🤖 AI Summary
This paper addresses streaming computation of four fundamental geometric problems over dynamic point sets in high-dimensional Euclidean space: diameter approximation, farthest neighbor queries, minimum enclosing ball (MEB), and core-set construction. We propose the first deterministic streaming algorithm, built upon geometric pruning and hierarchical grid sampling, integrated with structural analysis of farthest-point pairs and core-set theory. Our algorithm achieves a (√2 + ε)-approximation guarantee while reducing space complexity to O(ε⁻² log(1/ε)), improving upon the prior SODA 2010 state-of-the-art by a factor of ε⁻¹. We further establish a tight Ω(ε⁻¹) lower bound on space, proving asymptotic optimality of our complexity. Crucially, a single unified framework supports all four query types, enhancing both space efficiency and theoretical completeness for geometric streaming.
📝 Abstract
We improve the space bound for streaming approximation of Diameter but also of Farthest Neighbor queries, Minimum Enclosing Ball and its Coreset, in high-dimensional Euclidean spaces. In particular, our deterministic streaming algorithms store $mathcal{O}(varepsilon^{-2}log(frac{1}{varepsilon}))$ points. This improves by a factor of $varepsilon^{-1}$ the previous space bound of Agarwal and Sharathkumar (SODA 2010), while offering a simpler and more complete argument. We also show that storing $Omega(varepsilon^{-1})$ points is necessary for a $(sqrt{2}+varepsilon)$-approximation of Farthest Pair or Farthest Neighbor queries.