C++ Random number generation Generating a pseudo-random number
Example
A pseudo-random number generator generates values that can be guessed based on previously generated values. In other words: it is deterministic. Do not use a pseudo-random number generator in situations where a true random number is required.
#include <iostream>
#include <random>
int main()
{
std::default_random_engine pseudo_random_generator;
std::uniform_int_distribution<int> int_distribution(0, 9);
int actual_distribution[10] = {0,0,0,0,0,0,0,0,0,0};
for(int i = 0; i < 10000; i++) {
int result = int_distribution(pseudo_random_generator);
actual_distribution[result]++;
}
for(int i = 0; i <= 9; i++) {
std::cout << actual_distribution[i] << " ";
}
return 0;
}
This code creates a random number generator, and a distribution that generates integers in the range [0,9] with equal likelihood. It then counts how many times each result was generated.
The template parameter of std::uniform_int_distribution<T> specifies the type of integer that should be generated. Use std::uniform_real_distribution<T> to generate floats or doubles.
