The final contest of the 2024-2025 USACO season will run from March 21st to March 24th. Good luck to everyone! Please wait until the contest is over for everyone before discussing anything contest-related (including but not limited to your scores or anything about the problems).
There are some new rules regarding the gold division of USACO, please refer to the website regarding the updates, especially if you are trying to promote into platinum.
For those unfamiliar with the USACO contest format, please refer to the contest instructions and rules. We provide a short FAQ but folks should read all the rules carefully.
I have a question about the contest. Where do I ask it?
Email the contest director via the instructions above. Do not post anything publicly about the questions (including but not limited to your scores, how you felt about the problems, any content of the problems, etc) until after the contest is over for everyone. Do not DM me or anyone else affiliated with USACO, only the contest director can assist you. The contest director does not monitor Codeforces, this blog post is merely a courtesy to inform other people of the contest.
When can I enter the contest?
For bronze and silver, the contest will open on March 21st. For gold and platinum, the contest opens at 12pm ET on Saturday, and you must start the contest between 12pm and 12:15pm ET on Saturday to get a certified score.
If I submit multiple programs, which one gets evaluated?
Only the last submission will be evaluated for official scoring purposes.
Can I use prewritten code / templates?
No.
Can I use AI tools during the contest including but not limited to ChatGPT and Copilot?
No.
Am I allowed to use outside resources during the contest?
You may only refer to language documentation.
Can I solve problems in Rust?
No, the only languages supported are C, C++, Java, and Python. Consult the instructions for language-specific technical details.
Will Rust support be added?
Probably not. Petition IOI to add Rust support first.
Why is USACO still stuck on C++17
Python 3.6 is 7 years old and Java 11 is like 13 :skull (but pretty much no one upgrades Java :)
Why does USACO jump C++14 :(
It was there, but was removed at some point.
In Romania we use C++11 so be happy with 17
Yes, and until 2020, we didn't know what score we were getting at the final of the contest. The sources from each problem were put on a memory stick and were evaluated by the commission. We found out our scores in the evening. And that was at the national stage. Now this only happens at some of the regional stages.
Well, at least it's consistent with the past two IOIs.
https://www.ioi2024.eg/gradingenvironment
Why is IOI still stuck on C++17
says the rules
Can I create a burner account and submit only for one problem there, because I got the idea of how to solve the problem in the last minute fully and didn't have enough time to implement it?
no
No. Just wait for results, then you can submit in analysis mode
The contest window is over, so as usual, here are my written and video solutions for Bronze and Silver.
bronze p1: blog, video
bronze p2: blog, video
bronze p3: blog, video
silver p1: blog, video
silver p2: blog, video
silver p3: blog, video
I think your code of silver p2 is wrong. For example, it give wrong answer in following input:
The output of your code is 1. But the answer should be 2.
Thank you for spotting the bug! I will fix it during the upsolving process, it got AC during the contest, I guess the testdata was weak
Sir, everytime you are creating new account and giving contest, because it's not possible to give silver everytime right? Is it allowed to create new account for every contest?
As far as I know, there is no restriction involving that rule as long as the other rules are not broken otherwise.
Ohkk thank you sir
According to Brian Dean himself, "It is not allowed unless there is a compelling reason for this – you’ll get to see and practice with all the problems after the contest ends with your one primary account"
(I emailed him)
Thanks for the reply!
Please correct me if I'm wrong, so my interpretation is that someone is allowed to take the lower divisions during the contest window if and only if they have already competed on their primary account (in my case, Platinum division).
Where are you getting this from? Multiple accounts are not allowed.
I thought that the "after the contest ends" part referred to the 4/5 hour window I have on my main account so that I couldn't get spoilers from the lower divisions, now I understood. Thank you for clarifying!
https://usaco.org/index.php?page=instructions
But in his case, it seems like creating an observer account to solve lower division problems is okay
Anyone who does not already have an account and isn't pre-college is free to create a (single) observer account to compete.
The question asked in the video was about upsolving, which I assume means solving the problems after the contest has ended, not during. Anyone with an account can do this, so you should not create multiple logins for this purpose.
i think it is pretty explicit what he meant in that video....did you watch it?
While the question was about upsolving, his reply made it clear that he is talking about contest time.
He clearly says that he doesn't want the scoreboards of lower divisions to be polluted by experts solving the problems, but if you are an observer, it is fine. Correct me if i am mistaken, but there is no scoreboard for upsolving.
I did watch it.
Yeah, it's strange how the reply doesn't quite address the question that was asked, but it should not be taken to mean that it is okay to use multiple accounts.
I asked Brian about this to clarify, and he said that no one should be using multiple accounts unless he has explicitly approved it (he has granted a very small number of exceptions to this rule).
of course i never wanted to claim this video is reason for be allowed to use multiple accounts. People make mistakes. Rules change. Anything can happen.
However, the video is very very explicit on what Brian Dean thought at that specific time, with no possible misinterpretations, and I think its disingenuous to claim otherwise (like you did in your previous reply).
Observer account is even the official word for the past high school students participating in USACO.
Again, I do not object to you saying it is not allowed, or clarifying that the rules have changed since this video.
I think that this is completely false, and that it definitely depends on the context. E.g., if Brian had assumed the question was coming from a parent that didn't already have an account, then the response would make much more sense.
If you listen to 6:40 — 6:55 the host says that the questions are coming from parents.
I have difficulty with time arrangements.
As a Chinese gold user, I have to start the contest between 0:00am and 0:15am.
Obviously, it is impossible for me to spend the whole evening on this contest, so I would never reach platinum.
But I really want to join platinum, what should I do?
Same. Got fullscore in gold smoothly in two hours, and found I'm not promoted to platinum in contest. And then I finally realize what the certified score for gold means...
I don't think it's a good idea to participate while the sun is actually at the other side of Earth. :(
Cutoff predictions (silver -> gold) and maybe all divisions pls
gold->plat probably 800 but im praying for 750
It's like 50/50 whether it is 750 or 800
Code for Plat 1, Plat 2 (open25-*.cpp)
I failed to debug Plat 3 in time :(
794 on gold it might be fries in the bag for me
:( same. i hope the floodgates get opened
bustin.bi orz
What is the solution for MOO Decomposition (first problem in gold)? I have found the formula for L=1 but didn't know how to evaluate the product for large L.
you just raise it to the power of L LMAO
Why?the terms are not equal.
wdym? if you consider it from the back, it becomes apparent each string copy is independent from one another bc u have to finish the matching within each copy
Did they say that I have to finish in each copy independently??!
implicitly yes, because you must use all the characters for each copy
envy orz
Gold p1 would have been a much better fit for silver
Anyone has links to gold/plat statements? Can't see on website