Hi. I'm excited to announce my partnership with Harbour.Space, which will include free Olympiad classes!
I will teach two groups:
- Easy: A course on competitive programming. You'll learn and practice algorithms, including topics from the USACO Guide Silver and Gold. Prerequisites: C++, BFS, DFS, binary search.
- Hard: We will mostly solve Olympiad problems, and cover topics from the USACO Guide Platinum and Advanced. This group is aimed at students who want to get an IOI medal.
The first semester will last from September until December, around 15 classes per group. As an optional pre-course, the Easy group will start next week (17.08.2026) with a few introductory classes in the second half of August.
- Time: Mondays (Easy) and Tuesdays (Hard) at 16:00-17:30 CEST
- Registration: https://harbour-space.typeform.com/to/CEQuahT4 (registration started on 15.08.2026)
- Platform: Discord group + Zoom classes (with recordings)
- Eligibility: high school students and younger
- Price: free
We haven’t decided on the participant limit yet. You cannot participate in these classes if you've already graduated high school, sorry. I'm planning to upload highlights (e.g. a nice problem or part of a lecture) to YouTube. You can also join my YT/Twitch livestreams, coming soon with a regular schedule.
Harbour.Space believes that exceptional talent deserves exceptional support. As part of our partnership, Harbour.Space sponsors my competitive programming initiatives, including intensive online bootcamps (like the IOI Online Camp), livestreams, and other educational activities.
Feel free to suggest any improvements, or other things that I should organize. See you soon!
is it okay if i just join with the recordings because of time zone?
lets goooo!
hi, thank you for organizing this! I have a question regarding the registration: At what time will the registration open on Saturday and where will the registration link/ form be posted? This would help me make sure I dont miss it. Thanks!
Where can i register for it?
for the 15th august course
The registration is open now. It's the same link for both groups (Easy starting in 2 days, Hard starting in 2 weeks).
can we register for both easy and hard groups?
Please choose one to register. Depending on the number of students, I might allow to attend both groups.
so where can i join this class?(link) and if its on discord server can you please forward the link?
and also will you be giving homework questions and all?
i graduated high school. can i have access to the yt channel for recordings??
Well, it's a public channel. https://www.youtube.com/errichto and https://www.youtube.com/errichto2
How to register?
where is the registration form?
How do we register for this?
bro is fatespeaker from temu
Would the hard training cover ioi gold medal levels ?
how to register ?
The registration has started (link in the blog).
The Easy classes will start in 2 days, the Hard classes will start on 31.08. The registration will be open at least until the end of the month.
Errichto do we get class links and announcements on this server?? and also how to get confirmed that i got registered successfully ? Thank You :)
There will be a new dedicated server for the Harbour.Space classes. You will get an invite via email on Monday morning. There's currently no automatic confirmation for the registration but I'll ask somebody to change that.
ok , thank you :)
if I registered today, do I still have a chance? also is it useful for Polish OI?
Yes, the registration is still open for both groups.
Yes, it's useful for POI. I will actually sometimes use POI problems in the Hard group.
just register yesterday, since its september now, do i still have a chance to join?
Woww !! Excited for these Olympiad classes !! But, I'm confused about for which group I should register for. Obviously, I'm not a beginner. I can easily solve most of the $$$\le 1400$$$ rated problems on CF. From last 4 contests, I consistently solved till D at Atcoder Beginner Contest during contest. Also, I solved some IOI , CEOI , POI , BOI , JOI problems. I know all the topics of USACO Silver level but don't know some topics of Gold level. Errichto, please help me to choose the right group. Or, can you give me a chance to try both groups and then let me pick the suitable group ?
You should try the Hard group.
Generally, choose whatever you think is better, and later you can switch. If you know most of USACO Guide Gold, you should choose Hard. If you solved some IOI/POI/etc. problems, you should choose Hard. So your situation is clear :)
I am graduated from college and right now coaching some high school students for olympiad. I have already solved most of Advanced and Platinum but wanted to join to learn more on pedagogy and how to teach those topics, can I join too?
Let's say that you can join if you do things for free in your community. I'm not sure about the format (i.e. whether you will be a part of the server or I will only send you some materials). Please send me a DM.
Do we get any confirmation mail after registration?.
There's currently no automatic confirmation for the registration, sorry. I've asked somebody to change that now.
You should get a Discord invite via email on Monday morning.
Will you still be teaching a year or two later? for free?
No guarantees on that.
Hi. How can we get the link for the server if we registered today?
very sad to hear that only high school students and younger :( Is there other ways that i can participate in those classes :(
Is it only me or are there others also who havent received the link for today's class right now?
Not only you!
I've just sent emails with Discord invites to everybody who registered for the Easy group. Send me a DM if you registered for Easy but didn't get any email now. The first two classes will be this Tuesday and Thursday.
If you're interested in the Hard group, you'll get an invite by 30.08. Don't worry about these first few Easy classes as we're starting with basic topics like Dijkstra and Prefix Sums.
The registration will last at least until the first week of September. There's already a huge number of students, and we need to internally discuss the format and whether to introduce any cap. Fun fact: we are almost at a perfect balance — around 51% of students chose the Hard group.
how much do you meant by a huge number of students??
If a student is rejected/accepted from the hard group they will receive an email by 30.08 is my understanding, is that correct??
Yes, you will receive an email by 30.08
Errichto sir , I am more comfortable with OI problems and able to solve many OI Problems, but I am not serious on CF Rating and also less active on codeforces than solving OI Problems. So will I rejected or accepted? I have applied for hard group .
We are now accepting everybody who is eligible (i.e. high school or below). You can join one group and switch later.
ok, once again thank you so much :)
Due to school, I will be unable to attend the free classes (both Easy and Hard, but it looks like Hard would be the correct group for me). Am I still able to register and watch the Zoom recordings when possible (and join the Discord group)?
Yes, currently it's allowed to register and not attend classes live. I'm not sure if we will keep it this way forever.
Thank you! I have registered!
is registration still open?
I believe so. Easy has already started and hard is starting in a few weeks.
What would be the group sizes for hard and easy classes?
I just registered but how to join the discord group I didn't get any email yet
Did you get the mail bro?
yes
Can you tell when did u get it?
i also waiting for mail .
I got it on 27 Aug like after 4 days I registered
Oh icy
Did you get a mail? I registered on the 17th but besides the Thank you for applying mail right after applying, i didn't get anything.
yeah i got it yesterday
i didnt got it bro
How will I be able to see those classes I have already registered eager to learn the logics
I've now sent email invites to everybody who registered for the Easy group in the past few days. I will send invites to the Hard group in the next 24 hours.
As a reminder: it's recommended but not required to attend the classes live. Even if the 16:00 CEST time is not suitable for you, you can still join the group and watch recordings. I might also do some classes on Saturdays at earlier time, which should be better for many time zones.
Will we be added if we register now or its closed now.
I registered on the 17th but haven't received any email besides the "Thank you for applying" notification. Will I still receive an email (it's already the 30th for me)?
Are registration for easy course still open since the course is probably already started for easy group.
I registered yesterday and got added
I registered today so I probably wont get added, I think I should try to apply in hard group since he said that they will add those students in next 24 hours.
The registration is still open for both groups.
I have not gotten any mail about the hard group..
https://codeforces.me/blog/entry/155971?#comment-1388878
same
Hey errichto i have registered for the camp today. Can you please accept my registration i have not recieved any email yet.
i have registered on the day when this post was written , and still waiting for email . May be we will get email today.
yeah bro i am also waiting for it.
Hey errichto. I have applied for the easy camp today. I know i am late but i was not aware of this i was not using codeforces. But since it is a greaat opportunity for me to learn from you. i dont want to miss this opportunity. Please kindy accept my registration. my name is Shilpi Kumari.( i have filled the registration form)
Errichto I have also registered. Sorry for being late. Am I eligible to join your program and how will I be notified ???