Abstract
Let \(P\) be a set of \(n\) points in the plane in general position. A subset \(H\) of \(P\) consisting of \(k\) elements that are the vertices of a convex polygon is called a \(k\)-hole of \(P\), if there is no element of \(P\) in the interior of its convex hull. A set \(B\) of points in the plane blocks the \(k\)-holes of \(P\) if any \(k\)-hole of \(P\) contains at least one element of \(B\) in the interior of its convex hull. In this paper we establish upper and lower bounds on the sizes of \(k\)-hole blocking sets, with emphasis in the case \(k=5\).
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Notes
Another proof of this result has independently been found recently by Valtr, inspired by discussions during a meeting in Spain in May 2011 (personal communication).
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A. García, Ferran Hurtado and J. Tejel were partially supported by projects E58 (ESF)-DGA, MICINN MTM2009-07242, MINECO MTM2012-30951, and ESF EUROCORES programme EuroGIGA, CRP ComPoSe: MICINN Project EUI-EURC-2011-4306 J. Urrutia was partially supported by projects MTM2006-03909 (Spain), and SEP-CONACYT of Mexico, Proyecto 80268.
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Cano, J., García, A., Hurtado, F. et al. Blocking the \(k\)-Holes of Point Sets in the Plane. Graphs and Combinatorics 31, 1271–1287 (2015). https://doi.org/10.1007/s00373-014-1488-z
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DOI: https://doi.org/10.1007/s00373-014-1488-z