This book constitutes the refereed proceedings of the 13th International Symposium on Experimental Algorithms, SEA 2014, held in Copenhagen, Denmark, in June/July 2014.

The 36 revised full papers presented together with 3 invited presentations were carefully reviewed and selected from 81 submissions. The papers are organized in topical sections on combinatorial optimization, data structures, graph drawing, shortest path, strings, graph algorithms and suffix structures.

This book constitutes the refereed proceedings of the 18th Annual International Conference on Computing and Combinatorics, held in Sydney, Australia, in August 2012. The 50 revised full papers presented were carefully reviewed and selected from 121 submissions. Topics covered are algorithms and data structures; algorithmic game theory and online algorithms; automata, languages, logic, and computability; combinatorics related to algorithms and complexity; complexity theory; computational learning theory and knowledge discovery; cryptography, reliability and security, and database theory; computational biology and bioinformatics; computational algebra, geometry, and number theory; graph drawing and information visualization; graph theory, communication networks, and optimization.

The Scandinavian Workshop on Algorithm Theory (SWAT) is a biennial int- national conferenceintended as a forum for researchersin the area of design and analysisofalgorithmsanddatastructures. The?rstSWATworkshopwasheldin Halmstad, Sweden, in 1988. Since then it has been held biennially, rotating - tween the ?ve Nordic countries - Denmark, Finland, Iceland, Norway and S- den, with the exception of 2006 when it was in Riga. Earlier SWATs were held in Humlebaek, Denmark (2004), Turku, Finland (2002), Bergen, Norway (2000), ? Stockholm, Sweden (1998), Reykjavik, Iceland (1996), Arhus, Denmark (1994), Helsinki,Finland(1992),Bergen,Norway(1990)andHalmstad,Sweden(1988). This volume contains the contributed papers presented at the 11th Sc- dinavian Workshop on Algorithm Theory (SWAT 2008), held in Gothenburg, Sweden, July 2-4, 2008. In addition, the volume also includes abstracts of an invited talk by Michael Mitzenmacher on "A Survey of Results for Deletion Channels and Related Synchronization Channels"and by Vijay V. Vazirani on "Nash Bargaining via Flexible Budget Markets. " Papers were solicited for original research on algorithms and data structures in all areas, including but not limited to: approximation algorithms, compu- tionalbiology,computationalgeometry,distributedalgorithms,external-memory algorithms,graphalgorithms,online algorithms,optimization algorithms,par- lel algorithms, randomized algorithms, string algorithms and algorithmic game theory. The 36 contributed papers were chosen from 111 submissions. Revised and expanded versions of selected papers will be considered for publication in a special issue of Algorithmica. The best paper award was given to Yossi Azar, Uriel Feige and Daniel Glasner for their paper "A Preemptive Algorithm for Maximizing Disjoint Paths on Trees. " Eachpaperwasreviewedbyatleastthreereferees,andevaluatedonthequ- ity,originalityandrelevanceto the symposium.