Why is it not giving random number?

Question

it only giving 41 as a result

Answer 1

You need to randomise the seed for RNG algorithm. The most commonly used way is by using system time.

#include <iostream>
#include <cstdlib>
#include <ctime>

int main()
{
srand(time(0));
std::cout << rand();

return 0;
}

Answer 2

because you didn't use srand(time(0));