Fill a vector with random numbers c++

Question

I\'ve got a vector that I\'m trying to fill up with random numbers. I keep running into an issue however that the vector mostly outputs 0 each time that I\'m running it (it

Answer 1

You can use std::generate algorithm to fill a vector of n elements with random numbers.

In modern C++ it’s recommended not to use any time-based seeds and std::rand, but instead to use random_device to generate a seed. For software-based engine, you always need to specify the engine and distribution. Read More..

#include 
#include 
#include 
#include 
#include 

using namespace std;

int main()
{
    // First create an instance of an engine.
    random_device rnd_device;
    // Specify the engine and distribution.
    mt19937 mersenne_engine {rnd_device()};  // Generates random integers
    uniform_int_distribution dist {1, 52};

    auto gen = [&dist, &mersenne_engine](){
                   return dist(mersenne_engine);
               };

    vector vec(10);
    generate(begin(vec), end(vec), gen);

    // Optional
    for (auto i : vec) {
        cout << i << " ";
    }


}

If you want to rearrange the elements of a range in a random order:

  std::shuffle(begin(vec), end(vec), mersenne_engine);