Half-Guarding Weakly-Visible Polygons and Terrains

Document Type

Conference Article

Publication Title

Leibniz International Proceedings in Informatics, LIPIcs


We consider a variant of the art gallery problem where all guards are limited to seeing 180°. Guards that can only see in one direction are called half-guards. We give a polynomial time approximation scheme for vertex guarding the vertices of a weakly-visible polygon with half-guards. We extend this to vertex guarding the boundary of a weakly-visible polygon with half-guards. We also show NP-hardness for vertex guarding a weakly-visible polygon with half-guards. Lastly, we show that the orientation of half-guards is critical in terrain guarding. Depending on the orientation of the half-guards, the problem is either very easy (polynomial time solvable) or very hard (NP-hard).



Publication Date


This document is currently not available here.