Journal of Computer and System Sciences最新文献

Embedding hypercubes into torus and Cartesian product of paths and/or cycles for minimizing wirelength 将超立方体嵌入环面和路径及/或循环的笛卡尔乘积，以尽量减少线长

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2024-11-13 DOI: 10.1016/j.jcss.2024.103603

Zhiyi Tang

引用次数: 0

Algorithms and Turing kernels for detecting and counting small patterns in unit disk graphs 检测和计算单位盘图中的小模式的算法和图灵内核

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2024-11-05 DOI: 10.1016/j.jcss.2024.103600

Jesper Nederlof, Krisztina Szilágyi

{"title":"Algorithms and Turing kernels for detecting and counting small patterns in unit disk graphs","authors":"Jesper Nederlof, Krisztina Szilágyi","doi":"10.1016/j.jcss.2024.103600","DOIUrl":"10.1016/j.jcss.2024.103600","url":null,"abstract":"<div><div>In this paper we investigate the parameterized complexity of counting and detecting small patterns in unit disk graphs: Given an n-vertex unit disk graph G with an embedding of ply p (i.e. G is an intersection graph of closed unit disks, and each point is contained in at most p disks) and a k-vertex unit disk graph P, count the number of (induced) copies of P in G. For general patterns P, we give an <math><msup><mrow><mn>2</mn></mrow><mrow><mi>O</mi><mo>(</mo><mi>p</mi><mi>k</mi><mo>/</mo><mi>log</mi><mo>⁡</mo><mi>k</mi><mo>)</mo></mrow></msup><msup><mrow><mi>n</mi></mrow><mrow><mi>O</mi><mo>(</mo><mn>1</mn><mo>)</mo></mrow></msup></math> time algorithm for counting pattern occurrences. We show this is tight, even for ply <math><mi>p</mi><mo>=</mo><mn>2</mn></math>: any <math><msup><mrow><mn>2</mn></mrow><mrow><mi>o</mi><mo>(</mo><mi>n</mi><mo>/</mo><mi>log</mi><mo>⁡</mo><mi>n</mi><mo>)</mo></mrow></msup><msup><mrow><mi>n</mi></mrow><mrow><mi>O</mi><mo>(</mo><mn>1</mn><mo>)</mo></mrow></msup></math> time algorithm violates the Exponential Time Hypothesis (ETH). Our approach combines tools developed for planar subgraph isomorphism such as ‘efficient inclusion-exclusion’ from Nederlof (2020) [15], and ‘isomorphisms checks’ from Bodlaender et al. (2016) [5] with a different separator hierarchy and a new bound on the number of non-isomorphic separations tailored for unit disk graphs.</div></div>","PeriodicalId":50224,"journal":{"name":"Journal of Computer and System Sciences","volume":"148 ","pages":"Article 103600"},"PeriodicalIF":1.1,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654144","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

Backwards-reachability for cooperating multi-pushdown systems 多推杆合作系统的后向可达性

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2024-10-31 DOI: 10.1016/j.jcss.2024.103601

Chris Köcher , Dietrich Kuske

引用次数: 0

On computing optimal temporal branchings and spanning subgraphs 关于计算最佳时间分支和跨度子图

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2024-10-22 DOI: 10.1016/j.jcss.2024.103596

Daniela Bubboloni , Costanza Catalano , Andrea Marino , Ana Silva

引用次数: 0

Single-exponential FPT algorithms for enumerating secluded F-free subgraphs and deleting to scattered graph classes 枚举僻静无 F 子图和删除到分散图类的单指数 FPT 算法

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2024-10-21 DOI: 10.1016/j.jcss.2024.103597

Bart M.P. Jansen , Jari J.H. de Kroon , Michał Włodarczyk

{"title":"Single-exponential FPT algorithms for enumerating secluded F-free subgraphs and deleting to scattered graph classes","authors":"Bart M.P. Jansen , Jari J.H. de Kroon , Michał Włodarczyk","doi":"10.1016/j.jcss.2024.103597","DOIUrl":"10.1016/j.jcss.2024.103597","url":null,"abstract":"<div><div>The celebrated notion of important separators bounds the number of small <math><mo>(</mo><mi>S</mi><mo>,</mo><mi>T</mi><mo>)</mo></math>-separators in a graph which are ‘farthest from S’ in a technical sense. In this paper, we introduce a generalization of this powerful algorithmic primitive, tailored to undirected graphs, that is phrased in terms of k-secluded vertex sets: sets with an open neighborhood of size at most k. In this terminology, the bound on important separators says that there are at most <math><msup><mrow><mn>4</mn></mrow><mrow><mi>k</mi></mrow></msup></math> maximal k-secluded connected vertex sets C containing S but disjoint from T. We generalize this statement significantly: even when we demand that <math><mi>G</mi><mo>[</mo><mi>C</mi><mo>]</mo></math> avoids a finite set <math><mi>F</mi></math> of forbidden induced subgraphs, the number of such maximal subgraphs is <math><msup><mrow><mn>2</mn></mrow><mrow><mi>O</mi><mo>(</mo><mi>k</mi><mo>)</mo></mrow></msup></math> and they can be enumerated efficiently. This enumeration algorithm allows us to give improved parameterized algorithms for Connected k-Secluded <math><mi>F</mi></math>-Free Subgraph and for deleting into scattered graph classes.</div></div>","PeriodicalId":50224,"journal":{"name":"Journal of Computer and System Sciences","volume":"148 ","pages":"Article 103597"},"PeriodicalIF":1.1,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554741","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

Parameterized results on acyclic matchings with implications for related problems 非循环匹配的参数化结果及其对相关问题的影响

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2024-10-21 DOI: 10.1016/j.jcss.2024.103599

Juhi Chaudhary , Meirav Zehavi

{"title":"Parameterized results on acyclic matchings with implications for related problems","authors":"Juhi Chaudhary , Meirav Zehavi","doi":"10.1016/j.jcss.2024.103599","DOIUrl":"10.1016/j.jcss.2024.103599","url":null,"abstract":"<div><div>A matching M in a graph G is an acyclic matching if the subgraph of G induced by the endpoints of the edges of M is a forest. Given a graph G and <math><mi>ℓ</mi><mo>∈</mo><mi>N</mi></math>, Acyclic Matching asks whether G has an acyclic matching of size at least ℓ. In this paper, we prove that assuming <math><mi>W</mi><mo>[</mo><mn>1</mn><mo>]</mo><mo>⊈</mo><mi>FPT</mi></math>, there does not exist any <math><mi>FPT</mi></math>-approximation algorithm for Acyclic Matching that approximates it within a constant factor when parameterized by ℓ. Our reduction also asserts <math><mi>FPT</mi></math>-inapproximability for Induced Matching and Uniquely Restricted Matching. We also consider three below-guarantee parameters for Acyclic Matching, viz. <math><mfrac><mrow><mi>n</mi></mrow><mrow><mn>2</mn></mrow></mfrac><mo>−</mo><mi>ℓ</mi></math>, <math><mrow><mi>MM</mi><mo>(</mo><mi>G</mi><mo>)</mo></mrow><mo>−</mo><mi>ℓ</mi></math>, and <math><mrow><mi>IS</mi><mo>(</mo><mi>G</mi><mo>)</mo></mrow><mo>−</mo><mi>ℓ</mi></math>, where <math><mi>n</mi><mo>=</mo><mi>V</mi><mo>(</mo><mi>G</mi><mo>)</mo></math>, <math><mi>MM</mi><mo>(</mo><mi>G</mi><mo>)</mo></math> is the matching number, and <math><mi>IS</mi><mo>(</mo><mi>G</mi><mo>)</mo></math> is the independence number of G. Also, we show that Acyclic Matching does not exhibit a polynomial kernel with respect to vertex cover number (or vertex deletion distance to clique) plus the size of the matching unless <math><mrow><mi>NP</mi></mrow><mo>⊆</mo><mrow><mi>coNP</mi></mrow><mo>/</mo><mrow><mi>poly</mi></mrow></math>.</div></div>","PeriodicalId":50224,"journal":{"name":"Journal of Computer and System Sciences","volume":"148 ","pages":"Article 103599"},"PeriodicalIF":1.1,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142530067","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

Exact and parameterized algorithms for the independent cutset problem 独立切集问题的精确算法和参数化算法

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2024-10-18 DOI: 10.1016/j.jcss.2024.103598

Johannes Rauch , Dieter Rautenbach , Uéverton S. Souza

{"title":"Exact and parameterized algorithms for the independent cutset problem","authors":"Johannes Rauch , Dieter Rautenbach , Uéverton S. Souza","doi":"10.1016/j.jcss.2024.103598","DOIUrl":"10.1016/j.jcss.2024.103598","url":null,"abstract":"<div><div>The Independent Cutset problem asks whether there is a set of vertices in a given graph that is both independent and a cutset. This problem is <figure><img></figure>-complete even when the input graph is planar and has maximum degree five. We first present a <math><msup><mrow><mi>O</mi></mrow><mrow><mo>⁎</mo></mrow></msup><mo>(</mo><msup><mrow><mn>1.4423</mn></mrow><mrow><mi>n</mi></mrow></msup><mo>)</mo></math>-time algorithm to compute a minimum independent cutset (if any). Since the property of having an independent cutset is MSO1-expressible, our main results are concerned with structural parameterizations for the problem considering parameters incomparable with clique-width. We present <figure><img></figure>-time algorithms under the following parameters: the dual of the maximum degree, the dual of the solution size, the size of a dominating set (where a dominating set is given as an additional input), the size of an odd cycle transversal, the distance to chordal graphs, and the distance to <math><msub><mrow><mi>P</mi></mrow><mrow><mn>5</mn></mrow></msub></math>-free graphs. We close by introducing the notion of α-domination, which generalizes key ideas of this article.</div></div>","PeriodicalId":50224,"journal":{"name":"Journal of Computer and System Sciences","volume":"148 ","pages":"Article 103598"},"PeriodicalIF":1.1,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554742","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

Approximate realizations for outerplanaric degree sequences 外平面度序列的近似实现

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2024-10-10 DOI: 10.1016/j.jcss.2024.103588

Amotz Bar-Noy , Toni Böhnlein , David Peleg , Yingli Ran , Dror Rawitz

{"title":"Approximate realizations for outerplanaric degree sequences","authors":"Amotz Bar-Noy , Toni Böhnlein , David Peleg , Yingli Ran , Dror Rawitz","doi":"10.1016/j.jcss.2024.103588","DOIUrl":"10.1016/j.jcss.2024.103588","url":null,"abstract":"<div><div>We study the question of whether a sequence <math><mi>d</mi><mo>=</mo><mo>(</mo><msub><mrow><mi>d</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>,</mo><mo>…</mo><mo>,</mo><msub><mrow><mi>d</mi></mrow><mrow><mi>n</mi></mrow></msub><mo>)</mo></math> of positive integers is the degree sequence of some outerplanar graph G. If so, G is an outerplanar realization of d and d is an outerplanaric sequence. The case where <math><mo>∑</mo><mi>d</mi><mo>≤</mo><mn>2</mn><mi>n</mi><mo>−</mo><mn>2</mn></math> is easy, as d has a realization by a forest. In this paper, we consider the family <math><mi>D</mi></math> of all sequences d of even sum <math><mn>2</mn><mi>n</mi><mo>≤</mo><mo>∑</mo><mi>d</mi><mo>≤</mo><mn>4</mn><mi>n</mi><mo>−</mo><mn>6</mn><mo>−</mo><mn>2</mn><msub><mrow><mi>ω</mi></mrow><mrow><mn>1</mn></mrow></msub></math>, where <math><msub><mrow><mi>ω</mi></mrow><mrow><mi>x</mi></mrow></msub></math> is the number of x's in d. We partition <math><mi>D</mi></math> into two disjoint subfamilies, <math><mi>D</mi><mo>=</mo><msub><mrow><mi>D</mi></mrow><mrow><mi>N</mi><mi>O</mi><mi>P</mi></mrow></msub><mo>∪</mo><msub><mrow><mi>D</mi></mrow><mrow><mn>2</mn><mi>P</mi><mi>B</mi><mi>E</mi></mrow></msub></math>, such that every sequence in <math><msub><mrow><mi>D</mi></mrow><mrow><mi>N</mi><mi>O</mi><mi>P</mi></mrow></msub></math> is provably non-outerplanaric, and every sequence in <math><msub><mrow><mi>D</mi></mrow><mrow><mn>2</mn><mi>P</mi><mi>B</mi><mi>E</mi></mrow></msub></math> is given a realizing graph G enjoying a 2-page book embedding (and moreover, one of the pages is also bipartite).</div></div>","PeriodicalId":50224,"journal":{"name":"Journal of Computer and System Sciences","volume":"148 ","pages":"Article 103588"},"PeriodicalIF":1.1,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142530102","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

The complexity of growing a graph 图形增长的复杂性

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2024-09-27 DOI: 10.1016/j.jcss.2024.103587

George Mertzios , Othon Michail , George Skretas , Paul G. Spirakis , Michail Theofilatos

引用次数: 0

Priority Promotion with Parysian flair 具有 Parysian 特色的优先权推广

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2024-08-28 DOI: 10.1016/j.jcss.2024.103580

Massimo Benerecetti , Daniele Dell'Erba , Fabio Mogavero , Sven Schewe , Dominik Wojtczak

引用次数: 0