TY - GEN
T1 - PTAS for geometric hitting set problems via local search
AU - Mustafa, Nabil H.
AU - Ray, Saurabh
PY - 2009/12/4
Y1 - 2009/12/4
N2 - We consider the problem of computing minimum geometric hitting sets in which, given a set of geometric objects and a set of points, the goal is to compute the smallest subset of points that hit all geometric objects. The problem is known to be strongly NP-hard even for simple geometric objects like unit disks in the plane. Therefore, unless P=NP, it is not possible to get Fully Polynomial Time Approximation Algorithms (FPTAS) for such problems. We give the first PTAS for this problem when the geometric objects are halfspaces in ℝ3 and when they are an r-admissible set regions in the plane (this includes pseudo-disks as they are 2-admissible). Quite surprisingly, our algorithm is a very simple local search algorithm which iterates over local improvements only.
AB - We consider the problem of computing minimum geometric hitting sets in which, given a set of geometric objects and a set of points, the goal is to compute the smallest subset of points that hit all geometric objects. The problem is known to be strongly NP-hard even for simple geometric objects like unit disks in the plane. Therefore, unless P=NP, it is not possible to get Fully Polynomial Time Approximation Algorithms (FPTAS) for such problems. We give the first PTAS for this problem when the geometric objects are halfspaces in ℝ3 and when they are an r-admissible set regions in the plane (this includes pseudo-disks as they are 2-admissible). Quite surprisingly, our algorithm is a very simple local search algorithm which iterates over local improvements only.
KW - Approximation algorithm
KW - Epsilon nets
KW - Hitting sets
KW - Local search
UR - http://www.scopus.com/inward/record.url?scp=70849098296&partnerID=8YFLogxK
U2 - 10.1145/1542362.1542367
DO - 10.1145/1542362.1542367
M3 - Conference contribution
AN - SCOPUS:70849098296
SN - 9781605585017
T3 - Proceedings of the Annual Symposium on Computational Geometry
SP - 17
EP - 22
BT - Proceedings of the 25th Annual Symposium on Computational Geometry, SCG'09
T2 - 25th Annual Symposium on Computational Geometry, SCG'09
Y2 - 8 June 2009 through 10 June 2009
ER -