Recently, I felt lack of knowledge and techniques for solving various number of cases, probability and expected number problems.
I did not managed to solve a lot of problems including
- Dstorv,
- Gem Island,
- Do I wanna know,
- Solitaire, and
- BBQ Hard.
(For the first three problems, I did not managed to solve problem in contest. And, I think it led to unsatisfying results.)
I really want to be good at this kind of problems, so could anyone give sufficient number of problems, or materials (including book) to improve my skill?
Read a book on combinatorics/probability. You can also check out my two blogs: one, two.
I skimmed through your blogs, and I think I know basic concepts of expected value.
Can you recommend a book on combinatorics?
Contribution technique and "ordered pairs" are more than basic concepts for sure. (but ofc. maybe you already know them)
Idk about a particular book. I learned combinatorics and pbility in school&uni.