Simpler and Faster Directed Low-Diameter Decompositions
Jason Li
TL;DR
This work presents a simpler and faster algorithm for directed low-diameter decompositions that matches the best known loss factor $ell(n)=O(log n\ log log n)$ and improves running time to $O((m+n\ log\log n)\ log^2 n)$ for graphs with integral, polynomially-bounded weights. The approach replaces geometric ball-growing with CKR-style uniform-radius balls processed in random order and introduces heavy-vertex elimination to reduce recursion depth, enabling a robust, near-linear-time decomposition. By combining these techniques with a careful probabilistic analysis of edge cuts and a recursive Seymour-like framework, the paper achieves the same asymptotic loss as prior work while significantly improving practical efficiency. The results advance directed LDDs as a tool for near-linear time graph algorithms and related applications in directed settings, including negative-weight shortest-path-related techniques and multi-cut problems.
Abstract
We present a simpler and faster algorithm for low-diameter decompositions on directed graphs, matching the $O(\log n\log\log n)$ loss factor from Bringmann, Fischer, Haeupler, and Latypov (ICALP 2025) and improving the running time to $O((m+n\log\log n)\log^2n)$.
