Hi,
I am happy to extend you to the invitation to participate in annual programming contest of IIIT Hyderabad. It's an ACM style programming contest, except that it's for individuals and not teams.
You will have a chance to devour some really nice(hopefully!) problems. I think considering the wide difficulty levels in problems everyone will find some interesting/challenging problems to solve.
It begins on 25th Jan, 2015 at 1400 IST.
To see time in other time zones: http://bit.ly/1u8sdBI
Visit http://felicity.iiit.ac.in/threads/codecraft/#content for rules.
Register here: http://felicity.iiit.ac.in/register/
Join facebook event page here for further notifications: https://www.facebook.com/events/378291325683458
Also, there will be some attractive prizes for winners(to be announced soon).
By the way, here's the leaderboard for last years contest:
Happy Coding!
Contributors(setters and testers):
1nikhil9 aka_007 alok123t ashu1461 darkshadows darkscale karanaggarwal pulkitg10 sak_agg sherlock_holms tanmaysahay94 Baba thunderking viv001
UPD1: Prizes worth 20,000 INR to be won.
UPD2: Here is the contest link: http://felicity.iiit.ac.in/codecraft/public/
UPD3:
Like all good things, this one must come to an end as well. Yet another successful CodeCraft comes to an end.
With 2982 submissions, this was one of the most prolific editions of CodeCraft!
tourist wins CodeCraft '15 with 10 correct solutions.
anta comes a close 2nd, also with 10 accepted solutions.
natsugiri comes 3rd with 9 submissions.
Here's the link to the scoreboard:
Just like last year, 1 problem went unsolved. But, we'll be accepting solutions for the next 48 hours, in case you want to try out the problems at your pace.
Editorials will be released in a day or two.
Hope you enjoyed the event. See you next year!
UPD: Here are the detailed editorials by jury: http://codeforces.net/blog/entry/16099
For practice use gym: http://codeforces.net/gym/100589
Your website for event is awesome , specially soundtrack
Gender: Male — Female — Other There's no Other gender o.O
Look up hermaphroditism. There are other cases too which might fall under the category "other".
You seem to be pretty knowledgeable about this matter.
The website is really good. However, how can one view his contest/submission history? The username appears un-clickable at the moment.
A gentle reminder! Contest begins soon.
How the Java class is to be named?
You can name it anything as long as Main function is there.
Link for the contest? Where to find it?
I think it is here, but it doesn't work right now... http://felicity.iiit.ac.in/codecraft/
Hi, this is the link: http://felicity.iiit.ac.in/codecraft/public/
Sorry for delay.
Where's the contest link.?
How i can submit my code -_- ?
Hi, You have to go to Overview section. Its the standard dom format.
What a Java-friendly contest.
How to solve qutree? Was it possible to get AC with O(m^2) solution?
I guess they set m <= 10^4 just because the answer is bounded by 10^18 in this case.
Sqrt Decompostion on euler tour
What complexity do you have?
O(sqrt(n)) per query (update or query)
I solved it with O(m^2 lg).
Jury solution was O(n sqrtm logn). Using sqrt decomposition of queries(updating the whole tree when queries exceed sqrt m).
The same can be done in O(n * sqrt(n)) in offline mode.
where can we find the editorial for the contest???
How to solve DSET?
IMHO:
1) for every i: si is a segment from left position to right position
2) only adjacent si can be equal
I have a solution with binary search, but it's O(Answer * log3(n)) for every query. It's too slow. it's smth like this
How to solve it faster?
Solution with complexity O(log(N)) exist. Editorials will be posted soon. Till then the judges is on for up solving, although the contest leader board is different.
If possible you can add the contest in GYM, so it will be helpful for some to practice good problems in future.
Yes, I think that's a good idea. Will try to do that. :)
Also, we can post editorials on CF blog only.
Contest added to the GYM. http://codeforces.net/gym/100589
where can I try to submit my solution to the problems ??
http://felicity.iiit.ac.in/codecraft/team/index.php
How did you guys solve CWAYS? I failed so hard on that problem. TT
Number of safe paths from (1, 1) to (n, m) is equal to (all paths from(1, 1) to (n, m) (which is binomial)) minus sum_over_all_i(good path from (1, 1) to (x[i], y[i]) and then any path from (x[i], y[i]) to (n, m)). So we need to count the same, but for smaller rectangles. Looks pretty messy but hope it makes sense.
Ohhh that makes sense. Thanks a lot!
I got TLE for that with fast expo and memoization. How do you optimize?
I can share my code if you give me a hint about how to pull my solution out of the website :)
Maybe you can precompute the inverses of all the factorials (1!-200000!) first, so you can evaluate C(n,r) faster.
Wouldn't that take O(nlogn) time and that would be the same as computing the inverse online won't it?
Use fact invFact[n] = (n+1) * invFact[n+1] % p. Just calculate invFact for 200000 in logn time then use above fact to calculate every other value in O(1). This will take O(n) overall.
Oh wow I didn't know such a property existed :D Awesome! Can you give me a link to the proof of this property?
This can be easily seen
Here inv(i) is (1 / i) % p
p > n and prime
Great!! That was really helpful, thanks a lot! :D
Problem — Laughing Out Loud
Problem Link
I calculated for every O in the string number of L left to it and right. and add product of this to the final result .
My code
It gives correct answer on sample cases but did not pass the submission in contest.
Does my approach is wrong or there is some other way to calculate it
You should cast ints to long long because it might overload. As I remember, size of s can be 1O^6; therefore, In an example like LLLLLL...OLLLLLLL..., it would overload. Instead of casting, you can also use vectors of long longs, which is generally faster, but it uses more memory.
Some of the past problems in codecraft: 2011 in Spoj: http://apps.topcoder.com/forums/?module=Thread&threadID=698512&start=0 2013 in Spoj: http://apps.topcoder.com/forums/?module=Thread&threadID=779918&start=0&mc=5 2014 in CodeChef: http://www.codechef.com/CDCRFT14
For all thode who could not give the contest, it has been added to the GYM section and will start in a few minutes. http://codeforces.net/gym/100589
Looks like tests for Desolation of Smaug are incorrect :( Can someone discuss it with me in private?
Here are the detailed editorials by jury: http://codeforces.net/blog/entry/16099