Is it possible to specify the upper and lower bounds for nextInt in Mersenne Twister RNG (Java)

Question

I have a requirement to generate random numbers, specifically using the Mersenne Twister algorithm, in either Java/Kotlin (for Android). I've tried using the Apache commons-math Mersenne Twister implementation which works great to generate random integers. However I need to specify a fairly small range for these, the ints must be between 1 and 100.

It doesn't seem to be possible to specify upper and lower bounds with the Apache implementation. Does anyone know of any alternative Mersenne Twister options for Java/Kotlin that accept bounds for the nextInt generated?

Answer 1

AFAIK you can pass upper boundary of generated int to nextInt method, so it is possible to write simple extension function like that:

fun MersenneTwister.nextInt(min: Int, max: Int) = min + nextInt(max - min)

Please note that like MT's nextInt result does not include upper boundary, so you might want to add 1 to nextInt's argument if you need this behavior.

Also note that I did not test this function well, so do it yourself before using it.