The blog publish date is incorrect, should be around 12.07.2025. CF saved the draft date.
Hi, I'm organizing paid group classes on Dynamic Programming in August. Last year, I did something similar with general problem-solving (link).
There will be two groups of different style and difficulty. Each group gets 8 lessons of 1h30m each, from 28.07.2025 to 24-31.08.2025. Group size up to 12 people. You get access to recordings and problems from both groups, but you should actively attend only one. There's a lot of homework, some to be discussed next lesson. I will create new original CF/Polygon problems, especially for the easy group. These problems will eventually be published for everybody!
Price: 250 EUR with a small country-based discount.
Registration: You should pay via link (Stripe) and choose the group there. I will send you the Discord invite link via e-mail. Contact me if you're from a country outside Europe/USA/India so I could give you a small discount. The price is already set to 20000 INR for India, 20% off.
Platform: Discord for classes, links and extra discussion. Codeforces group (private GYM/mashup contest) for CF+original problems. YouTube for (private) recordings of the class.
Easy group, solving dp problems
Tuesdays and Fridays at 14:00 CEST.
Prerequisites: multi-dimensional arrays; knowing any way to compute N-th Fibonacci number in $$$O(N)$$$; being able to read C++ (so you would understand my code).
You will thoroughly learn iterative DP by solving 50+ easy/medium problems. You will learn how to come up with states and transitions, use multiple dimensions, iterate in correct order. I will often show a few lines of code in order to discuss e.g. array size, initialization, for-loop order, off-by-one errors. We'll cover knapsack variations (e.g. repetitions or small weights), optimal path reconstruction (with and without "breadcrumbs"), and using prefix sums to speed up transitions.
Hard group, dp techniques
Tuesdays and Fridays at 16:00 CEST.
Prerequisites: Prefix sums, knapsack, bitmasks. Being able to solve (almost) any easy dp problem. Being able to solve at least half of the problems from AtCoder DP Contest.
This group will be more lecture-style, ofc. with asking questions and suggesting solutions to a problem/issue. But you mainly get to solve problems as homework. We'll cover switching dimension/answer, knapsack without one, last 1-2 tricks/problems from here, bitmask dp (briefly) & broken profile, SOS, small-to-large tree DP, some optimizations from here and tricks from here. We'll solve 2-3 very hard DP problems too.
LeetCode classes
Starting from August, I will also do weekly Sunday classes where we cover problems from the most recent LeetCode Weekly contest. 150 EUR / month. Registration soon.
Reach out to me (CF or errichto@gmail.com) if you have any questions. Cheers.
Hi errichto, have you posted payment link yet? I am interested in the registering your class.
I've updated the blog with a payment link now.
orz, Errichto is back guys
Could you please specify the exact days on which these lessons will take place during the given time span?
I am pretty sure that you can find that information if you read closely enough...
OK, let me clarify my question. In the message, we're given the time span from 28.07.2025 to 24–31.08.2025, and for both groups, the lessons are scheduled on Tuesdays and Fridays. So let's count the lessons, given that we are supposed to have 8 in total:
1)29.07 2)01.08 3)05.08 4)08.08 5)12.08 6)15.08 7)19.08 8)22.08
Do you understand my question now, or am I missing something?
The last lesson is supposed to take place on 22.08, but Errichto gave the time span as 28.07.2025 to 24–31.08.2025. I wanted to know which dates are exceptions, if any.
24–31.08.2025 means 24 or 31 August depending on adjustments in schedule. In other words, those 8 are the ones that are currently planned, and the lessons may span up to 31 August if there are adjustments in schedule due to some students unavailable on some date.
I confirm this. It ends on 24.08.2025 by default — unless we skip a date or two. A year ago, I wasn't available one day because of an onsite event. The students actually suggested to have a full week of a break to catch up with homework. Another possible reason of skipping a date would be a CF round.
Do let me know in 1-2 days (until Wednesday, 23.07) if you are going to join the classes. If I don't get more people, I will cancel this and refund everybody. For context, 3 people per group joined so far.
Hello Errichto, is registration still available?