Unifying Gathering Strategies for Swarms of Mobile Robots -- The Complexity of Secure RAMs -- Selected Combinatorial Problems Through the Prism of Random Intersection Graphs Models -- The power of the Binary Value Principle -- Independent Set under a Change Constraint from an Initial Solution -- Asynchronous Fully-Decentralized SGD in the Cluster-Based Model -- Non-Crossing Shortest Paths Lengths in Planar Graphs in Linear Time -- How Vulnerable is an Undirected Planar Graph with respect to Max Flow -- Maximum Flows in Parametric Graph Templates -- Dynamic Coloring on Restricted Graph Classes -- Enumeration of Minimal Tropical Connected Sets -- Dynamic Flows with Time-Dependent Capacities -- On One-Sided Testing Affine Subspaces -- Stable Scheduling in Transactional Memory -- Parameterizing Path Partitions -- Maintaining Triconnected Components under Node Expansion -- Approximating Power Node-Deletion Problems -- Phase transition in count approximation by Count-Min sketch with conservative updates -- Minimum-link ´ $C$-Oriented Paths Visiting a Sequence of Regions in the Plane -- Grouped Domination Parameterized by Vertex Cover, Twin Cover, and Beyond -- Broadcasting in Split Graphs -- Partitioning Subclasses of Chordal Graphs with Few Deletions -- Complete Decomposition of Symmetric Tensors in Linear Time and Polylogarithmic Precision -- Improved Deterministic Leader Election in Diameter-Two Networks -- Fast Cauchy Sum Algorithms for Polynomial Zeros and Matrix Eigenvalues -- On the Parameterized Complexity of the Structure of Lineal Topologies (Depth-First Spanning Trees) of Finite Graphs: The Number of Leaves -- Efficiently Enumerating All Spanning Trees of a Plane 3-Tree -- Communication-Efficient Distributed Graph Clustering and Sparsification under Duplication Models.

This book constitutes the refereed proceedings of the 13th International Conference on Algorithms and Complexity, CIAC 2023, which took place in Larnaca, Cyprus, during June 13-16, 2023. The 25 full papers included in this book were carefully reviewed and selected from 49 submissions. They cover all important areas of research on algorithms and complexity such as algorithm design and analysis; sequential, parallel and distributed algorithms; data structures; computational and structural complexity; lower bounds and limitations of algorithms; randomized and approximation algorithms; parameterized algorithms and parameterized complexity classes; smoothed analysis of algorithms; alternatives to the worst-case analysis of algorithms (e.g., algorithms with predictions), on-line computation and competitive analysis, streaming algorithms, quantum algorithms and complexity, algorithms in algebra, geometry, number theory and combinatorics, computational geometry, algorithmic game theory and mechanism design, algorithmic economics (including auctions and contests), computational learning theory, computational biology and bioinformatics, algorithmic issues in communication networks, algorithms for discrete optimization (including convex optimization) and algorithm engineering.