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Minimum r-Star Cover of Class-3 Orthogonal Polygons

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Part of the book series: Lecture Notes in Computer Science ((LNTCS,volume 8986))

Abstract

We are interested in the problem of covering simple orthogonal polygons with the minimum number of r-stars; an orthogonal polygon is an r-star if it is star-shaped. The problem has been considered by Worman and Keil [13] who described an algorithm running in \(O(n^{17} \hbox {poly-log}\, n)\) time where n is the size of the input polygon.

In this paper, we consider the above problem on simple class-3 orthogonal polygons, i.e., orthogonal polygons that have dents along at most 3 different orientations. By taking advantage of geometric properties of these polygons, we give an output-sensitive \(O(n + k \log k)\)-time algorithm where k is the size of a minimum r-star cover; this is the first purely geometric algorithm for this problem. Ideas in this algorithm may be generalized to yield faster algorithms for the problem on general simple orthogonal polygons.

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References

  1. Aggarwal, A.: The art gallery theorem: its variations, applications, and algorithmic aspects. Ph.D. thesis, Department of Electrical Engineering and Computer Science, Johns Hopkins University (1984)

    Google Scholar 

  2. Culberson, J., Reckhow, R.A.: Orthogonally convex coverings of orthogonal polygons without holes. J. Comput. Syst. Sci. 39(2), 166–204 (1989)

    Article  MATH  MathSciNet  Google Scholar 

  3. Hertel, S., Mehlhorn, K.: Fast triangulation of simple polygons. In: FCT 1983: Proceedings of the 4th International Conference on Fundamentals of Computation Theory, pp. 207–218 (1983)

    Google Scholar 

  4. Gewali, L., Keil, M., Ntafos, S.C.: On covering orthogonal polygons with star-shaped polygons. Inf. Sci. 65, 45–63 (1992)

    Article  MATH  MathSciNet  Google Scholar 

  5. Kahn, J., Klawe, M., Kleitman, D.: Traditional galleries require fewer watchmen. SIAM J. Algebraic Discrete Methods 4(2), 194–206 (1983)

    Article  MATH  MathSciNet  Google Scholar 

  6. Keil, J.M.: Decomposing a polygon into simpler components. SIAM J. Comput. 14, 799–817 (1985)

    Article  MATH  MathSciNet  Google Scholar 

  7. Keil, J.M.: Minimally covering a horizontally convex orthogonal polygon. In: SoCG 1986: Proceedings of the 2nd Annual ACM Symposium Computational Geometry, pp. 43–51 (1986)

    Google Scholar 

  8. Li, G., Zhang, H.: A rectangular partition algorithm for planar self-assembly. In: IROS 2005: Proceedings of the IEEE/RSJ International Conference on Intelligent Robots and Systems, pp. 3213–3218 (2005)

    Google Scholar 

  9. Lingas, A., Palios, L., Wasylewicz, A., Żyliński, P.: Corrigendum: note on covering orthogonal polygons. Inf. Process. Lett. 114, 646–654 (2014)

    Article  MATH  Google Scholar 

  10. Lingas, A., Wasylewicz, A., Żyliński, P.: Note on covering orthogonal polygons with star-shaped polygons. Inf. Process. Lett. 104(6), 220–227 (2007)

    Article  MATH  Google Scholar 

  11. Lingas, A., Wasylewicz, A., Żyliński, P.: Linear-time 3-approximation algorithm for the \(r\)-star covering problem. Int. J. Comput. Geom. Appl. 22(2), 103–141 (2012)

    Article  MATH  Google Scholar 

  12. Motwani, R., Raghunathan, A., Saran, H.: Covering orthogonal polygons with star polygons: the perfect graph approach. J. Comput. Syst. Sci. 40, 19–48 (1990)

    Article  MATH  MathSciNet  Google Scholar 

  13. Worman, C., Keil, J.M.: Polygon decomposition and the orthogonal art gallery problem. Int. J. Comput. Geom. Appl. 17(2), 105–138 (2007)

    Article  MATH  MathSciNet  Google Scholar 

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Acknowledgments

This research has been co-financed by the European Union (European Social Fund - ESF) and Greek national funds through the Operational Program “Education and Lifelong Learning” of the National Strategic Reference Framework (NSRF) - Research Funding Program: THALIS UOA (MIS 375891) - Investing in knowledge society through the European Social Fund.

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Correspondence to Leonidas Palios .

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Palios, L., Tzimas, P. (2015). Minimum r-Star Cover of Class-3 Orthogonal Polygons. In: Jan, K., Miller, M., Froncek, D. (eds) Combinatorial Algorithms. IWOCA 2014. Lecture Notes in Computer Science(), vol 8986. Springer, Cham. https://doi.org/10.1007/978-3-319-19315-1_25

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  • DOI: https://doi.org/10.1007/978-3-319-19315-1_25

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  • Publisher Name: Springer, Cham

  • Print ISBN: 978-3-319-19314-4

  • Online ISBN: 978-3-319-19315-1

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