C#实现不用随机函数(Random)的洗牌算法

代码不多,先看效果:

类代码:

static class  ShuffleCards
{
    private static int lastHash = 0;
    public static void Work(byte[] cards)
    {
        if (lastHash == 0)
            lastHash = System.Environment.TickCount;
        int len = cards.Length - 2;
        int mod = 0;
        byte temp = 0;
        for (int i = cards.Length - 1; i >= 0 && len>0; i--)
        {
            lastHash = (lastHash << 5) - lastHash + i;
            mod = lastHash < 0 ? lastHash % len * (-1) : lastHash % len;
            temp = cards[mod];
            cards[mod] = cards[i];
            cards[i] = temp;
            len--;
        }
    }
}

测试代码:

//16张牌0~F
byte[] cards = new byte[16];
//洗上99次
for (int j = 0; j < 100; j++)
{
    //每次都初始化顺序为 0~F
    for (int i = 0; i < cards.Length; i++)
        cards[i] = (byte)i;
    //洗牌调用
    ShuffleCards.Work(cards);
    StringBuilder ret = new StringBuilder();
    //输出
    for (int i = 0; i < cards.Length; i++)
        ret.Append(cards[i].ToString("X") + " ");
    Console.WriteLine(j.ToString()+" > "+ ret.ToString());
}
Console.ReadLine();