Greetings Codeforces Community!

CodeChef invites you all to join us at CodeChef’s monthly serving of the Cookoff. A 2.5 hours contest with five servings of challenging problems for you and your peers to relish. Crafted out of the very best ideas, our set of curated problems will take your codebuds on a delightful trip.

Further, the February Cookoff will be the perfect opportunity to give a boost to your CodeChef ratings and rankings. Meanwhile, you can also share with us some original and engaging problem ideas which can be used in CodeChef's future contests, here: www.codechef.com/problemsetting/new-ideas.

I hope you will participate with your fellow programmers and enjoy the contest problems. Joining me on the problem setting panel are:

- Setters: teja349 (Teja Reddy), adarshagr8 (Adarsh Agrawal), fugazi ( Prashant Shishodia), codewiz (Nitish Gupta), taran_1407 (Taranpreet Singh), nagpaljatin1411 (Jatin Nagpal)
- Editorialist: (Akash Bhalotia)
- Tester: raja1999 (Raja Vardhan Reddy)
- Statement Verifier: Xellos (Jakub Safin)
- Admin: teja349 (Teja Reddy)
- Mandarin Translator: UoA_ZQC (Qingchuan Zhang)
- Vietnamese Translator: Team VNOI
- Russian Translator: Mediocrity (Fedor Korobeinikov)
- Bengali Translator: solaimanope (Mohammad Solaiman)
- Hindi Translator: Akash Shrivastava

#### Contest Details:

**Time:** 16th February 2020 (2130 hrs) to 16th February2020 (0000 hrs). (Indian Standard Time — +5:30 GMT) — Check your timezone.

**Contest link:**http://bit.ly/COOK115-Codeforces**Registration:**You just need to have a CodeChef handle to participate. For all those who are interested and do not have a CodeChef handle, are requested to register in order to participate.**Prizes:**Top 10 performers in Global and top 10 performers in the Indian category will get CodeChef laddus, with which the winners can claim cool CodeChef goodies. Know more here: https://discuss.codechef.com/t/how-do-i-win-a-codechef-goodie/7344

Good Luck!

Hope to see you participating!!

Happy Programming!!

Bump. Contest starts in 10 minutes.

How to solve cyclesum. Div1 B.

General Case.

In our case w=n, just append the input to itself and find max subarray sum with window<=n

You do realize you replied 5 minutes before the end of the round right?

How to solve https://www.codechef.com/COOK115B/problems/XORGM?

You probably missed the fact that $$$N$$$ is odd.

No, I just didn't knew how to use it. Care to explain in detail or is it too easy?

Xor all the A[]s and the B[]s and since n is odd, you get the value of A[1] xor C[1]

Edit: typo

Regarding the last problem, what's the complexity of finding the next largest element for each index of an array, using path compression?

$$$O(n)$$$ with a stack, while the top is <= x pop, then top is the next largest element and push x to the stack.

Yeah, that's what I implemented as well, but the path compression version is quite elegant, I am curious what it's complexity is. My guess is n log (n).

What do you mean by path compression ?

Here is one variant — Suppose you denote the original array as a[] and the required array as nxt[]. To find nxt[i], start with cur = i + 1 and keep doing cur = nxt[cur], until you find cur such that a[cur] > a[i] and set nxt[i] = cur.

This is likely just DSU, as was pointed out in another comment.

It's the same as dsu, you can also use union by size to make it "faster".

Did anyone notice that the handle for one of the setters isn't provided? Well here it is! codewiz(Nitish Gupta).

Edit : Thanks raja1999 for the update and sorry for the trouble.