I have a question. Does anyone knows what name of this proof technique? Similar approach is very often used in proofs of correctness of algorithms. I'll start from simplest case which isn't well representative

Usually a suffix array takes me 60 lines of code, this is without building lcp and rmq. So it seems to me that I'm doing something wrong. Could you give me a good implementation of building a suffix array?

Hi, i am now learning to solve geometric problems. I need to cross two lines. On the internet i found only solution through solving the system of equations, but i heared there is another solution that uses vector (dot / cross) product. Could you tell me there i can read about it or explain/give me the code.