misc/random.hpp

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Last update: 2024-01-08 00:27:17+09:00
Include: #include "misc/random.hpp"

Code

#pragma once

class Random {
   public:
    // returns a random integer in the range [0, n)
    unsigned int next_int(int n) { return xorshift() % n; }

    // returns a random double number in the range [0, 1)
    double next_double() { return xorshift() * (1.0 / 0xFFFFFFFFu); }

   private:
    unsigned int x = 123456789, y = 362436069, z = 521288629, w = 88675123;

    unsigned int xorshift() {
        unsigned int t;
        t = x ^ (x << 11);
        x = y;
        y = z;
        z = w;
        return w = w ^ (w >> 19) ^ (t ^ (t >> 8));
    }
};

#line 2 "misc/random.hpp"

class Random {
   public:
    // returns a random integer in the range [0, n)
    unsigned int next_int(int n) { return xorshift() % n; }

    // returns a random double number in the range [0, 1)
    double next_double() { return xorshift() * (1.0 / 0xFFFFFFFFu); }

   private:
    unsigned int x = 123456789, y = 362436069, z = 521288629, w = 88675123;

    unsigned int xorshift() {
        unsigned int t;
        t = x ^ (x << 11);
        x = y;
        y = z;
        z = w;
        return w = w ^ (w >> 19) ^ (t ^ (t >> 8));
    }
};