#ifndef __RANDOM_H__
#define __RANDOM_H__

#include <stdint.h>
class Random
{
private:
    uint32_t seed_;

public:
    explicit Random(uint32_t s) : seed_(s & 0x7fffffffu)
    {
        // Avoid bad seeds.
        if (seed_ == 0 || seed_ == 2147483647L)
        {
            seed_ = 1;
        }
    }
    uint32_t Next()
    {
        static const uint32_t M = 2147483647L; // 2^31-1
        static const uint64_t A = 16807;       // bits 14, 8, 7, 5, 2, 1, 0
        uint64_t product = seed_ * A;
        seed_ = static_cast<uint32_t>((product >> 31) + (product & M));
        if (seed_ > M)
        {
            seed_ -= M;
        }
        return seed_;
    }
    uint32_t Uniform(int n) { return Next() % n; }
    bool OneIn(int n) { return (Next() % n) == 0; }
    uint32_t Skewed(int max_log) { return Uniform(1 << Uniform(max_log + 1)); }
};

#endif