirst)[key] = value; ((IDictionary)_owner._firstToSecond)[value] = key; } } public ICollection<TSecond> Keys { get { return _owner._secondToFirst.Keys; } } ICollection IDictionary.Keys { get { return ((IDictionary)_owner._secondToFirst).Keys; } } IEnumerable<TSecond> IReadOnlyDictionary<TSecond, TFirst>.Keys { get { return ((IReadOnlyDictionary<TSecond, TFirst>)_owner._secondToFirst).Keys; } } public ICollection<TFirst> Values { get { return _owner._secondToFirst.Values; } } ICollection IDictionary.Values { get { return ((IDictionary)_owner._secondToFirst).Values; } } IEnumerable<TFirst> IReadOnlyDictionary<TSecond, TFirst>.Values { get { return ((IReadOnlyDictionary<TSecond, TFirst>)_owner._secondToFirst).Values; } } public IEnumerator<KeyValuePair<TSecond, TFirst>> GetEnumerator () { return _owner._secondToFirst.GetEnumerator(); } IEnumerator IEnumerable.GetEnumerator () { return GetEnumerator(); } IDictionaryEnumerator IDictionary.GetEnumerator () { return ((IDictionary)_owner._secondToFirst).GetEnumerator(); } public void Add (TSecond key, TFirst value) { _owner._secondToFirst.Add(key, value); _owner._firstToSecond.Add(value, key); } void IDictionary.Add (object key, object value) { ((IDictionary)_owner._secondToFirst).Add(key, value); ((IDictionary)_owner._firstToSecond).Add(value, key); } public void Add (KeyValuePair<TSecond, TFirst> item) { _owner._secondToFirst.Add(item); _owner._firstToSecond.Add(item.Reverse()); } public bool ContainsKey (TSecond key) { return _owner._secondToFirst.ContainsKey(key); } public bool Contains (KeyValuePair<TSecond, TFirst> item) { return _owner._secondToFirst.Contains(item); } public bool TryGetValue (TSecond key, out TFirst value) { return _owner._secondToFirst.TryGetValue(key, out value); } public bool Remove (TSecond key) { TFirst value; if (_owner._secondToFirst.TryGetValue(key, out value)) { _owner._secondToFirst.Remove(key); _owner._firstToSecond.Remove(value); return true; } else return false; } void IDictionary.Remove (object key) { var firstToSecond = (IDictionary)_owner._secondToFirst; if (!firstToSecond.Contains(key)) return; var value = firstToSecond[key]; firstToSecond.Remove(key); ((IDictionary)_owner._firstToSecond).Remove(value); } public bool Remove (KeyValuePair<TSecond, TFirst> item) { return _owner._secondToFirst.Remove(item); } public bool Contains (object key) { return ((IDictionary)_owner._secondToFirst).Contains(key); } public void Clear () { _owner._secondToFirst.Clear(); _owner._firstToSecond.Clear(); } public void CopyTo (KeyValuePair<TSecond, TFirst>[] array, int arrayIndex) { _owner._secondToFirst.CopyTo(array, arrayIndex); } void ICollection.CopyTo (Array array, int index) { ((IDictionary)_owner._secondToFirst).CopyTo(array, index); } } } internal class DictionaryDebugView<TKey, TValue> { private readonly IDictionary<TKey, TValue> _dictionary; [DebuggerBrowsable (DebuggerBrowsableState.RootHidden)] public KeyValuePair<TKey, TValue>[] Items { get { var array = new KeyValuePair<TKey, TValue>[_dictionary.Count]; _dictionary.CopyTo(array, 0); return array; } } public DictionaryDebugView (IDictionary<TKey, TValue> dictionary) { if (dictionary == null) throw new ArgumentNullException("dictionary"); _dictionary = dictionary; } } public static class KeyValuePairExts { public static KeyValuePair<TValue, TKey> Reverse<TKey, TValue> (this KeyValuePair<TKey, TValue> @this) { return new KeyValuePair<TValue, TKey>(@this.Value, @this.Key); } } |
在这个答案中,您提到的问题也显示了一对一的实现。添加removebyfirst和removebysecond是很简单的——实现额外的接口等也是如此。
这和公认的答案是一样的,但我也提供了
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 | public class BiDictionary<TKey1, TKey2> : IEnumerable<Tuple<TKey1, TKey2>> { Dictionary<TKey1, TKey2> _forwards; Dictionary<TKey2, TKey1> _reverses; public int Count { get { if (_forwards.Count != _reverses.Count) throw new Exception("somewhere logic went wrong and your data got corrupt"); return _forwards.Count; } } public ICollection<TKey1> Key1s { get { return _forwards.Keys; } } public ICollection<TKey2> Key2s { get { return _reverses.Keys; } } public BiDictionary(IEqualityComparer<TKey1> comparer1 = null, IEqualityComparer<TKey2> comparer2 = null) { _forwards = new Dictionary<TKey1, TKey2>(comparer1); _reverses = new Dictionary<TKey2, TKey1>(comparer2); } public bool ContainsKey1(TKey1 key) { return ContainsKey(key, _forwards); } private static bool ContainsKey<S, T>(S key, Dictionary<S, T> dict) { return dict.ContainsKey(key); } public bool ContainsKey2(TKey2 key) { return ContainsKey(key, _reverses); } public TKey2 GetValueByKey1(TKey1 key) { return GetValueByKey(key, _forwards); } private static T GetValueByKey<S, T>(S key, Dictionary<S, T> dict) { return dict[key]; } public TKey1 GetValueByKey2(TKey2 key) { return GetValueByKey(key, _reverses); } public bool TryGetValueByKey1(TKey1 key, out TKey2 value) { return TryGetValue(key, _forwards, out value); } private static bool TryGetValue<S, T>(S key, Dictionary<S, T> dict, out T value) { return dict.TryGetValue(key, out value); } public bool TryGetValueByKey2(TKey2 key, out TKey1 value) { return TryGetValue(key, _reverses, out value); } public bool Add(TKey1 key1, TKey2 key2) { if (ContainsKey1(key1) || ContainsKey2(key2)) // very important return false; AddOrUpdate(key1, key2); return true; } public void AddOrUpdateByKey1(TKey1 key1, TKey2 key2) { if (!UpdateByKey1(key1, key2)) AddOrUpdate(key1, key2); } // dont make this public; a dangerous method used cautiously in this class private void AddOrUpdate(TKey1 key1, TKey2 key2) { _forwards[key1] = key2; _reverses[key2] = key1; } public void AddOrUpdateKeyByKey2(TKey2 key2, TKey1 key1) { if (!UpdateByKey2(key2, key1)) AddOrUpdate(key1, key2); } public bool UpdateKey1(TKey1 oldKey, TKey1 newKey) { return UpdateKey(oldKey, _forwards, newKey, (key1, key2) => AddOrUpdate(key1, key2)); } private static bool UpdateKey<S, T>(S oldKey, Dictionary<S, T> dict, S newKey, Action<S, T> updater) { T otherKey; if (!TryGetValue(oldKey, dict, out otherKey) || ContainsKey(newKey, dict)) return false; Remove(oldKey, dict); updater(newKey, otherKey); return true; } public bool UpdateKey2(TKey2 oldKey, TKey2 newKey) { return UpdateKey(oldKey, _reverses, newKey, (key1, key2) => AddOrUpdate(key2, key1)); } public bool UpdateByKey1(TKey1 key1, TKey2 key2) { return UpdateByKey(key1, _forwards, _reverses, key2, (k1, k2) => AddOrUpdate(k1, k2)); } private static bool UpdateByKey<S, T>(S key1, Dictionary<S, T> forwards, Dictionary<T, S> reverses, T key2, Action<S, T> updater) { T otherKey; if (!TryGetValue(key1, forwards, out otherKey) || ContainsKey(key2, reverses)) return false; if (!Remove(otherKey, reverses)) throw new Exception("somewhere logic went wrong and your data got corrupt"); updater(key1, key2); return true; } public bool UpdateByKey2(TKey2 key2, TKey1 key1) { return UpdateByKey(key2, _reverses, _forwards, key1, (k1, k2) => AddOrUpdate(k2, k1)); } public bool RemoveByKey1(TKey1 key) { return RemoveByKey(key, _forwards, _reverses); } private static bool RemoveByKey<S, T>(S key, Dictionary<S, T> keyDict, Dictionary<T, S> valueDict) { T otherKey; if (!TryGetValue(key, keyDict, out otherKey)) return false; if (!Remove(key, keyDict) || !Remove(otherKey, valueDict)) throw new Exception("somewhere logic went wrong and your data got corrupt"); return true; } private static bool Remove<S, T>(S key, Dictionary<S, T> dict) { return dict.Remove(key); } public bool RemoveByKey2(TKey2 key) { return RemoveByKey(key, _reverses, _forwards); } public void Clear() { _forwards.Clear(); _reverses.Clear(); } public IEnumerator<Tuple<TKey1, TKey2>> GetEnumerator() { if (_forwards.Count != _reverses.Count) throw new Exception("somewhere logic went wrong and your data got corrupt"); foreach (var item in _forwards) yield return Tuple.Create(item.Key, item.Value); } IEnumerator IEnumerable.GetEnumerator() { return GetEnumerator(); } } |
和我这里的答案相似
需要注意的几点:
我只执行了
1 |
我曾尝试在这里和那里抛出一些奇怪的异常——只是为了数据完整性。只是为了更安全一点,这样你就知道我的代码是否有错误。
性能:您可以使用
对已接受答案的另一个扩展。它实现IEnumerable,因此可以将foreach与它一起使用。我知道IEnumerable实现有更多的答案,但是这个实现使用结构,所以它是垃圾收集器友好的。这在Unity引擎中尤其有用(使用探查器进行检查)。
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 | /// <summary> /// This is a dictionary guaranteed to have only one of each value and key. /// It may be searched either by TFirst or by TSecond, giving a unique answer because it is 1 to 1. /// It implements garbage-collector-friendly IEnumerable. /// </summary> /// <typeparam name="TFirst">The type of the"key"</typeparam> /// <typeparam name="TSecond">The type of the"value"</typeparam> public class BiDictionary<TFirst, TSecond> : IEnumerable<BiDictionary<TFirst, TSecond>.Pair> { public struct Pair { public TFirst First; public TSecond Second; } public struct Enumerator : IEnumerator<Pair>, IEnumerator { public Enumerator(Dictionary<TFirst, TSecond>.Enumerator dictEnumerator) { _dictEnumerator = dictEnumerator; } public Pair Current { get { Pair pair; pair.First = _dictEnumerator.Current.Key; pair.Second = _dictEnumerator.Current.Value; return pair; } } object IEnumerator.Current { get { return Current; } } public void Dispose() { _dictEnumerator.Dispose(); } public bool MoveNext() { return _dictEnumerator.MoveNext(); } public void Reset() { throw new NotSupportedException(); } private Dictionary<TFirst, TSecond>.Enumerator _dictEnumerator; } #region Exception throwing methods /// <summary> /// Tries to add the pair to the dictionary. /// Throws an exception if either element is already in the dictionary /// </summary> /// <param name="first"></param> /// <param name="second"></param> public void Add(TFirst first, TSecond second) { if (_firstToSecond.ContainsKey(first) || _secondToFirst.ContainsKey(second)) throw new ArgumentException("Duplicate first or second"); _firstToSecond.Add(first, second); _secondToFirst.Add(second, first); } /// <summary> /// Find the TSecond corresponding to the TFirst first /// Throws an exception if first is not in the dictionary. /// </summary> /// <param name="first">the key to search for</param> /// <returns>the value corresponding to first</returns> public TSecond GetByFirst(TFirst first) { TSecond second; if (!_firstToSecond.TryGetValue(first, out second)) throw new ArgumentException("first"); return second; } /// <summary> /// Find the TFirst corresponing to the Second second. /// Throws an exception if second is not in the dictionary. /// </summary> /// <param name="second">the key to search for</param> /// <returns>the value corresponding to second</returns> public TFirst GetBySecond(TSecond second) { TFirst first; if (!_secondToFirst.TryGetValue(second, out first)) throw new ArgumentException("second"); return first; } /// <summary> /// Remove the record containing first. /// If first is not in the dictionary, throws an Exception. /// </summary> /// <param name="first">the key of the record to delete</param> public void RemoveByFirst(TFirst first) { TSecond second; if (!_firstToSecond.TryGetValue(first, out second)) throw new ArgumentException("first"); _firstToSecond.Remove(first); _secondToFirst.Remove(second); } /// <summary> /// Remove the record containing second. /// If second is not in the dictionary, throws an Exception. /// </summary> /// <param name="second">the key of the record to delete</param> public void RemoveBySecond(TSecond second) { TFirst first; if (!_secondToFirst.TryGetValue(second, out first)) throw new ArgumentException("second"); _secondToFirst.Remove(second); _firstToSecond.Remove(first); } #endregion #region Try methods /// <summary> /// Tries to add the pair to the dictionary. /// Returns false if either element is already in the dictionary /// </summary> /// <param name="first"></param> /// <param name="second"></param> /// <returns>true if successfully added, false if either element are already in the dictionary</returns> public bool TryAdd(TFirst first, TSecond second) { if (_firstToSecond.ContainsKey(first) || _secondToFirst.ContainsKey(second)) return false; _firstToSecond.Add(first, second); _secondToFirst.Add(second, first); return true; } /// <summary> /// Find the TSecond corresponding to the TFirst first. /// Returns false if first is not in the dictionary. /// </summary> /// <param name="first">the key to search for</param> /// <param name="second">the corresponding value</param> /// <returns>true if first is in the dictionary, false otherwise</returns> public bool TryGetByFirst(TFirst first, out TSecond second) { return _firstToSecond.TryGetValue(first, out second); } /// <summary> /// Find the TFirst corresponding to the TSecond second. /// Returns false if second is not in the dictionary. /// </summary> /// <param name="second">the key to search for</param> /// <param name="first">the corresponding value</param> /// <returns>true if second is in the dictionary, false otherwise</returns> public bool TryGetBySecond(TSecond second, out TFirst first) { return _secondToFirst.TryGetValue(second, out first); } /// <summary> /// Remove the record containing first, if there is one. /// </summary> /// <param name="first"></param> /// <returns> If first is not in the dictionary, returns false, otherwise true</returns> public bool TryRemoveByFirst(TFirst first) { TSecond second; if (!_firstToSecond.TryGetValue(first, out second)) return false; _firstToSecond.Remove(first); _secondToFirst.Remove(second); return true; } /// <summary> /// Remove the record containing second, if there is one. /// </summary> /// <param name="second"></param> /// <returns> If second is not in the dictionary, returns false, otherwise true</returns> public bool TryRemoveBySecond(TSecond second) { TFirst first; if (!_secondToFirst.TryGetValue(second, out first)) return false; _secondToFirst.Remove(second); _firstToSecond.Remove(first); return true; } #endregion /// <summary> /// The number of pairs stored in the dictionary /// </summary> public Int32 Count { get { return _firstToSecond.Count; } } /// <summary> /// Removes all items from the dictionary. /// </summary> public void Clear() { _firstToSecond.Clear(); _secondToFirst.Clear(); } public Enumerator GetEnumerator() { //enumerator.Reset(firstToSecond.GetEnumerator()); return new Enumerator(_firstToSecond.GetEnumerator()); } IEnumerator<Pair> IEnumerable<Pair>.GetEnumerator() { return GetEnumerator(); } IEnumerator IEnumerable.GetEnumerator() { return GetEnumerator(); } private Dictionary<TFirst, TSecond> _firstToSecond = new Dictionary<TFirst, TSecond>(); private Dictionary<TSecond, TFirst> _secondToFirst = new Dictionary<TSecond, TFirst>(); } |
我使用c5集合类创建了这样一个类。
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 | public class Mapper<K,T> : IEnumerable<T> { C5.TreeDictionary<K,T> KToTMap = new TreeDictionary<K,T>(); C5.HashDictionary<T,K> TToKMap = new HashDictionary<T,K>(); /// <summary> /// Initializes a new instance of the Mapper class. /// </summary> public Mapper() { KToTMap = new TreeDictionary<K,T>(); TToKMap = new HashDictionary<T,K>(); } public void Add(K key, T value) { KToTMap.Add(key, value); TToKMap.Add(value, key); } public bool ContainsKey(K key) { return KToTMap.Contains(key); } public int Count { get { return KToTMap.Count; } } public K this[T obj] { get { return TToKMap[obj]; } } public T this[K obj] { get { return KToTMap[obj]; } } public IEnumerator<T> GetEnumerator() { return KToTMap.Values.GetEnumerator(); } System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator() { return KToTMap.Values.GetEnumerator(); } } |
有点晚了,但这里有一个我前一段时间写的实现。它处理一些有趣的边缘情况,例如当键重写相等检查以执行部分相等时。这导致主字典存储
您可以通过
1 2 3 | var map = new BidirectionalDictionary<int, int>(); map.Add(1, 2); var result = map.Inverse[2]; // result is 1 |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 | // // BidirectionalDictionary.cs // // Author: // Chris Chilvers <[email protected]> // // Copyright (c) 2009 Chris Chilvers // // Permission is hereby granted, free of charge, to any person obtaining // a copy of this software and associated documentation files (the //"Software"), to deal in the Software without restriction, including // without limitation the rights to use, copy, modify, merge, publish, // distribute, sublicense, and/or sell copies of the Software, and to // permit persons to whom the Software is furnished to do so, subject to // the following conditions: // // The above copyright notice and this permission notice shall be // included in all copies or substantial portions of the Software. // // THE SOFTWARE IS PROVIDED"AS IS", WITHOUT WARRANTY OF ANY KIND, // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. // using System; using System.Collections; using System.Collections.Generic; namespace Cadenza.Collections { public class BidirectionalDictionary<TKey, TValue> : IDictionary<TKey, TValue> { private readonly IEqualityComparer<TKey> keyComparer; private readonly IEqualityComparer<TValue> valueComparer; private readonly Dictionary<TKey, TValue> keysToValues; private readonly Dictionary<TValue, TKey> valuesToKeys; private readonly BidirectionalDictionary<TValue, TKey> inverse; public BidirectionalDictionary () : this (10, null, null) {} public BidirectionalDictionary (int capacity) : this (capacity, null, null) {} public BidirectionalDictionary (IEqualityComparer<TKey> keyComparer, IEqualityComparer<TValue> valueComparer) : this (10, keyComparer, valueComparer) { } public BidirectionalDictionary (int capacity, IEqualityComparer<TKey> keyComparer, IEqualityComparer<TValue> valueComparer) { if (capacity < 0) throw new ArgumentOutOfRangeException ("capacity", capacity,"capacity cannot be less than 0"); this.keyComparer = keyComparer ?? EqualityComparer<TKey>.Default; this.valueComparer = valueComparer ?? EqualityComparer<TValue>.Default; keysToValues = new Dictionary<TKey, TValue> (capacity, this.keyComparer); valuesToKeys = new Dictionary<TValue, TKey> (capacity, this.valueComparer); inverse = new BidirectionalDictionary<TValue, TKey> (this); } private BidirectionalDictionary (BidirectionalDictionary<TValue, TKey> inverse) { this.inverse = inverse; keyComparer = inverse.valueComparer; valueComparer = inverse.keyComparer; valuesToKeys = inverse.keysToValues; keysToValues = inverse.valuesToKeys; } public BidirectionalDictionary<TValue, TKey> Inverse { get { return inverse; } } public ICollection<TKey> Keys { get { return keysToValues.Keys; } } public ICollection<TValue> Values { get { return keysToValues.Values; } } public IEnumerator<KeyValuePair<TKey, TValue>> GetEnumerator () { return keysToValues.GetEnumerator (); } IEnumerator IEnumerable.GetEnumerator () { return GetEnumerator (); } void ICollection<KeyValuePair<TKey, TValue>>.CopyTo (KeyValuePair<TKey, TValue>[] array, int arrayIndex) { ((ICollection<KeyValuePair<TKey, TValue>>) keysToValues).CopyTo (array, arrayIndex); } public bool ContainsKey (TKey key) { if (key == null) throw new ArgumentNullException ("key"); return keysToValues.ContainsKey (key); } public bool ContainsValue (TValue value) { if (value == null) throw new ArgumentNullException ("value"); return valuesToKeys.ContainsKey (value); } bool ICollection<KeyValuePair<TKey, TValue>>.Contains (KeyValuePair<TKey, TValue> item) { return ((ICollection<KeyValuePair<TKey, TValue>>) keysToValues).Contains (item); } public bool TryGetKey (TValue value, out TKey key) { if (value == null) throw new ArgumentNullException ("value"); return valuesToKeys.TryGetValue (value, out key); } public bool TryGetValue (TKey key, out TValue value) { if (key == null) throw new ArgumentNullException ("key"); return keysToValues.TryGetValue (key, out value); } public TValue this[TKey key] { get { return keysToValues [key]; } set { if (key == null) throw new ArgumentNullException ("key"); if (value == null) throw new ArgumentNullException ("value"); //foo[5] ="bar"; foo[6] ="bar"; should not be valid //as it would have to remove foo[5], which is unexpected. if (ValueBelongsToOtherKey (key, value)) throw new ArgumentException ("Value already exists","value"); TValue oldValue; if (keysToValues.TryGetValue (key, out oldValue)) { // Use the current key for this value to stay consistent // with Dictionary<TKey, TValue> which does not alter // the key if it exists. TKey oldKey = valuesToKeys [oldValue]; keysToValues [oldKey] = value; valuesToKeys.Remove (oldValue); valuesToKeys [value] = oldKey; } else { keysToValues [key] = value; valuesToKeys [value] = key; } } } public int Count { get { return keysToValues.Count; } } bool ICollection<KeyValuePair<TKey, TValue>>.IsReadOnly { get { return false; } } public void Add (TKey key, TValue value) { if (key == null) throw new ArgumentNullException ("key"); if (value == null) throw new ArgumentNullException ("value"); if (keysToValues.ContainsKey (key)) throw new ArgumentException ("Key already exists","key"); if (valuesToKeys.ContainsKey (value)) throw new ArgumentException ("Value already exists","value"); keysToValues.Add (key, value); valuesToKeys.Add (value, key); } public void Replace (TKey key, TValue value) { if (key == null) throw new ArgumentNullException ("key"); if (value == null) throw new ArgumentNullException ("value"); // replaces a key value pair, if the key or value already exists those mappings will be replaced. // e.g. you have; a -> b, b -> a; c -> d, d -> c // you add the mapping; a -> d, d -> a // this will remove both of the original mappings Remove (key); inverse.Remove (value); Add (key, value); } void ICollection<KeyValuePair<TKey, TValue>>.Add (KeyValuePair<TKey, TValue> item) { Add (item.Key, item.Value); } public bool Remove (TKey key) { if (key == null) throw new ArgumentNullException ("key"); TValue value; if (keysToValues.TryGetValue (key, out value)) { keysToValues.Remove (key); valuesToKeys.Remove (value); return true; } else { return false; } } bool ICollection<KeyValuePair<TKey, TValue>>.Remove (KeyValuePair<TKey, TValue> item) { bool removed = ((ICollection<KeyValuePair<TKey, TValue>>) keysToValues).Remove (item); if (removed) valuesToKeys.Remove (item.Value); return removed; } public void Clear () { keysToValues.Clear (); valuesToKeys.Clear (); } private bool ValueBelongsToOtherKey (TKey key, TValue value) { TKey otherKey; if (valuesToKeys.TryGetValue (value, out otherKey)) // if the keys are not equal the value belongs to another key return !keyComparer.Equals (key, otherKey); else // value doesn't exist in map, thus it cannot belong to another key return false; } } } |
GitHub上的原始源和测试。