Jan Bok , Nikola Jedličková , Barnaby Martin , Pascal Ochem , Daniël Paulusma , Siani Smith
{"title":"无环、星形和内射着色:无h图的复杂度图","authors":"Jan Bok , Nikola Jedličková , Barnaby Martin , Pascal Ochem , Daniël Paulusma , Siani Smith","doi":"10.1016/j.jcss.2025.103662","DOIUrl":null,"url":null,"abstract":"<div><div>A (proper) colouring is acyclic, star, or injective if any two colour classes induce a forest, star forest or disjoint union of vertices and edges, respectively. The corresponding decision problems are <span>Acyclic Colouring</span>, <span>Star Colouring</span> and <span>Injective Colouring</span>. We give almost complete complexity classifications for <span>Acyclic Colouring</span>, <span>Star Colouring</span> and <span>Injective Colouring</span> on <em>H</em>-free graphs (for each of the problems, we have one open case). Moreover, we give full complexity classifications if the number of colours <em>k</em> is fixed, that is, not part of the input. From our study it follows that for fixed <em>k</em>, the three problems behave in the same way, but this is no longer true if <em>k</em> is part of the input. To obtain several of our results we prove stronger complexity results that in particular involve the girth of a graph and the class of line graphs of multigraphs.</div></div>","PeriodicalId":50224,"journal":{"name":"Journal of Computer and System Sciences","volume":"154 ","pages":"Article 103662"},"PeriodicalIF":1.1000,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Acyclic, star and injective colouring: A complexity picture for H-free graphs\",\"authors\":\"Jan Bok , Nikola Jedličková , Barnaby Martin , Pascal Ochem , Daniël Paulusma , Siani Smith\",\"doi\":\"10.1016/j.jcss.2025.103662\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>A (proper) colouring is acyclic, star, or injective if any two colour classes induce a forest, star forest or disjoint union of vertices and edges, respectively. The corresponding decision problems are <span>Acyclic Colouring</span>, <span>Star Colouring</span> and <span>Injective Colouring</span>. We give almost complete complexity classifications for <span>Acyclic Colouring</span>, <span>Star Colouring</span> and <span>Injective Colouring</span> on <em>H</em>-free graphs (for each of the problems, we have one open case). Moreover, we give full complexity classifications if the number of colours <em>k</em> is fixed, that is, not part of the input. From our study it follows that for fixed <em>k</em>, the three problems behave in the same way, but this is no longer true if <em>k</em> is part of the input. To obtain several of our results we prove stronger complexity results that in particular involve the girth of a graph and the class of line graphs of multigraphs.</div></div>\",\"PeriodicalId\":50224,\"journal\":{\"name\":\"Journal of Computer and System Sciences\",\"volume\":\"154 \",\"pages\":\"Article 103662\"},\"PeriodicalIF\":1.1000,\"publicationDate\":\"2025-05-05\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"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/S0022000025000443\",\"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/S0022000025000443","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}
Acyclic, star and injective colouring: A complexity picture for H-free graphs
A (proper) colouring is acyclic, star, or injective if any two colour classes induce a forest, star forest or disjoint union of vertices and edges, respectively. The corresponding decision problems are Acyclic Colouring, Star Colouring and Injective Colouring. We give almost complete complexity classifications for Acyclic Colouring, Star Colouring and Injective Colouring on H-free graphs (for each of the problems, we have one open case). Moreover, we give full complexity classifications if the number of colours k is fixed, that is, not part of the input. From our study it follows that for fixed k, the three problems behave in the same way, but this is no longer true if k is part of the input. To obtain several of our results we prove stronger complexity results that in particular involve the girth of a graph and the class of line graphs of multigraphs.
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.
Research areas include traditional subjects such as:
• Theory of algorithms and computability
• Formal languages
• Automata theory
Contemporary subjects such as:
• Complexity theory
• Algorithmic Complexity
• Parallel & distributed computing
• Computer networks
• Neural networks
• Computational learning theory
• Database theory & practice
• Computer modeling of complex systems
• Security and Privacy.