{"title":"扩充图形以最小化半径","authors":"Joachim Gudmundsson , Yuan Sha","doi":"10.1016/j.comgeo.2023.101996","DOIUrl":null,"url":null,"abstract":"<div><p>We study the problem of augmenting a metric graph by adding <em>k</em> edges while minimizing the radius of the augmented graph. We give a simple 3-approximation algorithm and show that there is no polynomial-time <span><math><mo>(</mo><mn>5</mn><mo>/</mo><mn>3</mn><mo>−</mo><mi>ϵ</mi><mo>)</mo></math></span>-approximation algorithm, for any <span><math><mi>ϵ</mi><mo>></mo><mn>0</mn></math></span>, unless <span><math><mi>P</mi><mo>=</mo><mi>N</mi><mi>P</mi></math></span>.</p><p>We also give two exact algorithms for the special case when the input graph is a tree, one of which is generalized to handle metric graphs with bounded treewidth.</p></div>","PeriodicalId":51001,"journal":{"name":"Computational Geometry-Theory and Applications","volume":null,"pages":null},"PeriodicalIF":0.4000,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Augmenting graphs to minimize the radius\",\"authors\":\"Joachim Gudmundsson , Yuan Sha\",\"doi\":\"10.1016/j.comgeo.2023.101996\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>We study the problem of augmenting a metric graph by adding <em>k</em> edges while minimizing the radius of the augmented graph. We give a simple 3-approximation algorithm and show that there is no polynomial-time <span><math><mo>(</mo><mn>5</mn><mo>/</mo><mn>3</mn><mo>−</mo><mi>ϵ</mi><mo>)</mo></math></span>-approximation algorithm, for any <span><math><mi>ϵ</mi><mo>></mo><mn>0</mn></math></span>, unless <span><math><mi>P</mi><mo>=</mo><mi>N</mi><mi>P</mi></math></span>.</p><p>We also give two exact algorithms for the special case when the input graph is a tree, one of which is generalized to handle metric graphs with bounded treewidth.</p></div>\",\"PeriodicalId\":51001,\"journal\":{\"name\":\"Computational Geometry-Theory and Applications\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.4000,\"publicationDate\":\"2023-08-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Computational Geometry-Theory and Applications\",\"FirstCategoryId\":\"94\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0925772123000160\",\"RegionNum\":4,\"RegionCategory\":\"计算机科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q4\",\"JCRName\":\"MATHEMATICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Computational Geometry-Theory and Applications","FirstCategoryId":"94","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0925772123000160","RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"MATHEMATICS","Score":null,"Total":0}
We study the problem of augmenting a metric graph by adding k edges while minimizing the radius of the augmented graph. We give a simple 3-approximation algorithm and show that there is no polynomial-time -approximation algorithm, for any , unless .
We also give two exact algorithms for the special case when the input graph is a tree, one of which is generalized to handle metric graphs with bounded treewidth.
期刊介绍:
Computational Geometry is a forum for research in theoretical and applied aspects of computational geometry. The journal publishes fundamental research in all areas of the subject, as well as disseminating information on the applications, techniques, and use of computational geometry. Computational Geometry publishes articles on the design and analysis of geometric algorithms. All aspects of computational geometry are covered, including the numerical, graph theoretical and combinatorial aspects. Also welcomed are computational geometry solutions to fundamental problems arising in computer graphics, pattern recognition, robotics, image processing, CAD-CAM, VLSI design and geographical information systems.
Computational Geometry features a special section containing open problems and concise reports on implementations of computational geometry tools.