Generating puzzles for the Rush Hour game.
Currently only does random search. Apparently this is not enough to find hard puzzles.
Here is at least one approach that works:
@phdthesis{servais2005finding,
title={Finding hard initial configurations of Rush Hour with binary decision diagrams},
author={Servais, Fr{\'e}d{\'e}ric},
year={2005},
school={M. Sc. thesis, Universit{\'e} libre de Bruxelles, Facult{\'e} des sciences}
}