First Comment! xD

Will Anton still coordinate Codeforces Rounds?

When will you distribute prize of August cook-off?

Am I the only one who hates the timing of CodeChef Cookoff?

Are there any prizes for non-indian div 3 participants?

How to solve Permutation and GCD set?

I got that if $$$m > log(n)$$$ or $$$s_{1} > 1$$$ the answer is 0 since its only possible if $$$s_{(i - 1)}$$$ divides $$$s_i$$$ for all $$$i > 1$$$ and the $$$gcd(a_1, \ldots, a_n) = 1$$$.

After that I got the $$$O(n logn)$$$ expected value dp idea (placed $$$i$$$ digits and at gcd $$$s_j$$$, prob of moving to $$$(i + 1, s_j)$$$ is $$$((n / s_j) - i) / (n - i)$$$, similar for $$$s_{j - 1}$$$)

But I have no clue how to solve this any faster.

Also really liked Pairdist and Half Sequence. Chess Kings felt a bit too standard for its position.

Oof, I missed the contest. How come Codechef CookOff happened on the 19th? Doesn't it usually happen in the last weekend before the next month?

As a participant, I loved the small and clear statements this time. Specially loved the problem Half Sequence

How to solve CKCGAME?

Here is some feedback:

• FAKESWAP: Almost trivial. Ok.
• PAIRDIST: This was very hard (considering its position in the problemset) for me. I spent a lot of time on the construction for $$$n=4$$$ (which, in the end, is very elegant). The statement is a bit artificial, the solution is nice. Nice problem.
• HFSEQ: Standard problem. Easy to convince oneself that if $$$n$$$ is big the answer is yes (apart from special cases) and otherwise one can check all possible subsets. Asking for $$$gcd = 2$$$ instead of $$$1$$$ does not make any sense.
• CKCGAME: Amazing problem. The question is just so natural, and the solution is clean and not obvious.
• PGCDS: Simple and interesting statement, but the solution is a bit standard. This one felt easy for its position, for me it was just unrolling the statement until I had a full solution, no moment of "aha!". Nice problem.
• ONEPILE: I thought about this one for 30 minutes, without understanding which positions are winning. The described game is very simple and therefore the problem is very good. On a side note, I don't like problems which are clearly split in two (here one has to find a characterization of winning positions and then count them) unless there is a clear reason (is there a reason in this case?).
• STQ: I thought about this one for 30 minutes, coming up with a solution which gets TLE but I think is not too far from getting AC (that is, with some small changes it may become AC). For each query, choose randomly $$$30$$$ elements in the intervals, and for each prime which divides at least one such element find whether it divides the strict majority of the element in the intervals.

Overall, it was a very good contest. Thank you to the authors!

Problem .Half Sequence, please explain anyone .

I never cared about cheaters. I always knew that these ratings are just numbers that have no value in the outside world, but today during the contest, when my rank was around 15-20 (in div 3) for more than 2 hours, and suddenly it dropped to 300, I realized that it is not just a rating that gets affected, but the whole motive of "competition" goes into vain.

These are just my personal opinions. I am not going to write some blogs or anything for these cheaters but just wanted to tell these cheaters don't even understand the meaning of "competitive programming."

Any directions on what we need to do to get the coupon code , I have got the mail today , but don't know when and where to find coupon code

are the prizes for August LunchTime rolled out? or even any confirmation mail