Combinatorial Algorithms 33rd International Workshop, IWOCA 2022, Trier, Germany, June 7-9, 2022, Proceedings

• Main Authors: International Workshop on Combinatorial Algorithms, Bazgan, Cristina, Fernau, Henning
• Format: eBook Book Conference Proceeding
• Language: English
• Published: Cham Springer Nature 2022; Springer; Springer International Publishing AG; Springer International Publishing
• Edition: 1
• Series: Lecture Notes in Computer Science
• Subjects: Algorithm Analysis and Problem Complexity; Algorithms-Congresses; Combinatorial analysis; Combinatorial analysis > Congresses; Computer algorithms; Computer algorithms > Congresses; Computer Graphics; Computer Science; Data processing Computer science; Data Structures; Discrete Mathematics in Computer Science; Information Systems and Communication Service; Numeric Computing

This book constitutes the refereed proceedings of the 33rd International Workshop on Combinatorial Algorithms, IWOCA 2022, which took place as a hybrid event in Trier, Germany, during June 7-9, 2022.The 35 papers presented in these proceedings were carefully reviewed and selected from 86 submissions...

Table of Contents:

• 4 Computing a BOS in the Far Distant and Distant Cases -- References -- A New Temporal Interpretation of Cluster Editing -- 1 Introduction -- 1.1 Related Work -- 1.2 Organisation of the Paper -- 2 Preliminaries -- 2.1 Notation and Definitions -- 2.2 Problem Specification -- 3 Basic Observations on ETC -- 4 ETC on Paths -- 4.1 NP-Completeness -- 4.2 Bounding the Number of Edge Appearances -- 5 Completion to Temporal Cluster Graphs -- 6 A Local Characterisation of Cluster Temporal Graphs -- 6.1 The Five-Vertex Characterisation -- 6.2 A Search-Tree Algorithm -- 7 Conclusions and Open Problems -- References -- List Covering of Regular Multigraphs -- 1 Introduction -- 2 Preliminaries -- 3 Proof of Theorem 1 -- 3.1 Multicovers -- 3.2 Reduction from Hypergraph Coloring -- 3.3 The Non-bipartite Case -- 4 Sausages and Rings -- 5 Towards Strong Dichotomy for Cubic Graphs -- 6 Concluding Remarks -- References -- The Slotted Online One-Sided Crossing Minimization Problem on 2-Regular Graphs -- 1 Introduction -- 1.1 Related Work -- 1.2 Our Contribution -- 2 Lower Bounds on General Graphs -- 3 Lower Bound for 2-Regular Graphs -- 4 Preliminaries and Notation -- 5 Upper Bound for 2-Regular Graphs -- 5.1 Structural Properties -- 5.2 The 4-0 Crossings -- 5.3 The 3-0 Crossings -- 5.4 The Upper Bound -- 6 Conclusion -- References -- Perfect Matching Cuts Partitioning a Graph into Complementary Subgraphs -- 1 Introduction -- 2 Preliminaries -- 3 Results on Some Ck-Free Graphs -- 4 Results on Some Pk-Free Graphs -- 5 Concluding Remarks -- References -- On the Intractability Landscape of Digraph Intersection Representations -- 1 Introduction -- 2 Notation and Basic Definitions -- 3 Hardness of Approximation for General DAGs -- 4 Hardness for Arborescences -- 5 An Asymptotic FPTAS for Arborescence Graphs -- 6 Open Problems -- References
• 4 Computing the Longest Lyndon Subsequence -- 4.1 Basic Trie Traversal -- 4.2 Improving Time Bounds -- 4.3 Online Computation -- 5 Longest Common Lyndon Subsequence -- References -- Structure-Aware Combinatorial Group Testing: A New Method for Pandemic Screening -- 1 Introduction -- 2 Cover-Free Families -- 3 Structure-Aware Cover-Free Families -- 4 Structure-Aware CFFs: Non-overlapping Edges -- 4.1 Sperner-Type Constructions for r=1 -- 4.2 Kronecker Product Constructions (General r) -- 4.3 Array and Hypercube Constructions -- 4.4 Construction from Polynomials -- 5 Structure-Aware CFFs: Overlapping Edges -- References -- Convex Grid Drawings of Planar Graphs with Constant Edge-Vertex Resolution -- 1 Introduction -- 2 Preliminaries -- 3 Convex Planar Grid Disk-Link Drawings -- 4 Open Problems -- References -- 1-Extendability of Independent Sets -- 1 Introduction and Motivation -- 1.1 Definitions and Related Work -- 1.2 Contribution -- 1.3 Organization of the Paper -- 2 Notation and Basic Results -- 2.1 Notation and Definitions -- 2.2 Links Between 1-Extendability and Maximum Independent Set -- 3 Generic Transformations -- 4 Hardness of 1-Extendability on Subcubic Planar Graphs -- 4.1 Gadget -- 4.2 Planar Embedding -- 5 Parameterized Algorithms -- 6 Conclusion and Further Research -- References -- Tukey Depth Histograms -- 1 Introduction -- 2 The Condition is Necessary -- 2.1 Two Special Configurations -- 3 The Condition is Sufficient -- 3.1 Moving Points -- 3.2 Inserting a New Point -- 3.3 Putting Everything Together -- 4 Number of Depth Histograms -- 5 Conclusion -- References -- An Efficient Algorithm for the Proximity Connected Two Center Problem -- 1 Introduction -- 2 Preliminaries and Definitions -- 3 Computing a BOS in the Nearby Case -- 3.1 Computing rm,l -- 3.2 Searching the Doubly-Marked Elements -- 3.3 Obtaining (Dm,l-,Dm,l+) Having rm,l
• Intro -- Preface -- Organization -- Graphs as Algorithms: Characterizing Motion-Planning Gadgets through Simulation and Complexity (Abstract of Invited Talk) -- Contents -- Invited Papers -- Distance from Triviality 2.0: Hybrid Parameterizations -- 1 Introduction to Parameterized Algorithmics -- 2 Vertex Deletion Problems and Hybrid Parameters -- 3 Elimination Distance/Tree Decomposition to H -- 4 Vertex Deletion to H Parameterized by edH(G)/twH(G) -- 5 Equivalence of Elimination/Decomposition/Deletion -- 6 Implication/Applications of the Equivalence Result -- 7 Conclusion and Open Problems -- References -- On the Existence of EFX Allocations -- 1 Fair and Efficient Allocation of Indivisible Goods -- 1.1 EFX with Bounded Charity ch2CKMS21 -- 1.2 Complete EFX Allocations for Three Agents ch2CGM20 -- 1.3 EFX with Bounded Charity and High Nash Welfare ch2CGMehta -- 1.4 Reduction to a Problem in Extremal Graph Theory ch2CGMMM21 -- References -- Contributed Papers -- Lower Bounds for Restricted Schemes in the Two-Adaptive Bitprobe Model -- 1 Introduction -- 2 Restricted Schemes -- 3 Premise -- 4 Nodes and Paths -- 5 Universe of Elements -- 6 Bad Elements -- 7 Modified Schemes -- 8 Lower Bound -- 9 Conclusion -- References -- Perfect Matchings with Crossings -- 1 Introduction -- 2 Exactly k Crossings -- 2.1 Gaps in the Number of Crossings -- 3 At Most k Crossings -- 4 Convex Position -- 5 Conclusion -- References -- Graph Parameters, Implicit Representations and Factorial Properties -- 1 Introduction -- 2 Preliminaries -- 2.1 Graph Classes -- 2.2 Tools -- 3 Graph Parameters -- 3.1 Symmetric Difference -- 3.2 Double-Star Partition Number -- 4 Implicit Representations -- 4.1 Ft,p-Free Bipartite Graphs -- 4.2 One-Sided Forbidden Induced Bipartite Subgraphs -- 5 Factorial Properties -- References
• The Red-Blue Separation Problem on Graphs -- 1 Introduction -- 2 Complexity and Algorithms for Red-Blue Separation -- 2.1 Hardness -- 2.2 Positive Algorithmic Results -- 3 Extremal Values and Bounds for max-sepRB -- 3.1 Lower Bounds for General Graphs -- 3.2 Upper Bound for General Graphs -- 3.3 Upper Bound for Trees -- 4 Algorithmic Results for Max Red-Blue Separation -- 5 Conclusion -- References -- Harmless Sets in Sparse Classes -- 1 Introduction -- 2 Preliminaries -- 2.1 Bounded Expansion Classes and Kernels -- 2.2 The Bounded Expansion Toolkit -- 2.3 Waterlilies -- 3 A Sparse Kernel for p-Bounded Harmless Set -- 4 Sparse Parametrisation -- 4.1 Modulator to 2-Spider-Forest -- 4.2 Subexponential Time Algorithm -- 5 Conclusion -- References -- The Parameterized Complexity of s-Club with Triangle and Seed Constraints -- 1 Introduction -- 2 Vertex Triangle s-Club -- 3 Edge Triangle s-Club -- 4 Seeded s-Club -- 5 Conclusion -- References -- Space-Efficient B Trees via Load-Balancing -- 1 Introduction -- 1.1 Related Work -- 1.2 Our Contribution -- 2 Preliminaries -- 3 Space-Efficient B Trees -- 3.1 Resource Management by Distributing Keys -- 3.2 Shifting Keys Among Large Leaves -- 3.3 Final Space Complexity -- 3.4 Low Number of Keys -- 4 Augmenting with Aggregate Values -- 4.1 Updates in Batch -- 4.2 Updates by Merging -- 5 Conclusion -- References -- An Additive Approximation Scheme for the Nash Social Welfare Maximization with Identical Additive Valuations -- 1 Introduction -- 1.1 Nash Social Welfare Maximization -- 1.2 Our Contribution: Approximation Algorithm -- 1.3 Related Work: Additive PTAS -- 1.4 Technical Highlights -- 2 Description of the Algorithm -- 2.1 Preprocessing -- 2.2 Main Procedure -- 3 Analysis of Approximation Performance -- 3.1 Approximation Performance of MainProcedure -- 3.2 Approximation Performance of MaxNashWelfare
• References
• Approximating Subset Sum Ratio via Subset Sum Computations -- 1 Introduction -- 1.1 Related Work -- 1.2 Our Contribution -- 2 Preliminaries -- 3 Approximation Scheme for a Restricted Version -- 3.1 Outline of the Algorithm -- 3.2 Regarding only Large Elements -- 3.3 General (1+)-Approximation Solutions -- 4 Final Algorithm -- 5 Complexity -- 5.1 Complexity to Find the '-Close Pairs -- 5.2 Total Complexity -- 6 Conclusion and Future Work -- References -- Faster Algorithm for Finding Maximum 1-Restricted Simple 2-Matchings -- 1 Introduction -- 2 Algorithm -- 2.1 Outline -- 2.2 Alternations and Augmentations -- 2.3 Edge Directions -- 2.4 Blocking Augmentations -- 2.5 Bounding the Number of Phases -- References -- Lower Bounds on the Performance of Online Algorithms for Relaxed Packing Problems -- 1 Introduction -- 1.1 Our Results -- 1.2 Adaptive Item Sizing in Designing Hard Instances for Online Algorithms -- 2 Online Removable Knapsack -- 2.1 Deterministic Online Algorithms for the Proportional and Unit Cases -- 2.2 Randomized Online Algorithms for the Proportional Case -- 3 The Online Minimum Peak Appointment Scheduling Problem -- 3.1 Warm-Up: Deterministic Online Algorithms for MPAS -- 3.2 A Lower Bound for Randomized Algorithms for MPAS -- References -- An Adjacency Labeling Scheme Based on a Decomposition of Trees into Caterpillars -- 1 Introduction -- 1.1 Preliminaries -- 1.2 Summary of Our Results -- 1.3 Previous and Related Work -- 2 A Caterpillar-Type Balanced Decomposition -- 3 An Adjacency Labeling Scheme -- References -- Computing Longest (Common) Lyndon Subsequences -- 1 Introduction -- 2 Preliminaries -- 3 Lexicographically Smallest Subsequence -- 3.1 Dynamic Programming Approach -- 3.2 Speeding up String Comparisons -- 3.3 Most Competitive Subsequence -- 3.4 Lexicographically Smallest Common Subsequence