External Data Structures for Shortest Path Queries on Planar Digraphs

In this paper we present space-query trade-offs for external memory data structures that answer shortest path queries on planar directed graphs. For any S = Ω(N1+ ) and S = O(N2 /B), our main result is a family of structures that use S space and answer queries in O(N2 SB ) I/Os, thus obtaining optimal space-query product O(N2 /B). An S space structure can be constructed in O( √ S · sort(N)) I/Os, where sort(N) is the number of I/Os needed to sort N elements, B is the disk block size, and N is the size of the graph.

• Type: Conference
• Year: 2005
• Where: ISAAC
• Authors: Lars Arge, Laura Toma
• Keywords: External Memory Data, ISAAC 2005, Planar Directed Graphs, Shortest Path Queries