Summary: I/O­Efficient Dynamic Point Location in
Monotone Planar Subdivisions
(Extended Abstract)
Pankaj K. Agarwal \Lambda Lars Arge y Gerth Stølting Brodal z Jeffrey S. Vitter x
Abstract
We present an efficient external­memory dynamic data struc­
ture for point location in monotone planar subdivisions. Our
data structure uses O(N=B) disk blocks to store a monotone
subdivision of size N , where B is the size of a disk block.
It supports queries in O(log 2
B N) I/Os (worst­case) and up­
dates in O(log 2
B N) I/Os (amortized).
We also propose a new variant of B­trees, called level­
balanced B­trees, which allow insert, delete, merge, and split
operations in O((1+ b
B log M=B
N
B ) log b N) I/Os (amortized),
2 Ÿ b Ÿ B=2, even if each node stores a pointer to its par­

Source: Arge, Lars - Department of Computer Science, Aarhus Universitet

Collections: Computer Technologies and Information Sciences