To name a few concepts: "Permutation & Combination", "Proofs with induction", "Probability". I did learn some of them from university courses, but writing code for them(in terms of coding problems) helped cement few of the them for me.
Thanks for sharing. Hope you’re doing well now. Wondering where do you write daily, is it like a physical diary or digitally?
I’ve started writing of late, but I like writing on a physical diary. The only problem I’ve with physical diary is searching the entries based on a word - which I often find myself in the need of.