Journal of Computer and System Sciences最新文献

On the complexity of rainbow vertex colouring diametral path graphs 关于彩虹顶点对直径路径图着色的复杂性

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2025-07-03 DOI: 10.1016/j.jcss.2025.103683

Jakob Dyrseth , Paloma T. de Lima

引用次数: 0

Making the interval membership width of temporal graphs connected and bidirectional 使时间图的区间隶属度宽度连通和双向

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2025-07-03 DOI: 10.1016/j.jcss.2025.103684

Filippos Christodoulou , Pierluigi Crescenzi , Andrea Marino , Ana Silva , Dimitrios M. Thilikos

引用次数: 0

Complexity framework for forbidden subgraphs IV: The Steiner Forest problem 禁止子图的复杂度框架IV：斯坦纳森林问题

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2025-06-27 DOI: 10.1016/j.jcss.2025.103682

Hans L. Bodlaender , Matthew Johnson , Barnaby Martin , Jelle J. Oostveen , Sukanya Pandey , Daniël Paulusma , Siani Smith , Erik Jan van Leeuwen

{"title":"Complexity framework for forbidden subgraphs IV: The Steiner Forest problem","authors":"Hans L. Bodlaender , Matthew Johnson , Barnaby Martin , Jelle J. Oostveen , Sukanya Pandey , Daniël Paulusma , Siani Smith , Erik Jan van Leeuwen","doi":"10.1016/j.jcss.2025.103682","DOIUrl":"10.1016/j.jcss.2025.103682","url":null,"abstract":"<div><div>We study <span>Steiner Forest</span> on <em>H</em>-subgraph-free graphs, that is, graphs that do not contain some fixed graph <em>H</em> as a (not necessarily induced) subgraph. In contrast to the related <span>Steiner Tree</span> problem, <span>Steiner Forest</span> falls outside a recent framework that completely characterizes the complexity of many problems on <em>H</em>-subgraph-free graphs. Hence, the complexity of <span>Steiner Forest</span> on <em>H</em>-subgraph-free graphs remained open. Our main results are four polynomial-time algorithms for different excluded graphs <em>H</em> that are central to further understand its complexity. We also study the complexity of <span>Steiner Forest</span> for graphs with a small <em>c</em>-deletion set, that is, a small set <em>X</em> of vertices such that each connected component of <span><math><mi>G</mi><mo>−</mo><mi>X</mi></math></span> has size at most <em>c</em>. For this parameter, we give two algorithms that we later employ as subroutines (including a faster algorithm when <span><math><mi>c</mi><mo>=</mo><mn>1</mn></math></span>, that is, the vertex cover number) and exhibit a dichotomy theorem.</div></div>","PeriodicalId":50224,"journal":{"name":"Journal of Computer and System Sciences","volume":"154 ","pages":"Article 103682"},"PeriodicalIF":1.1,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144557500","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 edit distance to k-subsequence universality 对k-子序列通用性的编辑距离

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2025-06-16 DOI: 10.1016/j.jcss.2025.103681

Joel D. Day , Pamela Fleischmann , Maria Kosche , Tore Koß , Florin Manea , Stefan Siemer

{"title":"The edit distance to k-subsequence universality","authors":"Joel D. Day , Pamela Fleischmann , Maria Kosche , Tore Koß , Florin Manea , Stefan Siemer","doi":"10.1016/j.jcss.2025.103681","DOIUrl":"10.1016/j.jcss.2025.103681","url":null,"abstract":"<div><div>A word <em>u</em> is a subsequence of another word <em>w</em> if <em>u</em> is obtained from <em>w</em> by deleting some of its letters. In the 1970s, Simon defined the relation <span><math><msub><mrow><mo>∼</mo></mrow><mrow><mi>k</mi></mrow></msub></math></span> (called now Simon-Congruence) as follows: two words having the same set of subsequences of length <em>k</em> are <span><math><msub><mrow><mo>∼</mo></mrow><mrow><mi>k</mi></mrow></msub></math></span>-congruent. It is thus natural to ask, for non <em>k</em>-equivalent words <em>w</em> and <em>u</em>, what is the minimal number of edit operations that we need to perform on <em>w</em> to obtain a word which is <span><math><msub><mrow><mo>∼</mo></mrow><mrow><mi>k</mi></mrow></msub></math></span>-equivalent to <em>u</em>. Here, we consider this problem in a specific setting: when <em>u</em> is a <em>k</em>-subsequence universal word. A word <em>u</em> with <span><math><mi>a</mi><mi>l</mi><mi>p</mi><mi>h</mi><mo>(</mo><mi>u</mi><mo>)</mo><mo>=</mo><mi>Σ</mi></math></span> is called <em>k</em>-subsequence universal if the set of length-<em>k</em> subsequences of <em>u</em> contains all possible words of length <em>k</em> over Σ. As such, our results are a series of efficient algorithms computing the edit distance from <em>w</em> to the language of <em>k</em>-subsequence universal words.</div></div>","PeriodicalId":50224,"journal":{"name":"Journal of Computer and System Sciences","volume":"154 ","pages":"Article 103681"},"PeriodicalIF":1.1,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144314092","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

On the parameterized complexity of lineal topologies (depth-first spanning trees) with many or few leaves 多叶或少叶线性拓扑（深度优先生成树）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 : 2025-05-27 DOI: 10.1016/j.jcss.2025.103680

Benjamin Bergougnoux , Nello Blaser , Michael Fellows , Petr Golovach , Frances Rosamond , Emmanuel Sam

{"title":"On the parameterized complexity of lineal topologies (depth-first spanning trees) with many or few leaves","authors":"Benjamin Bergougnoux , Nello Blaser , Michael Fellows , Petr Golovach , Frances Rosamond , Emmanuel Sam","doi":"10.1016/j.jcss.2025.103680","DOIUrl":"10.1016/j.jcss.2025.103680","url":null,"abstract":"<div><div>This paper considers four problems with possible applications in network design: Given a graph <em>G</em> with <span><math><mo>|</mo><mi>G</mi><mo>|</mo><mo>=</mo><mi>n</mi></math></span> and an integer <span><math><mi>k</mi><mo>≥</mo><mn>0</mn></math></span>, does <em>G</em> have a DFS tree with (i) ≤<em>k</em> leaves, (ii) ≥<em>k</em> leaves, (iii) <span><math><mo>≤</mo><mi>n</mi><mo>−</mo><mi>k</mi></math></span> leaves, and (iv) <span><math><mo>≥</mo><mi>n</mi><mo>−</mo><mi>k</mi></math></span> leaves? We show that all four problems are NP-hard. When parameterized by <em>k</em>, we prove that while (i) is para-NP-hard and (ii) is W[1]-hard, both (iii) and (iv) admit polynomial kernels with <span><math><mi>O</mi><mo>(</mo><msup><mrow><mi>k</mi></mrow><mrow><mn>3</mn></mrow></msup><mo>)</mo></math></span> vertices, implying FPT algorithms running in <span><math><msup><mrow><mi>k</mi></mrow><mrow><mi>O</mi><mo>(</mo><mi>k</mi><mo>)</mo></mrow></msup><mo>⋅</mo><msup><mrow><mi>n</mi></mrow><mrow><mi>O</mi><mo>(</mo><mn>1</mn><mo>)</mo></mrow></msup></math></span> time. Our polynomial kernels are based on a <span><math><mi>O</mi><mo>(</mo><mi>k</mi><mo>)</mo></math></span>-sized vertex cover structure associated with the solution of these problems. As a byproduct, we obtain polynomial kernels for these problems parameterized by the vertex cover number of the input graph.</div></div>","PeriodicalId":50224,"journal":{"name":"Journal of Computer and System Sciences","volume":"154 ","pages":"Article 103680"},"PeriodicalIF":1.1,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144205444","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

An FPT algorithm for timeline cover 时间线覆盖的FPT算法

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2025-05-22 DOI: 10.1016/j.jcss.2025.103679

Riccardo Dondi , Manuel Lafond

引用次数: 0

Weighted group search on the disk & improved lower bounds for priority evacuation 磁盘上的加权群搜索&改进的优先疏散下界

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2025-05-15 DOI: 10.1016/j.jcss.2025.103678

Konstantinos Georgiou, Xin Wang

引用次数: 0

Acyclic, star and injective colouring: A complexity picture for H-free graphs 无环、星形和内射着色：无h图的复杂度图

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2025-05-05 DOI: 10.1016/j.jcss.2025.103662

Jan Bok , Nikola Jedličková , Barnaby Martin , Pascal Ochem , Daniël Paulusma , Siani Smith

引用次数: 0

State complexity of one-way quantum finite automata together with classical states 单向量子有限自动机与经典态的状态复杂性

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2025-05-02 DOI: 10.1016/j.jcss.2025.103659

Ligang Xiao , Daowen Qiu

{"title":"State complexity of one-way quantum finite automata together with classical states","authors":"Ligang Xiao , Daowen Qiu","doi":"10.1016/j.jcss.2025.103659","DOIUrl":"10.1016/j.jcss.2025.103659","url":null,"abstract":"<div><div>One-way quantum finite automata together with classical states (1QFAC) proposed by Qiu et al. is a new one-way quantum finite automata (1QFA) model that integrates quantum finite automata (QFA) and deterministic finite automata (DFA). The relationshipsand balances between quantum states and classical states in 1QFAC are still not clear. In this paper, we obtain the following results: (1) We optimize the bound given by Qiu et al. that characterizes the relationships between quantum basis states and classical states as well as the equivalent minimal DFA. (2) We give an upper bound showing how many classical states are needed upon reducing the quantum basis states of 1QFAC. (3) We give a lower bound on the classical state number of 1QFAC for recognizing any given regular language, and show that the lower bound is exact if the given language is finite. (4) We show that 1QFAC are exponentially more succinct than DFA and probabilistic finite automata (PFA) for some regular languages. (5) We point out essential relationships between 1QFAC, MO-1QFA and multi-letter 1QFA, and induce a result regarding quantitative relationships between multi-letter 1QFA and DFA.</div></div>","PeriodicalId":50224,"journal":{"name":"Journal of Computer and System Sciences","volume":"154 ","pages":"Article 103659"},"PeriodicalIF":1.1,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143916823","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

Compact distributed certification of geometric graph classes 几何图类的紧凑分布证明

IF 1.1 3区计算机科学

Journal of Computer and System Sciences Pub Date : 2025-05-02 DOI: 10.1016/j.jcss.2025.103661

Benjamin Jauregui , Pedro Montealegre , Diego Ramirez-Romero , Ivan Rapaport

{"title":"Compact distributed certification of geometric graph classes","authors":"Benjamin Jauregui , Pedro Montealegre , Diego Ramirez-Romero , Ivan Rapaport","doi":"10.1016/j.jcss.2025.103661","DOIUrl":"10.1016/j.jcss.2025.103661","url":null,"abstract":"<div><div>Distributed proofs allow network nodes to collectively verify if the network satisfies a given predicate. The most versatile mechanism, known as a proof labeling scheme (PLS), functions as the distributed equivalent of NP, where a non-trustable prover assigns each node a certificate. Nodes exchange these certificates with their neighbors to prove the graph satisfies the predicate, with the certificate size being the primary complexity measure. Many graph properties, like planarity or bounded tree-width, can be certified with <span><math><mi>O</mi><mo>(</mo><mi>log</mi><mo>⁡</mo><mi>n</mi><mo>)</mo></math></span>-bit certificates on <em>n</em>-node graphs.</div><div>This paper presents <span><math><mi>O</mi><mo>(</mo><mi>log</mi><mo>⁡</mo><mi>n</mi><mo>)</mo></math></span> distributed certifications for recognizing geometric graph classes commonly found in distributed systems: interval graphs, chordal graphs, circular arc graphs, trapezoid graphs, and permutation graphs. It also establishes tight lower bounds on the certificate sizes required for these geometric intersection graph classes, proving that the proposed certifications are optimal.</div></div>","PeriodicalId":50224,"journal":{"name":"Journal of Computer and System Sciences","volume":"154 ","pages":"Article 103661"},"PeriodicalIF":1.1,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143935544","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