PhD Seminar • Algorithms and Complexity • Distance Oracles for Interval Graphs via Breadth-First Rank/Select in Succinct Trees

Wednesday, February 1, 2023 2:00 pm - 3:00 pm EST (GMT -05:00)

Please note: This PhD seminar will take place in DC 1304 and virtually over Zoom.

Kaiyu (Kevin) Wu, PhD candidate
David R. Cheriton School of Computer Science

Supervisor: Professor J. Ian Munro

We present succinct distance oracles for (unweighted) interval graphs and related classes of graphs, using a novel succinct data structure for ordinal trees that supports the mapping between preorder (i.e., depth-first) ranks and level-order (breadth-first) ranks of nodes in constant time.

Our distance oracles for interval graphs also support navigation queries — testing adjacency, computing node degrees, neighborhoods, and shortest paths — all in optimal time. Our technique also yields optimal distance oracles for proper interval graphs (unit-interval graphs) and circular-arc graphs. Our tree data structure supports all operations provided by different approaches in previous work, as well as mapping to and from level-order ranks and retrieving the last (first) internal node before (after) a given node in a level-order traversal, all in constant time.