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arXiv 2111.03361cs.DS
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快速确定性全动态距离逼近

Fast Deterministic Fully Dynamic Distance Approximation

Jan van den Brand, Sebastian Forster, Yasamin Nazari

摘要:

在本文中,我们开发了确定性的全动态算法计算近似距离的最坏情况下的更新时间保证的图。特别地,我们获得了改进的动态算法,给定经历边插入和删除的未加权和无向图$G=(V,E)$以及参数$ 0 < ε\leq 1 $,保持$st$的$(1+ε)$ -近似-给定节点对$ s $和$ t $之间的距离、从单个源到所有节点的距离(“SSSP”)、从多个源到所有节点的距离(“MSSP”),或者所有节点之间的距离(“APSP”)。我们的主要结果是一个确定性的算法保持$(1+ε)$ -近似$st$ -距离与最坏情况下的更新时间$O(n^{1.407})$(为当前最好的已知的约束上的矩阵乘法指数$ω$)。这甚至改进了这个问题的最快已知的随机算法。与其他几个经过充分研究的动态问题(其最新最差情况更新时间为$O(n^{1.407})$)类似,这与条件下限相匹配[BNS,FOCS 2019]。我们进一步给出了一个确定性的算法,用于保持$(1+ε)$近似单源距离的最坏情况下的更新时间$O(n^{1.529})$,这也符合一个条件的下限。在核心,我们的方法是结合代数距离维护数据结构与近添加剂仿真器建设。这也导致了新的动态算法,用于维护$(1+ε, β)$ -仿真器,改进了现有技术,这可能是独立的利益。我们的技术还导致改进的随机算法,如精确的$st$距离和直径近似的几个问题。

英文摘要:

In this paper, we develop deterministic fully dynamic algorithms for computing approximate distances in a graph with worst-case update time guarantees. In particular, we obtain improved dynamic algorithms that, given an unweighted and undirected graph $G=(V,E)$ undergoing edge insertions and deletions, and a parameter $ 0 < ε\leq 1 $, maintain $(1+ε)$-approximations of the $st$-distance between a given pair of nodes $ s $ and $ t $, the distances from a single source to all nodes ("SSSP"), the distances from multiple sources to all nodes ("MSSP"), or the distances between all nodes ("APSP"). Our main result is a deterministic algorithm for maintaining $(1+ε)$-approximate $st$-distance with worst-case update time $O(n^{1.407})$ (for the current best known bound on the matrix multiplication exponent $ω$). This even improves upon the fastest known randomized algorithm for this problem. Similar to several other well-studied dynamic problems whose state-of-the-art worst-case update time is $O(n^{1.407})$, this matches a conditional lower bound [BNS, FOCS 2019]. We further give a deterministic algorithm for maintaining $(1+ε)$-approximate single-source distances with worst-case update time $O(n^{1.529})$, which also matches a conditional lower bound. At the core, our approach is to combine algebraic distance maintenance data structures with near-additive emulator constructions. This also leads to novel dynamic algorithms for maintaining $(1+ε, β)$-emulators that improve upon the state of the art, which might be of independent interest. Our techniques also lead to improved randomized algorithms for several problems such as exact $st$-distances and diameter approximation.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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