This book constitutes the refereed proceedings of the 14th Latin American Symposium on Theoretical Informatics, LATIN 2020, held in Sao Paulo, Brazil, in January 2021. The 50 full papers presented in this book were carefully reviewed and selected from 136 submissions. The papers are grouped into these topics: approximation algorithms; parameterized algorithms; algorithms and data structures; computational geometry; complexity theory; quantum computing; neural networks and biologically inspired computing; randomization; combinatorics; analytic and enumerative combinatorics; graph theory. Due to the Corona pandemic the event was postponed from May 2020 to January 2021.

This book constitutes the proceedings of the 15th Latin American Symposium on Theoretical Informatics, LATIN 2022, which took place in Guanajuato, Mexico, in November 2022. The 46 papers presented in this volume were carefully reviewed and selected from 114 submissions. They were organized in topical sections as follows: Algorithms and Data Structures; Approximation Algorithms; Cryptography; Social Choice Theory; Theoretical Machine Learning; Automata Theory and Formal Languages; Combinatorics and Graph Theory; Complexity Theory; Computational Geometry. Chapter “Klee’s Measure Problem Made Oblivious” is available open access under a CC BY 4.0 license.

This book contains the invited and contributed papers selected for presentation at SOFSEM 2021, the 47th International Conference on Current Trends in Theory and Practice of Computer Science, which was held online during January 25–28, 2021, hosted by the Free University of Bozen-Bolzano, Italy. The 33 full and 7 short papers included in the volume were carefully reviewed and selected from 100 submissions. They were organized in topical sections on: foundations of computer science; foundations of software engineering; foundations of data science and engineering; and foundations of algorithmic computational biology. The book also contains 5 invited papers.