This is special issue of Algorithmica for the 28th London Stringology Days & London Algorithmic Workshop (LSD & LAW) was organised by the Algorithm and Data Analysis research group at King’s College London in February 2020. The contents cover theoretical and applied aspects of discrete algorithms topics, including String Algorithms, Combinatorics on Words, Bioinformatics, Graph and Network Algorithms, and Computational Complexity. These selected journal articles were reviewed according to the rigorous standards of Algorithmica.

We would like to thank the authors for submitting their work, as well as their cooperation during the review and revision process. We would also like to thank all the reviewers for their constructive feedback which enabled us to complete this publication. Finally, we would like to thank the Editorial Board of Algorithmica for giving us this opportunity to organise this special issue.

Mai Alzamel, King’s College London, UK.

Costas S. Iliopoulos, King's College London, UK.

Dimitrios Letsios, King's College London, UK.

Nicola Prezza, Ca’ Foscari University, Italy.