 
Summary: Cache Oblivious Distribution Sweeping
Gerth Stølting Brodal1, ,
and Rolf Fagerberg1,
BRICS , Department of Computer Science, University of Aarhus, Ny Munkegade,
DK8000 °Arhus C, Denmark. Email: {gerth,rolf}@brics.dk
Abstract We adapt the distribution sweeping method to the cache
oblivious model. Distribution sweeping is the name used for a general
approach for divideandconquer algorithms where the combination of
solved subproblems can be viewed as a merging process of streams. We
demonstrate by a series of algorithms for specific problems the feasibility
of the method in a cache oblivious setting. The problems all come from
computational geometry, and are: orthogonal line segment intersection
reporting, the all nearest neighbors problem, the 3D maxima problem,
computing the measure of a set of axisparallel rectangles, computing the
visibility of a set of line segments from a point, batched orthogonal range
queries, and reporting pairwise intersections of axisparallel rectangles.
Our basic building block is a simplified version of the cache oblivious
sorting algorithm Funnelsort of Frigo et al., which is of independent in
terest.
1 Introduction
