Abstract
It is shown that a set of $n$ disjoint line segments in the plane can always be illuminated by $\lfloor (n+1)/2\rfloor$ light sources, improving an earlier bound of $\lfloor 2n/3\rfloor$ due to Czyzowicz et al. It is also shown that $\lfloor 4(n+1)/5 \rfloor$ light sources are always sufficient and sometimes necessary to illuminate the free space and both sides of $n$ disjoint line segments for every $n\geq 2$.
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Tóth, C. Illuminating Disjoint Line Segments in the Plane. Discrete Comput Geom 30, 489–505 (2003). https://doi.org/10.1007/s00454-003-2797-9
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DOI: https://doi.org/10.1007/s00454-003-2797-9