Hello CodeForces Community!

I on behalf of my team — Akatsuki would like to invite you all to the first contest of the final season of IPC’s ICPC Preparatory Series. The contest is open to all those who have been shortlisted in the previous rounds. On top of this, we will be hosting a mirror contest with an hour delay in parallel to this. I hope it would serve as a good preparatory ground for all the ACM ICPC aspirants who are preparing for upcoming regionals.

Joining me in the problem setting panel, we have: sarveshmahajan (Sarvesh Mahajan), aditya1495 (Aditya Shah), deathsurgeon (Rupesh Maity), pakhandi (Asim Krishna Prasad).

Contest details Time: 25th September 2016 (2000 hrs) to 26th September 2016 (0100 hrs). (Indian Standard Time — +5:30 GMT) — Check your timezone. Contest link: https://www.codechef.com/IPC15FLA Mirror Contest details: Link: https://www.codechef.com/IPC15AMR Date: Sunday, 25th September 2016, 9:00 PM, IST. Check your timezone. Duration: 5 hrs. Note: This contest is open for the whole community.

Prizes: Cash prizes for the top three spots are declared after taking into consideration of the cumulative score (of the final 3 contests):

Global Category:

1st Prize: $1000

2nd Prize: $500

3rd Prize: $200

Indian Category:

1st Prize: INR 50,000

2nd Prize: INR 25,000

3rd Prize: INR 10,000

More details about the preparatory series can be found here: https://www.codechef.com/ipc/2015

Good Luck! Hope to see you participating!!

UPD : Editorials

LUFFY ASYA2 TREE02 ASYAPATH BOBPRIME TREEPAL HIKARU

In the problem topcoder Problem, we are asked to find minimum count of numbers to be inserted between two numbers such that in the final list, consecutive elements are coprime. For all the test cases ( both the numbers <= 100000) , the answer is <=2. Is it always true? In other words, Is it always true that For any two numbers x & y, x<y , we can find a & b such that x<a<b<y and gcd(x,a) = gcd(a,b)=gcd(b,y)=1 ?