Algorithmica最新文献_第2页

The SLO Hierarchy of Pseudo-Boolean Functions and Runtime of Evolutionary Algorithms 伪布尔函数的SLO层次结构与进化算法的运行时间。

IF 0.7 4区计算机科学

Algorithmica Pub Date : 2026-03-24 DOI: 10.1007/s00453-025-01359-z

Duc-Cuong Dang, Per Kristian Lehre

{"title":"The SLO Hierarchy of Pseudo-Boolean Functions and Runtime of Evolutionary Algorithms","authors":"Duc-Cuong Dang, Per Kristian Lehre","doi":"10.1007/s00453-025-01359-z","DOIUrl":"10.1007/s00453-025-01359-z","url":null,"abstract":"<div>While some common fitness landscape characteristics are critical when determining the runtime of evolutionary algorithms (EAs), the relationship between fitness landscape structure and the runtime of EAs is poorly understood. Recently, Dang, Eremeev, and Lehre introduced a classification of pseudo-Boolean problems showing that “sparsity” of local optima and the “density” of fitness valleys can be crucial characteristics when determining the runtime of EAs Dang et al. (in Proceedings of the Genetic and Evolutionary Computation Conference. Association for Computing Machinery, New York, NY, USA, GECCO’21, pp 1133–1141, https://doi.org/10.1145/3449639.3459398, 2021c). However, their approach could only classify some classes of pseudo-Boolean functions and thus defined an incomplete hierarchy. We generalise the previous work to a complete hierarchy for all pseudo-Boolean functions, denoted Slo(^alpha _{varepsilon ,r}). The hierarchy is consistent with existing results for the runtime of EAs. The easiest problems are in Slo(^{alpha }_{varepsilon }) for (alpha =1) and (varepsilon =0). As we increase (varepsilon ) and decrease (alpha ), the function class contains more interesting functions, including instances of hard combinatorial optimisation problems and problems perturbed by static noise. For (alpha =O(1/n)) and (varepsilon =1,) the problem class contains every problem, including problems closed under permutation (No Free Lunch). Problem classes where local optima sparsity exceed fitness valley density are shown to have exponential black-box complexity. We also study how random perturbations of a function can change its classification. E.g., randomly perturbing search points in OneMax with constant probability leads to a problem class that can still be optimised efficiently with appropriately tuned non-elitist EAs.</div>","PeriodicalId":50824,"journal":{"name":"Algorithmica","volume":"88 2","pages":""},"PeriodicalIF":0.7,"publicationDate":"2026-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13013112/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147522531","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}

引用次数: 0

Shortest Two Disjoint Paths in Conservative Graphs 保守图中最短的两条不相交路径

IF 0.7 4区计算机科学

Algorithmica Pub Date : 2026-03-21 DOI: 10.1007/s00453-026-01375-7

Ildikó Schlotter

引用次数: 0

Max-Utility Matchings with Popularity via Critical Vertices 通过关键顶点与人气的最大效用匹配

IF 0.7 4区计算机科学

Algorithmica Pub Date : 2026-03-19 DOI: 10.1007/s00453-025-01347-3

Telikepalli Kavitha

{"title":"Max-Utility Matchings with Popularity via Critical Vertices","authors":"Telikepalli Kavitha","doi":"10.1007/s00453-025-01347-3","DOIUrl":"10.1007/s00453-025-01347-3","url":null,"abstract":"<div>Let G be a bipartite graph where every vertex has a strict preference order over its neighbors. The preferences of a vertex over its neighbors extend naturally to preferences over matchings. A matching N is more popular than matching M if the vertices that prefer N to M outnumber those that prefer M to N. A matching M is popular if there is no matching more popular than M. Every stable matching is popular, thus popular matchings always exist in G and can be efficiently computed. We consider the following problem: edges in G have utilities and it is only max-utility matchings that are relevant. Our goal is to find a popular max-utility matching, i.e., a max-utility matching M such that there is no max-utility matching more popular than M. We show there always exists a popular max-utility matching; furthermore, such a matching can be efficiently computed. The popular critical matching algorithm is the key subroutine in our algorithm. Given a set of prioritized or critical vertices in G, we are interested in only those matchings that match as many critical vertices as possible. We call such matchings “critical” and seek a popular critical matching, i.e., a critical matching M such that there is no critical matching more popular than M. We show popular critical matchings always exist in G and a min-size/max-size such matching can be efficiently computed. We focus on max-size critical matchings and show a compact extended formulation for the popular max-critical matching polytope, i.e., the polytope of max-size critical matchings that are popular within the set of all max-size critical matchings. Thus we can efficiently solve linear optimization problems over the set of popular max-size critical matchings.</div>","PeriodicalId":50824,"journal":{"name":"Algorithmica","volume":"88 2","pages":""},"PeriodicalIF":0.7,"publicationDate":"2026-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00453-025-01347-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147560418","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}

引用次数: 0

Testing Isomorphism of Chordal Graphs of Bounded Leafage is Fixed-Parameter Tractable 有界叶弦图的同构检验是固定参数可处理的

IF 0.7 4区计算机科学

Algorithmica Pub Date : 2026-03-17 DOI: 10.1007/s00453-026-01374-8

Vikraman Arvind, Roman Nedela, Ilia Ponomarenko, Peter Zeman

引用次数: 0

Delaunay-Like Triangulation of Smooth Orientable Submanifolds by (ell _1)-Norm Minimization 光滑可定向子流形的类delaunay三角剖分(ell _1) -范数最小化

IF 0.7 4区计算机科学

Algorithmica Pub Date : 2026-03-10 DOI: 10.1007/s00453-025-01367-z

Dominique Attali, André Lieutier

引用次数: 0

The Voronoi Diagram of Rotating Rays with Applications to Floodlight Illumination 旋转光线的Voronoi图及其在泛光灯照明中的应用

IF 0.7 4区计算机科学

Algorithmica Pub Date : 2026-03-09 DOI: 10.1007/s00453-025-01368-y

Carlos Alegría, Ioannis Mantas, Evanthia Papadopoulou, Marko Savić, Carlos Seara, Martin Suderland

{"title":"The Voronoi Diagram of Rotating Rays with Applications to Floodlight Illumination","authors":"Carlos Alegría, Ioannis Mantas, Evanthia Papadopoulou, Marko Savić, Carlos Seara, Martin Suderland","doi":"10.1007/s00453-025-01368-y","DOIUrl":"10.1007/s00453-025-01368-y","url":null,"abstract":"<div>We study the Voronoi Diagram of Rotating Rays, a Voronoi structure where the input sites are rays and the distance function between a point and a site/ray is their counterclockwise angular distance. This novel Voronoi diagram is motivated by illumination and coverage problems, where a domain must be covered by floodlights, which are wedges of uniform angle, and the goal is to find the minimum angle necessary to cover the domain. This angle is called the Brocard angle and it is encoded in the Voronoi diagram of rotating rays. We study the diagram in the plane and present its structural properties, its combinatorial complexity bounds, and a construction algorithm. If the rays are induced by a convex polygon, we show how to construct the rotating rays Voronoi diagram within the polygon in optimal linear time. We can thus compute the Brocard angle of the polygon in the same time. Floodlights are used to model devices with limited sensing range, like surveillance cameras or directional antennas. In this context, the Brocard angle reveals the minimum range necessary for a set of devices to cover a domain.</div>","PeriodicalId":50824,"journal":{"name":"Algorithmica","volume":"88 2","pages":""},"PeriodicalIF":0.7,"publicationDate":"2026-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147440936","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}

引用次数: 0

Bipartite Independent Set Reconfiguration: General and RNA-Inspired Parameterized Algorithms 二部独立集重构：一般和rna启发的参数化算法

IF 0.7 4区计算机科学

Algorithmica Pub Date : 2026-03-05 DOI: 10.1007/s00453-026-01371-x

Théo Boury, Laurent Bulteau, Bertrand Marchand, Yann Ponty

{"title":"Bipartite Independent Set Reconfiguration: General and RNA-Inspired Parameterized Algorithms","authors":"Théo Boury, Laurent Bulteau, Bertrand Marchand, Yann Ponty","doi":"10.1007/s00453-026-01371-x","DOIUrl":"10.1007/s00453-026-01371-x","url":null,"abstract":"<div>Computing the energy barrier between RNA structures is a classic NP-hard problem in bioinformatics, of which the Independent Set (IS) reconfiguration in bipartite graphs represents a natural generalization. Parameterized algorithms, based on parameters taking limited or bounded values on biological instances, are thus crucial towards practical solutions. In this work, we show that bipartite IS reconfiguration is slice-wise Polynomial (XP) solvable for both the range (rho ) of IS sizes allowed along the reconfiguration, and the arboricity (Phi ) when the input is restricted to a circle graph. Such a setting is relevant to Bioinformatics as it provides a solution to the RNA energy barrier problem. We propose algorithms based on a divide-and-conquer approach, yielding a (Oleft( n^{2}right) )-space, (Oleft( n^{2rho +2.5}right) )-time algorithm for the range (rho ), and a (Oleft( n^{Phi + 2}right) )-space, (Oleft( n^{Phi +3}right) )-time algorithm for the arboricity (Phi ). We demonstrate the practicality of our algorithms on benchmarks respectively consisting of random Erdös-Rényi bipartite graphs, random pairs of RNA structures and experimentally-supported instances of RNA kinetics.</div>","PeriodicalId":50824,"journal":{"name":"Algorithmica","volume":"88 2","pages":""},"PeriodicalIF":0.7,"publicationDate":"2026-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147362760","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}

引用次数: 0

The Telephone k-Multicast Problem 电话k-多播问题

IF 0.7 4区计算机科学

Algorithmica Pub Date : 2026-03-02 DOI: 10.1007/s00453-026-01377-5

Daniel Hathcock, Guy Kortsarz, R. Ravi

{"title":"The Telephone k-Multicast Problem","authors":"Daniel Hathcock, Guy Kortsarz, R. Ravi","doi":"10.1007/s00453-026-01377-5","DOIUrl":"10.1007/s00453-026-01377-5","url":null,"abstract":"<div>We consider minimum time multicasting problems in directed and undirected graphs: given a root node and a subset of t terminal nodes, multicasting seeks to find the minimum number of rounds within which all terminals can be informed with a message originating at the root. In each round, the telephone model we study allows the information to move via a matching from the informed nodes to the uninformed nodes. Since minimum time multicasting in digraphs is poorly understood compared to the undirected variant, we study an intermediate problem in undirected graphs that specifies a target (k < t), and requires that only k of the terminals be informed in the minimum number of rounds. For this problem, we improve the implications of the previous results and obtain a multiplicative approximation factor of (tilde{O}(t^{1/3})). For the directed version, we obtain an additive (tilde{O}(k^{1/2})) approximation algorithm (with a polylogarithmic multiplicative factor). Our algorithms are based on reductions to the related problems of finding k-trees of minimum poise (sum of maximum degree and diameter) and applying a combination of greedy network decomposition techniques and set covering under partition matroid constraints. We also study the problem of bounded degree Directed Steiner Tree, for which we obtain improved polylogarithmic approximations for the special case of bounded treewidth graphs. This extends prior work on the Group Steiner Tree problem.</div>","PeriodicalId":50824,"journal":{"name":"Algorithmica","volume":"88 2","pages":""},"PeriodicalIF":0.7,"publicationDate":"2026-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00453-026-01377-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147336138","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}

引用次数: 0

Graph Exploration: The Impact of a Distance Constraint 图探索：距离约束的影响

IF 0.7 4区计算机科学

Algorithmica Pub Date : 2026-02-28 DOI: 10.1007/s00453-026-01378-4

Stéphane Devismes, Yoann Dieudonné, Arnaud Labourel

{"title":"Graph Exploration: The Impact of a Distance Constraint","authors":"Stéphane Devismes, Yoann Dieudonné, Arnaud Labourel","doi":"10.1007/s00453-026-01378-4","DOIUrl":"10.1007/s00453-026-01378-4","url":null,"abstract":"<div>A mobile agent, starting from a node s of a simple undirected graph (G=(V,E)), has to explore all nodes and edges of G. To do so, the agent uses a deterministic algorithm that allows it to gain information on G as it traverses its edges. During its exploration, the agent must always respect the constraint of knowing a path of length at most D to go back to node s. The upper bound D is fixed as being equal to ((1+alpha )r), where r is the eccentricity of node s and (alpha ) is any positive real constant. This task has been introduced by Duncan et al. (ACM Trans Algorithms 2(3):380–402, 2006) and is known as distance-constrained exploration. The penalty of an exploration algorithm running in G is the number of edge traversals made by the agent in excess of |E|. In Panaite and Pelc (J Algorithms 33(2):281–295, 1999), Panaite and Pelc gave an algorithm for solving exploration without any constraint on the moves that is guaranteed to work in every graph G with a (small) penalty in (mathcal {O}(|V|)). Can we obtain a distance-constrained exploration algorithm with the same guarantee? In this paper, we provide a negative answer to this question. We also observe that an algorithm working in every graph G with a linear penalty in |V| cannot be obtained for the task of fuel-constrained exploration, another variant studied in the literature. This solves an open problem posed by Duncan et al. (ACM Trans Algorithms 2(3):380–402, 2006) and shows a fundamental separation with the task of exploration without constraint on the moves.</div>","PeriodicalId":50824,"journal":{"name":"Algorithmica","volume":"88 2","pages":""},"PeriodicalIF":0.7,"publicationDate":"2026-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147342689","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}

引用次数: 0

Towards a Practical, Budget-Oblivious Algorithm for the Adwords Problem Under Small Bids 一种实用的、预算无关的小竞价广告问题算法

IF 0.7 4区计算机科学

Algorithmica Pub Date : 2026-02-19 DOI: 10.1007/s00453-026-01369-5

Vijay V. Vazirani

引用次数: 0