def next(self): self.seed = (self.a * self.seed + self.b) % self.m return self.seed >> 16 这段代码的作用

这段代码定义了 `LCG` 类的一个方法 `next()`，其作用如下：

1. 计算新的种子值：根据线性同余生成器（LCG）的公式 `(a * seed + b) % m`，将当前种子 `self.seed` 乘以乘数 `self.a`，加上增量 `self.b`，再对模数 `self.m` 取模运算，得到新的种子值。
2. 将新的种子值右移16位：使用位运算符 `>>` 将新的种子值右移16位。
3. 返回右移后的值：将右移后的值作为方法的返回值。

综上所述，这段代码的作用是根据线性同余生成器的公式计算下一个伪随机数，并返回该伪随机数的右移16位后的值。这个方法可以用于生成伪随机数序列的下一个数。

相关问题

#!/usr/bin/env python3 import os from Crypto.Util.number import getPrime, getRandomRange def isSquare(a, p): return pow(a, (p-1)//2, p) != p-1 class SquareRNG(object): def __init__(self, p, sa, sb): assert sa != 0 and sb != 0 (self.p, self.sa, self.sb) = (p, sa, sb) self.x = 0 def int(self, nbits): v, s = 0, 1 for _ in range(nbits): self.x = (self.x + 1) % p s += pow(self.sa, self.x, self.p) * pow(self.sb, self.x, self.p) s %= self.p v = (v << 1) | int(isSquare(s, self.p)) return v def bool(self): self.x = (self.x + 1) % self.p t = (pow(self.sa, self.x, self.p) + pow(self.sb, self.x, self.p)) t %= self.p return isSquare(t, self.p) p = getPrime(256) sb1 = int(input("Bob's seed 1: ")) % p sb2 = int(input("Bob's seed 2: ")) % p for _ in range(77): sa = getRandomRange(1, p) r1 = SquareRNG(p, sa, sb1) print("Random 1:", hex(r1.int(32))) r2 = SquareRNG(p, sa, sb2) print("Random 2:", hex(r2.int(32))) guess = int(input("Guess next bool [0 or 1]: ")) if guess == int(r1.bool()): print("OK!") else: print("NG...") break else: print("Congratz!") print(os.getenv("FLAG", "nek0pts{*** REDACTED ***}"))

以下是您提供的Python代码的翻译版本：

#!/usr/bin/env python3
import os
from Crypto.Util.number import getPrime, getRandomRange

def isSquare(a, p):
    return pow(a, (p-1)//2, p) != p-1

class SquareRNG(object):
    def __init__(self, p, sa, sb):
        assert sa != 0 and sb != 0
        (self.p, self.sa, self.sb) = (p, sa, sb)
        self.x = 0

    def int(self, nbits):
        v, s = 0, 1
        for _ in range(nbits):
            self.x = (self.x + 1) % p
            s += pow(self.sa, self.x, self.p) * pow(self.sb, self.x, self.p)
            s %= self.p
            v = (v << 1) | int(isSquare(s, self.p))
        return v

    def bool(self):
        self.x = (self.x + 1) % self.p
        t = (pow(self.sa, self.x, self.p) + pow(self.sb, self.x, self.p))
        t %= self.p
        return isSquare(t, self.p)

p = getPrime(256)

sb1 = int(input("Bob's seed 1: ")) % p
sb2 = int(input("Bob's seed 2: ")) % p
for _ in range(77):
    sa = getRandomRange(1, p)
    r1 = SquareRNG(p, sa, sb1)
    print("Random 1:", hex(r1.int(32)))
    r2 = SquareRNG(p, sa, sb2)
    print("Random 2:", hex(r2.int(32)))

    guess = int(input("Guess next bool [0 or 1]: "))
    if guess == int(r1.bool()):
        print("OK!")
    else:
        print("NG...")
        break
else:
    print("Congratz!")
    print(os.getenv("FLAG", "nek0pts{*** REDACTED ***}"))

请注意，这是直接的翻译，可能需要根据您的具体需求进行进一步调整和优化。如果您有任何其他问题，请随时提问。

python random 源代码

以下是 Python 中 random 模块的源代码：

import _random
import math
import os
import sys
import time

class Random(_random.Random):
    VERSION = 3     # 版本号

    def seed(self, a=None, version=2):
        if version == 1 or version == 2 and isinstance(a, (str, bytes, bytearray)):
            a = hash(a)      # 将字符串类型的种子转换成整数类型的种子
            super().seed(a)
        elif version == 2 and isinstance(a, int):
            super().seed(a)
        elif version == 3 and isinstance(a, (str, bytes, bytearray)):
            if isinstance(a, str):
                a = a.encode()
            a += os.urandom(2500)
            super().seed(int.from_bytes(hashlib.sha512(a).digest(), 'big'))
        else:
            raise TypeError("a must be None, int, str or bytes")

    def getstate(self):
        return self.VERSION, super().getstate()

    def setstate(self, state):
        version = state[0]
        if version == 3:
            state = state[1]
        super().setstate(state)

    def jumpahead(self, n):
        if n >= 0:
            if n < 2**64:
                super().jumpahead(n)
            else:
                if not isinstance(n, int):
                    raise TypeError("n must be an integer")
                if n < 0:
                    raise ValueError("n must be non-negative")
                while n > 0:
                    if n & 1:
                        super().next()
                    n >>= 1
        else:
            raise ValueError("n must be non-negative")

    def __getstate__(self):
        return self.getstate()

    def __setstate__(self, state):
        self.setstate(state)

_inst = Random()
seed = _inst.seed
random = _inst.random
uniform = _inst.uniform
randrange = _inst.randrange
choice = _inst.choice
shuffle = _inst.shuffle
sample = _inst.sample
choices = _inst.choices

这是 random 模块的基础实现，用于生成伪随机数。你可以使用 `import random` 来使用该模块的功能。