Tatamibari is NP-complete The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. Citation Adler, Aviv et al. “Tatamibari is NP-complete.” 10th International Conference on Fun with Algorithms, May-June 2021, Favignana Island, Italy, Schloss Dagstuhl and Leibniz Center for Informatics, 2021. © 2021 The Author(s) As Published 10.4230/LIPIcs.FUN.2021.1 Publisher Schloss Dagstuhl, Leibniz Center for Informatics Version Final published version Citable link https://hdl.handle.net/1721.1/129836 Terms of Use Creative Commons Attribution 3.0 unported license Detailed Terms https://creativecommons.org/licenses/by/3.0/ Tatamibari Is NP-Complete Aviv Adler Massachusetts Institute of Technology, Cambridge, MA, USA
[email protected] Jeffrey Bosboom Massachusetts Institute of Technology, Cambridge, MA, USA
[email protected] Erik D. Demaine Massachusetts Institute of Technology, Cambridge, MA, USA
[email protected] Martin L. Demaine Massachusetts Institute of Technology, Cambridge, MA, USA
[email protected] Quanquan C. Liu Massachusetts Institute of Technology, Cambridge, MA, USA
[email protected] Jayson Lynch Massachusetts Institute of Technology, Cambridge, MA, USA
[email protected] Abstract In the Nikoli pencil-and-paper game Tatamibari, a puzzle consists of an m × n grid of cells, where each cell possibly contains a clue among , , . The goal is to partition the grid into disjoint rectangles, where every rectangle contains exactly one clue, rectangles containing are square, rectangles containing are strictly longer horizontally than vertically, rectangles containing are strictly longer vertically than horizontally, and no four rectangles share a corner. We prove this puzzle NP-complete, establishing a Nikoli gap of 16 years.