A Faster Deterministic Algorithm for Mader's $\mathcal{S}$-Path Packing

Fuente: arXiv
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Autori principali: Iwata, Satoru, Kinoshita, Hirota
Natura: Preprint
Pubblicazione: 2024
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author Iwata, Satoru
Kinoshita, Hirota
author_facet Iwata, Satoru
Kinoshita, Hirota
contents Given an undirected graph $G = (V,E)$ with a set of terminals $T\subseteq V$ partitioned into a family $\mathcal{S}$ of disjoint blocks, find the maximum number of vertex-disjoint paths whose endpoints belong to two distinct blocks while no other internal vertex is a terminal. This problem is called Mader's $\mathcal{S}$-path packing. It has been of remarkable interest as a common generalization of the non-bipartite matching and vertex-disjoint $s\text{-}t$ paths problem. This paper presents a new deterministic algorithm for this problem via known reduction to linear matroid parity. The algorithm utilizes the augmenting-path algorithm of Gabow and Stallmann (1986), while replacing costly matrix operations between augmentation steps with a faster algorithm that exploits the original $\mathcal{S}$-path packing instance. The proposed algorithm runs in $O(mnk)$ time, where $n = |V|$, $m = |E|$, and $k = |T|\le n$. This improves on the previous best bound $O(mn^ω)$ for deterministic algorithms, where $ω\ge2$ denotes the matrix multiplication exponent.
format Preprint
id arxiv_https___arxiv_org_abs_2411_18292
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle A Faster Deterministic Algorithm for Mader's $\mathcal{S}$-Path Packing
Iwata, Satoru
Kinoshita, Hirota
Data Structures and Algorithms
Discrete Mathematics
Combinatorics
Given an undirected graph $G = (V,E)$ with a set of terminals $T\subseteq V$ partitioned into a family $\mathcal{S}$ of disjoint blocks, find the maximum number of vertex-disjoint paths whose endpoints belong to two distinct blocks while no other internal vertex is a terminal. This problem is called Mader's $\mathcal{S}$-path packing. It has been of remarkable interest as a common generalization of the non-bipartite matching and vertex-disjoint $s\text{-}t$ paths problem. This paper presents a new deterministic algorithm for this problem via known reduction to linear matroid parity. The algorithm utilizes the augmenting-path algorithm of Gabow and Stallmann (1986), while replacing costly matrix operations between augmentation steps with a faster algorithm that exploits the original $\mathcal{S}$-path packing instance. The proposed algorithm runs in $O(mnk)$ time, where $n = |V|$, $m = |E|$, and $k = |T|\le n$. This improves on the previous best bound $O(mn^ω)$ for deterministic algorithms, where $ω\ge2$ denotes the matrix multiplication exponent.
title A Faster Deterministic Algorithm for Mader's $\mathcal{S}$-Path Packing
topic Data Structures and Algorithms
Discrete Mathematics
Combinatorics
url https://arxiv.org/abs/2411.18292