| | 1 | | namespace Towel.DataStructures; |
| | 2 | |
|
| | 3 | | /// <summary>Implements a First-In-Last-Out stack data structure.</summary> |
| | 4 | | /// <typeparam name="T">The generic type within the structure.</typeparam> |
| | 5 | | public interface IStack<T> : IDataStructure<T>, |
| | 6 | | DataStructure.ICountable, |
| | 7 | | DataStructure.IClearable |
| | 8 | | { |
| | 9 | | #region Methods |
| | 10 | |
|
| | 11 | | /// <summary>Adds an item to the top of the stack.</summary> |
| | 12 | | /// <param name="push">The item to add to the stack.</param> |
| | 13 | | void Push(T push); |
| | 14 | | /// <summary>Returns the most recent addition to the stack.</summary> |
| | 15 | | /// <returns>The most recent addition to the stack.</returns> |
| | 16 | | T Peek(); |
| | 17 | | /// <summary>Removes and returns the most recent addition to the stack.</summary> |
| | 18 | | /// <returns>The most recent addition to the stack.</returns> |
| | 19 | | T Pop(); |
| | 20 | |
|
| | 21 | | #endregion |
| | 22 | | } |
| | 23 | |
|
| | 24 | | /// <summary>Implements a First-In-Last-Out stack data structure using a linked list.</summary> |
| | 25 | | /// <typeparam name="T">The generic type within the structure.</typeparam> |
| | 26 | | public class StackLinked<T> : IStack<T>, ICloneable<StackLinked<T>> |
| | 27 | | { |
| | 28 | | internal Node? _top; |
| | 29 | | internal int _count; |
| | 30 | |
|
| | 31 | | #region Nested Types |
| | 32 | |
|
| | 33 | | internal class Node |
| | 34 | | { |
| | 35 | | internal T Value; |
| | 36 | | internal Node? Down; |
| | 37 | |
|
| 20129 | 38 | | internal Node(T value, Node? down = null) |
| 20129 | 39 | | { |
| 20129 | 40 | | Value = value; |
| 20129 | 41 | | Down = down; |
| 20129 | 42 | | } |
| | 43 | | } |
| | 44 | |
|
| | 45 | | #endregion |
| | 46 | |
|
| | 47 | | #region Constructors |
| | 48 | |
|
| | 49 | | /// <summary>Constructs a new stack.</summary> |
| 12 | 50 | | public StackLinked() |
| 12 | 51 | | { |
| 12 | 52 | | _top = null; |
| 12 | 53 | | _count = 0; |
| 12 | 54 | | } |
| | 55 | |
|
| | 56 | | /// <summary>This constructor is for cloning purposes.</summary> |
| | 57 | | /// <param name="stack">The stack to clone.</param> |
| 0 | 58 | | internal StackLinked(StackLinked<T> stack) |
| 0 | 59 | | { |
| 0 | 60 | | if (stack._top is not null) |
| 0 | 61 | | { |
| 0 | 62 | | _top = new Node(value: stack._top.Value); |
| 0 | 63 | | Node? a = stack._top.Down; |
| 0 | 64 | | Node? b = _top; |
| 0 | 65 | | while (a is not null) |
| 0 | 66 | | { |
| 0 | 67 | | b.Down = new Node(value: a.Value); |
| 0 | 68 | | b = b.Down; |
| 0 | 69 | | a = a.Down; |
| 0 | 70 | | } |
| 0 | 71 | | _count = stack._count; |
| 0 | 72 | | } |
| 0 | 73 | | } |
| | 74 | |
|
| | 75 | | #endregion |
| | 76 | |
|
| | 77 | | #region Properties |
| | 78 | |
|
| | 79 | | /// <inheritdoc/> |
| 5 | 80 | | public int Count => _count; |
| | 81 | |
|
| | 82 | | #endregion |
| | 83 | |
|
| | 84 | | #region Methods |
| | 85 | |
|
| | 86 | | /// <inheritdoc/> |
| 0 | 87 | | public StackLinked<T> Clone() => new(this); |
| | 88 | |
|
| | 89 | | /// <inheritdoc/> |
| | 90 | | public T[] ToArray() |
| 0 | 91 | | { |
| 0 | 92 | | if (_count is 0) |
| 0 | 93 | | { |
| 0 | 94 | | return Array.Empty<T>(); |
| | 95 | | } |
| 0 | 96 | | T[] array = new T[_count]; |
| 0 | 97 | | for (var (i, node) = (0, _top); node is not null; node = node.Down, i++) |
| 0 | 98 | | { |
| 0 | 99 | | array[i] = node.Value; |
| 0 | 100 | | } |
| 0 | 101 | | return array; |
| 0 | 102 | | } |
| | 103 | |
|
| | 104 | | /// <inheritdoc/> |
| | 105 | | public void Push(T addition) |
| 20129 | 106 | | { |
| 20129 | 107 | | _top = new Node(value: addition, down: _top); |
| 20129 | 108 | | _count++; |
| 20129 | 109 | | } |
| | 110 | |
|
| | 111 | | /// <inheritdoc/> |
| | 112 | | public T Peek() |
| 0 | 113 | | { |
| 0 | 114 | | if (_top is null) |
| 0 | 115 | | { |
| 0 | 116 | | throw new InvalidOperationException("Attempting to remove from an empty queue."); |
| | 117 | | } |
| 0 | 118 | | T peek = _top.Value; |
| 0 | 119 | | return peek; |
| 0 | 120 | | } |
| | 121 | |
|
| | 122 | | /// <inheritdoc/> |
| | 123 | | public T Pop() |
| 20099 | 124 | | { |
| 20099 | 125 | | if (_count is 0) |
| 2 | 126 | | { |
| 2 | 127 | | throw new InvalidOperationException("attempting to pop from an empty stack."); |
| | 128 | | } |
| 20097 | 129 | | if (_top is null) |
| 0 | 130 | | { |
| 0 | 131 | | throw new TowelBugException($"{nameof(Count)} is greater than 0 but {nameof(_top)} is null"); |
| | 132 | | } |
| 20097 | 133 | | T pop = _top.Value; |
| 20097 | 134 | | _top = _top.Down; |
| 20097 | 135 | | _count--; |
| 20097 | 136 | | return pop; |
| 20097 | 137 | | } |
| | 138 | |
|
| | 139 | | /// <inheritdoc/> |
| | 140 | | public void Clear() |
| 0 | 141 | | { |
| 0 | 142 | | _top = null; |
| 0 | 143 | | _count = 0; |
| 0 | 144 | | } |
| | 145 | |
|
| | 146 | | /// <inheritdoc/> |
| | 147 | | public StepStatus StepperBreak<TStep>(TStep step = default) |
| | 148 | | where TStep : struct, IFunc<T, StepStatus> |
| 3 | 149 | | { |
| 38 | 150 | | for (Node? node = _top; node is not null; node = node.Down) |
| 16 | 151 | | { |
| 16 | 152 | | if (step.Invoke(node.Value) is Break) |
| 0 | 153 | | { |
| 0 | 154 | | return Break; |
| | 155 | | } |
| 16 | 156 | | } |
| 3 | 157 | | return Continue; |
| 3 | 158 | | } |
| | 159 | |
|
| 0 | 160 | | System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator() => GetEnumerator(); |
| | 161 | |
|
| | 162 | | /// <inheritdoc/> |
| | 163 | | public System.Collections.Generic.IEnumerator<T> GetEnumerator() |
| 6 | 164 | | { |
| 76 | 165 | | for (Node? node = _top; node is not null; node = node.Down) |
| 32 | 166 | | { |
| 32 | 167 | | yield return node.Value; |
| 32 | 168 | | } |
| 6 | 169 | | } |
| | 170 | |
|
| | 171 | | #endregion |
| | 172 | | } |
| | 173 | |
|
| | 174 | | /// <summary>Implements a First-In-Last-Out stack data structure using an array.</summary> |
| | 175 | | /// <typeparam name="T">The generic type within the structure.</typeparam> |
| | 176 | | public class StackArray<T> : IStack<T>, ICloneable<StackArray<T>> |
| | 177 | | { |
| | 178 | | internal const int DefaultMinimumCapacity = 1; |
| | 179 | |
|
| | 180 | | internal T[] _array; |
| | 181 | | internal int _count; |
| | 182 | | internal int? _minimumCapacity; |
| | 183 | |
|
| | 184 | | #region Constructors |
| | 185 | |
|
| | 186 | | /// <summary>Constructs a new stack.</summary> |
| | 187 | | public StackArray() |
| | 188 | | { |
| | 189 | | _array = new T[DefaultMinimumCapacity]; |
| | 190 | | _count = 0; |
| | 191 | | } |
| | 192 | |
|
| | 193 | | /// <summary>Constructs a new stack.</summary> |
| | 194 | | /// <param name="minimumCapacity">The minimum capacity of the stack.</param> |
| | 195 | | public StackArray(int minimumCapacity) |
| | 196 | | { |
| | 197 | | if (minimumCapacity <= 0) |
| | 198 | | { |
| | 199 | | throw new ArgumentOutOfRangeException(nameof(minimumCapacity), minimumCapacity, $"{nameof(minimumCapacity)} <= 0") |
| | 200 | | } |
| | 201 | | _array = new T[minimumCapacity]; |
| | 202 | | _count = 0; |
| | 203 | | _minimumCapacity = minimumCapacity; |
| | 204 | | } |
| | 205 | |
|
| | 206 | | internal StackArray(T[] array, int count, int? minimumCapacity) |
| | 207 | | { |
| | 208 | | _array = array; |
| | 209 | | _count = count; |
| | 210 | | _minimumCapacity = minimumCapacity; |
| | 211 | | } |
| | 212 | |
|
| | 213 | | /// <summary>This constructor is for cloning purposes.</summary> |
| | 214 | | /// <param name="stack">The stack to clone.</param> |
| | 215 | | internal StackArray(StackArray<T> stack) |
| | 216 | | { |
| | 217 | | _array = (T[])stack._array.Clone(); |
| | 218 | | _count = stack._count; |
| | 219 | | _minimumCapacity = stack._minimumCapacity; |
| | 220 | | } |
| | 221 | |
|
| | 222 | | #endregion |
| | 223 | |
|
| | 224 | | #region Properties |
| | 225 | |
|
| | 226 | | /// <summary>Gets the current capacity of the list.</summary> |
| | 227 | | public int CurrentCapacity => _array.Length; |
| | 228 | |
|
| | 229 | | /// <summary>Allows you to adjust the minimum capacity of this list.</summary> |
| | 230 | | public int? MinimumCapacity |
| | 231 | | { |
| | 232 | | get => _minimumCapacity; |
| | 233 | | set |
| | 234 | | { |
| | 235 | | if (!value.HasValue) |
| | 236 | | { |
| | 237 | | _minimumCapacity = value; |
| | 238 | | } |
| | 239 | | else if (value < 1) |
| | 240 | | { |
| | 241 | | throw new InvalidOperationException("Attempting to set a minimum capacity to a negative or zero value."); |
| | 242 | | } |
| | 243 | | else if (value > _array.Length) |
| | 244 | | { |
| | 245 | | Array.Resize<T>(ref _array, value.Value); |
| | 246 | | } |
| | 247 | | _minimumCapacity = value; |
| | 248 | | } |
| | 249 | | } |
| | 250 | |
|
| | 251 | | /// <inheritdoc/> |
| | 252 | | public int Count => _count; |
| | 253 | |
|
| | 254 | | #endregion |
| | 255 | |
|
| | 256 | | #region Methods |
| | 257 | |
|
| | 258 | | /// <inheritdoc/> |
| | 259 | | public StackArray<T> Clone() => new(this); |
| | 260 | |
|
| | 261 | | /// <inheritdoc/> |
| | 262 | | public T[] ToArray() => _count is 0 ? Array.Empty<T>() : _array[.._count]; |
| | 263 | |
|
| | 264 | | /// <inheritdoc/> |
| | 265 | | public void Push(T addition) |
| | 266 | | { |
| | 267 | | if (_count == _array.Length) |
| | 268 | | { |
| | 269 | | if (_array.Length > int.MaxValue / 2) |
| | 270 | | { |
| | 271 | | throw new InvalidOperationException("your queue is so large that it can no longer double itself (Int32.MaxValue |
| | 272 | | } |
| | 273 | | Array.Resize<T>(ref _array, _array.Length * 2); |
| | 274 | | } |
| | 275 | | _array[_count++] = addition; |
| | 276 | | } |
| | 277 | |
|
| | 278 | | /// <inheritdoc/> |
| | 279 | | public T Pop() |
| | 280 | | { |
| | 281 | | if (_count is 0) |
| | 282 | | { |
| | 283 | | throw new InvalidOperationException("attempting to pop from an empty stack."); |
| | 284 | | } |
| | 285 | | if (_count < _array.Length / 4 && _array.Length / 2 > _minimumCapacity) |
| | 286 | | { |
| | 287 | | Array.Resize<T>(ref _array, _array.Length / 2); |
| | 288 | | } |
| | 289 | | T returnValue = _array[--_count]; |
| | 290 | | return returnValue; |
| | 291 | | } |
| | 292 | |
|
| | 293 | | /// <inheritdoc/> |
| | 294 | | public T Peek() => _array[_count - 1]; |
| | 295 | |
|
| | 296 | | /// <inheritdoc/> |
| | 297 | | public void Clear() |
| | 298 | | { |
| | 299 | | _array = new T[_minimumCapacity ?? DefaultMinimumCapacity]; |
| | 300 | | _count = 0; |
| | 301 | | } |
| | 302 | |
|
| | 303 | | /// <inheritdoc/> |
| | 304 | | public StepStatus StepperBreak<TStep>(TStep step = default) |
| | 305 | | where TStep : struct, IFunc<T, StepStatus> => |
| | 306 | | _array.StepperBreak(0, _count, step); |
| | 307 | |
|
| | 308 | | System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator() => GetEnumerator(); |
| | 309 | |
|
| | 310 | | /// <inheritdoc/> |
| | 311 | | public System.Collections.Generic.IEnumerator<T> GetEnumerator() |
| | 312 | | { |
| | 313 | | for (int i = 0; i < _count; i++) |
| | 314 | | { |
| | 315 | | yield return _array[i]; |
| | 316 | | } |
| | 317 | | } |
| | 318 | |
|
| | 319 | | #endregion |
| | 320 | | } |