Random

http://en.cppreference.com/w/cpp/numeric/random/rand

#include <cstdlib>
#include <iostream>
#include <ctime>
 
int main() 
{
    std::srand(std::time(0)); // use current time as seed for random generator
    int random_variable = std::rand();
    std::cout << "Random value on [0 " << RAND_MAX << "]: " 
              << random_variable << '\n';
}

#include <random>
    std::random_device rd;
    std::uniform_int_distribution<int> dist(0, 9);
    for (int n = 0; n < 10; ++n) {
        std::cout<<dist(rd)<<"\n";

http://en.cppreference.com/w/cpp/header/random

http://en.cppreference.com/w/cpp/numeric/random/random_device

http://en.cppreference.com/w/cpp/numeric/random/uniform_int_distribution