Random Number Generator is always generating the same numbers

Question

I am trying to fill my array with random numbers using the following piece of code

#include
#include

int main(){
int n = 5;
int li         


        

Answer 1

If a random hardware device is not available to the implementation, a pseudo random number engine is used. Is a random number hardware device available? By that, I mean not only physically there, but also available to that particular implementation of std::random_device.

Answer 2

Call the entropy() member function on std::random_device to find out whether your implementation implements it properly:

std::random_device may be implemented in terms of an implementation-defined pseudo-random number engine if a non-deterministic source (e.g. a hardware device) is not available to the implementation. In this case each std::random_device object may generate the same number sequence.

(Source)

If this is the case, a call to entropy() will return 0:

A deterministic random number generator (e.g. a pseudo-random engine) has entropy zero.

If that is the case, you need to use a different fallback mechanism for seeding. For instance, you could use a time-based seed like in the old C-days.

On desktop platforms in particular, you should expect std::random_device to be implemented as a proper non-deterministic source though. If this is not the case, you might just be using a very old version of the standard library implementation. If you have the feeling that the implementation should support non-deterministic std::random_device but it does not, consider filing a bug report with your standard library maintainer.