如何将范围设置为随机库

Question

我真的不喜欢 rand() 函数。我想使用该库，但我真的不知道如何设置一个范围，例如从 1 到 3。我想“随机”这些数字（ 1,2,3) 而不是像 243245 这样的大数字。这段代码是您如何使用随机库并打印随机数的方法

#include <iostream>
#include <string>
#include <random>
using namespace std;
int main()
{
    minstd_rand simple_rand;

    simple_rand.seed(NULL);

    for (int ii = 0; ii < 10; ++ii)
    {
        std::cout << simple_rand() << '\n';
    }
}

Answer 1

使用std::uniform_int_distribution:

#include <ctime>
#include <iostream>
#include <random>

int main()
{
    std::mt19937 rng(std::time(0)); // `std::minstd_rand` would also work.
    std::uniform_int_distribution d(1,3);

    for (int i = 0; i < 10; i++)
    {
        std::cout << d(rng) << '\n';
    }
}

Answer 2

#include <iostream>
#include <random>
    int main()
    {
        std::random_device rd;  //Will be used to obtain a seed for the random number engine
        std::mt19937 gen(rd()); //Standard mersenne_twister_engine seeded with rd()
        std::uniform_int_distribution<> dis(1, 3);

        for (int n=0; n<10; ++n)
            //Use dis to transform the random unsigned int generated by gen into an int in [1, 6]
            std::cout << dis(gen) << ' ';
        std::cout << '\n';
    }

感谢@holyBlackCat 致谢：cppreference.com