10963 - The Swallowing Ground

[little joey]

I don't know who the organiser of this contest is, so I don't know who to send an email, so I'll post here:

The input for problem F contains negative values for the width of the gap. You can only get accepted by answering "no" when this width is non-positive. This is stupid.

[little joey]

Also the number of people in problem B can be bigger than 500.

There's also something wrong with the input of problem D, because my asserts indicate that both coordinates can differ between two consecutive points on a route (while the sections should be paralel to either streets or avenues).

I'm giving up on this pile of rubbish. I hope that UVA corrects the errors before putting the problems into the 24h judge...

[Cho]

Someone took 65 submissions to get AC.
Your post makes me to be the very few who can get AC in the first attempt.

[Adrian Kuegel]

For problem D, I just printed "No" in cases when the given paths were wrong (not horizontal and vertical). With this I got Accepted.

[Observer]

I hope that UVA corrects the errors before putting the problems into the 24h judge...

Will they put the tasks into the 24h judge? I mean, since task A is just the same as #10420 "List of Conquests"...

The mistake in Problem B (P > 500) bothered us greatly. That gave us 6 WA's and we've spent so much time looking for non-existing bug in our perfect code........ That's just bad... and we don't even want to see the contest rejudged, after so much time and effort wasted.....

[misof]

There's also something wrong with the input of problem D, because my asserts indicate that both coordinates can differ between two consecutive points on a route (while the sections should be paralel to either streets or avenues).

So this was the problem! I spent quite a bunch of submissions on other asserts... and also I wasn't sure how to handle boundary cases like
- will the villagers stop and wait at the end of their journey or do they "go home" immediately?
- can they meet in a middle of a road (if they swap places in some step)?
so I tried submitting versions that handled these cases differently... until I became bored and annoyed and let it be. Kudoz to Adrian for pushing this one through in the last minutes.

BTW if I'm not mistaken, the only change I made in my solution of task C to change it from WA to AC was to change the bound for the number of items from 12 to 100. As the number of items was supposed to be <=10, this looks like yet another problem with the test data.

[ardiankp]

Hmm.. I got accepted without considering that case.. (actually I've never checked that case).

For problem F, is that means the output should be "no" whenever there is an input with y1 < y2?

[misof]

Hmm.. I got accepted without considering that case.. (actually I've never checked that case).

Well, in that case consider yourself extremely lucky (Take a look at the number of failed submissions...)

For problem F, is that means the output should be "no" whenever there is an input with y1 < y2?

There are inputs with negative W. (No columns descriptions follow, just as if W=0.) There can be cases with y1 < y2, I didn't check that and I handled them the same way I handled normal, valid input.

I.e., for the input

Code: Select all

3

0

-2

2
3 5
2 4

my program outputs

Code: Select all

yes

no

yes

BTW in the contest I got TLE twice, because to read the column data I used the following code:

Code: Select all

scanf("%d ",&W);
while (W--) { ... }

Imagine my surprise when I saw that my short piece of code with just a few scanf()s and printf()s timeouts

[Adrian Kuegel]

So this was the problem! I spent quite a bunch of submissions on other asserts... and also I wasn't sure how to handle boundary cases like
- will the villagers stop and wait at the end of their journey or do they "go home" immediately?
- can they meet in a middle of a road (if they swap places in some step)?
so I tried submitting versions that handled these cases differently... until I became bored and annoyed and let it be. Kudoz to Adrian for pushing this one through in the last minutes.

I assumed they "go home" immediately, and they can meet in the middle of a road.

[ardiankp]

LOL..

I assumed that they are waiting at the end...

[pipo]

hi all...

In my opinion, this problem is very easy...

but, I got WA T.T

what is the critical input ? Could you give me some sample inputs and outputs ?

the WA code is following....

Code: Select all

cutted after Acc..

thanks in advance...

[Cho]

It's problem F in this thread:
http://online-judge.uva.es/board/viewtopic.php?t=9300
I don't know whether the data is corrected in the online judge.

[pipo]

thanks very much...

I read the thread...

and then, I changed my code.. but still WA

excuse me but could you send me your accepted code ??

I am exhausted..

help me T.T

The email address is kki2406@nate.com

Thanks in advance..

[little joey]

The testdata was corrected.
Your double loop construction reads too much data in case of failure. Insert something like "if(!flag) i++;" between the two loops. (Or rewrite the whole thing so that it reads the input in one loop).

[pipo]

wow!! thanks you very much, little joey...

you're right...

I had a mistake about it...

it's very stupid of me to do that...

I changed my code to rewriting a part of the input in one loop..

in the end, i got AC.. thanks again