文章基本信息

标题：External Memory Planar Point Location with Fast Updates
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作者：John Iacono ; Ben Karsin ; Grigorios Koumoutsos 等
期刊名称：LIPIcs : Leibniz International Proceedings in Informatics
电子版ISSN：1868-8969
出版年度：2019
卷号：149
页码：1-18
DOI：10.4230/LIPIcs.ISAAC.2019.58
出版社：Schloss Dagstuhl -- Leibniz-Zentrum fuer Informatik
摘要：We study dynamic planar point location in the External Memory Model or Disk Access Model (DAM). Previous work in this model achieves polylog query and polylog amortized update time. We present a data structure with O(log_B^2 N) query time and O(1/B^(1-epsilon) log_B N) amortized update time, where N is the number of segments, B the block size and epsilon is a small positive constant, under the assumption that all faces have constant size. This is a B^(1-epsilon) factor faster for updates than the fastest previous structure, and brings the cost of insertion and deletion down to subconstant amortized time for reasonable choices of N and B. Our structure solves the problem of vertical ray-shooting queries among a dynamic set of interior-disjoint line segments; this is well-known to solve dynamic planar point location for a connected subdivision of the plane with faces of constant size.
关键词：point location; data structures; dynamic algorithms; computational geometry