I invite you to experience 3 hours of uninterrupted coding experience at the January Lunchtime. This 3-hour contest will offer 5 challenging problems to solve. A showdown to reach the top spot. So sharpen your coding skills and get ready to pack your Lunchtime with a box of Code.

The problem statements of the contest will be available in English, Hindi, Bengali, Russian, Mandarin, and Vietnamese. Also, if you have some original and engaging problem ideas, and you’re interested in them being used in the CodeChef's contests, you can share them 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:kingofnumbers (Hasan Jaddouh), Ashish (Ashish Lal), Farhod_Farmon (Farhod Farmon), infinitepro (Adithya Dsilva), KharYusuf (Yusuf Kharodawala)

Tester: teja349 (Teja Vardhan Reddy)

Editorialist: Discombobulated (Taranpreet Singh)

Statement Verifier: Xellos (Jakub Safin)

Mandarin Translator: UoA_ZQC (Qingchuan Zhang)

Vietnamese Translator: Team VNOI

Russian Translator: Fedosik (Fedor Korobeinikov)

Bengali Translator: solaimanope (Mohammad Solaiman)

Hindi Translator: Akash Shrivastava

#### Contest Details:

**Time:**25th January 2020 (1930 hrs) to 25th January 2020 (2230 hrs). (Indian Standard Time — +5:30 GMT) — Check your timezone.**Contest link:**www.codechef.com/LTIME80**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 Indian and top 10 Global school students from ranklist will receive certificates and CodeChef laddus, with which the winners can claim cool CodeChef goodies. Know more here. Good Luck!

Hope to see you participating!!

Happy Programming!!

Please make it balanced.

My prediction, it will be unbalanced.

Spoilerits a fact

Correct Prediction

.

Post contest discussion stream

Warning: Don't Read ,it's painfulGot stuck at 1999 Rating :(

Is both the recurrence relation are same?

F(n)= m*F(n-1)-(m-1)*F(n-3)

F(n)=(m-1)*(F(n-1)+F(n-2))

I have seen this recurrence relation in comments of codechef lunchtime discussion?How can we convert 1st recuurence relation into 2nd recurrence relation, Help me

If you subtract $$$F_{n-1} = (m-1)(F_{n-2} + F_{n-3})$$$ from $$$F_n = (m-1) (F_{n-1} + F_{n-2})$$$ you'll obtain $$$F_n - F_{n-1} = (m-1)(F_{n-1} - F_{n-3})$$$, which is exactly the first recurrence. Thus first recurrence is the consequence of the second one. It doesn't necessarily holds in the other direction.

Why not have two functions?

$G(n)$ is the number of ways to have an array of size n with end $$$xx$$$.

$$$F(n)$$$ is the number of ways to have an array of size n with end $$$xy \mid x\neq y$$$.

What is wrong with latex inside comment?