Contributions.

[commander-trashdin]

Are you interested in them? I can dig up some code I was writing to check performance. Pretty sure for example I had a non recursive DFS, real quick, somewhere.

[privet-kitty]

Hi. Any corrections or suggestions are welcome. When it comes to constant factors of performance, however, I'm not always striving for it. In many cases I focus on making it easy to read and modify my code in a contest.

(If I remember correctly, you suggested DP to reduce operations for matrix multiplication somewhere before. I like to read such tips or articles.)

[commander-trashdin]

Okay, several things.

1) Here is my (torn out of context) dfs macro (which performs non-recursive dfs. It also calls proper visitors (or so I hope). I am afraid it needs some rewriting before you could use it in your code, but maybe if you are interested, I can help with that. https://gist.github.com/thrashdin/b90abc53fc6890d4d5c78dab1df03b02

2) I suggested it here (https://github.com/numcl/numcl/issues/17#issuecomment-557381849) and I actually posted my code there (which works all but maybe a macro I wrote). People told me I need more like a compiler-macro for that, but I don't know how to make one. Again, if you are interested, maybe you can help me there). Also, there is ofc a wiki article on that. https://en.wikipedia.org/wiki/Matrix_chain_multiplication It mentions a faster algorithm -- pretty long one. Me and my friend are planning to implement it, both in C++ and CL. Asa it happens, I am willing to share the CL part)

3) Me and that friend I mentioned are actually planning to implement several high-level algorithms using CL, such as Mikkel Thorup algorithm (a faster Dijkstra). Willing to share them too.

4) I think your coding style is more advanced compared to mine => In many cases things I submit would need some corrections. Keep that in mind when you agree to deal with my stuff)

[privet-kitty]

Thanks. All your work is interesting. If you write Thorup's algorithm, I will enjoy looking at your code. This repository is, however, aimed at competitive programming in the first place (though I also learn and write new algorithms never used in a competition, sometimes out of curiosity and sometimes out of necessity).

If I respond to a yes-no question, whether I accept other lisper's contribution or not, the answer is yes. However, for now I don't intend to make this repository a public project in the true meaning. Anyway, thank you for being interested in my work!

[commander-trashdin]

Well, yea, I mean, if I wasn't busy with all the other (mostly non Cl ;(( ) stuff, I should have made something like this myself by now. I actually attempted deque a year ago, but wasn't experienced enough.

Now, uhh, I got the idea about competetive programming, so.... Should I actually try to make some contributions (seems like yes?) and in what form -- a pull request? I take it as I can't just throw my gists in all directions)

[commander-trashdin]

Hey, we are bulding a certain library that might be nice for collection like yours. It's here https://github.com/commander-trashdin/cl-overload and the discussion is here https://github.com/markcox80/specialization-store

I was thinking about which functions should be included with your library in mind. So I would appreciate any suggestions if you have them. I think it can also be possible to make the way you generate your structures less...macro-based.

[privet-kitty]

Hi. I won't be able to introduce such a dense abstraction layer for competitive programming (except for the possibility, major contest sites adopt a totally different judge system).

More importantly, however, I'm expecting great things from these kinds of attempt to fill in the missing piece of Common Lisp, parametric polymorphism. Keep it up.

[commander-trashdin]

Okay, Just for clarity though, the main goal of the project is to have 0-cost (in terms of runtime) abstraction. All of our specializations are carefully inlined and dispatched in such a way, that if you declare the types (which is about the same as just name functions according to the types) there will be exactly 0 performance costs.

[commander-trashdin]

No idea how to otherwise contact you, but here's an example of what I had in mind (I cannot do this atm, so I haven't finished the project, and this gist is merely a bad sketch, but it does convey the idea)

https://gist.github.com/commander-trashdin/e8582ba36b8d07f66a3646cf7bd7ad99

[commander-trashdin]

It (static dispatch) became half usable now (https://github.com/lisp-polymorph), and I intend to upgrade it more. At some point I'd like to take some of the basic structures you have here + finished red-black tree I once started. I hope I have your permission to take your impls? (I expect them to be performance oriented since, duh, competitive)l.

[privet-kitty]

I saw it. Nice and laborious work, I think. Most code in this project is under public domain, so please feel free to reuse it.

[commander-trashdin]

Uh, sorry to bother you so much, but I suppose you aren't available for direct help (mostly with data structures implementation/review) right now or around now? I don't even know anybody else in the CL community who did as much as you in this area.

[privet-kitty]

Hi. If your problem is deeply related to CL, I think you can ask it on reddit r/lisp, otherwise you can ask it on stackoverflow etc.. (Of course you can ask it here if you have a good reason to do so, but anyway I believe it's better to submit a question in an open forum first.)

[commander-trashdin]

You are good at writing data structures and thats what we also need for our polymorphism library.