Hi!
Ad Infinitum is back with Infinitum July'14, a monthly contest restricted to mathematics domain, held on HackerRank.
Register at https://www.hackerrank.com/infinitum-jul14
The contest commences on 11th July 15:30 UTC. You are allowed to enter the contest anytime, for tie breaking the timer will start when you view the challenge, which allows you to start late at your convenience, but once started try to finish as fast as possible to be on top of the leaderboard :)
It's a 2 day contest with 8 problems (3 Easy, 3 Medium, 2 Hard)
Scoring Distribution: 20 20 20 40 60 80 100 120
problem statements in English, Russian and Chinese
Top 10 on leaderboard gets Cool HackerRank T shirt
Contributers
kevinsogo
tmt514
Bidhan
darkshadows
amitp08
caopeng
aka_007
Detailed editorials will be available by the end of contest :) I suggest you to try all challenges and at the end of contest understand the solutions.
GL&HF
Problems are too easy for a 2 day contest :(
winger, Congrats!
Contest is built by the community, if you feel problems were not challenging enough please come forward and contribute.
But just to clear so far you are the only person to finish all problems. Also, contest is more about learning and solving, so the duration is deliberate for the beginners and learners.
I am sorry if the contest disappointed you.
How to solve the last problem?
I have the formula:
But how to calculate this expression quickly? I managed to get only 55 points with O(NlogK) for a query.
Fcdkbear you can check this editorial
https://www.hackerrank.com/contests/infinitum-jul14/challenges/costly-graphs/editorial
Also from leaderboard check bayleef's submission it's really elegant. We are working on it's proof which is really tricky. If anyone can prove it it's really awesome
Okay, thank you. And by the way, thank you for the great contest! I am not good at math at all, but it was really interesting for me to take part in this contest.
They already published an editorial. Looks a little bit scary:)
BTW, Wolfram Alpha gives nice explicit formulas for K=1..3... And some ugly ones with generalized hypergeometric function for K>3)
rating?
In 24 minutes from now :)
Other profile was updated by the system but my wasn't https://www.hackerrank.com/dariodsa.
keep calm it's still running
You have some fixed time for rating updates, like "in X hours after contest ending"? What are these X hours for? Appeals and stuff like that? I like it, when you say "it will be in 24 minutes from now" and it really updates in 24 minutes, not like on CF/TC where it looks like "it will be updated soon. maybe in few minutes. maybe in few hours. as fast as we can. just keep calm and wait".
Yes we run a cron job for such stuff. And that cron was scheduled at 12:30 Am as per my IST time so I said exactly 24 minutes as that's when the job would start.
By the way so far Contest rating were updated after approx 24 hours but from next contest onwards it'll be in 2 hours.
Updated :) congrats