添加基础枚举扩展

Runtime/MicroLibrary/MacroList.cs

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+using System;
+using System.Collections;
+using System.Collections.Concurrent;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading;
+
+using UnityEngine;
+
+namespace XericLibrary.Runtime.MacroLibrary
+{
+	public static partial class MacroMath
+	{
+		#region 洗牌算法
+
+		/// <summary>
+		/// Fisher-Yates洗牌算法，时间复杂度为O(n*n),空间复杂度为O(n)
+		/// </summary>
+		/// <param name="length">待选项目的索引长度</param>
+		/// <param name="select">输出项目的索引长度</param>
+		/// <returns></returns>
+		public static List<int> FisherYatesShuffle(int length, int select)
+		{
+			var random = new System.Random();
+
+			List<int> arr = Enumerable.Range(1, length).ToList();
+			List<int> res = new List<int>();
+
+			for(int i = 0; i < select; ++i)
+			{
+				int k = random.Next(arr.Count);
+				res.Add(arr[k]);
+				arr.RemoveAt(k);
+			}
+
+			return res;
+		}
+
+		/// <summary>
+		/// 蓄水池抽样算法，可以在线程安全的情况下完成洗牌。
+		/// </summary>
+		/// <param name="arr"></param>
+		/// <param name="select">需要抽取的样本 M</param>
+		/// <param name="reservoir"></param>
+		/// <param name="cancellationToken"></param>
+		public static void ReservoirSampling(List<int> arr, int select, ConcurrentBag<int> reservoir, CancellationToken cancellationToken)
+		{
+			/**
+			 * int M = 3; // 需要抽样的元素个数
+			 * int totalElements = 10; // 输入数据的总元素个数
+			 * var arr = new List<int>();
+			 * 
+			 * for (int i = 1; i <= totalElements; i++)
+			 * {
+			 *	arr.Add(i);
+			 * }
+			 * 
+			 * ConcurrentBag<int> reservoir = new ConcurrentBag<int>();
+			 * Random random = new Random();
+			 * 
+			 * var cancellationTokenSource = new CancellationTokenSource();
+			 * var cancellationToken = cancellationTokenSource.Token;
+			 * 
+			 * ThreadPool.QueueUserWorkItem(state =>
+			 * 	ReservoirSampling(arr, M, reservoir, random, cancellationToken);
+			 * , null);
+			 * 
+			 * // 停止抽样
+			 * cancellationTokenSource.Cancel();
+			 */
+			var random = new System.Random();
+
+			for(int i = select; i < arr.Count; ++i)
+			{
+				if(cancellationToken.IsCancellationRequested)
+					return;
+
+				int k = random.Next(i + 1); // 生成一个随机数 k，范围是 [0, i]
+				if(k < select)
+				{
+					// 如果 k 小于 M，将 arr[k] 添加到抽样结果中
+					reservoir.Add(arr[k]);
+				}
+			}
+		}
+
+		#endregion
+	}
+}