English

Nearly Optimal Fault Tolerant Distance Oracle

Data Structures and Algorithms 2026-04-08 v8

Abstract

We present an ff-fault tolerant distance oracle for an undirected weighted graph where each edge has an integral weight from [1W][1 \dots W]. Given a set FF of ff edges, as well as a source node ss and a destination node tt, our oracle returns the \emph{shortest path} from ss to tt avoiding FF in O((cflog(nW))O(f2))O((cf \log (nW))^{O(f^2)}) time, where c>1c > 1 is a constant. The space complexity of our oracle is O(f4n2log2(nW))O(f^4n^2\log^2 (nW)). For a constant ff, our oracle is nearly optimal both in terms of space and time (barring some logarithmic factor).

Keywords

Cite

@article{arxiv.2402.12832,
  title  = {Nearly Optimal Fault Tolerant Distance Oracle},
  author = {Dipan Dey and Manoj Gupta},
  journal= {arXiv preprint arXiv:2402.12832},
  year   = {2026}
}

Comments

We found the following error in the paper: in subcase (b) of case (III) of Section 9.3.1, we claimed that $se_k=su \odot ue_k$, which is not correct in some cases. For example, when $x$ and $e_k$ lie on different branches of $T_s$, it may be that in $T_x$, the path from $x$ to $e_k$ uses a different path that goes through $u$. However, the technical claims about the Jump Sequence are correct