I just gave a talk at PSC2016 conference in Prague based on a paper with Neerja Mhaskar, Forced repetitions over alphabet lists. This paper explores further the problem posed by Grytczuk in 2010 regarding the construction of non-repetitive strings over alphabet lists where each alphabet has 3 symbols. We use some string combinatorics, as well as an approach based on the Crossing sequences technique from complexity theory. The conference took place at České vysoké učeni technické v Praze – Fakulta stavebni, which is quite a mouthful to say, even for a fellow slav :), and is the Czech Technical University in Prague.
Slides are attached:
Some other pictures: