Flavia Bonomo-Braberman , Nick Brettell , Andrea Munaro , Daniël Paulusma
{"title":"利用极小宽度求解广义凸图问题","authors":"Flavia Bonomo-Braberman , Nick Brettell , Andrea Munaro , Daniël Paulusma","doi":"10.1016/j.jcss.2023.103493","DOIUrl":null,"url":null,"abstract":"<div><p>A bipartite graph <span><math><mi>G</mi><mo>=</mo><mo>(</mo><mi>A</mi><mo>,</mo><mi>B</mi><mo>,</mo><mi>E</mi><mo>)</mo></math></span> is <span><math><mi>H</mi></math></span>-convex for some family of graphs <span><math><mi>H</mi></math></span> if there exists a graph <span><math><mi>H</mi><mo>∈</mo><mi>H</mi></math></span> with <span><math><mi>V</mi><mo>(</mo><mi>H</mi><mo>)</mo><mo>=</mo><mi>A</mi></math></span> such that the neighbours in <em>A</em> of each <span><math><mi>b</mi><mo>∈</mo><mi>B</mi></math></span> induce a connected subgraph of <em>H</em>. Many <span><math><mi>NP</mi></math></span>-complete problems are polynomial-time solvable for <span><math><mi>H</mi></math></span>-convex graphs when <span><math><mi>H</mi></math></span> is the set of paths. The underlying reason is that the class has bounded mim-width. We extend this result to families of <span><math><mi>H</mi></math></span>-convex graphs where <span><math><mi>H</mi></math></span> is the set of cycles, or <span><math><mi>H</mi></math></span> is the set of trees with bounded maximum degree and a bounded number of vertices of degree at least 3. As a consequence, we strengthen many known results via one general and short proof. We also show that the mim-width of <span><math><mi>H</mi></math></span>-convex graphs is unbounded if <span><math><mi>H</mi></math></span> is the set of trees with arbitrarily large maximum degree or an arbitrarily large number of vertices of degree at least 3.</p></div>","PeriodicalId":50224,"journal":{"name":"Journal of Computer and System Sciences","volume":"140 ","pages":"Article 103493"},"PeriodicalIF":1.1000,"publicationDate":"2023-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0022000023000983/pdfft?md5=fde8f2dacccba7a95013faa87b835770&pid=1-s2.0-S0022000023000983-main.pdf","citationCount":"0","resultStr":"{\"title\":\"Solving problems on generalized convex graphs via mim-width\",\"authors\":\"Flavia Bonomo-Braberman , Nick Brettell , Andrea Munaro , Daniël Paulusma\",\"doi\":\"10.1016/j.jcss.2023.103493\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>A bipartite graph <span><math><mi>G</mi><mo>=</mo><mo>(</mo><mi>A</mi><mo>,</mo><mi>B</mi><mo>,</mo><mi>E</mi><mo>)</mo></math></span> is <span><math><mi>H</mi></math></span>-convex for some family of graphs <span><math><mi>H</mi></math></span> if there exists a graph <span><math><mi>H</mi><mo>∈</mo><mi>H</mi></math></span> with <span><math><mi>V</mi><mo>(</mo><mi>H</mi><mo>)</mo><mo>=</mo><mi>A</mi></math></span> such that the neighbours in <em>A</em> of each <span><math><mi>b</mi><mo>∈</mo><mi>B</mi></math></span> induce a connected subgraph of <em>H</em>. Many <span><math><mi>NP</mi></math></span>-complete problems are polynomial-time solvable for <span><math><mi>H</mi></math></span>-convex graphs when <span><math><mi>H</mi></math></span> is the set of paths. The underlying reason is that the class has bounded mim-width. We extend this result to families of <span><math><mi>H</mi></math></span>-convex graphs where <span><math><mi>H</mi></math></span> is the set of cycles, or <span><math><mi>H</mi></math></span> is the set of trees with bounded maximum degree and a bounded number of vertices of degree at least 3. As a consequence, we strengthen many known results via one general and short proof. We also show that the mim-width of <span><math><mi>H</mi></math></span>-convex graphs is unbounded if <span><math><mi>H</mi></math></span> is the set of trees with arbitrarily large maximum degree or an arbitrarily large number of vertices of degree at least 3.</p></div>\",\"PeriodicalId\":50224,\"journal\":{\"name\":\"Journal of Computer and System Sciences\",\"volume\":\"140 \",\"pages\":\"Article 103493\"},\"PeriodicalIF\":1.1000,\"publicationDate\":\"2023-11-07\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.sciencedirect.com/science/article/pii/S0022000023000983/pdfft?md5=fde8f2dacccba7a95013faa87b835770&pid=1-s2.0-S0022000023000983-main.pdf\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Computer and System Sciences\",\"FirstCategoryId\":\"94\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0022000023000983\",\"RegionNum\":3,\"RegionCategory\":\"计算机科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"BUSINESS, FINANCE\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Computer and System Sciences","FirstCategoryId":"94","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0022000023000983","RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"BUSINESS, FINANCE","Score":null,"Total":0}
Solving problems on generalized convex graphs via mim-width
A bipartite graph is -convex for some family of graphs if there exists a graph with such that the neighbours in A of each induce a connected subgraph of H. Many -complete problems are polynomial-time solvable for -convex graphs when is the set of paths. The underlying reason is that the class has bounded mim-width. We extend this result to families of -convex graphs where is the set of cycles, or is the set of trees with bounded maximum degree and a bounded number of vertices of degree at least 3. As a consequence, we strengthen many known results via one general and short proof. We also show that the mim-width of -convex graphs is unbounded if is the set of trees with arbitrarily large maximum degree or an arbitrarily large number of vertices of degree at least 3.
期刊介绍:
The Journal of Computer and System Sciences publishes original research papers in computer science and related subjects in system science, with attention to the relevant mathematical theory. Applications-oriented papers may also be accepted and they are expected to contain deep analytic evaluation of the proposed solutions.
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