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Colorful Strips

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Abstract

We study the following geometric hypergraph coloring problem: 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 sufficiently many points contains all colors. We show that if the strip contains at least 2k − 1 points, such a coloring can always be found. In dimension d, we show that the same holds provided the strip contains at least k(4 ln k + ln d) points. We also consider the dual 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 dimension d the required coverage is at most d(k − 1) + 1. This complements recent impossibility results on decomposition of strip coverings with arbitrary orientations. From the computational point of view, we show that deciding whether a three-dimensional point set can be 2-colored so that any strip containing at least three points contains both colors is NP-complete. This shows a big contrast with the planar case, for which this decision problem is easy.

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References

  1. Alon N.: A simple algorithm for edge-coloring bipartite multigraphs. Inf. Proc. Lett. 85(6), 301–302 (2003). doi:10.1016/S0020-0190(02)00446-5

    Article  MATH  Google Scholar 

  2. Alon N., Spencer J.: The Probabilistic Method, 2nd edn. John Wiley, New York (2000)

    Book  MATH  Google Scholar 

  3. Aloupis, G., Cardinal, J., Collette, S., Langerman, S., Orden, D., Ramos, P.: Decomposition of multiple coverings into more parts. In: Proceedings of the ACM-SIAM Symposium on Discrete Algorithms (SODA’09) (2009)

  4. Aloupis G., Cardinal J., Collette S., Langerman S., Smorodinsky S.: Coloring geometric range spaces. Discret. Comput. Geom. 41(2), 348–362 (2009)

    Article  MathSciNet  MATH  Google Scholar 

  5. Alspach B.: The wonderful walecki construction. Bull. Inst. Combin. Appl. 52, 7–20 (2008)

    MathSciNet  MATH  Google Scholar 

  6. Buchsbaum, A., Efrat, A., Jain, S., Venkatasubramanian, S., Yi, K.: Restricted strip covering and the sensor cover problem. In: ACM-SIAM Symposium on Discrete Algorithms (SODA’07) (2007)

  7. Cole R., Ost K., Schirra S.: Edge-coloring bipartite multigraphs in O(Elog D) time. Combinatorica 21(1), 5–12 (2001)

    Article  MathSciNet  MATH  Google Scholar 

  8. Even G., Lotker Z., Ron D., Smorodinsky S.: Conflict-free colorings of simple geometric regions with applications to frequency assignment in cellular networks. SIAM J. Comput. 33(1), 94–136 (2004)

    Article  MathSciNet  Google Scholar 

  9. Garey, M.R., Johnson, D.S.: Computers and Intractability : A Guide to the Theory of NP-Completeness. W. H. Freeman, San Francisco (1979)

  10. Gibson, M., Varadarajan, K.R.: Decomposing coverings and the planar sensor cover problem. In: FOCS, pp. 159–168. IEEE Computer Society, Washington (2009)

  11. Haxell P., Szabó T., Tardos G.: Bounded size components: partitions and transversals. J. Comb. Theory Ser. B 88(2), 281–297 (2003). doi:10.1016/S0095-8956(03)00031-5

    Article  MATH  Google Scholar 

  12. Mani, P., Pach, J.: Decomposition problems for multiple coverings with unit balls, (manuscript) (1986)

  13. Moser, R.A., Tardos, G.: A constructive proof of the general lovász local lemma. J. ACM 57(2) (2010)

  14. Pach, J.: Decomposition of multiple packing and covering. In: 2. Kolloq. über Diskrete Geom., pp. 169–178. Inst. Math. Univ. Salzburg (1980)

  15. Pach, J.: Decomposition of multiple packing and covering. In: 2. Kolloquium Uber Diskrete Geometrie, pp. 169–178. Inst. Math. Univ. Salzburg, Salzburg, 1980

  16. Pach J.: Covering the plane with convex polygons. Discret. Comput. Geom. 1, 73–81 (1986)

    Article  MathSciNet  MATH  Google Scholar 

  17. Pach, J., Tardos, G., Tóth, G.: Indecomposable coverings. In: The China–Japan Joint Conference on Discrete Geometry, Combinatorics and Graph Theory (CJCDGCGT 2005). Lecture Notes in Computer Science, pp. 135–148 (2007)

  18. Pach, J., Tóth, G.: Decomposition of multiple coverings into many parts. In: Proceedings of the ACM Symposium on Computational Geometry, pp. 133–137 (2007)

  19. Schaefer, T.J.: The complexity of satisfiability problems. In: STOC, pp. 216–226. ACM (1978)

  20. Smorodinsky S.: On the chromatic number of some geometric hypergraphs. SIAM J. Discret. Math. 21(3), 676–687 (2007)

    Article  MathSciNet  MATH  Google Scholar 

  21. Stanton, R.G., Cowan, D.D., James, L.O.: Some results on path numbers. In: Louisiana Conference on Combinatorics, Graph Theory and Computing (1970)

  22. Tardos G., Tóth G.: Multiple coverings of the plane with triangles. Discret. Comput. Geom. 38(2), 443–450 (2007)

    Article  MATH  Google Scholar 

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Correspondence to Greg Aloupis.

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Chargé de Recherches du FRS-FNRS.

Maître de Recherches du FRS-FNRS.

Supported by the Communauté française de Belgique - ARC.

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Aloupis, G., Cardinal, J., Collette, S. et al. Colorful Strips. Graphs and Combinatorics 27, 327–339 (2011). https://doi.org/10.1007/s00373-011-1014-5

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