Hi Codeforces community!

I'm just reaching out to see if anyone could help me model a max flow solution. I'm preparing for Code Jam Round 2, and was looking at Round 2 2017 problem B (https://code.google.com/codejam/contest/5314486/dashboard#s=p1). And while I'm aware that it's not the large test case solution, for educational purposes it caught my eye in the editorial that this problem could be modelled and solved with max flow for the small test case bounds. I've been struggling with it for a while, max flow is also pretty new to me, I can easily model a graph that would implement the restriction of each ticket only being used once, or each customer only taking a single seat on each ride, but I can't seem to model a graph that takes both into account.

Also I'm assuming the solution would use binary search right? Or is there a way to maybe assign costs to the solution so that a max flow min cost algorithm could also minimize the amount of rides needed?

Thank you in advance!

Inspired by the other test case parsers users have been making, I made a version that suits my needs better. If anyone wants to use it, feel free to take a look at the repo.

In short, it parses a contest and puts all sample tests into separate files A.txt, B.txt, A.out, B.out etc. with all inputs and correct outputs, and there's also a script that'll run your executable on all the test cases and check whether output is correct.

Hope you enjoy, if you're interested.

I was recently trying to research my chances of qualifying for ACM ICPC by looking at the latest regionals I could find problems for, ACPC 2015, which can be found at the ACM-ICPC Live Archive. I had first solved a few of the problems on the Hackerrank instance before I found the official one, but when I tried submitting my code that solved the Hackerrank instance of them it would give WA on the ICPC OJ.

Also it seems there are no successful submissions whatsoever to the whole contest on the whole OJ which seems suspicious. Does anyone know if the ICPC OJ is known for having wrong test cases? Or is output formatting more strict or something?

As a reference to test it if anyone wants to try to solve the very easiest problem (it's div 2 problem A level) they can try here.

My code for solving it was this. And I really can't see how it should be wrong, and also as previously mentioned the Hackerrank instance accepted it.

If anyone could help enlighten me that would be awesome.

Let's discuss solutions here. I know I'd be curious to hear other peoples approaches.

Google Code Jam registrations open today!

Register here: https://code.google.com/codejam in 9 hours :D.

Good luck to all when it starts in April!

Hello,

I'm trying to start up a competitive programming group at my school, and since a lot of people are newcomers (as in need to practice problem A's) it would be so awesome for the group to have the opportunity to create a codeforces group to be able to create custom easy contests for our members for practice on easier problems. This is where I hope a benevolent div. 1 coder comes in. As far as I understand only div. 1 coders can create groups. I am optimistic I'm getting close to a level of a div. 1 coder (in my dreams at least) but even assuming that's correct I would still need somewhere between 5-10 contests to actually get my rating there (and that's assuming I'm not just dreaming). It would be so awesome to motivate the people at my Uni to start competitive coding to be able to host these competitions, so I was hoping there was maybe a div. 1 coder that would be so nice as to create a group for us, and make me co-manager of it.

If you're interested please contact me, here or by PM. At least thank you for reading this and considering it!

Kind regards, Goldsmith94