Hello everyone!
The next Starter round is here.
Repovive Starter Round 4 will be held this Sunday.
Starter rounds are designed to be beginner-friendly, with a level close to Codeforces Div.3 / AtCoder ABC.
- Start Time: Sunday, 5 July 2026, 14:35 (UTC)
- Duration: $$$2$$$ hours
- Registration: https://repovive.com/contests/15
The contest is rated for participants with rating below $$$1700$$$, whose role is at most Sushi Roll. It is unrated for Steaks.
- Writers: _R00T, Bahamin and AmShZ
- Testers: Hamed_Ghaffari and mohammadsam
See you on the leaderboard!
UPD1: Congratulations to the top participants:

The Codeforces handles of the top 10 participants:
1: tkdgkb
2: alexwice
4: maspy
5: baluteshih
6: Denisov
7: abc864197532
9: _Jahongir_
Those of you who tested the contest in advance: AKprinceofpersia, Thrb_73, nimoxide, Siyah, AmiraliRafiei and _Robi.








The previous Starter round was really nice. Looking forward to this one too!
Hi guys!
If you want to test this contest, please send your Codeforces handle and your Repovive registration email to my Telegram account: @H_3014.
For testing, you can either time yourself or solve the problems at your own pace.
All feedback must be sent in Telegram at least 3 hours before the contest starts.
We will update this blog after the contest to include the names of our testers and the top participants.
Good luck ♡ :)
First, use the correct flag
Reminder: About 4 hours to the contest.
Tbh contest seemed more like a div.4
Problem quality was really good, especially F which I really liked.
I loved the problem both quantitatively and qualitatively. I'm looking forward to the next round. Thank you!
For problem F, if we remove the constraint that the distance between $$$1$$$ and $$$n$$$ is even, is there a better solution that $$$O(n^2)$$$?
wait there was an O(n^2) solution?
I am talking about the case when the distance between $$$1$$$ and $$$n$$$ is not necessarily even. In that case you have to make a move which reduces the distance between the two iron blocks by 1 anytime in the game(so if the path is of length $$$m$$$, then you can have a $$$O(m^2)$$$ solution with $$$dp[l][r]$$$ as the number of ways if one block is at $$$path[l]$$$ and the other at $$$path[r]$$$). Your sample code fails on the tree with two vertices.
Here is an O(n) solution.
Oh, I get it now. I thought changing
to
would work.
See the submission by @alexwice, he handled both cases.
Oh, I see!! Nice to meet you haha Let's be friends from now on!!
Interesting, looks like the number of states is actually $$$O(n)$$$ even if you use the above mentioned sol.