This book constitutes the refereed proceedings of the 17th Annual European Symposium on Algorithms, ESA 2009, held in Copenhagen, Denmark, in September 2009 in the context of the combined conference ALGO 2009. The 67 revised full papers presented together with 3 invited lectures were carefully reviewed and selected: 56 papers out of 222 submissions for the design and analysis track and 10 out of 36 submissions in the engineering and applications track. The papers are organized in topical sections on trees, geometry, mathematical programming, algorithmic game theory, navigation and routing, graphs and point sets, bioinformatics, wireless communiations, flows, matrices, compression, scheduling, streaming, online algorithms, bluetooth and dial a ride, decomposition and covering, algorithm engineering, parameterized algorithms, data structures, and hashing and lowest common ancestor.

This book constitutes the refereed proceedings of the 20th Annual European Symposium on Algorithms, ESA 2012, held in Ljubljana, Slovenia, in September 2012 in the context of the combined conference ALGO 2012. The 69 revised full papers presented were carefully reviewed and selected from 285 initial submissions: 56 out of 231 in track design and analysis and 13 out of 54 in track engineering and applications. The papers are organized in topical sections such as algorithm engineering; algorithmic aspects of networks; algorithmic game theory; approximation algorithms; computational biology; computational finance; computational geometry; combinatorial optimization; data compression; data structures; databases and information retrieval; distributed and parallel computing; graph algorithms; hierarchical memories; heuristics and meta-heuristics; mathematical programming; mobile computing; on-line algorithms; parameterized complexity; pattern matching, quantum computing; randomized algorithms; scheduling and resource allocation problems; streaming algorithms.

This book constitutes the refereed proceedings of the 23rd Annual European Symposium on Algorithms, ESA 2015, held in Patras, Greece, in September 2015, as part of ALGO 2015. The 86 revised full papers presented together with two invited lectures were carefully reviewed and selected from 320 initial submissions: 71 out of 261 in Track A, Design and Analysis, and 15 out of 59 in Track B, Engineering and Applications. The papers present real-world applications, engineering, and experimental analysis of algorithms.

This book constitutes the refereed proceedings of the 22st Annual European Symposium on Algorithms, ESA 2014, held in Wrocław, Poland, in September 2014, as part of ALGO 2014. The 69 revised full papers presented were carefully reviewed and selected from 269 initial submissions: 57 out of 221 in Track A, Design and Analysis, and 12 out of 48 in Track B, Engineering and Applications. The papers present original research in the areas of design and mathematical analysis of algorithms; engineering, experimental analysis, and real-world applications of algorithms and data structures.

This Festschrift was published in honor of Hans L. Bodlaender on the occasion of his 60th birthday. The 14 full and 5 short contributions included in this volume show the many transformative discoveries made by H.L. Bodlaender in the areas of graph algorithms, parameterized complexity, kernelization and combinatorial games. The papers are written by his former Ph.D. students and colleagues as well as by his former Ph.D. advisor, Jan van Leeuwen.

For a long time computer scientists have distinguished between fast and slow algo rithms. Fast (or good) algorithms are the algorithms that run in polynomial time, which means that the number of steps required for the algorithm to solve a problem is bounded by some polynomial in the length of the input. All other algorithms are slow (or bad). The running time of slow algorithms is usually exponential. This book is about bad algorithms. There are several reasons why we are interested in exponential time algorithms. Most of us believe that there are many natural problems which cannot be solved by polynomial time algorithms. The most famous and oldest family of hard problems is the family of NP complete problems. Most likely there are no polynomial time al gorithms solving these hard problems and in the worst case scenario the exponential running time is unavoidable. Every combinatorial problem is solvable in ?nite time by enumerating all possi ble solutions, i. e. by brute force search. But is brute force search always unavoid able? De?nitely not. Already in the nineteen sixties and seventies it was known that some NP complete problems can be solved signi?cantly faster than by brute force search. Three classic examples are the following algorithms for the TRAVELLING SALESMAN problem, MAXIMUM INDEPENDENT SET, and COLORING.

This book studies exponential time algorithms for NP-hard problems. In this modern area, the aim is to design algorithms for combinatorially hard problems that execute provably faster than a brute-force enumeration of all candidate solutions. After an introduction and survey of the field, the text focuses first on the design and especially the analysis of branching algorithms. The analysis of these algorithms heavily relies on measures of the instances, which aim at capturing the structure of the instances, not merely their size. This makes them more appropriate to quantify the progress an algorithm makes in the process of solving a problem. Expanding the methodology to design exponential time algorithms, new techniques are then presented. Two of them combine treewidth based algorithms with branching or enumeration algorithms. Another one is the iterative compression technique, prominent in the design of parameterized algorithms, and adapted here to the design of exponential time algorithms. This book assumes basic knowledge of algorithms and should serve anyone interested in exactly solving hard problems.

ALGOSENSORS, the International International Workshop on Algorithmic - pectsofWirelessSensorNetworks,isanannualforumforpresentationofresearch on all algorithmic aspects of sensor networks, including the theory, design, an- ysis, implementation, and application of algorithms for sensor networks. The 5th edition of ALGOSENSORS was held during July 10–11, 2009, on Rhodes, Greece. There were 41 extended abstracts submitted to ALGOSENSORS this year, and this volume contains the 21 contributions selected by the Program C- mittee. All submitted papers were read and evaluated by at least three Program Committeemembers,assistedbyexternalreviewers.The?naldecisionregarding every paper was taken following an electronic discussion. The proceedings also include two two-page-long Brief Announcements (BA). TheseBAsarepresentationsofongoingworksforwhichfullpapersarenotready yet, or of recent results whose full description will soon be presented or has been recently presented in other conferences. Researchers use the BA track to quickly draw the attention of the community to their experiences, insights and results from ongoing distributed computing research and projects. ALGOSENSORS 2009 was organized in cooperation with the EATCS and ICALP 2009. The support of Ben-Gurion University, the Foundations of Ad- tiveNetworkedSocieties ofTinyArtefacts(FRONTS) project,andCTIisgra- fully acknowledged. August 2009 Shlomi Dolev S C T A E Organization ALGOSENSORS, the International International Workshop on Algorithmic - pects of WirelessSensor Networks,is an annual forum for researchpresentations on all algoritmicfacets of sensor networks.ALGOSENSORS 2009 wasorganized in cooperation with the EATCS and ICALP 2009.

The Boolean satisfiability problem (SAT) and its generalization to variables of higher arities - constraint satisfaction problems (CSP) - can arguably be called the most "natural" of all NP-complete problems. The present work is concerned with their algorithmic treatment. It consists of two parts. The first part investigates CSPs for which satisfiability follows from the famous Lovasz Local Lemma. Since its discovery in 1975 by Paul Erdos and Laszlo Lovasz, it has been known that CSPs without dense spots of interdependent constraints always admit a satisfying assignment. However, an iterative procedure to discover such an assignment was not available. We refine earlier attempts at making the Local Lemma algorithmic and present a polynomial time algorithm which is able to make almost all known applications constructive. In the second part, we leave behind the class of polynomial time tractable problems and instead investigate the randomized exponential time algorithm devised and analyzed by Uwe Schoning in 1999, which solves arbitrary clause satisfaction problems. Besides some new interesting perspectives on the algorithm, the main contribution of this part consists of a refinement of earlier approaches at derandomizing Schoning's algorithm. We present a deterministic variant which losslessly reaches the performance of the randomized original.

This comprehensive and self-contained textbook presents an accessible overview of the state of the art of multivariate algorithmics and complexity. Increasingly, multivariate algorithmics is having significant practical impact in many application domains, with even more developments on the horizon. The text describes how the multivariate framework allows an extended dialog with a problem, enabling the reader who masters the complexity issues under discussion to use the positive and negative toolkits in their own research. Features: describes many of the standard algorithmic techniques available for establishing parametric tractability; reviews the classical hardness classes; explores the various limitations and relaxations of the methods; showcases the powerful new lower bound techniques; examines various different algorithmic solutions to the same problems, highlighting the insights to be gained from each approach; demonstrates how complexity methods and ideas have evolved over the past 25 years.

This book constitutes the refereed proceedings of the 7th International Conference on Algorithms and Computation, CIAC 2010, held in Rome, Italy, in May 2010. The 30 revised full papers presented together with 3 invited papers were carefully reviewed and selected from 114 submissions. Among the topics addressed are graph algorithms I, computational complexity, graph coloring, tree algorithms and tree decompositions, computational geometry, game theory, graph algorithms II, and string algorithms.