A Fast 3-Approximation for the Capacitated Tree Cover Problem with Edge Loads

Fuente: arXiv
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Main Author: Rockel-Wolff, Benjamin
Format: Preprint
Published: 2024
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author Rockel-Wolff, Benjamin
author_facet Rockel-Wolff, Benjamin
contents The capacitated tree cover problem with edge loads is a variant of the tree cover problem, where we are given facility opening costs, edge costs and loads, as well as vertex loads. We try to find a tree cover of minimum cost such that the total edge and vertex load of each tree does not exceed a given bound. We present an $\mathcal{O}(m\log n)$ time 3-approximation algorithm for this problem. This is achieved by starting with a certain LP formulation. We give a combinatorial algorithm that solves the LP optimally in time $\mathcal{O}(m\log n)$. Then, we show that a linear time rounding and splitting technique leads to an integral solution that costs at most 3 times as much as the LP solution. Finally, we prove that the integrality gap of the LP is $3$, which shows that we can not improve the rounding step in general.
format Preprint
id arxiv_https___arxiv_org_abs_2404_10638
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle A Fast 3-Approximation for the Capacitated Tree Cover Problem with Edge Loads
Rockel-Wolff, Benjamin
Data Structures and Algorithms
Discrete Mathematics
Combinatorics
68R10, 68W25, 05C05, 90C27
F.2.2; G.2.1; G.2.2
The capacitated tree cover problem with edge loads is a variant of the tree cover problem, where we are given facility opening costs, edge costs and loads, as well as vertex loads. We try to find a tree cover of minimum cost such that the total edge and vertex load of each tree does not exceed a given bound. We present an $\mathcal{O}(m\log n)$ time 3-approximation algorithm for this problem. This is achieved by starting with a certain LP formulation. We give a combinatorial algorithm that solves the LP optimally in time $\mathcal{O}(m\log n)$. Then, we show that a linear time rounding and splitting technique leads to an integral solution that costs at most 3 times as much as the LP solution. Finally, we prove that the integrality gap of the LP is $3$, which shows that we can not improve the rounding step in general.
title A Fast 3-Approximation for the Capacitated Tree Cover Problem with Edge Loads
topic Data Structures and Algorithms
Discrete Mathematics
Combinatorics
68R10, 68W25, 05C05, 90C27
F.2.2; G.2.1; G.2.2
url https://arxiv.org/abs/2404.10638