A 3-Approximation Algorithm for Guarding Orthogonal Art Galleries with Sliding Cameras
نویسندگان
چکیده
A sliding camera travelling along a line segment s in a polygon P can see a point p in P if and only if p lies on a line segment contained in P that intersects s at a right angle. The objective of the minimum sliding cameras (MSC) problem is to guard P with the fewest sliding cameras possible, each of which is a horizontal or vertical line segment. In this paper, we give an O(n)-time 3-approximation algorithm for the MSC problem on any simple orthogonal polygon with n vertices. Our algorithm involves establishing a connection between the MSC problem and the problem of guarding simple grids with periscope guards.
منابع مشابه
Guarding Orthogonal Art Galleries with Sliding Cameras
We study the problem of guarding an orthogonal art gallery with security cameras sliding back and forth along straight tracks. We show that if only vertical (alternatively, horizontal) tracks are allowed, then a solution minimizing the number of tracks can be found in polynomial time, and if both orientations are allowed, then a 3-approximation can be found in polynomial time.
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