# European Symposium on Algorithms

The European Symposium on Algorithms (ESA) is an international conference covering the field of algorithms. It has been held annually since 1993, typically in early Autumn in a different European location each year. Like most theoretical computer science conferences its contributions are strongly peer-reviewed; the articles appear in proceedings published in Springer Lecture Notes in Computer Science. Acceptance rate of ESA is 24% in 2012 in both Design and Analysis and Engineering and Applications tracks.

## History

The first ESA was held in 1993 and contained 35 papers. The intended scope was all research in algorithms, theoretical as well as applied, carried out in the fields of computer science and discrete mathematics. An explicit aim was to intensify the exchange between these two research communities.

### Workshop on Algorithms Engineering

In 2002, ESA incorporated the conference Workshop on Algorithms Engineering (WAE). In its current format, ESA contains two distinct tracks with their own programme committees: a track on the design an analysis of algorithms, and a track on engineering and applications, together accepting around 70 contributions.

## ESA Awards
### ESA Test-of-Time Award

The ESA Test-of-Time Award (ESA ToTA) recognizes outstanding papers in algorithms research that were published in the ESA proceedings 19–21 years ago and which are still influential and stimulating for the field today. Because the Workshop on Algorithms Engineering (WAE) merged in with ESA, the Steering Committee decided that the papers from WAE 1999 to WAE 2001 were also to be considered.
ESA Test-of-Time Award :
| Year | Winners | Award Committee |
| 2022 | Marianne Durand, Philippe Flajolet: Loglog Counting of Large Cardinalities (Extended Abstract). In ESA 2003 Ulrik Brandes, Marco Gaertler, Dorothea Wagner: Experiments on Graph Clustering Algorithms. In ESA 2003 | Edith Cohen, Christos Zaroliagis, Andrew Goldberg |
| 2021 | Andrew Goldberg, Jason Hartline: Competitive Auctions for Multiple Digital Goods. In ESA 2001 Giuseppe Lancia, Vineet Bafna, Sorin Istrail, Ross Lippert, and Russell Schwartz: SNPs Problems, Complexity, and Algorithms. In ESA 2001 | Samir Khuller, Edith Cohen, Christos Zaroliagis |
| 2020 | Rasmus Pagh, Flemming Friche Rodler: Cuckoo Hashing. In ESA 2001 | Uri Zwick, Samir Khuller, Edith Cohen |
| 2019 | Ulrich Meyer, Peter Sanders: Delta-Stepping: A Parallel Single Source Shortest Path Algorithm. In ESA 1998 | Giuseppe F. Italiano, Uri Zwick, Samir Khuller |
| 2018 | Bernard Chazelle: Car-Pooling as a Data Structuring Device: The Soft Heap. In ESA 1998 | Giuseppe F. Italiano, Jan van Leeuwen, Uri Zwick |
| 2017 | James Abello, Adam L. Buchsbaum, and Jeffery R. Westbrook: A Functional Approach to External Graph Algorithms. In ESA 1998 | Jan van Leeuwen, Kurt Mehlhorn, Mike Paterson |
| 2016 | Boris V. Cherkassky, Andrew V. Goldberg: Negative-cycle detection algorithms. In ESA 1996 | Kurt Mehlhorn, Mike Paterson, Jan van Leeuwen |
| 2015 | Mechthild Stoer, Frank Wagner: A Simple Min Cut Algorithm. In ESA 1994 Sudipto Guha, Samir Khuller: Approximation Algorithms for Connected Dominating Sets. In ESA 1996 | Jan van Leeuwen, Kurt Mehlhorn, Mike Paterson |

### ESA Best Paper Awards

ESA Best Paper Awards :
| Year | Track A Best Paper | Track B Best Paper | Track A Best Student Paper | Track B Best Student Paper |
| 2022 | Stefan Walzer: Insertion Time of Random Walk Cuckoo Hashing below the Peeling Threshold (extended abstract) | Chris Schwiegelshohn and Omar Ali Sheikh-Omar: An Empirical Evaluation of k-Means Coresets | Zoe Xi and William Kuszmaul: Approximating Dynamic Time Warping Distance Between Run-Length Encoded Strings | Tim Zeitz and Nils Werner: Combining Predicted and Live Traffic with Time-Dependent A* Potentials |
| 2021 | Zhiyang He, Jason Li and Magnus Wahlström: Near-linear-time, Optimal Vertex Cut Sparsifiers in Directed Acyclic Graphs | Simon D. Fink, Matthias Pfretzschner and Ignaz Rutter: Experimental Comparison of PC-Trees and PQ-Trees | Wojciech Nadara, Mateusz Radecki, Marcin Smulewicz and Marek Sokołowski: Determining 4-edge-connected components in linear time | Florian Wörz and Jan-Hendrik Lorenz: Evidence for Long-Tails in SLS Algorithms |
| 2020 | Moritz Venzin, Friedrich Eisenbrand: Approximate $CVP_{\infty}$ in time $2^{0.802 n}$ | Georg Osang, Mael Rouxel-Labbé, Monique Teillaud: Generalizing CGAL Periodic Delaunay Triangulations | Hanrui Zhang: Improved Prophet Inequalities for Combinatorial Welfare Maximization with (Approximately) Subadditive Agents | |
| 2019 | Peyman Afshani, Rolf Fagerberg, David Hammer, Riko Jacob, Irina Kostitsyna, Ulrich Meyer, Manuel Penschuck and Nodari Sitchinava: Fragile Complexity of Comparison-Based Algorithms | Thomas Bläsius, Tobias Friedrich, Maximilian Katzmann, Ulrich Meyer, Manuel Penschuck and Christopher Weyand: Efficiently Generating Geometric Inhomogeneous and Hyperbolic Random Graphs | Cornelius Brand: Patching Colors with Tensors | |
| 2018 | Jacob Holm, Giuseppe F. Italiano, Adam Karczmarz, Jakub Łącki, Eva Rotenberg: Decremental SPQR-trees for Planar Graphs | Daniel R. Schmidt, Bernd Zey, François Margot: An Exact Algorithm for the Steiner Forest Problem | Maximilian Probst: On the Complexity of the (Approximate) Nearest Colored Node Problem | Max Bannach, Sebastian Berndt: Practical Access to Dynamic Programming on Tree Decompositions |
| 2017 | Marek Cygan, Lukasz Kowalik and Arkadiusz Socala: Improving TSP tours using dynamic programming over tree decompositions | Hisao Tamaki: Positive-instance driven dynamic programming for treewidth | Marc Roth: Counting restricted homomorphisms via Möbius inversion over matroid lattice | |
| 2016 | Stefan Kratsch: A randomized polynomial kernelization for Vertex Cover with a smaller parameter | Thomas Bläsius, Tobias Friedrich, Anton Krohmer and Sören Laue: Efficient Embedding of Scale-Free Graphs in the Hyperbolic Plane | Adam Kunysz: The Strongly Stable Roommates Problem | Michele Borassi and Emanuele Natale: KADABRA is an ADaptive Algorithm for Betweenness via Random Approximation |
Since 2022, ESA also awards the best paper for the Simplicity Track:
* 2022. Alejandro Flores-Velazco: Improved Search of Relevant Points for Nearest-Neighbor Classification.

## ALGO conferences

Since 2001, ESA is co-located with other algorithms conferences and workshops in a combined meeting called ALGO. This is the largest European event devoted to algorithms, attracting hundreds of researchers.
Other events in the ALGO conferences include the following.
* WABI, the Workshop on Algorithms in Bioinformatics, is part of ALGO in most years.
* WAOA, the Workshop on Approximation and Online Algorithms, has been part of ALGO since 2003.
* ATMOS, the Workshop on Algorithmic Approaches for Transportation Modeling, Optimization and Systems, formerly the Workshop on Algorithmic Methods and Models for Optimization of Railways, has been part of ALGO in 2003–2006 and 2008–2009.
* IPEC, the International Symposium on Parameterized and Exact Computation, founded in 2004 and formerly the International Workshop on Parameterized and Exact Computation (IWPEC), is part of ALGO since 2011
ATMOS was co-located with the International Colloquium on Automata, Languages and Programming (ICALP) in 2001–2002.