We invite you to participate in CodeChef’s July Cookoff, today — 28th July, from 8:00 PM — 10:30 PM IST. Note the unusual time.
There will be 7 problems in all divisions.
The contest will be rated for all three Divisions. The July Cook-Off also marks the launch of our new prize structure for global & Indian participants. More details are given below.
Joining us on the problem setting panel are:
Contest Admins: Ashish Ashishgup Gupta and Jatin jtnydv25 Yadav
Head Admin: Alex Um_nik Danilyuk
Tester: Aryan aryanc403 Choudhary
Statement Verifier: Riley Monogon Borgard
Editorialist: Vichitr Vichitr Gandas, Srikkanth srikkanthr R, Hriday the_hyp0cr1t3 G
Setters: Souradeep Paul, Prasant prasant21 Kumar, Vichitr Vichitr Gandas, Soumyadeep soumyadeep_pal_21 Pal, Riley Monogon Borgard, Smarth Athem Mehta, Milos vladalos Puric, Evgeny 74TrAkToR Karpovich
Video Editorialists: Chirayu Chirayu Jain, Prachi agarwal19 Agarwal, Darshan darshancool25 Lokhande, Yashodhan ay21 Agnihotri, Shivam Bohra, Aryan Agarwala, Meet myth_gemphir Singh Gambhir, Rajarshi RestingRajarshi Basu, Istasis ista2000 Mishra, Bharat Singla
Mandarin Translator: Qingchuan qingczha Zhang
Vietnamese Translator: Team VNOI
Russian Translator: Fedor Mediocrity Korobeinikov
Bengali Translator: Sakib SakibAbrar Abrar
Problem Submission: If you have original problem ideas, and you’re interested in them being used in CodeChef's contests, you can share them here.
Prizes:
Global Rank List:
- Top 10 global Division One users will get $100 each.
- Non-Indians will receive the prize via money transfer to their account.
- Indian users will receive Amazon vouchers for the amount converted in INR.
Indian Rank List:
- Top ten Indian Division One coders will get Amazon Vouchers worth Rs. 3750 each.
- The rest in the top 100 will get Amazon Vouchers worth Rs. 1500 each.
- First-time winners in Div 2 who make it to the top 200 for the first time will get Amazon Vouchers worth Rs. 750 each.
- First-time winners in Div 3 players who make it to the top 200 for the first time will get Amazon Vouchers worth Rs. 750 each.
The video editorials of the problems will be available on our YouTube channel as soon as the contest ends. Subscribe to get notifications about our new editorials.
Good luck and have fun!
Edit: Contest is extended by 15 minutes.
Finally a rated contest after a month.
:( internal error occurred in the system
Sorry, it will be fixed in a minute.
speed chef
I didn't have to, this easily passed in 1.5s
Why you want people to get useless WA in https://www.codechef.com/COOK131B/problems/MODEQUAL due to integer overflow? What's wrong with having A[i]<=1e9?
That's why some people always use 64 bit integers.
The dynamic endpoints of the special nodes can be maintained online through a segment tree as well.
Ashishgup, Will it be possible to postpone (by 2 hrs) July Lunchtime as it is clashing with ICPC practice session.
If we postpone it, it will clash with TCO R4. It seems that the clash in unavoidable :(
I was not aware that contest is extended by 15 mins. I closed my laptop and after 2 mins later I realised it's been extended.
As many new features have been added in Chef (copying sample input) please also make a pop up feature for any announcement.
Also, doubt support too. As we can ask for clarification of problems on codeforces, a similar thing should also be there on CodeChef.
You can ask for clarifications in the comments — we answer them during the contest!
But yes, I agree — clarification support system should be better.
Issue with pop-up is that CodeChef does not have a registration system yet, so the notification would end up being pushed to everyone using the site at the time.
I believe CodeChef is working on adding this feature in the future — since it has non-trivial backend work, it may take some time though.
I believe it's the most important feature required right now.
Why aren’t you make a team for banning those YouTube channel who spoil the excitement of contest by upload logic even full AC code durning contest?
It turned out that today the distributor could not upload the code faster than me solving the problem (Div 2 Till D), So I'm happy that i did not get affected by cheating and all. Hence, The only solution to this scenario is to just get better than the distributor. Perhaps, It's quite challenging but exciting at same it :)
I got WA for one of my solution. So i spent time debugging it.At the last second i did not change anything that could change output but AC anyway. I resubmitted WA solution got AC after the contest. WA verdict sol now showing AC but no announcement about changing test data. why?
p.s: There was an announcement but no pop up.(new at chef). But still i did one wrong submission for this error.Issue has been fixed. Tnx to chef jumped up few ranks :p
In interactive problem, generally you don't have to flush output between consecutive lines. But in the 4th problem today solutions which were not flushing output between consecutive lines got WA. They corrected it after contest.
Tnx, now i got it!
Why codechef don't have more rated contests as Codeforces have?
Maybe lack of problem proposal is one of the reason. Second reason maybe the cost of contest that is roughly INR 4-5 Lakh which in Codeforces is in some thousands. I don't think the money might be the great factor but ya it can be one of the reason, lack of problem proposal remains at first
As someone who used to hate codechef for their server issues every contest and stopped participating, I must say that the quality of the problems has really gone up! And now I am more excited about the next Lunchtime than CF round 735 :P Can't believe I said that. Kudos to the problem-setters and the admins. All the best!
Ashishgup Can you clarify what it means to be Indian in this context? What if one doesn't live in India but has overseas citizenship?
Only Indian citizens are considered for the prizes. OCIs are not considered.
When can we get those prizes?
Can someone explain how to solve Beautiful Subsequence? I am not able to understand the editorial.
Are memory limits on the problems still 1.5 GB ? If not, can you guys add a tab which shows the memory limit of a problem ?
Yeah, the memory limit is still 1.5 GB for the problems, as far as I am aware.
How to solve MATBEAUT (Make the Matrix Beautiful)?
Given a permutation of length $$$N$$$ one can sort it with N-1 swaps. One can sort first $$$M-1$$$ columns using atmax $$$(N-1)*(M-1)$$$ using operations with $$$y_2=M$$$.
Now if the no of inversions in the last column is odd then the answer is $$$-1$$$ (proof left as an exercise for the reader until the editorial is out).
If $$$N \leq 2$$$ or $$$M \leq 2$$$ then we cant sort last column if it isn't sorted yet. Otherwise, on work out on paper a way to cyclic shift 3 numbers in last column using 4 operations. Repeatedly cyclic shift 3 numbers to get one number at its correct position. It needs atmax $$$4*(N-2)$$$ operations.
Overall atmax $$$(N-1)*(M-1)+4*(N-2)$$$ operations.
Tester soln if you want to refer it.
When will we receive the mails regarding prizes for this contest?
Ashishgup CodeChef_admin
Within 4 weeks, admin clarified it already
Did anyone receive the mails regarding prizes for the contest yet? It has been over 4 weeks now ..