TY - JOUR
AU - Akitaya, Hugo
AU - Brunner, Josh
AU - Demaine, Erik D.
AU - Hendrickson, Dylan
AU - Luo, Victor
AU - Tockman, Andy
PY - 2023/12/31
Y2 - 2024/10/08
TI - Complexity of Simple Folding of Mixed Orthogonal Crease Patterns: Discrete and Computational Geometry, Graphs, and Games
JF - Thai Journal of Mathematics
JA - Thai J Math
VL - 21
IS - 4
SE - Articles
DO -
UR - https://thaijmath2.in.cmu.ac.th/index.php/thaijmath/article/view/1563
SP - 1025–1046
AB - <p>Continuing results from JCDCGGG 2016 and 2017, we solve several new cases of the simple foldability problem -- deciding which crease patterns can be folded flat by a sequence of (some model of) simple folds. We give new efficient algorithms for mixed crease patterns, where some creases are assigned mountain/valley while others are unassigned, for all 1D cases and for 2D rectangular paper with orthogonal one-layer simple folds. By contrast, we show strong NP-completeness for mixed orthogonal crease patterns on 2D rectangular paper with some-layers simple folds, complementing a previous result for all-layers simple folds. We also prove strong NP-completeness for finite simple folds (no matter the number of layers) of unassigned orthogonal crease patterns on arbitrary paper, complementing a previous result for assigned crease patterns, and contrasting with a previous positive result for infinite all-layers simple folds. In total, we obtain a characterization of polynomial vs.\ NP-hard for all cases -- finite/infinite one/some/all-layers simple folds of assigned/unassigned/mixed orthogonal crease patterns on 1D/rectangular/arbitrary paper -- except the unsolved case of infinite all-layers simple folds of assigned orthogonal crease patterns on arbitrary paper.</p>
ER -