Home/ Questions/Q 7675015
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-31T16:51:58+00:00

I created a test application that generates 10k random numbers in a range from

  • 0

I created a test application that generates 10k random numbers in a range from 0 to 250 000. Then I calculated MAX and min values and noticed that the MAX value is always around 32k…

Do you have any idea how to extend the possible range? I need a range with MAX value around 250 000!

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    This is according to the definition of rand(), see:

    http://cplusplus.com/reference/clibrary/cstdlib/rand/

    http://cplusplus.com/reference/clibrary/cstdlib/RAND_MAX/

    If you need larger random numbers, you can use an external library (for example http://www.boost.org/doc/libs/1_49_0/doc/html/boost_random.html) or calculate large random numbers out of multiple small random numbers by yourself.

    But pay attention to the distribution you want to get. If you just sum up the small random numbers, the result will not be equally distributed.

    If you just scale one small random number by a constant factor, there will be gaps between the possible values.

    Taking the product of random numbers also doesn’t work.

    A possible solution is the following:

    1) Take two random numbers a,b
2) Calculate a*(RAND_MAX+1)+b

    So you get equally distributed random values up to (RAND_MAX+1)^2-1

    • 0