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Approximating the Canadian Traveller Problem with Online Randomization Algorithmica (IF 0.65) Pub Date : 2021-01-08 Erik D. Demaine, Yamming Huang, Chung-Shou Liao, Kunihiko Sadakane
In this paper, we study online algorithms for the Canadian Traveller Problem defined by Papadimitriou and Yannakakis in 1991. This problem involves a traveller who knows the entire road network in advance, and wishes to travel as quickly as possible from a source vertex s to a destination vertex t, but discovers online that some roads are blocked (e.g., by snow) once reaching them. Achieving a bounded
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Computing the Largest Bond and the Maximum Connected Cut of a Graph Algorithmica (IF 0.65) Pub Date : 2021-01-08 Gabriel L. Duarte, Hiroshi Eto, Tesshu Hanaka, Yasuaki Kobayashi, Yusuke Kobayashi, Daniel Lokshtanov, Lehilton L. C. Pedrosa, Rafael C. S. Schouery, Uéverton S. Souza
The cut-set \(\partial (S)\) of a graph \(G=(V,E)\) is the set of edges that have one endpoint in \(S\subset V\) and the other endpoint in \(V\setminus S\), and whenever G[S] is connected, the cut \([S,V\setminus S]\) of G is called a connected cut. A bond of a graph G is an inclusion-wise minimal disconnecting set of G, i.e., bonds are cut-sets that determine cuts \([S,V\setminus S]\) of G such that
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Polynomial Time Approximation Schemes for All 1-Center Problems on Metric Rational Set Similarities Algorithmica (IF 0.65) Pub Date : 2021-01-04 Marc Bury, Michele Gentili, Chris Schwiegelshohn, Mara Sorella
In this paper, we investigate algorithms for finding centers of a given collection \(\mathcal N\) of sets. In particular, we focus on metric rational set similarities, a broad class of similarity measures including Jaccard and Hamming. A rational set similarity S is called metric if \(D=1-S\) is a distance function. We study the 1-center problem on these metric spaces. The problem consists of finding
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Packing Arc-Disjoint Cycles in Tournaments Algorithmica (IF 0.65) Pub Date : 2021-01-04 Stéphane Bessy, Marin Bougeret, R. Krithika, Abhishek Sahu, Saket Saurabh, Jocelyn Thiebaut, Meirav Zehavi
A tournament is a directed graph in which there is a single arc between every pair of distinct vertices. Given a tournament T on n vertices, we explore the classical and parameterized complexity of the problems of determining if T has a cycle packing (a set of pairwise arc-disjoint cycles) of size k and a triangle packing (a set of pairwise arc-disjoint triangles) of size k. We refer to these problems
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The Price of Defense Algorithmica (IF 0.65) Pub Date : 2021-01-04 Marios Mavronicolas, Loizos Michael, Vicky Papadopoulou Lesta, Giuseppe Persiano, Anna Philippou, Paul G. Spirakis
We consider a game on a graph \(G=\langle V, E\rangle \) with two confronting classes of randomized players: \(\nu \) attackers, who choose vertices and seek to minimize the probability of getting caught, and a single defender, who chooses edges and seeks to maximize the expected number of attackers it catches. In a Nash equilibrium, no player has an incentive to unilaterally deviate from her randomized
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A Fast Algorithm for the Product Structure of Planar Graphs Algorithmica (IF 0.65) Pub Date : 2021-01-04 Pat Morin
Dujmović et al. (FOCS2019) recently proved that every planar graph G is a subgraph of \(H\boxtimes P\), where \(\boxtimes\) denotes the strong graph product, H is a graph of treewidth 8 and P is a path. This result has found numerous applications to linear graph layouts, graph colouring, and graph labelling. The proof given by Dujmović et al. is based on a similar decomposition of Pilipczuk and Siebertz
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Improved Streaming Algorithms for Maximizing Monotone Submodular Functions under a Knapsack Constraint Algorithmica (IF 0.65) Pub Date : 2021-01-03 Chien-Chung Huang, Naonori Kakimura
In this paper, we consider the problem of maximizing a monotone submodular function subject to a knapsack constraint in a streaming setting. In such a setting, elements arrive sequentially and at any point in time, and the algorithm can store only a small fraction of the elements that have arrived so far. For the special case that all elements have unit sizes (i.e., the cardinality-constraint case)
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Universal Reconfiguration of Facet-Connected Modular Robots by Pivots: The O (1) Musketeers Algorithmica (IF 0.65) Pub Date : 2021-01-02 Hugo A. Akitaya, Esther M. Arkin, Mirela Damian, Erik D. Demaine, Vida Dujmović, Robin Flatland, Matias Korman, Belen Palop, Irene Parada, André van Renssen, Vera Sacristán
We present the first universal reconfiguration algorithm for transforming a modular robot between any two facet-connected square-grid configurations using pivot moves. More precisely, we show that five extra “helper” modules (“musketeers”) suffice to reconfigure the remaining n modules between any two given configurations. Our algorithm uses \(O(n^2)\) pivot moves, which is worst-case optimal. Previous
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Matching Cut in Graphs with Large Minimum Degree Algorithmica (IF 0.65) Pub Date : 2020-11-23 Chi-Yeh Chen, Sun-Yuan Hsieh, Hoang-Oanh Le, Van Bang Le, Sheng-Lung Peng
In a graph, a matching cut is an edge cut that is a matching. Matching Cut is the problem of deciding whether or not a given graph has a matching cut, which is known to be \({\mathsf {NP}}\)-complete. While Matching Cut is trivial for graphs with minimum degree at most one, it is \({\mathsf {NP}}\)-complete on graphs with minimum degree two. In this paper, we show that, for any given constant \(c>1\)
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The Runtime of the Compact Genetic Algorithm on Jump Functions Algorithmica (IF 0.65) Pub Date : 2020-11-13 Benjamin Doerr
In the first and so far only mathematical runtime analysis of an estimation-of-distribution algorithm (EDA) on a multimodal problem, Hasenöhrl and Sutton (GECCO 2018) showed for any \(k = o(n)\) that the compact genetic algorithm (cGA) with any hypothetical population size \(\mu = \Omega (ne^{4k} + n^{3.5+\varepsilon })\) with high probability finds the optimum of the n-dimensional jump function with
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Budget Feasible Mechanisms on Matroids Algorithmica (IF 0.65) Pub Date : 2020-11-13 Stefano Leonardi, Gianpiero Monaco, Piotr Sankowski, Qiang Zhang
Motivated by many practical applications, in this paper we study budget feasible mechanisms with the goal of procuring an independent set of a matroid. More specifically, we are given a matroid \({\mathcal {M}}=(E,{\mathcal {I}})\). Each element of the ground set E is controlled by a selfish agent and the cost of the element is private information of the agent itself. A budget limited buyer has additive
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Towards a Polynomial Kernel for Directed Feedback Vertex Set Algorithmica (IF 0.65) Pub Date : 2020-11-04 Benjamin Bergougnoux, Eduard Eiben, Robert Ganian, Sebastian Ordyniak, M. S. Ramanujan
In the Directed Feedback Vertex Set (DFVS) problem, the input is a directed graph D and an integer k. The objective is to determine whether there exists a set of at most k vertices intersecting every directed cycle of D. DFVS was shown to be fixed-parameter tractable when parameterized by solution size by Chen et al. (J ACM 55(5):177–186, 2008); since then, the existence of a polynomial kernel for
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The Complex Parameter Landscape of the Compact Genetic Algorithm Algorithmica (IF 0.65) Pub Date : 2020-11-04 Johannes Lengler, Dirk Sudholt, Carsten Witt
The compact Genetic Algorithm (cGA) evolves a probability distribution favoring optimal solutions in the underlying search space by repeatedly sampling from the distribution and updating it according to promising samples. We study the intricate dynamics of the cGA on the test function OneMax, and how its performance depends on the hypothetical population size K, which determines how quickly decisions
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Lower Bounds on the Runtime of Crossover-Based Algorithms via Decoupling and Family Graphs Algorithmica (IF 0.65) Pub Date : 2020-11-04 Andrew M. Sutton, Carsten Witt
The runtime analysis of evolutionary algorithms using crossover as search operator has recently produced remarkable results indicating benefits and drawbacks of crossover and illustrating its working principles. Virtually all these results are restricted to upper bounds on the running time of the crossover-based algorithms. This work addresses this lack of lower bounds and rigorously bounds the optimization
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Improved Runtime Results for Simple Randomised Search Heuristics on Linear Functions with a Uniform Constraint Algorithmica (IF 0.65) Pub Date : 2020-11-04 Frank Neumann, Mojgan Pourhassan, Carsten Witt
In the last decade remarkable progress has been made in development of suitable proof techniques for analysing randomised search heuristics. The theoretical investigation of these algorithms on classes of functions is essential to the understanding of the underlying stochastic process. Linear functions have been traditionally studied in this area resulting in tight bounds on the expected optimisation
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Non-Greedy Online Steiner Trees on Outerplanar Graphs Algorithmica (IF 0.65) Pub Date : 2020-10-16 Akira Matsubayashi
This paper addresses the classic online Steiner tree problem on edge-weighted graphs. It is known that a greedy (nearest neighbor) online algorithm has a tight competitive ratio for wide classes of graphs, such as trees, rings, any class including series-parallel graphs, and unweighted graphs with bounded diameter. However, we do not know any greedy or non-greedy tight deterministic algorithm for other
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The Inverse Voronoi Problem in Graphs II: Trees Algorithmica (IF 0.65) Pub Date : 2020-10-15 Édouard Bonnet, Sergio Cabello, Bojan Mohar, Hebert Pérez-Rosés
We consider the inverse Voronoi diagram problem in trees: given a tree T with positive edge-lengths and a collection \(\mathbb {U}\) of subsets of vertices of V(T), decide whether \({\mathbb {U}}\) is a Voronoi diagram in T with respect to the shortest-path metric. We show that the problem can be solved in \(O(N+n \log ^2 n)\) time, where n is the number of vertices in T and \(N=n+\sum _{U\in {\mathbb
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Simultaneous Feedback Edge Set: A Parameterized Perspective Algorithmica (IF 0.65) Pub Date : 2020-10-10 Akanksha Agrawal, Fahad Panolan, Saket Saurabh, Meirav Zehavi
Agrawal et al. (ACM Trans Comput Theory 10(4):18:1–18:25, 2018. https://doi.org/10.1145/3265027) studied a simultaneous variant of the classic Feedback Vertex Set problem, called Simultaneous Feedback Vertex Set (Sim-FVS). Here, we consider the edge variant of the problem, namely, Simultaneous Feedback Edge Set (Sim-FES). In this problem, the input is an n-vertex graph G, a positive integer k, and
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High Entropy Random Selection Protocols Algorithmica (IF 0.65) Pub Date : 2020-10-03 Harry Buhrman, Matthias Christandl, Michal Koucký, Zvi Lotker, Boaz Patt-Shamir, Nikolay Vereshchagin
We study the two party problem of randomly selecting a common string among all the strings of length n. We want the protocol to have the property that the output distribution has high Shannon entropy or high min entropy, even when one of the two parties is dishonest and deviates from the protocol. We develop protocols that achieve high, close to n, Shannon entropy and simultaneously min entropy close
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Approximation Guarantee of OSP Mechanisms: The Case of Machine Scheduling and Facility Location Algorithmica (IF 0.65) Pub Date : 2020-10-03 Diodato Ferraioli, Carmine Ventre
Obvious strategyproofness (OSP) is an appealing concept as it allows to maintain incentive compatibility even in the presence of agents that are not fully rational, i.e., those who struggle with contingent reasoning (Li in Am Econ Rev 107(11):3257–3287, 2017). However, it has been shown to impose some limitations, e.g., no OSP mechanism can return a stable matching (Ashlagi and Gonczarowski in J Econ
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Fault-Tolerant Covering Problems in Metric Spaces Algorithmica (IF 0.65) Pub Date : 2020-09-29 Santanu Bhowmick, Tanmay Inamdar, Kasturi Varadarajan
In this article, we study some fault-tolerant covering problems in metric spaces. In the metric multi-cover problem (MMC), we are given two point sets Y (servers) and X (clients) in an arbitrary metric space \((X \cup Y, d)\), a positive integer k that represents the coverage demand of each client, and a constant \(\alpha \ge 1\). Each server can host a single ball of arbitrary radius centered on it
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On Orthogonally Guarding Orthogonal Polygons with Bounded Treewidth Algorithmica (IF 0.65) Pub Date : 2020-09-27 Therese Biedl, Saeed Mehrabi
There exist many variants of guarding an orthogonal polygon in an orthogonal fashion: sometimes a guard can see within a rectangle, along a staircase, or along an orthogonal path with at most k bends. In this paper, we study all these guarding models for the special case of orthogonal polygons that have bounded treewidth in some sense. As our main result, we show that the problem of finding the minimum
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The Complexity of Computational Problems About Nash Equilibria in Symmetric Win-Lose Games Algorithmica (IF 0.65) Pub Date : 2020-09-19 Vittorio Bilò, Marios Mavronicolas
We revisit the complexity of deciding, given a bimatrix game, whether it has a Nash equilibrium with certain natural properties; such decision problems were early known to be \({{\mathcal{N}}{\mathcal{P}}}\)-hard (Gilboa and Zemel in Games Econ Behav 1(1):80–93, 1989). We show that \({{\mathcal{N}}{\mathcal{P}}}\)-hardness still holds under two significant restrictions in simultaneity: the game is
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Constrained Minimum Passage Time in Random Geometric Graphs Algorithmica (IF 0.65) Pub Date : 2020-09-18 Ghurumuruhan Ganesan
Let \(G\) be a random geometric graph formed by \(n\) nodes with adjacency distance \(r_n\) and let each edge of \(G\) be assigned an independent exponential passage time with mean that depends on the graph size \(n.\) We connect \(G\) to two nodes source \(s_A\) and destination \(s_B\) at deterministic locations spaced \(d_n\) apart in the unit square and find upper and lower bounds on the minimum
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On the Complexity of Colouring Antiprismatic Graphs Algorithmica (IF 0.65) Pub Date : 2020-09-18 Myriam Preissmann, Cléophée Robin, Nicolas Trotignon
A graph G is prismatic if for every triangle T of G, every vertex of G not in T has a unique neighbour in T. The complement of a prismatic graph is called antiprismatic. The complexity of colouring antiprismatic graphs is still unknown. Equivalently, the complexity of the clique cover problem in prismatic graphs is not known. Chudnovsky and Seymour gave a full structural description of prismatic graphs
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On the Tree Augmentation Problem Algorithmica (IF 0.65) Pub Date : 2020-09-15 Zeev Nutov
In the Tree Augmentation problem we are given a tree \(T=(V,F)\) and a set \(E \subseteq V \times V\) of edges with positive integer costs \(\{c_e:e \in E\}\). The goal is to augment T by a minimum cost edge set \(J \subseteq E\) such that \(T \cup J\) is 2-edge-connected. We obtain the following results. Recently, Adjiashvili [SODA 17] introduced a novel LP for the problem and used it to break the
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Distance and Routing Labeling Schemes for Cube-Free Median Graphs Algorithmica (IF 0.65) Pub Date : 2020-09-14 Victor Chepoi, Arnaud Labourel, Sébastien Ratel
Distance labeling schemes are schemes that label the vertices of a graph with short labels in such a way that the distance between any two vertices u and v can be determined efficiently by merely inspecting the labels of u and v, without using any other information. Similarly, routing labeling schemes label the vertices of a graph in a such a way that given the labels of a source node and a destination
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CADbots: Algorithmic Aspects of Manipulating Programmable Matter with Finite Automata Algorithmica (IF 0.65) Pub Date : 2020-09-04 Sándor P. Fekete, Robert Gmyr, Sabrina Hugo, Phillip Keldenich, Christian Scheffer, Arne Schmidt
We contribute results for a set of fundamental problems in the context of programmable matter by presenting algorithmic methods for evaluating and manipulating a collective of particles by a finite automaton that can neither store significant amounts of data, nor perform complex computations, and is limited to a handful of possible physical operations. We provide a toolbox for carrying out fundamental
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Polynomial Treedepth Bounds in Linear Colorings Algorithmica (IF 0.65) Pub Date : 2020-09-03 Jeremy Kun, Michael P. O’Brien, Marcin Pilipczuk, Blair D. Sullivan
Low-treedepth colorings are an important tool for algorithms that exploit structure in classes of bounded expansion; they guarantee subgraphs that use few colors have bounded treedepth. These colorings have an implicit tradeoff between the total number of colors used and the treedepth bound, and prior empirical work suggests that the former dominates the run time of existing algorithms in practice
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Covert Computation in Self-Assembled Circuits Algorithmica (IF 0.65) Pub Date : 2020-09-02 Angel A. Cantu, Austin Luchsinger, Robert Schweller, Tim Wylie
Traditionally, computation within self-assembly models is hard to conceal because the self-assembly process generates a crystalline assembly whose computational history is inherently part of the structure itself. With no way to remove information from the computation, this computational model offers a unique problem: how can computational input and computation be hidden while still computing and reporting
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Tight Bounds for Online Coloring of Basic Graph Classes Algorithmica (IF 0.65) Pub Date : 2020-08-25 Susanne Albers, Sebastian Schraink
We resolve a number of long-standing open problems in online graph coloring. More specifically, we develop tight lower bounds on the performance of online algorithms for fundamental graph classes. An important contribution is that our bounds also hold for randomized online algorithms, for which hardly any results were known. Technically, we construct lower bounds for chordal graphs. The constructions
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On Structural Parameterizations of the Bounded-Degree Vertex Deletion Problem Algorithmica (IF 0.65) Pub Date : 2020-08-19 Robert Ganian, Fabian Klute, Sebastian Ordyniak
We study the parameterized complexity of the Bounded-Degree Vertex Deletion problem (BDD), where the aim is to find a maximum induced subgraph whose maximum degree is below a given degree bound. Our focus lies on parameters that measure the structural properties of the input instance. We first show that the problem is W[1]-hard parameterized by a wide range of fairly restrictive structural parameters
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Guess Free Maximization of Submodular and Linear Sums Algorithmica (IF 0.65) Pub Date : 2020-08-14 Moran Feldman
We consider the problem of maximizing the sum of a monotone submodular function and a linear function subject to a general solvable polytope constraint. Recently, Sviridenko et al. (Math Oper Res 42(4):1197–1218, 2017) described an algorithm for this problem whose approximation guarantee is optimal in some intuitive and formal senses. Unfortunately, this algorithm involves a guessing step which makes
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Graph Isomorphism for $$(H_1,H_2)$$ ( H 1 , H 2 ) -Free Graphs: An Almost Complete Dichotomy Algorithmica (IF 0.65) Pub Date : 2020-08-05 Marthe Bonamy, Nicolas Bousquet, Konrad K. Dabrowski, Matthew Johnson, Daniël Paulusma, Théo Pierron
We resolve the computational complexity of Graph Isomorphism for classes of graphs characterized by two forbidden induced subgraphs \( H_{1} \) and \(H_2\) for all but six pairs \((H_1,H_2)\). Schweitzer had previously shown that the number of open cases was finite, but without specifying the open cases. Grohe and Schweitzer proved that Graph Isomorphism is polynomial-time solvable on graph classes
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Iterative Partial Rounding for Vertex Cover with Hard Capacities Algorithmica (IF 0.65) Pub Date : 2020-08-03 Mong-Jen Kao
We provide a simple and novel algorithmic design technique, for which we call iterative partial rounding, that gives a tight rounding-based approximation for vertex cover with hard capacities (VC-HC). In particular, we obtain an f-approximation for VC-HC on hypergraphs, improving over a previous results of Cheung et al. (In: SODA’14, 2014) to the tight extent. This also closes the gap of approximation
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Enumerating k -Arc-Connected Orientations Algorithmica (IF 0.65) Pub Date : 2020-08-03 Sarah Blind, Kolja Knauer, Petru Valicov
We study the problem of enumerating the k-arc-connected orientations of a graph G, i.e., generating each exactly once. A first algorithm using submodular flow optimization is easy to state, but intricate to implement. In a second approach we present a simple algorithm with \(O(knm^2)\) time delay and amortized time \(O(m^2)\), which improves over the analysis of the submodular flow algorithm. As ingredients
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Learning Privately with Labeled and Unlabeled Examples Algorithmica (IF 0.65) Pub Date : 2020-08-03 Amos Beimel, Kobbi Nissim, Uri Stemmer
A private learner is an algorithm that given a sample of labeled individual examples outputs a generalizing hypothesis while preserving the privacy of each individual. In 2008, Kasiviswanathan et al. (FOCS 2008) gave a generic construction of private learners, in which the sample complexity is (generally) higher than what is needed for non-private learners. This gap in the sample complexity was then
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Subexponential-Time Algorithms for Finding Large Induced Sparse Subgraphs Algorithmica (IF 0.65) Pub Date : 2020-07-31 Jana Novotná, Karolina Okrasa, Michał Pilipczuk, Paweł Rzążewski, Erik Jan van Leeuwen, Bartosz Walczak
Let \({\mathcal {C}}\) and \({\mathcal {D}}\) be hereditary graph classes. Consider the following problem: given a graph \(G\in {\mathcal {D}}\), find a largest, in terms of the number of vertices, induced subgraph of G that belongs to \({\mathcal {C}}\). We prove that it can be solved in \(2^{o(n)}\) time, where n is the number of vertices of G, if the following conditions are satisfied: the graphs
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List 3-Coloring Graphs with No Induced $$P_6+rP_3$$ P 6 + r P 3 Algorithmica (IF 0.65) Pub Date : 2020-07-30 Maria Chudnovsky, Shenwei Huang, Sophie Spirkl, Mingxian Zhong
For an integer t, we let \(P_t\) denote the t-vertex path. We write \(H+G\) for the disjoint union of two graphs H and G, and for an integer r and a graph H, we write rH for the disjoint union of r copies of H. We say that a graph G is H-free if no induced subgraph of G is isomorphic to the graph H. In this paper, we study the complexity of k-coloring, for a fixed integer k, when restricted to the
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Privately Outsourcing Exponentiation to a Single Server: Cryptanalysis and Optimal Constructions Algorithmica (IF 0.65) Pub Date : 2020-07-30 Céline Chevalier, Fabien Laguillaumie, Damien Vergnaud
We address the problem of speeding up group computations in cryptography using a single untrusted computational resource. We analyze the security of two efficient protocols for securely outsourcing (multi-)exponentiations. We show that the schemes do not achieve the claimed security guarantees and we present practical polynomial-time attacks on the delegation protocols which allow the untrusted helper
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Correction to: Randomized Algorithms for Tracking Distributed Count, Frequencies, and Ranks Algorithmica (IF 0.65) Pub Date : 2020-07-28 Zengfeng Huang, Ke Yi, Qin Zhang
After publication of the article [1] the authors have noticed that the funding information are not published in online and print version of the article. The omitted funding acknowledgement is given below.
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Fault Tolerant Approximate BFS Structures with Additive Stretch Algorithmica (IF 0.65) Pub Date : 2020-07-28 Merav Parter, David Peleg
This paper addresses the problem of designing a \(\beta \)-additive fault-tolerant approximate BFS (or FT-ABFS for short) structure, namely, a subgraph H of the network G such that subsequent to the failure of a single edge e, the surviving part of H still contains an approximate BFS spanning tree for (the surviving part of) G, whose distances satisfy \(\mathrm{dist}(s,v,H{\setminus } \{e\}) \le \mathrm{dist}(s
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Flip Distances Between Graph Orientations Algorithmica (IF 0.65) Pub Date : 2020-07-27 Oswin Aichholzer, Jean Cardinal, Tony Huynh, Kolja Knauer, Torsten Mütze, Raphael Steiner, Birgit Vogtenhuber
Flip graphs are a ubiquitous class of graphs, which encode relations on a set of combinatorial objects by elementary, local changes. Skeletons of associahedra, for instance, are the graphs induced by quadrilateral flips in triangulations of a convex polygon. For some definition of a flip graph, a natural computational problem to consider is the flip distance: Given two objects, what is the minimum
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Building a Nest by an Automaton Algorithmica (IF 0.65) Pub Date : 2020-07-25 Jurek Czyzowicz, Dariusz Dereniowski, Andrzej Pelc
A robot modeled as a deterministic finite automaton has to build a structure from material available to it. The robot navigates in the infinite oriented grid \({\mathbb {Z}} \times {\mathbb {Z}}\). Some cells of the grid are full (contain a brick) and others are empty. The subgraph of the grid induced by full cells, called the shape, is initially connected. The (Manhattan) distance between the furthest
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Parameterized Dynamic Cluster Editing Algorithmica (IF 0.65) Pub Date : 2020-07-25 Junjie Luo, Hendrik Molter, André Nichterlein, Rolf Niedermeier
We introduce a dynamic version of the NP-hard graph modification problem Cluster Editing. The essential point here is to take into account dynamically evolving input graphs: having a cluster graph (that is, a disjoint union of cliques) constituting a solution for a first input graph, can we cost-efficiently transform it into a “similar” cluster graph that is a solution for a second (“subsequent”) input
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Correction to: Reoptimization Time Analysis of Evolutionary Algorithms on Linear Functions Under Dynamic Uniform Constraints Algorithmica (IF 0.65) Pub Date : 2020-07-20 Feng Shi, Martin Schirneck, Tobias Friedrich, Timo Kötzing, Frank Neumann
In the article Reoptimization Time Analysis of Evolutionary Algorithms on Linear Functions Under Dynamic Uniform Constraints, we claimed a worst-case runtime of and for the Multi-Objective Evolutionary Algorithm and the Multi-Objective Genetic Algorithm, respectively, on linear profit functions under dynamic uniform constraint, where denotes the difference between the original constraint bound B and
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On Scheduling Coflows Algorithmica (IF 0.65) Pub Date : 2020-07-15 Saba Ahmadi, Samir Khuller, Manish Purohit, Sheng Yang
Applications designed for data-parallel computation frameworks such as MapReduce usually alternate between computation and communication stages. Coflow scheduling is a recent popular networking abstraction introduced to capture such application-level communication patterns in datacenters. In this framework, a datacenter is modeled as a single non-blocking switch with m input ports and m output ports
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On the Benefits of Populations for the Exploitation Speed of Standard Steady-State Genetic Algorithms Algorithmica (IF 0.65) Pub Date : 2020-07-15 Dogan Corus, Pietro S. Oliveto
It is generally accepted that populations are useful for the global exploration of multi-modal optimisation problems. Indeed, several theoretical results are available showing such advantages over single-trajectory search heuristics. In this paper we provide evidence that evolving populations via crossover and mutation may also benefit the optimisation time for hillclimbing unimodal functions. In particular
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Dynamic and Internal Longest Common Substring Algorithmica (IF 0.65) Pub Date : 2020-07-15 Amihood Amir, Panagiotis Charalampopoulos, Solon P. Pissis, Jakub Radoszewski
Given two strings S and T, each of length at most n, the longest common substring (LCS) problem is to find a longest substring common to S and T. This is a classical problem in computer science with an \(\mathcal {O}(n)\)-time solution. In the fully dynamic setting, edit operations are allowed in either of the two strings, and the problem is to find an LCS after each edit. We present the first solution
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An Adversarial Model for Scheduling with Testing Algorithmica (IF 0.65) Pub Date : 2020-07-10 Christoph Dürr, Thomas Erlebach, Nicole Megow, Julie Meißner
We introduce a novel adversarial model for scheduling with explorable uncertainty. In this model, the processing time of a job can potentially be reduced (by an a priori unknown amount) by testing the job. Testing a job j takes one unit of time and may reduce its processing time from the given upper limit \(\bar{p}_j\) (which is the time taken to execute the job if it is not tested) to any value between
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The Power of Linear-Time Data Reduction for Maximum Matching Algorithmica (IF 0.65) Pub Date : 2020-07-06 George B. Mertzios, André Nichterlein, Rolf Niedermeier
Finding maximum-cardinality matchings in undirected graphs is arguably one of the most central graph primitives. For m-edge and n-vertex graphs, it is well-known to be solvable in \(O(m\sqrt{n})\) time; however, for several applications this running time is still too slow. We investigate how linear-time (and almost linear-time) data reduction (used as preprocessing) can alleviate the situation. More
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Subgraph Isomorphism on Graph Classes that Exclude a Substructure Algorithmica (IF 0.65) Pub Date : 2020-07-02 Hans L. Bodlaender, Tesshu Hanaka, Yasuaki Kobayashi, Yusuke Kobayashi, Yoshio Okamoto, Yota Otachi, Tom C. van der Zanden
We study Subgraph Isomorphism on graph classes defined by a fixed forbidden graph. Although there are several ways for forbidding a graph, we observe that it is reasonable to focus on the minor relation since other well-known relations lead to either trivial or equivalent problems. When the forbidden minor is connected, we present a near dichotomy of the complexity of Subgraph Isomorphism with respect
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A Tight Runtime Analysis for the $${(\mu + \lambda )}$$(μ+λ) EA Algorithmica (IF 0.65) Pub Date : 2020-06-25 Denis Antipov, Benjamin Doerr
Despite significant progress in the theory of evolutionary algorithms, the theoretical understanding of evolutionary algorithms which use non-trivial populations remains challenging and only few rigorous results exist. Already for the most basic problem, the determination of the asymptotic runtime of the \((\mu +\lambda )\) evolutionary algorithm on the simple OneMax benchmark function, only the special
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Using a Min-Cut Generalisation to Go Beyond Boolean Surjective VCSPs Algorithmica (IF 0.65) Pub Date : 2020-06-24 Gregor Matl, Stanislav Živný
In this work, we first study a natural generalisation of the Min-Cut problem, where a graph is augmented by a superadditive set function defined on its vertex subsets. The goal is to select a vertex subset such that the weight of the induced cut plus the set function value are minimised. In addition, a lower and upper bound is imposed on the solution size. We present a polynomial-time algorithm for
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Efficient Online String Matching Based on Characters Distance Text Sampling Algorithmica (IF 0.65) Pub Date : 2020-06-20 Simone Faro, Francesco Pio Marino, Arianna Pavone
Searching for all occurrences of a pattern in a text is a fundamental problem in computer science with applications in many other fields, like natural language processing, information retrieval and computational biology. Sampled string matching is an efficient approach recently introduced in order to overcome the prohibitive space requirements of an index construction, on the one hand, and drastically
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Explicit Correlation Amplifiers for Finding Outlier Correlations in Deterministic Subquadratic Time Algorithmica (IF 0.65) Pub Date : 2020-06-20 Matti Karppa, Petteri Kaski, Jukka Kohonen, Padraig Ó Catháin
We derandomize Valiant’s (J ACM 62, Article 13, 2015) subquadratic-time algorithm for finding outlier correlations in binary data. This demonstrates that it is possible to perform a deterministic subquadratic-time similarity join of high dimensionality. Our derandomized algorithm gives deterministic subquadratic scaling essentially for the same parameter range as Valiant’s randomized algorithm, but
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Greed is Good for Deterministic Scale-Free Networks Algorithmica (IF 0.65) Pub Date : 2020-06-19 Ankit Chauhan, Tobias Friedrich, Ralf Rothenberger
Large real-world networks typically follow a power-law degree distribution. To study such networks, numerous random graph models have been proposed. However, real-world networks are not drawn at random. Therefore, Brach et al. (27th symposium on discrete algorithms (SODA), pp 1306–1325, 2016) introduced two natural deterministic conditions: (1) a power-law upper bound on the degree distribution (PLB-U)
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Online Bin Covering with Advice Algorithmica (IF 0.65) Pub Date : 2020-06-18 Joan Boyar, Lene M. Favrholdt, Shahin Kamali, Kim S. Larsen
The bin covering problem asks for covering a maximum number of bins with an online sequence of n items of different sizes in the range (0, 1]; a bin is said to be covered if it receives items of total size at least 1. We study this problem in the advice setting and provide asymptotically tight bounds of \(\Theta (n \log {\textsc {Opt}})\) on the size of advice required to achieve optimal solutions
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Non-preemptive Scheduling in a Smart Grid Model and Its Implications on Machine Minimization Algorithmica (IF 0.65) Pub Date : 2020-06-18 Fu-Hong Liu, Hsiang-Hsuan Liu, Prudence W. H. Wong
We study a scheduling problem arising in demand response management in smart grid. Consumers send in power requests with a flexible feasible time interval during which their requests can be served. The grid controller, upon receiving power requests, schedules each request within the specified interval. The electricity cost is measured by a convex function of the load in each timeslot. The objective
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Parameterized Complexity of Independent Set in H-Free Graphs Algorithmica (IF 0.65) Pub Date : 2020-06-17 Édouard Bonnet, Nicolas Bousquet, Pierre Charbit, Stéphan Thomassé, Rémi Watrigant
In this paper, we investigate the complexity of Maximum Independent Set (MIS) in the class of H-free graphs, that is, graphs excluding a fixed graph as an induced subgraph. Given that the problem remains NP-hard for most graphs H, we study its fixed-parameter tractability and make progress towards a dichotomy between FPT and W[1]-hard cases. We first show that MIS remains W[1]-hard in graphs forbidding
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