{"title":"Reducing the space used by the sieve of Eratosthenes when factoring","authors":"Samuel Hartman, Jonathan P. Sorenson","doi":"10.1016/j.ipl.2024.106537","DOIUrl":"10.1016/j.ipl.2024.106537","url":null,"abstract":"<div><div>We present a version of the sieve of Eratosthenes that can factor all integers ≤<em>x</em> in <span><math><mi>O</mi><mo>(</mo><mi>x</mi><mi>log</mi><mo></mo><mi>log</mi><mo></mo><mi>x</mi><mo>)</mo></math></span> arithmetic operations using at most <span><math><mi>O</mi><mo>(</mo><msqrt><mrow><mi>x</mi></mrow></msqrt><mo>/</mo><mi>log</mi><mo></mo><mi>log</mi><mo></mo><mi>x</mi><mo>)</mo></math></span> bits of space. Among algorithms that take the optimal <span><math><mi>O</mi><mo>(</mo><mi>x</mi><mi>log</mi><mo></mo><mi>log</mi><mo></mo><mi>x</mi><mo>)</mo></math></span> time, this new space bound is an improvement of a factor proportional to <span><math><mi>log</mi><mo></mo><mi>x</mi><mi>log</mi><mo></mo><mi>log</mi><mo></mo><mi>x</mi></math></span> over the implied previous bound of <span><math><mi>O</mi><mo>(</mo><msqrt><mrow><mi>x</mi></mrow></msqrt><mi>log</mi><mo></mo><mi>x</mi><mo>)</mo></math></span>. We also show our algorithm performs well in practice.</div></div>","PeriodicalId":56290,"journal":{"name":"Information Processing Letters","volume":"188 ","pages":"Article 106537"},"PeriodicalIF":0.7,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142552395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"An improved spectral lower bound of treewidth","authors":"Tatsuya Gima , Tesshu Hanaka , Kohei Noro , Hirotaka Ono , Yota Otachi","doi":"10.1016/j.ipl.2024.106536","DOIUrl":"10.1016/j.ipl.2024.106536","url":null,"abstract":"<div><div>We show that for every <em>n</em>-vertex graph with at least one edge, its treewidth is greater than or equal to <span><math><mi>n</mi><msub><mrow><mi>λ</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>/</mo><mo>(</mo><mi>Δ</mi><mo>+</mo><msub><mrow><mi>λ</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>)</mo><mo>−</mo><mn>1</mn></math></span>, where Δ and <span><math><msub><mrow><mi>λ</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span> are the maximum degree and the second smallest Laplacian eigenvalue of the graph, respectively. This lower bound improves the one by Chandran and Subramanian [<em>Inf. Process. Lett.</em>, 2003] and the subsequent one by the authors of the present paper [<em>IEICE Trans. Inf. Syst.</em>, 2024]. The new lower bound is <em>almost</em> tight in the sense that there is an infinite family of graphs such that the lower bound is only 1 less than the treewidth for each graph in the family. Additionally, using similar techniques, we also present a lower bound of treewidth in terms of the largest and the second smallest Laplacian eigenvalues.</div></div>","PeriodicalId":56290,"journal":{"name":"Information Processing Letters","volume":"188 ","pages":"Article 106536"},"PeriodicalIF":0.7,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Tighter bound for generalized multiple discrete logarithm problem via MDS matrix method","authors":"Haoxuan Wu , Jincheng Zhuang","doi":"10.1016/j.ipl.2024.106535","DOIUrl":"10.1016/j.ipl.2024.106535","url":null,"abstract":"<div><div>Discrete logarithm problem (DLP) is one of the fundamental hard problems used in cryptography. For <span><math><mn>1</mn><mo>≤</mo><mi>k</mi><mo>≤</mo><mi>n</mi></math></span>, solving the <em>k</em>-out-of-<em>n</em> DLP instances is an important problem emerging in certain scenarios in public-key cryptography. Ying and Kunihiro (ACNS 2017) pioneered in studying <em>k</em>-out-of-<em>n</em> instance solutions of DLP, which is a generalized version of multiple DLP. By reducing the multiple DLP to the generalized version, they established lower bounds on the computational complexity of <em>k</em>-out-of-<em>n</em> DLP for different parameter values of <em>k</em>.</div><div>In this paper, we further reduce the reduction complexity presented in Ying and Kunihiro's work and increase the range of <em>k</em> and <em>n</em> for the tight lower bound of <em>k</em>-out-of-<em>n</em> DLP in the generic group model, which has applications in related cryptographic schemes. To achieve the goal, the key technique is to utilize a variant of fast multipoint evaluation. We divide the discussion into two cases. In the special case when <em>n</em> divides <span><math><mi>p</mi><mo>−</mo><mn>1</mn></math></span>, by leveraging Number Theory Transform (NTT) technique, we expand <em>k</em> and <em>n</em> to a larger range. In the general case, by using a variant of fast multipoint evaluation, we increase <em>k</em> and <em>n</em> to a moderately larger range.</div></div>","PeriodicalId":56290,"journal":{"name":"Information Processing Letters","volume":"188 ","pages":"Article 106535"},"PeriodicalIF":0.7,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142441884","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
{"title":"Effective data reduction for strongly stable matching in very sparse graphs","authors":"Rosa Wolf, Klaus Heeger , André Nichterlein","doi":"10.1016/j.ipl.2024.106534","DOIUrl":"10.1016/j.ipl.2024.106534","url":null,"abstract":"<div><div>We provide a linear-time computable problem kernel of linear size for <span>Strongly Stable Roommates</span> parameterized by the feedback edge number of the acceptability graph (which encodes which agents may be matched to each other).</div></div>","PeriodicalId":56290,"journal":{"name":"Information Processing Letters","volume":"188 ","pages":"Article 106534"},"PeriodicalIF":0.7,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142441883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
{"title":"Counter abstraction for regular open teams","authors":"Shabana A.T., Alphy George, S. Sheerazuddin","doi":"10.1016/j.ipl.2024.106533","DOIUrl":"10.1016/j.ipl.2024.106533","url":null,"abstract":"<div><p>We study <em>open swarms</em> and <em>teams</em> of multi-agent systems where agents may join or leave the system at runtime. Kouvaros et al. <span><span>[1]</span></span> defined the verification problem for such systems and showed it to be undecidable, in general. Also, they have found one decidable class of open multi-agent systems and provided a partial decision procedure for another. In the same vein we present a subclass of open teams called <em>regular open teams</em> for which reachability is decidable. This is shown by employing a counter abstraction technique wherein the regular open team is abstracted into a finite state multi-counter system.</p></div>","PeriodicalId":56290,"journal":{"name":"Information Processing Letters","volume":"188 ","pages":"Article 106533"},"PeriodicalIF":0.7,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142240002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A 22k-approximation algorithm for minimum power k edge disjoint st-paths","authors":"Zeev Nutov","doi":"10.1016/j.ipl.2024.106532","DOIUrl":"10.1016/j.ipl.2024.106532","url":null,"abstract":"<div><p>In minimum power network design problems we are given an undirected graph <span><math><mi>G</mi><mo>=</mo><mo>(</mo><mi>V</mi><mo>,</mo><mi>E</mi><mo>)</mo></math></span> with edge costs <span><math><mo>{</mo><msub><mrow><mi>c</mi></mrow><mrow><mi>e</mi></mrow></msub><mo>:</mo><mi>e</mi><mo>∈</mo><mi>E</mi><mo>}</mo></math></span>. The goal is to find an edge set <span><math><mi>F</mi><mo>⊆</mo><mi>E</mi></math></span> that satisfies a prescribed property of minimum power <span><math><msub><mrow><mi>p</mi></mrow><mrow><mi>c</mi></mrow></msub><mo>(</mo><mi>F</mi><mo>)</mo><mo>=</mo><msub><mrow><mo>∑</mo></mrow><mrow><mi>v</mi><mo>∈</mo><mi>V</mi></mrow></msub><mi>max</mi><mo></mo><mo>{</mo><msub><mrow><mi>c</mi></mrow><mrow><mi>e</mi></mrow></msub><mo>:</mo><mi>e</mi><mo>∈</mo><mi>F</mi><mtext> is incident to </mtext><mi>v</mi><mo>}</mo></math></span>. In the <span>Min-Power</span> <em>k</em> <span>Edge Disjoint</span> <em>st</em><span>-Paths</span> problem <em>F</em> should contain <em>k</em> edge disjoint <em>st</em>-paths. The problem admits a <em>k</em>-approximation algorithm, and it was an open question to achieve an approximation ratio sublinear in <em>k</em> for simple graphs, even for unit costs. We give a <span><math><mn>2</mn><msqrt><mrow><mn>2</mn><mi>k</mi></mrow></msqrt></math></span>-approximation algorithm for general costs.</p></div>","PeriodicalId":56290,"journal":{"name":"Information Processing Letters","volume":"188 ","pages":"Article 106532"},"PeriodicalIF":0.7,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142012369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
George Giakkoupis , Volker Turau , Isabella Ziccardi
{"title":"Luby's MIS algorithms made self-stabilizing","authors":"George Giakkoupis , Volker Turau , Isabella Ziccardi","doi":"10.1016/j.ipl.2024.106531","DOIUrl":"10.1016/j.ipl.2024.106531","url":null,"abstract":"<div><p>We reconsider two well-known distributed randomized algorithms computing a maximal independent set, proposed in the seminal work of Luby (1986). We enhance these algorithms such that they become self-stabilizing without sacrificing their run-time, i.e., both stabilize in <span><math><mi>O</mi><mo>(</mo><mi>log</mi><mo></mo><mi>n</mi><mo>)</mo></math></span> synchronous rounds with high probability on any <em>n</em>-node graph. The first algorithm gets along with three states, but needs to know an upper bound on the maximum degree. The second does not need any information about the graph, but uses a number of states that is linear in the node degree. Both algorithms use messages of logarithmic size.</p></div>","PeriodicalId":56290,"journal":{"name":"Information Processing Letters","volume":"188 ","pages":"Article 106531"},"PeriodicalIF":0.7,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0020019024000619/pdfft?md5=8797cfe630838abf367b5e1ac7c3484f&pid=1-s2.0-S0020019024000619-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141985068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
{"title":"Algorithms for subgraph complementation to some classes of graphs","authors":"Dhanyamol Antony , Sagartanu Pal , R.B. Sandeep","doi":"10.1016/j.ipl.2024.106530","DOIUrl":"10.1016/j.ipl.2024.106530","url":null,"abstract":"<div><p>For a class <span><math><mi>G</mi></math></span> of graphs, the objective of <span>Subgraph Complementation to</span> <span><math><mi>G</mi></math></span> is to find whether there exists a subset <em>S</em> of vertices of the input graph <em>G</em> such that modifying <em>G</em> by complementing the subgraph induced by <em>S</em> results in a graph in <span><math><mi>G</mi></math></span>. We obtain a polynomial-time algorithm for the problem when <span><math><mi>G</mi></math></span> is the class of graphs with minimum degree at least <em>k</em>, for a constant <em>k</em>, answering an open problem by Fomin et al. (Algorithmica, 2020). When <span><math><mi>G</mi></math></span> is the class of graphs without any induced copies of the star graph on <span><math><mi>t</mi><mo>+</mo><mn>1</mn></math></span> vertices (for any constant <span><math><mi>t</mi><mo>≥</mo><mn>3</mn></math></span>) and diamond, we obtain a polynomial-time algorithm for the problem. This is in contrast with a result by Antony et al. (Algorithmica, 2022) that the problem is NP-complete and cannot be solved in subexponential-time (assuming the Exponential Time Hypothesis) when <span><math><mi>G</mi></math></span> is the class of graphs without any induced copies of the star graph on <span><math><mi>t</mi><mo>+</mo><mn>1</mn></math></span> vertices, for every constant <span><math><mi>t</mi><mo>≥</mo><mn>5</mn></math></span>.</p></div>","PeriodicalId":56290,"journal":{"name":"Information Processing Letters","volume":"188 ","pages":"Article 106530"},"PeriodicalIF":0.7,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141985069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"4/3 rectangle tiling lower bound","authors":"Grzegorz Głuch, Krzysztof Loryś","doi":"10.1016/j.ipl.2024.106523","DOIUrl":"10.1016/j.ipl.2024.106523","url":null,"abstract":"<div><p>The problem that we consider is the following: given an <span><math><mi>n</mi><mo>×</mo><mi>n</mi></math></span> array <em>A</em> of positive numbers and a natural number <em>p</em>, find a tiling using at most <em>p</em> rectangles (which means that each array element must be covered by some rectangle and no two rectangles must overlap) that minimizes the maximum weight of any rectangle (the weight of a rectangle is the sum of elements which are covered by it). We prove that it is NP-hard to approximate this problem to within a factor of <strong>1</strong><span><math><mfrac><mrow><mn>1</mn></mrow><mrow><mn>3</mn></mrow></mfrac></math></span> (the previous best result was <span><math><mn>1</mn><mfrac><mrow><mn>1</mn></mrow><mrow><mn>4</mn></mrow></mfrac></math></span>).</p></div>","PeriodicalId":56290,"journal":{"name":"Information Processing Letters","volume":"188 ","pages":"Article 106523"},"PeriodicalIF":0.7,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141940421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Robust probabilistic temporal logics","authors":"Martin Zimmermann","doi":"10.1016/j.ipl.2024.106522","DOIUrl":"10.1016/j.ipl.2024.106522","url":null,"abstract":"<div><p>We robustify PCTL and PCTL<sup>⁎</sup>, the most important specification languages for probabilistic systems, and show that robustness does not increase the complexity of their model-checking problems.</p></div>","PeriodicalId":56290,"journal":{"name":"Information Processing Letters","volume":"188 ","pages":"Article 106522"},"PeriodicalIF":0.7,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0020019024000528/pdfft?md5=a8b85e941455bedd212a2027c3c635b8&pid=1-s2.0-S0020019024000528-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141940422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}