伪随机函数C#实现

public class RandomCy
{


    private const long multiplier = 0x5DEECE66DL;


    private const long addend = 0xBL;


    private const long mask = (1L << 48) - 1;
    /**
* 默认的随机种子 是 -1
*/
    private long seed = -1;


    public RandomCy()
    {
        seed = -1;
    }
    /**
* 设置随机种子
* @param seed
*/
    public RandomCy(int seed)
    {
        this.seed = seed;
    }
    /**
* 设置随机种子
* @param seed
*/
    public void setSpeed(int seed)
    {
        this.seed = seed;
    }
    /**
* 获取lang 类型的随机数
* @return
*/
    public long nextLong()
    {
        return ((long)(next(32)) << 32) + next(32);
    }
    /**
* 获取int 类型的随机数
* @return
*/
    public int nextInt()
    {
        return next(32);
    }
    /**
* 运算
* @param step
* @return
*/
    protected int next(int step)
    {
        long nextSeed = 0;
        seed = (seed * multiplier + addend) & mask;
        nextSeed = seed;
        return (int)(nextSeed >> (48 - step));
    }
}