Approximate distance oracles for geometric spanners
Given an arbitrary real constant epsilon > 0, and a geometric graph G in d-dimensional Euclidean space with n points, O(n) edges, and constant dilation, our main result is a data structure that answers (1 + epsilon)-approximate shortest-path-length queries in constant time. The data structure can be constructed in O( n log n) time using O( n log n) space. This represents the first data structure t