Hello Codeforces!
I'm very super duper ultra excited to invite you to Weekend Practice round #8 , taking place on July 13, at 12:00 UTC. This is a rated contest at Eolymp.
NOTICE THAT THE ROUND TIME SCHEDULE GOT EARLIER BY 1 HOUR
Format and Difficulty
Same as in previous rounds, the competition is primarily aimed at improving practical skills. There will be $$$2$$$ hours for $$$5$$$ tasks of varying difficulty, the easiest of which can even be solved by beginners.
The scoring for each task being block-based (meaning points are awarded for each block of tests separately, and only if the solution passes all tests in the block). If there is a tie between two participants, the one whose last productive submission (i.e., a submission that added at least one point) was made earlier will be ranked higher in the leaderboard.
The statements will be available in the following languages: English, Ukrainian, French, Spanish, Azerbaijani, Russian.
Registration
You can join the competition on the competition page.
Prizes
The top-10 participants of the competition, as well as 10 random participants from those who rank from 11th to 100th place, will receive prizes in the form of t-shirts. Please, note, that we have changed how prizes are awarded,
Visit Frequently Asked Questions section to learn more.
Thanks a lot to:
- Denisov and MathModel For Coordinating The Round.
- MathModel For the $$$\underbrace{\mathtt{WWW..WW}}_{\infty}$$$ Coordination Debut.
- Sergey Kolodyazhnyy for creating Eolymp 😎.
- TheSensei , Denisov and Andriy Kholod for authoring problems .
- cadmiumky , satyam343 , de_sousa , Ignut , barbie ,VladiG , cowthecow , De3b0o , tibinyte2006 , chromate00 , ALnQ417 , feining_for_gm, Aritro_ for testing the contest 🧪.
Score Distribution:
Sponsors
This round is sponsored by Acai Travel
Acai Travel
Acai Travel is a seed-stage startup using AI to transform customer support in the travel industry. With $4M in funding and partnerships with leading global brands, our AI assistant integrates with travel and airline systems to deliver real-time information, automate ticket routing, analyze sentiment, and generate smart auto-replies—boosting efficiency and enhancing customer experiences.
We work with cutting-edge AI to solve real problems, not to chase trends. Our team, based in New York, Barcelona, and Pune, builds practical solutions rooted in strong values, curiosity, and a culture that fosters innovation and positive change.
Editorials ! :
A : Here
B : Here
C : Here
D : Here
E : Here
Winners:
First solvers:
A : Horka
B : wery0
C : Horka
D : k1r1t0
E : k1r1t0








as a tester, this contest has great problems!
excited to see your problems TheSensei!!
Looking forward to the contest TheSensei
NOTICE THAT THE ROUND TIME SCHEDULE GOT EARLIER BY 1 HOUR
I submitted ~200 lines of persistent segment tree code for the last problem with just a few seconds left — without even compiling it — and it turned out to be bug-free :)
It got a TLE on the last subtask. My solution has a time complexity of O(n log n + q log² n). Was this time complexity intended to get full score, or could one of the log factors have been avoided?
TheSensei
btw, 4th place is wrong :)I was 4 minutes short to AK :(
$$$O(q \log^2 n)$$$ is good enough if you use good enough DS to calculate kth ordered statistic on a segment. I've used this implementation and my solution passes in 1.6s.