using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace ConsoleApp5
{
class Program
{
static void Main(string[] args)
{
#region 红包算法一
Console.WriteLine("-----------------------------------红包算法一---------------------");
//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("按任意键继续");
Console.ReadKey();
#endregion
#region 红包算法二
Console.WriteLine("-----------------------------------红包算法二---------------------");
RedPackage pp = new RedPackage();
int packageNum = 15;
pp.remainCount = packageNum;
pp.remainMoney = 100;
var list = GetMoneys(pp);
Console.WriteLine("总金额 {0}", list.Sum());
#endregion
Console.ReadKey();
}
#region 算法一
/// <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;
}
#endregion
#region 算法二
/// 红包算法
/// </summary>
/// <param name="_redPacket"></param>
/// <returns></returns>
public static List<double> GetMoneys(RedPackage _redPacket)
{
//人均最小金额
double min = 0.01;
if (_redPacket.remainMoney < _redPacket.remainCount * min)
return null;
int num = _redPacket.remainCount;
List<double> array = new List<double>();
Random r = new Random();
for (int i = 0; i < num; i++)
{
if (_redPacket.remainCount == 1)
{
_redPacket.remainCount--;
array.Add(Convert.ToDouble(_redPacket.remainMoney.ToString("0.00")));
Console.WriteLine(string.Format("第{0}个红包：{1}元", i + 1, Convert.ToDouble(_redPacket.remainMoney.ToString("0.0"))));
}
else
{
//(_redPacket.remainMoney - (_redPacket.remainCount - 1) * min)：保存剩余金额可以足够的去分配剩余的红包数量
double max = (_redPacket.remainMoney - (_redPacket.remainCount - 1) * min) / _redPacket.remainCount * 2;
double money = r.NextDouble() * max;
money = Convert.ToDouble((money <= min ? min : money).ToString("0.00"));
_redPacket.remainCount--;
_redPacket.remainMoney -= money;
array.Add(money);
Console.WriteLine(string.Format("第{0}个红包：{1}元", i + 1, money));
}
}
//再次随机
return array.OrderBy(o => Guid.NewGuid()).ToList();
}
public class RedPackage
{
/// <summary>
/// 剩余的红包数量
/// </summary>
public int remainCount { set; get; }
/// <summary>
/// 剩余金额
/// </summary>
public double remainMoney { set; get; }
}
#endregion
}
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace ConsoleApp5
{
class Program
{
static void Main(string[] args)
{
Console.WriteLine("---------------红包算法三 按排名从多大小--------------");
RedPackage pp = new RedPackage();
pp.remainCount = 99;
pp.remainMoney = 100;
var list = GetMoneys(pp);
Console.WriteLine("总金额 {0}", list.Sum());
Console.ReadKey();
}
public static List<double> GetMoneys(RedPackage _redPackage)
{
double totalMoney = _redPackage.remainMoney;
int num = _redPackage.remainCount;
List<double> list = new List<double>();
List<int> rankList = new List<int>();
#region 获取所有排名
for (int i = 0; i < num; i++)
{
int rank = num - i; //从后往前排名
rankList.Add(rank);
}
#endregion
int k = rankList.Sum();
for (int i = 0; i < num; i++)
{
var p = Math.Round((double)(rankList[i]) / k, 6, MidpointRounding.ToEven);
double money = Math.Round(totalMoney * p, 2, MidpointRounding.ToEven);
_redPackage.remainCount--;
_redPackage.remainMoney -= money;
list.Add(money);
Console.WriteLine(string.Format("第{0}个红包：{1}元", i + 1, money));
}
return list.OrderBy(o => Guid.NewGuid()).ToList();
}
#region 算法三
public class RedPackage
{
/// <summary>
/// 剩余的红包数量
/// </summary>
public int remainCount { set; get; }
/// <summary>
/// 剩余金额
/// </summary>
public double remainMoney { set; get; }
}
#endregion
}
}
