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Discussion of Problem 1741. Communication Fiend

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Weak tests
Posted by unlucky [Vologda SPU] 3 Nov 2009 15:34
Мy very crazy program passed  19 Tests and get TLE 20. I may be wrong, but I think, that the first 19 tests are weak. My program can't passed so many tests with bug in algorithm.
My be it is needed to check this tests and emulate EVERY possible and impossible situations.
Re: Weak tests
Posted by Chmel_Tolstiy 3 Nov 2009 15:50
Your solution didn't pass so tests are OK. Tests are weak if your wrong solution passes all of them.
Re: Weak tests
Posted by unlucky [Vologda SPU] 3 Nov 2009 17:24
I wrote bad solution and get AC at 19!!! tests.
I use DP and DFS.
It is very strange, that this bad solition passed so many tests...
Re: Weak tests
Posted by Sevenk 3 Nov 2009 19:09
Maybe the first 19 tests are some small tests that some programs go wrong at it.
Re: Weak tests
Posted by unlucky [Vologda SPU] 3 Nov 2009 20:35
It is very strange...
Re: Weak tests
Posted by svr 3 Nov 2009 21:23
1741 is median of contest.
Halph of problems are harder hailpf are simpler.
I am myself made 1741 from 1 submission.
But there is 1735:modelling optimal packing different subsets sum problem for which great Erdesh was able to give 500$
Re: Weak tests
Posted by unlucky [Vologda SPU] 3 Nov 2009 21:37
Finally AC by DP.
I had a good sleep 8)
Re: Weak tests
Posted by Sandro (USU) 3 Nov 2009 23:39
Why do you think that 19 is "many"? Some problems on Timus Online Judge have more than 200 tests. :)
Re: Weak tests
Posted by unlucky [Vologda SPU] 4 Nov 2009 02:05
Problem not in amount, but in qualitative.
My wrong solution must not passed so many and get TLE, because it must get WA early :)
That's all. Topic closed.
Re: Weak tests
Posted by Alex Tolstov (Vologda STU) 4 Nov 2009 14:52
You must get AC for this problem with the first attempt. It's very easy problem. =) You should not think about "weak" tests in this case)
Re: Weak tests
Posted by unlucky [Vologda SPU] 5 Nov 2009 23:29
Fyodor Menshikov created test, where my AC program failure =)
Re: Weak tests
Posted by Samsonov Alex [USU] 5 Nov 2009 23:49
We always encourage you to send good tests to us :)
Re: Weak tests
Posted by unlucky [Vologda SPU] 6 Nov 2009 17:52
Yep =)
Some times I create "not bad" heuristic solution.
I know, that it is not good, but some times only my coatch (not Timus) can create failure test after he sees the code :)
Re: Weak tests
Posted by Crash_access_violation 15 Nov 2009 14:36
Please said me I'm right?

cracked on cracked, pirated
licensed on licensed, cracked
pirated on licensed, cracked, pirated

thanks!
Re: Weak tests
Posted by unlucky [Vologda SPU] 16 Nov 2009 12:34
Program can't be cracked.
Update can be cracked.
If update is Licensed or Cracked,then program became Licensed.
If update is Cracked or Pirated,then program became Pirated.
Re: Weak tests
Posted by Crash_access_violation 17 Nov 2009 02:59
I correct my code, but I also got wa#8.
What is wrong in my idea?
1) sort by xi;
2) linear algo to find D[n][pirated] and D[n][licensed]
3) when write(min(D[n][pirated], D[n][licensed]))

or please give me some useful tests.

thanks!

Edited by author 17.11.2009 02:59
Re: Weak tests
Posted by unlucky [Vologda SPU] 17 Nov 2009 15:26
Crash_access_violation wrote 17 November 2009 02:59
I correct my code, but I also got wa#8.
What is wrong in my idea?
1) sort by xi;
2) linear algo to find D[n][pirated] and D[n][licensed]
3) when write(min(D[n][pirated], D[n][licensed]))

or please give me some useful tests.

thanks!


Edited by author 17.11.2009 02:59
My solution use DFS. I try to get answer not for last program, but for first. We have one "start point" and many "end points". Use recursion to get min cost of updating to every version of program.
Other only via email(only Russian)

Edited by author 17.11.2009 15:28
Re: Weak tests
Posted by Alex Tolstov (Vologda STU) 18 Nov 2009 13:16
Oleg, use phrase "min cost" more carefully. =) Usually it means min cost max flow problem :))
Re: Weak tests
Posted by Alex Tolstov (Vologda STU) 18 Nov 2009 13:18
how to solve problems from this contest:
http://vkontakte.ru/topic-6732013_21978466
Re: Weak tests
Posted by Sandro (USU) 22 Nov 2009 22:20
Test by Fyodor Menshikov was added to the test set.
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