Shakashaka
Appearance
Shakashaka (シャカシャカ) is a logic puzzle developed by publisher Nikoli.[1] The objective is to fill the white squares in a given grid with a pattern of triangles such that each white area in the resulting grid has a rectangular shape. Furthermore, each black square in the grid marked with a number must be orthogonally adjacent to the specified number of triangles.[2]
Computational complexity
It is NP-complete to decide whether a given Shakashaka puzzle has a solution.[3] Furthermore, counting the number of solutions to a given Shakashaka puzzle is #P-complete.[3]
References
- ^ "Puzzles of nikoli.com". Nikoli. Retrieved 14 August 2014.
- ^ "Rules of Shakashaka puzzle". Nikoli. Retrieved 14 August 2014.
- ^ a b Demaine, Erik D.; Okamoto, Yoshio; Uehara, Ryuhei; Uno, Yushi (2014), "Computational complexity and an integer programming model of Shakashaka", IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, E97-A (6): 1213–1219, Bibcode:2014IEITF..97.1213D, doi:10.1587/transfun.E97.A.1213, hdl:10119/12147