NP-hardness and a PTAS for the Euclidean Steiner Line Problem

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Bartlmae, Simon, Jünger, Paul J., Langetepe, Elmar
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866915055733309440
author Bartlmae, Simon
Jünger, Paul J.
Langetepe, Elmar
author_facet Bartlmae, Simon
Jünger, Paul J.
Langetepe, Elmar
contents The Euclidean Steiner Tree Problem (EST) seeks a minimum-cost tree interconnecting a given set of terminal points in the Euclidean plane, allowing the use of additional intersection points. In this paper, we consider two variants that include an additional straight line $γ$ with zero cost, which must be incorporated into the tree. In the Euclidean Steiner fixed Line Problem (ESfL), this line is given as input and can be treated as a terminal. In contrast, the Euclidean Steiner Line Problem (ESL) requires determining the optimal location of $γ$. Despite recent advances, including heuristics and a 1.214-approximation algorithm for both problems, a formal proof of NP-hardness has remained open. In this work, we close this gap by proving that both the ESL and ESfL are NP-hard. Additionally, we prove that both problems admit a polynomial-time approximation scheme (PTAS), by demonstrating that approximation algorithms for the EST can be adapted to the ESL and ESfL with appropriate modifications. Specifically, we show ESfL$\leq_{\text{PTAS}}$EST and ESL$\leq_{\text{PTAS}}$EST, i.e., provide a PTAS reduction to the EST.
format Preprint
id arxiv_https___arxiv_org_abs_2412_07046
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle NP-hardness and a PTAS for the Euclidean Steiner Line Problem
Bartlmae, Simon
Jünger, Paul J.
Langetepe, Elmar
Computational Geometry
Data Structures and Algorithms
The Euclidean Steiner Tree Problem (EST) seeks a minimum-cost tree interconnecting a given set of terminal points in the Euclidean plane, allowing the use of additional intersection points. In this paper, we consider two variants that include an additional straight line $γ$ with zero cost, which must be incorporated into the tree. In the Euclidean Steiner fixed Line Problem (ESfL), this line is given as input and can be treated as a terminal. In contrast, the Euclidean Steiner Line Problem (ESL) requires determining the optimal location of $γ$. Despite recent advances, including heuristics and a 1.214-approximation algorithm for both problems, a formal proof of NP-hardness has remained open. In this work, we close this gap by proving that both the ESL and ESfL are NP-hard. Additionally, we prove that both problems admit a polynomial-time approximation scheme (PTAS), by demonstrating that approximation algorithms for the EST can be adapted to the ESL and ESfL with appropriate modifications. Specifically, we show ESfL$\leq_{\text{PTAS}}$EST and ESL$\leq_{\text{PTAS}}$EST, i.e., provide a PTAS reduction to the EST.
title NP-hardness and a PTAS for the Euclidean Steiner Line Problem
topic Computational Geometry
Data Structures and Algorithms
url https://arxiv.org/abs/2412.07046