The NP-completeness of pen and paper puzzles
Summary
Pen and paper puzzles are often NP-complete. When a problem is NP-complete, it is commonly understood that (under the assumption that P is not equal to NP) the problem is too complex for computers to compute a solution in reasonable time. In this paper we use the Hamiltonian grid graph problem and Planar NOR CircuitSAT to prove that respectively Arukone3 and Bariasensa are NP-complete.