Hello Codeforces!
The Algorithms and Coding Club, IIT Delhi (ANCC) in collaboration with Tryst, IIT Delhi, will host LOCKOUT and would like to invite you all for the same.
Lockout is a bracket tournament where contenders will solve CP problems to earn a higher score and secure their position in the next round. Participants will receive a set of problems to solve within a fixed time frame, with each problem carrying a set number of points. The first participant to solve a problem earns the points. Before the main event, a preliminary round will be held, and the top 16 participants will advance to the tournament.
Lockout Prelims Details:(Online)
The Lockout Prelims will be hosted on the Codeforces platform. The contest will serve as an online preliminary round for an on-site final. It will be an ICPC style 2 hour long contest. The top 16 participants with the highest scores will proceed to the onsite tournament.
- Date & Time : 3rd March 2024, 8-10 PM IST
- Duration: 2 hours
- Mode: Online
- Platform: Codeforces
- Registration link
- Prizes : 10k INR(5k+3k+2k) for top 3 Indian participants
- Problem Setters : WAtoAC2001, JagguBandar, Proelectro444, Dp_pratyaksh, Agile_Eagle
- Testers : MridulAhi,islingr, Azm1t, ghoul932, a-a-a, BladeRunner, etherinmatic, targeter2004, Surver
Lockout Tournament Details:(Offline)
- Date & Time : 29-31st March.
- Duration: 3 hours
- Mode: Offline
- Platform: Codeforces and Discord
- Prize worth: 40k+ INR
Stay tuned for our upcoming CP events, ICPC-de-Tryst (ICPC styled team contest) and Codemod (Project Euler style contest) during Tryst (29-31st March).
UPD : Contest Registration Link : https://mirror.codeforces.com/contestInvitation/f0ae7b221f308a925f3be2ec313bfc9ac44d46d1
UPD 2 : Congratulations to the winners!
Global Top 5
| Place | Participant |
|---|---|
| 1 | Ra16bit |
| 2 | jtnydv25 |
| 3 | Kira_1234 |
| 4 | mohit_jx64 |
| 5 | IceKnight1093 |
Prize Winners
jtnydv25 — 5000 INR
Kira_1234 — 3000 INR
IceKnight1093 — 2000 INR
We will be soon contacting the top-16 Indian participants for the onsite round to confirm their participation. In case someone opts out we will be contacting the next available participants for the same.
UPD 3 : Editorial
As a problem setter, no monkeys were harmed during the making of this contest.
why are the offline events clashing so perfectly with asia west?
Our tech fest is scheduled during that time only hence the offline event is also scheduled for the same date :(
As a tester, the problems are fun to solve !
Keeping prizes for the online prelims is very nice (for people who despise travelling)
How does the problem setting for the lockout work? 15 different problem sets or 4 problem sets one for each level?
As a problem-setter, I hope you like the problems and enjoy the contest.
why are you using unstop for registrations? There might be individuals who do not have an account on it and won't bother to register. Consider an alternative like a Google Form.
can the registration date be extended for a day?
Missed by one day....
We'll be extending the registration deadline to 3 March 2024, 9AM IST.
Can we register now?
i come across it just now!
same
https://mirror.codeforces.com/contests/508320
I got that, but I am not registered on unstop.
Unstop Registration Closed Why?
+1 :(
Yeah. 9am was the deadline. I missed it too. But you can still give the contest.
Where can you give link?
Your text to link here...
can we have round details? How many questions? their scoring ?
Contest is ICPC styled with each problem having the same score (1)
Will you publish the editorial after the contest?
Yes
The encoding of letters being in reverse cost me in D :( Submitted one minute late — https://mirror.codeforces.com/gym/508320/submission/249492478
Anyway nice problems, D is reed muller(davio) expression. First time using something from my major in a contest.
Problem B is a very nice problem with no edge cases to handle, and it doesn't really affect the standings much. Codeforces contests should have more problems like this.
hi
can you share the solution for problem B.
Basic Idea: precompute the answer for every size $$$k$$$ and answer it during the queries using binary search.
Now, the cases which we need to handle:
For $$$k \gt 2$$$, there can be 4 ways to select the subset of army:
For $$$k = 2$$$, all the above cases are included, and one more case: select any two indices
Apart from this, you need to be careful while binary search, as the precomputed answer array isn't necessarily sorted, due to the extra case handling when $$$k = 2$$$
makes sense. Thanks!!!
You can avoid the last step by computing prefix max values of all values one more time at the end to make it monotonic
This thing made me make more WAs :(
are you sure? I tried handling many edge cases , yet failed on TC 29. :(
Had the same issue, note that the precomputed array isn't necessarily sorted, so binary search could give wrong answer.
Oh , now I see , I had handled all the cases , but didnt see that they need not be sorted. Thanks ..
is problem C , similar to this? link
If it is ready provide editorial too