Yes. CP SAT crunches through it in no time, but of course larger grids would quickly make it take much longer.
See
https://gist.github.com/Macuyiko/86299dc120478fdff529cab386f...
I don't believe this works in general. If you have a set of tiles that connect to neither the horse nor to an exit, they can still keep each other reachable in this formulation.
I don't believe this works in general. If you have a set of tiles that connect to neither the horse nor to an exit, they can still keep each other reachable in this formulation.