Proceedings 41st Annual Symposium on Foundations of Computer Science (2000)

Redondo Beach, California

Nov. 12, 2000 to Nov. 14, 2000

ISSN: 0272-5428

ISBN: 0-7695-0850-2

pp: 219

T.M. Chan , Dept. of Comput. Sci., Waterloo Univ., Ont., Canada

ABSTRACT

Analyzing the worst-case complexity of the k-level in a planar arrangement of n curves is a fundamental problem in combinatorial geometry. We give the first subquadratic upper bound (roughly O(nk/sup 1-2/3/*)) for curves that are graphs of polynomial functions of an arbitrary fixed degree s. Previously, nontrivial results were known only for the case s=1 and s=2. We also improve the earlier bound for pseudo-parabolas (curves that pairwise intersect at most twice) to O(nk/sup 7/9/log/sup 2/3/ k). The proofs are simple and rely on a theorem of Tamaki and Tokuyama on cutting pseudo-parabolas into pseudo-segments, as well as a new observation for cutting pseudo-segments into pieces that can be extended to pseudo-lines. We mention applications to parametric and kinetic minimum spanning trees.

INDEX TERMS

computational complexity; computational geometry; polynomials; worst-case complexity; planar arrangement; combinatorial geometry; subquadratic upper bound; polynomial functions; pseudo-parabolas; pseudo-segments; kinetic minimum spanning trees

CITATION

T. Chan, "On levels in arrangements of curves,"

*Proceedings 41st Annual Symposium on Foundations of Computer Science(FOCS)*, Redondo Beach, California, 2000, pp. 219.

doi:10.1109/SFCS.2000.892109

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