Journal of Computer and System Sciences最新文献_第9页

Parameterized complexity of dominating set variants in almost cluster and split graphs 几乎聚类图和分裂图中支配集变量的参数化复杂度

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2025-06-01 Epub Date: 2025-02-03 DOI: 10.1016/j.jcss.2025.103631

Dishant Goyal , Ashwin Jacob , Kaushtubh Kumar , Diptapriyo Majumdar , Venkatesh Raman

{"title":"Parameterized complexity of dominating set variants in almost cluster and split graphs","authors":"Dishant Goyal , Ashwin Jacob , Kaushtubh Kumar , Diptapriyo Majumdar , Venkatesh Raman","doi":"10.1016/j.jcss.2025.103631","DOIUrl":"10.1016/j.jcss.2025.103631","url":null,"abstract":"<div><div>We consider structural parameterizations of several variants of Dominating Set in the parameter ecology program. We give improved FPT algorithms and lower bounds under well-known conjectures for Dominating Set and its variants in graphs that are k vertices away from a cluster graph or a split graph. These are graphs in which there is a set of k vertices (called the modulator) whose deletion results in a cluster graph or a split graph. We also call k as the deletion distance (to the appropriate class of graphs). For example, we show that when parameterized by the deletion distance k to cluster graphs: Dominating Set, Independent Dominating Set, Dominating Clique, Efficient Dominating Set and Total Dominating Set can be solved in <math><msup><mrow><mn>3</mn></mrow><mrow><mi>k</mi></mrow></msup><msup><mrow><mi>n</mi></mrow><mrow><mi>O</mi><mo>(</mo><mn>1</mn><mo>)</mo></mrow></msup></math>-time. Additionally, when parameterized by the deletion distance k to split graphs, we prove that Efficient Dominating Set can be solved in <math><msup><mrow><mn>3</mn></mrow><mrow><mi>k</mi><mo>/</mo><mn>2</mn></mrow></msup><msup><mrow><mi>n</mi></mrow><mrow><mi>O</mi><mo>(</mo><mn>1</mn><mo>)</mo></mrow></msup></math>-time breaking the <math><msup><mrow><mn>2</mn></mrow><mrow><mi>k</mi></mrow></msup></math> barrier.</div></div>","PeriodicalId":50224,"journal":{"name":"Journal of Computer and System Sciences","volume":"150 ","pages":"Article 103631"},"PeriodicalIF":1.1,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143386924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Dense graph partitioning on sparse and dense graphs 稀疏图和密集图上的密集图分割

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2025-06-01 Epub Date: 2025-01-21 DOI: 10.1016/j.jcss.2025.103619

Cristina Bazgan , Katrin Casel , Pierre Cazals

引用次数: 0

How similar are two elections? 两次选举有多相似？

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2025-06-01 Epub Date: 2025-02-03 DOI: 10.1016/j.jcss.2025.103632

Piotr Faliszewski , Piotr Skowron , Arkadii Slinko , Krzysztof Sornat , Stanisław Szufa , Nimrod Talmon

引用次数: 0

The complexity of transitively orienting temporal graphs 传递取向时间图的复杂性

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2025-06-01 Epub Date: 2025-02-03 DOI: 10.1016/j.jcss.2025.103630

George B. Mertzios , Hendrik Molter , Malte Renken , Paul G. Spirakis , Philipp Zschoche

{"title":"The complexity of transitively orienting temporal graphs","authors":"George B. Mertzios , Hendrik Molter , Malte Renken , Paul G. Spirakis , Philipp Zschoche","doi":"10.1016/j.jcss.2025.103630","DOIUrl":"10.1016/j.jcss.2025.103630","url":null,"abstract":"<div><div>In a temporal network with discrete time-labels on its edges, information can only “flow” along sequences of edges with non-decreasing (resp. increasing) time-labels. In this paper we make a first attempt to understand how the direction of information flow on one edge can impact the direction of information flow on other edges. By naturally extending the classical notion of a transitive orientation in static graphs, we introduce the fundamental notion of a temporal transitive orientation, and we systematically investigate its algorithmic behavior. Our main result is a conceptually simple, yet technically quite involved, polynomial-time algorithm for recognizing whether a temporal graph <math><mi>G</mi></math> is transitively orientable. In wide contrast we prove that, surprisingly, it is NP-hard to recognize whether <math><mi>G</mi></math> is strictly transitively orientable. Additionally we introduce further related problems to temporal transitivity, notably among them the temporal transitive completion problem, for which we prove both algorithmic and hardness results.</div></div>","PeriodicalId":50224,"journal":{"name":"Journal of Computer and System Sciences","volume":"150 ","pages":"Article 103630"},"PeriodicalIF":1.1,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143377232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Forbidden patterns in temporal graphs resulting from encounters in a corridor 在走廊中遇到的时间图形中被禁止的模式

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2025-06-01 Epub Date: 2025-01-17 DOI: 10.1016/j.jcss.2025.103620

Mónika Csikós , Michel Habib , Minh-Hang Nguyen , Mikaël Rabie , Laurent Viennot

引用次数: 0

Dominator coloring and CD coloring in almost cluster graphs 几乎聚类图中的支配子着色和CD着色

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2025-06-01 Epub Date: 2025-02-04 DOI: 10.1016/j.jcss.2025.103633

Aritra Banik , Prahlad Narasimhan Kasthurirangan , Venkatesh Raman

{"title":"Dominator coloring and CD coloring in almost cluster graphs","authors":"Aritra Banik , Prahlad Narasimhan Kasthurirangan , Venkatesh Raman","doi":"10.1016/j.jcss.2025.103633","DOIUrl":"10.1016/j.jcss.2025.103633","url":null,"abstract":"<div><div>In this paper, we study two variants of Coloring - Dominator Coloring and Class Domination Coloring. In both problems, we are given a graph G and a <math><mi>ℓ</mi><mo>∈</mo><mi>N</mi></math> and the goal is to properly color the vertices with at most ℓ colors. In Dominator Coloring, we require for each <math><mi>v</mi><mo>∈</mo><mi>V</mi><mo>(</mo><mi>G</mi><mo>)</mo></math>, a color c such that v dominates all vertices colored c. In Class Domination Coloring, we require for each color c, a <math><mi>v</mi><mo>∈</mo><mi>V</mi><mo>(</mo><mi>G</mi><mo>)</mo></math> which dominates all vertices colored c. We prove that Dominator Coloring is FPT when parameterized by the size of a graph's CVD set and that Class Domination Coloring is FPT parameterized by CVD set size plus the number of remaining cliques. En route, we design simpler algorithms when the problems are parameterized by the size of a graph's twin cover. When the parameter is the size of a graph's clique modulator, we design a randomized single-exponential time algorithm.</div></div>","PeriodicalId":50224,"journal":{"name":"Journal of Computer and System Sciences","volume":"150 ","pages":"Article 103633"},"PeriodicalIF":1.1,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143395174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Transformation of modular robots by rotation: 3 + 1 musketeers for all orthogonally convex shapes 模块化机器人的旋转变换：3个 + 1个火枪手为所有正交凸形状

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2025-06-01 Epub Date: 2025-01-08 DOI: 10.1016/j.jcss.2024.103618

Matthew Connor, Othon Michail

{"title":"Transformation of modular robots by rotation: 3 + 1 musketeers for all orthogonally convex shapes","authors":"Matthew Connor, Othon Michail","doi":"10.1016/j.jcss.2024.103618","DOIUrl":"10.1016/j.jcss.2024.103618","url":null,"abstract":"<div><div>We study programmable matter systems consisting of modules that perform the minimal mechanical operation of rotating by 90° around each other. We represent the modules as nodes lying on the cells of a two-dimensional square grid. We are interested in characterising families whose shapes can be transformed into each other by a sequence of rotation moves that maintains global connectivity. Shapes can only be transformed into each other by rotation if they are colour-consistent, meaning that their nodes have identical colour cardinalities on a checkered colouring of the grid. We develop a generic centralised transformation and prove that, for any pair A, B of connected, colour-consistent, orthogonally convex shapes, it can transform A into B, using a seed of 3 or 4 nodes to trigger the transformation. The running time of our transformation is an optimal <math><mi>O</mi><mo>(</mo><msup><mrow><mi>n</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>)</mo></math> sequential moves, where <math><mi>n</mi><mo>=</mo><mo>|</mo><mi>A</mi><mo>|</mo><mo>=</mo><mo>|</mo><mi>B</mi><mo>|</mo></math>.</div></div>","PeriodicalId":50224,"journal":{"name":"Journal of Computer and System Sciences","volume":"150 ","pages":"Article 103618"},"PeriodicalIF":1.1,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143182271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Fast deterministic algorithms for computing all eccentricities in (hyperbolic) Helly graphs 计算（双曲）Helly图中所有偏心率的快速确定性算法

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2025-05-01 Epub Date: 2024-11-28 DOI: 10.1016/j.jcss.2024.103606

Feodor F. Dragan , Guillaume Ducoffe , Heather M. Guarnera

{"title":"Fast deterministic algorithms for computing all eccentricities in (hyperbolic) Helly graphs","authors":"Feodor F. Dragan , Guillaume Ducoffe , Heather M. Guarnera","doi":"10.1016/j.jcss.2024.103606","DOIUrl":"10.1016/j.jcss.2024.103606","url":null,"abstract":"<div><div>A graph is Helly if every family of pairwise intersecting balls has a nonempty common intersection. The class of Helly graphs is the discrete analogue of the class of hyperconvex metric spaces. We study diameter, radius and all eccentricity computations within the Helly graphs. Under plausible complexity assumptions, neither the diameter nor the radius can be computed in truly subquadratic time on general graphs. In contrast to these negative results, it was recently shown that the radius and the diameter of an n-vertex m-edge Helly graph can be computed with high probability in <math><mover><mrow><mi>O</mi></mrow><mrow><mo>˜</mo></mrow></mover><mo>(</mo><mi>m</mi><msqrt><mrow><mi>n</mi></mrow></msqrt><mo>)</mo></math> time (i.e., subquadratic in <math><mi>n</mi><mo>+</mo><mi>m</mi></math>). In this paper, we improve that result by presenting a deterministic <math><mi>O</mi><mo>(</mo><mi>m</mi><msqrt><mrow><mi>n</mi></mrow></msqrt><mo>)</mo></math>-time algorithm which computes not only the radius and the diameter but also all vertex eccentricities in a Helly graph. Furthermore, we give a parameterized linear-time algorithm for this problem on Helly graphs, with the parameter being the Gromov hyperbolicity.</div></div>","PeriodicalId":50224,"journal":{"name":"Journal of Computer and System Sciences","volume":"149 ","pages":"Article 103606"},"PeriodicalIF":1.1,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143166229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A constant-factor approximation for weighted bond cover 加权债券覆盖的常因子近似

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2025-05-01 Epub Date: 2025-01-07 DOI: 10.1016/j.jcss.2024.103617

Eun Jung Kim , Euiwoong Lee , Dimitrios M. Thilikos

{"title":"A constant-factor approximation for weighted bond cover","authors":"Eun Jung Kim , Euiwoong Lee , Dimitrios M. Thilikos","doi":"10.1016/j.jcss.2024.103617","DOIUrl":"10.1016/j.jcss.2024.103617","url":null,"abstract":"<div><div>The Weighted <math><mi>F</mi></math>-Vertex Deletion for a class <math><mi>F</mi></math> of graphs asks, weighted graph G, for a minimum weight vertex set S such that <math><mi>G</mi><mo>−</mo><mi>S</mi><mo>∈</mo><mi>F</mi></math>. The case when <math><mi>F</mi></math> is minor-closed and excludes some graph as a minor has received particular attention but a constant-factor approximation remained elusive for Weighted <math><mi>F</mi></math>-Vertex Deletion. Only three cases of minor-closed <math><mi>F</mi></math> are known to admit constant-factor approximations, namely Vertex Cover, Feedback Vertex Set and Diamond Hitting Set. We study the problem for the class <math><mi>F</mi></math> of <math><msub><mrow><mi>θ</mi></mrow><mrow><mi>c</mi></mrow></msub></math>-minor-free graphs, under the equivalent setting of the Weighted c-Bond Cover problem, and present a constant-factor approximation algorithm using the primal-dual method. Besides making an important step in the quest of (dis)proving a constant-factor approximation for Weighted <math><mi>F</mi></math>-Vertex Deletion, our result may be useful as a template for algorithms for other minor-closed families.</div></div>","PeriodicalId":50224,"journal":{"name":"Journal of Computer and System Sciences","volume":"149 ","pages":"Article 103617"},"PeriodicalIF":1.1,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143166231","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Relating description complexity to entropy 将描述复杂性与熵联系起来

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2025-05-01 Epub Date: 2024-12-11 DOI: 10.1016/j.jcss.2024.103615

Reijo Jaakkola , Antti Kuusisto , Miikka Vilander

{"title":"Relating description complexity to entropy","authors":"Reijo Jaakkola , Antti Kuusisto , Miikka Vilander","doi":"10.1016/j.jcss.2024.103615","DOIUrl":"10.1016/j.jcss.2024.103615","url":null,"abstract":"<div><div>We demonstrate novel links between entropy and description complexity, a notion referring to the minimal formula length for specifying given properties. Let PLC denote propositional logic with the ability to count assignments, and let <math><msup><mrow><mi>PLC</mi></mrow><mrow><mn>1</mn></mrow></msup></math> be the fragment that counts only to one, essentially quantifying assignments. In the finite, <math><msup><mrow><mi>PLC</mi></mrow><mrow><mn>1</mn></mrow></msup></math> is expressively complete for specifying sets of variable assignments, while PLC is expressively complete for multisets. We show that for both logics, the model classes with maximal Boltzmann entropy are the ones with maximal description complexity. Concerning PLC, we show that expected Boltzmann entropy is asymptotically equivalent to expected description complexity multiplied by the number of proposition symbols considered. For contrast, we prove this link breaks for first-order logic over vocabularies with higher-arity relations. Our results relate to links between Kolmogorov complexity and entropy, providing analogous results in the logic-based scenario with relational structures classified by formulas of different sizes.</div></div>","PeriodicalId":50224,"journal":{"name":"Journal of Computer and System Sciences","volume":"149 ","pages":"Article 103615"},"PeriodicalIF":1.1,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143166230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0