10963 - The Swallowing Ground

All about problems in Volume 109. If there is a thread about your problem, please use it. If not, create one with its number in the subject.

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little joey
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Problem F in the running contest 10963

Post by little joey » Wed Nov 02, 2005 3:10 pm

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.
Last edited by brianfry713 on Tue Jan 21, 2014 10:34 pm, edited 1 time in total.
Reason: thread title

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little joey
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Post by little joey » Wed Nov 02, 2005 5:39 pm

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...

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Cho
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Post by Cho » Wed Nov 02, 2005 5:45 pm

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

Adrian Kuegel
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Post by Adrian Kuegel » Wed Nov 02, 2005 6:13 pm

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

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Post by Observer » Wed Nov 02, 2005 6:33 pm

little joey wrote: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.....
7th Contest of Newbies
Date: December 31st, 2011 (Saturday)
Time: 12:00 - 16:00 (UTC)
URL: http://uva.onlinejudge.org

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Post by misof » Wed Nov 02, 2005 11:10 pm

little joey wrote: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.

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Post by ardiankp » Thu Nov 03, 2005 5:31 am

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?

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Post by misof » Thu Nov 03, 2005 9:37 am

ardiankp wrote:Hmm.. I got accepted without considering that case.. (actually I've never checked that case).
Well, in that case consider yourself extremely lucky :D (Take a look at the number of failed submissions...)
ardiankp wrote: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 :D

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Post by Adrian Kuegel » Thu Nov 03, 2005 1:43 pm

misof wrote: 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.

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Post by ardiankp » Thu Nov 03, 2005 2:52 pm

LOL..

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

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10963 - The Swallowing Ground

Post by pipo » Sun Dec 11, 2005 4:53 pm

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... :)
Last edited by pipo on Mon Dec 12, 2005 2:12 pm, edited 1 time in total.

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Cho
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Post by Cho » Sun Dec 11, 2005 5:14 pm

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.

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Post by pipo » Sun Dec 11, 2005 5:54 pm

thanks very much...

I read the thread...

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

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

I am exhausted.. :cry:

help me T.T

The email address is kki2406@nate.com

Thanks in advance.. :)

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Post by little joey » Sun Dec 11, 2005 6:06 pm

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).

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Post by pipo » Mon Dec 12, 2005 2:11 pm

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... :cry:

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

in the end, i got AC.. thanks again :D

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