Below puzzle is known as GrandTour or RoundTrip. The purpose is to connect all dots and create a cycle. As you can see some paths are already predefined. I know how to generate a Hamiltonian path or cycle within nxn grid. But how about those predefined paths? How can I find the minimum paths (lets say clue) that would result in a unique Hamiltonian path or cycle? What type of algorithm should I look for? Thanks.
