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| 1 | +using System; |
| 2 | +using System.Collections.Generic; |
| 3 | +using System.Linq; |
| 4 | + |
| 5 | +namespace MotifSeeker2.Helpers |
| 6 | +{ |
| 7 | + /// <summary> |
| 8 | + /// Коллекция расширений над коллекциями. |
| 9 | + /// </summary> |
| 10 | + public static class LinqExt |
| 11 | + { |
| 12 | + #region firstWhere |
| 13 | + public static T FirstWhereMax<T>(this IEnumerable<T> lst, Func<T, int> f) |
| 14 | + { |
| 15 | + var data = default(T); |
| 16 | + var val = 0; |
| 17 | + var get = false; |
| 18 | + foreach (var item in lst) |
| 19 | + { |
| 20 | + var v = f(item); |
| 21 | + if (v <= val && get) continue; |
| 22 | + get = true; |
| 23 | + val = v; |
| 24 | + data = item; |
| 25 | + } |
| 26 | + if(!get) |
| 27 | + throw new Exception("Коллекция пуста"); |
| 28 | + return data; |
| 29 | + } |
| 30 | + |
| 31 | + public static T FirstWhereMaxOrDefault<T>(this IEnumerable<T> lst, Func<T, int> f) |
| 32 | + { |
| 33 | + var data = default(T); |
| 34 | + if (lst == null) |
| 35 | + return data; |
| 36 | + var val = 0; |
| 37 | + var get = false; |
| 38 | + foreach (var item in lst) |
| 39 | + { |
| 40 | + var v = f(item); |
| 41 | + if (v <= val && get) continue; |
| 42 | + get = true; |
| 43 | + val = v; |
| 44 | + data = item; |
| 45 | + } |
| 46 | + return data; |
| 47 | + } |
| 48 | + |
| 49 | + public static T FirstWhereMax<T,TV>(this IEnumerable<T> lst, Func<T, TV> f) where TV: IComparable |
| 50 | + { |
| 51 | + var data = default(T); |
| 52 | + var val = default(TV); |
| 53 | + var get = false; |
| 54 | + foreach (var item in lst) |
| 55 | + { |
| 56 | + var v = f(item); |
| 57 | + if (v.CompareTo(val) <= 0 && get) continue; |
| 58 | + get = true; |
| 59 | + val = v; |
| 60 | + data = item; |
| 61 | + } |
| 62 | + if (!get) |
| 63 | + throw new Exception("Коллекция пуста"); |
| 64 | + return data; |
| 65 | + } |
| 66 | + |
| 67 | + public static T FirstWhereMaxOrDefault<T, TV>(this IEnumerable<T> lst, Func<T, TV> f) where TV : IComparable |
| 68 | + { |
| 69 | + var data = default(T); |
| 70 | + if (lst == null) |
| 71 | + return data; |
| 72 | + var val = default(TV); |
| 73 | + var get = false; |
| 74 | + foreach (var item in lst) |
| 75 | + { |
| 76 | + var v = f(item); |
| 77 | + if (v.CompareTo(val) <= 0 && get) continue; |
| 78 | + get = true; |
| 79 | + val = v; |
| 80 | + data = item; |
| 81 | + } |
| 82 | + return data; |
| 83 | + } |
| 84 | + |
| 85 | + public static T FirstWhereMin<T>(this IEnumerable<T> lst, Func<T, int> f) |
| 86 | + { |
| 87 | + var data = default(T); |
| 88 | + var val = 0; |
| 89 | + var get = false; |
| 90 | + foreach (var item in lst) |
| 91 | + { |
| 92 | + var v = f(item); |
| 93 | + if (v >= val && get) continue; |
| 94 | + get = true; |
| 95 | + val = v; |
| 96 | + data = item; |
| 97 | + } |
| 98 | + if (!get) |
| 99 | + throw new Exception("Коллекция пуста"); |
| 100 | + return data; |
| 101 | + } |
| 102 | + |
| 103 | + public static T FirstWhereMinOrDefault<T>(this IEnumerable<T> lst, Func<T, int> f) |
| 104 | + { |
| 105 | + var data = default(T); |
| 106 | + if (lst == null) |
| 107 | + return data; |
| 108 | + var val = 0; |
| 109 | + var get = false; |
| 110 | + foreach (var item in lst) |
| 111 | + { |
| 112 | + var v = f(item); |
| 113 | + if (v >= val && get) continue; |
| 114 | + get = true; |
| 115 | + val = v; |
| 116 | + data = item; |
| 117 | + } |
| 118 | + return data; |
| 119 | + } |
| 120 | + |
| 121 | + public static T FirstWhereMin<T,TV>(this IEnumerable<T> lst, Func<T, TV> f) where TV: IComparable |
| 122 | + { |
| 123 | + var data = default(T); |
| 124 | + var val = default(TV); |
| 125 | + var get = false; |
| 126 | + foreach (var item in lst) |
| 127 | + { |
| 128 | + var v = f(item); |
| 129 | + if (v.CompareTo(val) < 0 || !get) |
| 130 | + { |
| 131 | + get = true; |
| 132 | + val = v; |
| 133 | + data = item; |
| 134 | + } |
| 135 | + } |
| 136 | + if (!get) |
| 137 | + throw new Exception("Коллекция пуста"); |
| 138 | + return data; |
| 139 | + } |
| 140 | + |
| 141 | + public static T FirstWhereMinOrDefault<T, TV>(this IEnumerable<T> lst, Func<T, TV> f) where TV : IComparable |
| 142 | + { |
| 143 | + var data = default(T); |
| 144 | + if (lst == null) |
| 145 | + return data; |
| 146 | + var val = default(TV); |
| 147 | + var get = false; |
| 148 | + foreach (var item in lst) |
| 149 | + { |
| 150 | + var v = f(item); |
| 151 | + if (v.CompareTo(val) < 0 || !get) |
| 152 | + { |
| 153 | + get = true; |
| 154 | + val = v; |
| 155 | + data = item; |
| 156 | + } |
| 157 | + } |
| 158 | + return data; |
| 159 | + } |
| 160 | + #endregion firstWhere |
| 161 | + |
| 162 | + public static int FirstIndexWhereMin<T, TV>(this T[] lst, Func<T, TV> f) where TV : IComparable |
| 163 | + { |
| 164 | + TV val = default(TV); |
| 165 | + bool get = false; |
| 166 | + int id = 0; |
| 167 | + for (int i = 0; i < lst.Length; i++) |
| 168 | + { |
| 169 | + var item = lst[i]; |
| 170 | + var v = f(item); |
| 171 | + if (v.CompareTo(val) < 0 || !get) |
| 172 | + { |
| 173 | + get = true; |
| 174 | + val = v; |
| 175 | + id = i; |
| 176 | + } |
| 177 | + } |
| 178 | + if (!get) |
| 179 | + throw new Exception("Коллекция пуста"); |
| 180 | + return id; |
| 181 | + } |
| 182 | + |
| 183 | + #region enumerate |
| 184 | + public static IEnumerable<List<T>> EnumerateByPacks<T>(this IEnumerable<T> data, int packSize) |
| 185 | + { |
| 186 | + var pack = new List<T>(packSize); |
| 187 | + foreach(var t in data) |
| 188 | + { |
| 189 | + pack.Add(t); |
| 190 | + if(pack.Count == packSize) |
| 191 | + { |
| 192 | + yield return pack; |
| 193 | + pack = new List<T>(packSize); |
| 194 | + } |
| 195 | + } |
| 196 | + if (pack.Count != 0) |
| 197 | + yield return pack; |
| 198 | + } |
| 199 | + |
| 200 | + /// <summary> |
| 201 | + /// Разбивает последовательность на пачки. Чётные содержат packSizeEven элементов, нечётные - packSizeOdd. |
| 202 | + /// Нулевая пачка - чётная. Размер последней пачки неопределён. |
| 203 | + /// </summary> |
| 204 | + public static IEnumerable<List<T>> EnumerateByPacks<T>(this IEnumerable<T> data, int packSizeEven, int packSizeOdd) |
| 205 | + { |
| 206 | + bool even = true; |
| 207 | + int curPackSize = packSizeEven; |
| 208 | + var pack = new List<T>(curPackSize); |
| 209 | + foreach (var t in data) |
| 210 | + { |
| 211 | + pack.Add(t); |
| 212 | + if (pack.Count == curPackSize) |
| 213 | + { |
| 214 | + yield return pack; |
| 215 | + even = !even; |
| 216 | + curPackSize = even ? packSizeEven : packSizeOdd; |
| 217 | + pack = new List<T>(curPackSize); |
| 218 | + } |
| 219 | + } |
| 220 | + if (pack.Count != 0) |
| 221 | + yield return pack; |
| 222 | + } |
| 223 | + |
| 224 | + public static IEnumerable<T[]> EnumerateGroups<T>(this IEnumerable<IEnumerable<T>> flows) |
| 225 | + { |
| 226 | + var data = flows.Select(p => p.GetEnumerator()).ToList(); |
| 227 | + while(true) |
| 228 | + { |
| 229 | + var ret = new T[data.Count]; |
| 230 | + bool rem = false; |
| 231 | + for(int i=0;i<ret.Length;i++) |
| 232 | + { |
| 233 | + if(data[i] == null) |
| 234 | + continue; |
| 235 | + if (data[i].MoveNext()) |
| 236 | + { |
| 237 | + ret[i] = data[i].Current; |
| 238 | + } |
| 239 | + else |
| 240 | + { |
| 241 | + data[i] = null; |
| 242 | + rem = true; |
| 243 | + } |
| 244 | + } |
| 245 | + if (rem) |
| 246 | + data.RemoveAll(p => p == null); |
| 247 | + if(data.Count == 0) |
| 248 | + yield break; |
| 249 | + yield return ret; |
| 250 | + } |
| 251 | + } |
| 252 | + #endregion enumerate |
| 253 | + |
| 254 | + /// <summary> |
| 255 | + /// Расщепляет поток на два списка. |
| 256 | + /// Увы, ленивым его не сделать. |
| 257 | + /// [ToDo] реализовать ленивый вариант. :) |
| 258 | + /// </summary> |
| 259 | + /// <typeparam name="T"></typeparam> |
| 260 | + /// <param name="flow">Конечный поток данных.</param> |
| 261 | + /// <param name="pred">Условие. Если верно, то в первый список. Если нет - то во второй.</param> |
| 262 | + public static Tuple<List<T>, List<T>> Split<T>(this IEnumerable<T> flow, Predicate<T> pred) |
| 263 | + { |
| 264 | + var tmp1 = new List<T>(); |
| 265 | + var tmp2 = new List<T>(); |
| 266 | + foreach(var f in flow) |
| 267 | + if(pred(f)) |
| 268 | + tmp1.Add(f); |
| 269 | + else |
| 270 | + tmp2.Add(f); |
| 271 | + |
| 272 | + return new Tuple<List<T>, List<T>>(tmp1, tmp2); |
| 273 | + } |
| 274 | + |
| 275 | + #region deNullable |
| 276 | + public static IEnumerable<T> DeNullabe<T>(this IEnumerable<T?> flow) where T: struct |
| 277 | + { |
| 278 | + if (flow == null) |
| 279 | + yield break; |
| 280 | + foreach (var t in flow) |
| 281 | + if (t.HasValue) |
| 282 | + yield return t.Value; |
| 283 | + } |
| 284 | + |
| 285 | + public static IEnumerable<TV> DeNullabe<T,TV>(this IEnumerable<T> flow, Func<T, TV?> f) where TV : struct |
| 286 | + { |
| 287 | + if (flow == null) |
| 288 | + yield break; |
| 289 | + foreach (var t in flow) |
| 290 | + { |
| 291 | + var v = f(t); |
| 292 | + if (v.HasValue) |
| 293 | + yield return v.Value; |
| 294 | + } |
| 295 | + } |
| 296 | + #endregion deNullable |
| 297 | + |
| 298 | + public static void ForEach<T>(this IEnumerable<T> c, Action<T> action) |
| 299 | + { |
| 300 | + if (c == null || action == null) |
| 301 | + return; |
| 302 | + |
| 303 | + foreach (T obj in c) |
| 304 | + action(obj); |
| 305 | + } |
| 306 | + |
| 307 | + public static IEnumerable<T> Prepare<T>(this IEnumerable<T> c, Action<T> action) |
| 308 | + { |
| 309 | + if (c == null) |
| 310 | + yield break; |
| 311 | + |
| 312 | + foreach (T obj in c) |
| 313 | + { |
| 314 | + if (action != null) |
| 315 | + action(obj); |
| 316 | + |
| 317 | + yield return obj; |
| 318 | + } |
| 319 | + } |
| 320 | + |
| 321 | + public static TValue TryGetValue<TKey, TValue>(this IDictionary<TKey, TValue> dictionary, TKey key) |
| 322 | + { |
| 323 | + TValue value; |
| 324 | + return dictionary.TryGetValue(key, out value) ? value : default(TValue); |
| 325 | + } |
| 326 | + |
| 327 | + public static Queue<T> ToQueue<T>(this IEnumerable<T> flow) |
| 328 | + { |
| 329 | + var ret = new Queue<T>(); |
| 330 | + flow.ForEach(ret.Enqueue); |
| 331 | + return ret; |
| 332 | + } |
| 333 | + |
| 334 | + public static Stack<T> ToStack<T>(this IEnumerable<T> flow) |
| 335 | + { |
| 336 | + return new Stack<T>(flow); |
| 337 | + } |
| 338 | + |
| 339 | + //public static SortedQueue<TK,TV> ToSortedQueue<TK,TV>(this IEnumerable<TV> flow, Func<TV,TK> f) |
| 340 | + //{ |
| 341 | + // var ret = new SortedQueue<TK, TV>(f); |
| 342 | + // flow.ForEach(ret.EnQueue); |
| 343 | + // return ret; |
| 344 | + //} |
| 345 | + |
| 346 | + public static double Prod(this IEnumerable<double> flow) |
| 347 | + { |
| 348 | + return flow.Aggregate(1.0, (current, f) => current * f); |
| 349 | + } |
| 350 | + } |
| 351 | +} |
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