We will hold AtCoder Regular Contest-- 224.
- Contest URL: https://atcoder.jp/contests/arc224
- Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20260712T2100&p1=248
- Duration: 120 minutes
- Writer: sheyasutaka, YoshikaMiyafuji, physics0523
- Tester: sheyasutaka, physics0523
- Rated range: 800 ~ 2399
- Point Values: 300-400-500-500-500-700
We are looking forward to your participation!
That's my third time in ARC!!!(my first time in arc--)
why -9??
I'm so nervous，good luck!This is my first time in arc.
First time too！
B and C are not very good problems. My first Arc--.
Overall, ARC224 offers a well-balanced set with a gentle start and a steep climb toward the end. Problems A–C are relatively light and serve as warm‑ups, while D and E demand more thoughtful reasoning. Problem F is the clear highlight in terms of complexity, featuring a non‑trivial counting task. The contest is fair, with no major pitfalls, though C might feel easier than expected for its slot. Suitable for both beginners looking for easy points and experts seeking a solid challenge in the last problem.
Bro you not only used AI in contest but also used AI to write comments.
Problem E feels like a standard Div3 task rather than an ARC task.
I have a problem on task E.
Editorial 1
Editorial 2
How to mathematically prove that the algorithms in official editorials always yields a best solution?
I think this contest is closer to ABC without problem A rather than ARC--.
Can problem "c" be solved by BFS? I thought this problem would easily solved by BFS. But in the end I was wrong. Can anybody explain this.
Nodes on some layer may be connected to multiple nodes from the previous one, so if you just set A_v=dist(1, v) there may be more than one node w satisfying A_w=A_v-1.
Omg. This contest is the only high-performance contest of this weekend (of my account). But I am unrated in this contest.