Question

超级noob问题（来自一个不理解按位的人）：

我在JavaScript（在我的服务器上）使用下面的伪随机数生成器。

Math.seed = function(s) {
    var m_w  = s;
    var m_z  = 987654321;
    var mask = 0xffffffff;

    return function() {
      m_z = (36969 * (m_z & 65535) + (m_z >> 16)) & mask;
      m_w = (18000 * (m_w & 65535) + (m_w >> 16)) & mask;

      var result = ((m_z << 16) + m_w) & mask;
      result /= 4294967296;

      return result + 0.5;
    }
}

var myRandomFunction = Math.seed(1234);
var randomNumber = myRandomFunction();

现在我想在Java中使用它（在我的客户端上）。这适用于int种子值（例如，1234的种子在JS和Java上给出相同的数字），但我的种子值很长。如何更改按位运算符？

public class CodeGenerator {
    private int m_w;
    private int mask;
    private int m_z;

    public CodeGenerator(int seed) {
        m_w = seed;
        m_z = 987654321;
        mask = 0xffffffff;
    }

    public int nextCode() {
        m_z = (36969 * (m_z & 65535) + (m_z >> 16)) & mask;
        m_w = (18000 * (m_w & 65535) + (m_w >> 16)) & mask;
        int result = ((m_z << 16) + m_w) & mask;
        double result2 = result / 4294967296.0;
        return (int)Math.floor((result2 + 0.5) * 999999);
    }
}

Answer 1

在Java中，您需要将种子掩码为unsigned int，然后生成与JS版本相同的数字。

新构造函数：

public CodeGenerator(long seed) {
    mask = 0xffffffff;
    m_w = (int) (seed & mask);
    m_z = 987654321;
}

Answer 2

您是否尝试过只声明种子和第一个结果？

public class CodeGenerator {
    private long m_w;
    private int mask;
    private int m_z;

    public static void main(String... a){
        System.out.println(new CodeGenerator(1234).nextCode()); //result = 237455
        System.out.println(new CodeGenerator(1234567891234L).nextCode()); //result = 246468
    }

    public CodeGenerator(long seed) {
        m_w = seed;
        m_z = 987654321;
        mask = 0xffffffff;
    }

    public int nextCode() {
        m_z = (36969 * (m_z & 65535) + (m_z >> 16)) & mask;
        m_w = (18000 * (m_w & 65535) + (m_w >> 16)) & mask;
        long result = ((m_z << 16) + m_w) & mask;
        double result2 = result / 4294967296.0;
        return (int)Math.floor((result2 + 0.5) * 999999);
    }
}

java中的随机数生成器，具有长种子值

2 个答案: