We will hold UNIQUE VISION Programming Contest 2025 Spring (AtCoder Beginner Contest 398).
- Contest URL: https://atcoder.jp/contests/abc398
- Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20250322T2100&p1=248
- Duration: 100 minutes
- Writer: physics0523, kyopro_friends, tatyam
- Tester: nok0, MMNMM
- Rated range: ~ 1999
- The point values: 100-250-300-425-425-500-600
We are looking forward to your participation!








why is kenkoooo not working these days?
Recent ABC contests are pretty good. Wish another fascinating ABC tonight!
Oh, this is a speed round.
More than 1000 people passed A~F.
Only 6 people passed G.
I feel speechless about this situation.
Have a good dream, everybody.
The special effect when clicking the left mouse button is quite interesting.
Hello AtCoder,
Please stop blocking kenkoooo thanks. Or please add pages like My Submissions or Friends' Submissions on AtCoder. Thank you!
F is too standard.
Yes, we have exactly same LC problem with given string as suffix !! One can easily convert that problem into prefix one by just 2 additonal reversals !!
The problem is LC 214..
And F has got an origin:) Link:[CERC2019] ABB
Another origin is SPOJ EPALIN
SO THIS PROBLEM HAS 3 ORIGINS AND 1 OCCURED IN ICPC
what happened to kenkooo? It has been freezing for over a week.
D is too hard for me
Me too, while F more easy
i think F needs some string algo to solve? like Kmp or we can do without it?
del
You could have waited for the contest to end perhaps?
Don't give hints while contest is running.
F
why was tle in c ? this code is n log n , is not ?
try to use
map!And here is my code:https://atcoder.jp/contests/abc398/submissions/64049872
the map is lg n too, why is better ? i am confusing
Because in fact I uesd
unordered_map(https://en.cppreference.com/w/cpp/container/unordered_map),it's just like a hash table.There're some features of it:
i tried and i do this code, is that ?
I think it is feasible.
You are wrong. You get TLE is only because
count(x)ofmultisetis $$$O(\log n+K)$$$, Where $$$K$$$ is the number of times the element $$$x$$$ appears in the 'multiset'. If all of the elements in themultisethas the same value, you will get TLE because now the functioncountofmultisetis $$$O(n)$$$.What a shit contest it is!
problem F is so shit!
For problem C,
I can't figure out how this is failing?
why use sorting just use the map and pick the largest element which only once, then find its index
Absolutely terrible contest.
F has no "takahash" substring.(Takahashi, same pronunciation with 它卡哈希 in Chinese which means the problem can't solve by hashing.) So it can be solved easily by hashing :) LOL
More, G is too hard for rated participant :(
Sorry, but can anybody explain why I can solve F with a weak hashing. I choosed
10to be thePin my code which should be an odd number instead of even number10.My F submission
Well, I choose
35to be theP, and I also solved it.Odd numbers are hard to be hacked, but even ones can be hack, so I was surprised that I got AC.
Can anyone prove that my solution is hard to be hacked?
problem G is well known in India
Please explain ur approach for G
Was it a codechef problem or a regionals? can you link if its not too much trouble ?
Was it just me who found the statement and samples for C contradicting (somehow or I am just dumb). (I eventually guessed it from samples).
What was the answer to problem G
Aoki or Takahashi
Louissun used AI in the competition.
True, this submission's
// Output the resultalmost made me laugh.Problem G is a harder version of Canada MO 2019/5.
I used Manacher algorithm to solve problem F, and I found it in the Japanese version of editorial. In fact, I just learned this algorithm from Codeforces Round 524 (Div. 2) E. Sonya and Matrix Beauty, maybe several months ago.
This really feels good, and makes me believe that everyone would always benefit from your practice sooner or later :D
For
the number of connected components where the number of vertices in both parts are both oddeditorial hasoeinstead ofooE is disturbing for such a strict output format.
Who can help me with problem E?
Thanks!