概率抽奖

Posted 2020-09-10

[TestMethod]

public void CheckTrue()

{

var reg = CommonTools.CheckTrue(1.001M);

}

 

/// <summary>

/// 根据中奖率判断是否中奖

/// </summary>

/// <param name="percent">中奖率（0~100）</param>

/// <returns></returns>

public static bool CheckTrue(decimal percent)

{

bool result = false;

if (percent >= 100)

{

result = true;

}

else if (percent <= 0)

{

result = false;

}

else

{

string strPercent = percent.ToString();

int rndCount = 0;//随机数个数

int rndMax = 0;//随机数最大值

int rand = 0;//抽中数

if (strPercent.IndexOf(‘.‘) == -1)//无小数位

{

rndMax = 100;

rndCount = (int)percent;

var rndList = GenerateRandom(rndMax, rndCount,false);

rand = rnd.Next(rndMax);

result = rndList.Contains(rand);

}

else

{

int accCount = strPercent.Length - strPercent.IndexOf(‘.‘)-1;

//rndMax= percent>=1? (int)Math.Pow(10, strPercent.Length+1): (int)Math.Pow(10, accCount+1);

rndMax = (int)Math.Pow(10, accCount + 2);

rndCount = (int)(percent * (int)Math.Pow(10, accCount));

var rndList = GenerateRandom(rndMax, rndCount, false);

rand = rnd.Next(rndMax);

result = rndList.Contains(rand);

}

}

return result;

}

 

public static List<int> GenerateRandom(int iMax, int iNum,bool isRepeat=true)

{

long lTick = DateTime.Now.Ticks;

List<int> lstRet = new List<int>();

for (int i = 0; i < iNum; i++)

{

Random ran = new Random((int)lTick * i);

int iTmp = ran.Next(iMax);

if (!isRepeat)

{

if (lstRet.Contains(iTmp))

{

i--;

lTick += (new Random((int)lTick).Next(978));

continue;

}

}

lstRet.Add(iTmp);

lTick += (new Random((int)lTick).Next(978));

}

return lstRet;

}