The Brute Force Microstates model considers an isolated system consisting of N identical, non-interacting quantum particles.  We wish to determine the total number of system microstates accessible to the system with energy E and hence the entropy.  This model is a supplemental simulation for the article "Enhancing the understanding of entropy through computation" in the American Journal of Physics 79(11), 1127-1132 (2011).
 
For distinguishable particles, the simplest brute force method that can be devised involves N nested loops, each over the list of single particle energy levels. This results in a computational scheme that scales exponentially with the system size. Still, this is an instructive method to apply because it shows the rapid increase in the number of microstates for moderate N, and the corresponding exponential increase in computational time.  The model displays the computation time as users to vary the number of particles N and the total energy E.

The Brute Force Microstates model was developed by Wolfgang Christian, Trisha Salagaram, and Nithaya Chetty using the Easy Java Simulations (Ejs) modeling tool.  It is distributed as a ready-to-run (compiled) Java archive.  Double clicking the  ejs_stp_BruteForceMicrostates.jar file will run the program if Java is installed.

Please note that this resource requires at least version 1.5 of Java.