External data structures for shortest path queries on planar digraphs

  • Authors:
  • Lars Arge;Laura Toma

  • Affiliations:
  • Duke University, Durham, NC;Bowdoin College, Brunswick, ME

  • Venue:
  • ISAAC'05 Proceedings of the 16th international conference on Algorithms and Computation
  • Year:
  • 2005

Quantified Score

Hi-index 0.00

Visualization

Abstract

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 $S = {\it \Omega}(N^{1 + \epsilon}$) and S=O(N2/B), our main result is a family of structures that use S space and answer queries in $O({{N^{2}}\over{SB}})$I/Os, thus obtaining optimal space-query product O(N2/B). An S space structure can be constructed in $O(\sqrt{S}\cdot {\rm sort}(N))$ 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.