2009/04/14 by Greg Aloupis, Aloupis, G., Jean Cardinal +15 · 1 citation
Computer Science · Engineering · Materials Science · #Computational Geometry (cs.CG) #Computational Geometry and Mesh Generation #FOS: Computer and information sciences #Quasicrystal Structures and Properties #Structural Analysis and Optimization
paper · pdf · doi:10.48550/arxiv.0904.2115
openalex publication_date 2009/04/14 · openalex created_date 2024/04/11 · openalex updated_date 2026/07/28
Given a planar point set and an integer k, we wish to color the points with k colors so that any axis-aligned strip containing enough points contains all colors. The goal is to bound the necessary size of such a strip, as a function of k. We show that if the strip size is at least 2k-1, such a coloring can always be found. We prove that the size of the strip is also bounded in any fixed number of dimensions. In contrast to the planar case, we show that deciding whether a 3D point set can be 2-colored so that any strip containing at least three points contains both colors is NP-complete. We also consider the problem of coloring a given set of axis-aligned strips, so that any sufficiently covered point in the plane is covered by k colors. We show that in d dimensions the required coverage is at most d(k-1)+1. Lower bounds are given for the two problems. This complements recent impossibility results on decomposition of strip coverings with arbitrary orientations. Finally, we study a variant where strips are replaced by wedges.