{"title":"The Maximum 4-Vertex-Path Packing of a Cubic Graph Covers At Least Two-Thirds of Its Vertices","authors":"","doi":"10.1007/s00373-023-02732-x","DOIUrl":null,"url":null,"abstract":"<h3>Abstract</h3> <p>Let <span> <span>\\(P_4\\)</span> </span> denote the path on four vertices. A <span> <span>\\(P_4\\)</span> </span>-packing of a graph <em>G</em> is a collection of vertex-disjoint copies of <span> <span>\\(P_4\\)</span> </span> in <em>G</em>. The maximum <span> <span>\\(P_4\\)</span> </span>-packing problem is to find a <span> <span>\\(P_4\\)</span> </span>-packing of maximum cardinality in a graph. In this paper, we prove that every simple cubic graph <em>G</em> on <em>v</em>(<em>G</em>) vertices has a <span> <span>\\(P_4\\)</span> </span>-packing covering at least <span> <span>\\(\\frac{2v(G)}{3}\\)</span> </span> vertices of <em>G</em> and that this lower bound is sharp. Our proof provides a quadratic-time algorithm for finding such a <span> <span>\\(P_4\\)</span> </span>-packing of a simple cubic graph.</p>","PeriodicalId":12811,"journal":{"name":"Graphs and Combinatorics","volume":"33 1","pages":""},"PeriodicalIF":0.6000,"publicationDate":"2023-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Graphs and Combinatorics","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.1007/s00373-023-02732-x","RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 0
Abstract
Let \(P_4\) denote the path on four vertices. A \(P_4\)-packing of a graph G is a collection of vertex-disjoint copies of \(P_4\) in G. The maximum \(P_4\)-packing problem is to find a \(P_4\)-packing of maximum cardinality in a graph. In this paper, we prove that every simple cubic graph G on v(G) vertices has a \(P_4\)-packing covering at least \(\frac{2v(G)}{3}\) vertices of G and that this lower bound is sharp. Our proof provides a quadratic-time algorithm for finding such a \(P_4\)-packing of a simple cubic graph.
期刊介绍:
Graphs and Combinatorics is an international journal devoted to research concerning all aspects of combinatorial mathematics. In addition to original research papers, the journal also features survey articles from authors invited by the editorial board.