Uniform Random Number Generation Across a Range

You seek a method to uniformly generate random numbers within a specified range [min, max].

Flaws with rand

Your current implementation using rand() and the modulus operator may not ensure uniform distribution, as its behavior depends on RAND_MAX and the range itself.

C 11 and Uniform Range Generation

In C 11, std::uniform_int_distribution offers a solution tailored to this need:

#include 

std::uniform_int_distribution distr(min, max);
std::random_device rand_dev;
std::mt19937 generator(rand_dev());

int random_number = distr(generator);

Additional Features of

The header provides a vast array of random number generators with varying distributions, such as Bernoulli, Poisson, and normal.

Container Shuffling

To shuffle a container, employ std::shuffle:

#include 
#include 

std::vector vec = {4, 8, 15, 16, 23, 42};
std::random_device random_dev;
std::mt19937 generator(random_dev());

std::shuffle(vec.begin(), vec.end(), generator);

Boost.Random

If using a C 11 compiler is not feasible, consider Boost.Random, which features a similar interface to the C 11 counterpart.