C#实现微信红包功能

class Program  {    static void Main(string[] args)    {      //初始化要发起的红包基础数据      double total = 100;      int num = 50;      double min = 0.01;      string temp;      bool flag = false;      Console.WriteLine(string.Format("是否需要自定义红包金额和数量（默认{0}元/{1}人）Y/N：", total, num));      temp = Console.ReadLine();      if (temp.Trim().ToLower().Equals("y") || temp.Trim().ToLower().Equals("yes"))      {        Console.WriteLine("请输入你要发起的红包金额：");        do        {          temp = Console.ReadLine();          flag = double.TryParse(temp, out total);          if (!flag)          {            Console.WriteLine("金额必须为整数或小数，请重新输入：");          }        } while (!flag);        Console.WriteLine("请输入你要发起的红包个数：");        do        {          temp = Console.ReadLine();          flag = int.TryParse(temp, out num);          if (!flag)          {            Console.WriteLine("红包个数必须为整数，请重新输入：");          }        } while (!flag);      }      total -= min * num;      if (total < 0)      {        Console.WriteLine("抱歉，你的金额不足！");        return;      }      //产生正态分布的随机红包金额，并计算相关的金额和数量保证数据的准确性      double average = total / num;      double variance = 1;      Random u1 = new Random();      Random u2 = new Random();      double[] nums = new double[num];      for (int i = 0; i < num; i++)      {        double? result = total;        if (i < num - 1 && total > 0)        {          do          {            result = Round((double)Normal(u1.NextDouble(), u2.NextDouble(), average, variance), 2);          } while (result == null || result < 0);          if (total > result)          {            total = (double)Round((total - (double)result), 2);          }          else          {            result = total;            total = 0;          }        }        else if (i == num - 1)        {          total = 0;        }        nums[i] = Math.Round(min + (double)result, 2); //浮点运算问题，这里需要四舍五入数据才正确        Console.WriteLine(string.Format("第{0}个红包金额：{1}", i + 1, (min + result)));        Console.WriteLine("剩余金额：" + ((i != num - 1 && total == 0) ? min * (num - i - 1) : total + (min * (num - i - 1))));      }      Console.WriteLine("最大金额：" + nums.Max());      Console.WriteLine("最小金额：" + nums.Min());      Console.WriteLine("总额：" + Round(nums.Sum(), 2));      Console.WriteLine("初始方差：" + variance);      Console.WriteLine("结果方差：" + Variance(nums));      Console.WriteLine("按任意键退出！");      Console.ReadKey();    }    /// <summary>    /// 产生符合正态分布的随机数    /// </summary>    /// <param name="u1">正态分布第一个随机数</param>    /// <param name="u2">正态分布第二个随机数</param>    /// <param name="averageValue">正态期望(平均值)</param>    /// <param name="variance">正态标准差(Math.Sqrt(方差))</param>    /// <returns></returns>    public static double? Normal(double u1, double u2, double averageValue, double variance)    {      double? result = null;      try      {        result = averageValue + Math.Sqrt(variance) * Math.Sqrt((-2) * Math.Log(u1)) * Math.Sin(2 * Math.PI * u2);      }      catch (Exception)      {        result = null;      }      return result;    }    /// <summary>    /// 求一组数据的方差    /// </summary>    /// <param name="list">要求的数组</param>    /// <returns></returns>    public static double Variance(double[] nums)    {      double average = nums.Sum() / nums.Length;      double sum = 0;      double variance = 0;      foreach (double num in nums)      {        sum += Math.Pow((num - average), 2);      }      variance = sum / nums.Length;      return variance;    }    /// <summary>    /// 截取小数指定小数位，且不四舍五入    /// </summary>    /// <param name="originNum">要截取的小数</param>    /// <param name="lastNum">截取小数后位数</param>    /// <returns></returns>    public static double? Round(double originNum, int lastNum)    {      double? result = null;      int index = originNum.ToString().IndexOf('.');      if (index != -1)      {        string temp = originNum.ToString();        result = Convert.ToDouble(temp.Substring(0, index + 1) + temp.Substring(index + 1, Math.Min(temp.Length - index - 1, lastNum)));      }      if (result == 0)      {        result = null;      }      else if (index == -1)      {        result = originNum;      }      return result;    }  }