生成随机长长 C++

Question

int generator

I currently generate deterministic pseudo-random int s using this code:

#include <chrono>
#include <ctime>
#include <random>
#include <stdint.h>

const uint32_t CurrentTime = static_cast<uint32_t>(std::chrono::duration_cast<std::chrono::seconds>(std::chrono::steady_clock::now().time_since_epoch()).count());

std::mt19937 Mersenne = std::mt19937(static_cast<std::mt19937::result_type>(CurrentTime));

int Min = 3;
int Max = 6;
std::uniform_int_distribution<> Distribution(Min, Max-1);

int Result = Distribution(Mersenne);

The problem

There's two problems with this:

1. The parameters for Distribution must be int s.
2. The result from Distribution(Mersenne) is an int .

The question

How do I generate a random long long instead of an int , with the Min and Max parameters also being long long s instead of int s?

The context

I'm creating a deterministic game (peer-to-peer architecture), and the large minimum-size of a long long is needed as a sort of fixed-point number (since float s can cause non-determinism).

I won't accept answers that:

• Use float s or double s
• Suggest generating an int and casting it to a long long
• Generate random numbers non-deterministically (ie mersenne is deterministic if the same seed is used)

I would much prefer a solution from the standard library if there is one.

Ideally, the solution should be at least as efficient as my existing code on a 64-bit machine.

Answer 1

the documentation says that the template parameter can be long long

long long Min = 3;
long long Max = 6;
std::uniform_int_distribution<long long> Distribution(Min, Max-1);

long long Result = Distribution(Mersenne);

Answer 2

Would that work for you?

#include <climits>
#include <random>
#include <iostream>

int main()
{
    std::random_device rd;
    std::mt19937 gen(rd()); // Here you can use any seed to make it deterministic
    std::uniform_int_distribution<long long> distrib(LLONG_MIN, LLONG_MAX);
    
    for (int n = 0; n < 5; ++n)
        std::cout << distrib(gen) << ' ';
    
    std::cout << '\n';
}