Hi everybody!
I'm inviting you to take part in the April Cook-off 2015 on CodeChef at http://www.codechef.com/COOK57. The problems are prepared by me this time.
Time: 19rd April 2015 (2130 hrs) to 20th April 2015 (0000 hrs). (Indian Standard Time — +5:30 GMT) — Check your timezone.
Details: http://www.codechef.com/COOK57
Registration: Just need to have a CodeChef user id to participate.
New users please register here
I would also like to thank all guys that were taking part in preparations of this contest:
- Tester and Mandarin Translator: Gedi Zheng(gediiiiiii)
- Editorialist: Miguel Oliveira(mogers)
- Contest Administrator: Praveen Dhinwa(PraveenDhinwa)
- Russian Translator: Sergey Kulik(CherryTree)
Good luck!
Hey its starts now
Huh, there are 0 problems in the contest. That was easy :D
And occasional errors 502 and 503.
UPD: The problems seem to be there.
Reminds me of this but with 0 problems (the ones we're supposed to solve).
502 Bad Gateway
Deja vu.
Every time they are having issues at the start of the contest. That's bad....
I thought they said that they resolved issues and improved system a lot; didn't they wrote about it after January Cook-off fail?.. And both February and March Cook-offs started relatively well... But now old CodeChef is back :)
Now mom asking me to go and wash dishes instead of waiting for problem to appears
I've just washed dishes too. Still no problems.
But at least no dirty dishes, either :D
There they are now! (of course, there are still countless failed requests)
Only the count-down timer is working perfectly
UPDATE : Codechef is back . I can see the problems
We are trying to get the site back. Apologies for the inconvenience. Request you all to wait for some time.
It seems the scoreboard is broken... the suspense is killing me!
You are 2nd after @anta0. Congrats. :)
How to solve LFIVE faster than O(n^2logn+q)? And is there anybody who solved it with this complexety? Thank you!
I solved it with that complexity: http://ideone.com/j7Ee34.
I solved it with this, too; after failing to optimize my O(QN) solution.
There was a way to optimize an O(N^2 + NQ) approach so it would get an AC. The key point is to use memory cache efficiently: multiplying two rows of a 2D matrix is five times faster than multiplying a row and a column of the same matrix.
So you create a transposed copy of the original matrix and then multiply the rows of these two matrices, or is there another way?
No, that's pretty much what you should do if you want to multiply a row and a column of one matrix in general case. Talking of this problem, you could store only one matrix just by making f[j][i] equal to f[i][j] (i < j).
oh yes missed that,thanks.
I have both O(N^2 log N + NQ) with efficient using of memcache and O(N^2 log N + Q) solutions and they run pretty much the same time.
I think solving the last problem(AGENTS) in python is quite easy : I have figured out the general equation(#)
And I know that there is a module available to solve system of linear equations. And so I directly used that, Here is my solution : http://www.codechef.com/viewsolution/6799925
To be honest, I didn't consider such an approach in Python while preparing the contest. But it's nice if you got an accepted with it since the main idea of the problem was not to solve a system of linear equations but to build that system.
Yes, developing the system is nice. It remembered me about my 12th class where we used to do lot of problems in integration. And I am excited that this is my first contest in which I have done hardest problem and ofcourse 3 problems.