10215 - The Largest/Smallest Box ...

[nukeu666]

bleh...finally got it accepted
the program works only with double
float gives the 3rd decimal place rounding off error
does this tell us double is more accurate than float? (even when talking about the 3rd decimal point?)

[mamun]

does this tell us double is more accurate than float? (even when talking about the 3rd decimal point?)

That is how it is. Nowhere I've used float but double.

[ayon]

i still cannot understand the problem. from observation V=(W-2x)(L-2x)x. for V(max), x has only one value, it has no trouble. but for V(min), x = 0, W/2, L/2; so to determine V(min), i printed 3 values of x, while W != L, and 2 values of x, while W = L, and i got WA. then i checked the board and found that, the program is accepted only for 2 values of x; x = 0 and x = min(W,L)/2. but why not x = 0, min(W,L)/2 and max(W,L)/2, while W != L ?

[mamun]

Instead of telling min() or max(), let's consider L>W. Other than 0, W/2 is one answer, you understand. But if you cut L/2 along L axis do you get enough length along W axis to cut the same amount?

[ayon]

i understand, thanks mamun. actually i was treating the problem only with the equation, not with its original visual body.

[DIR EN GREY]

Rejudgement makes this problem very very difficult one. Now, accept rate is only 2.0%, of cource I got WA too

http://acm.uva.es/p/problemstat.php?p=:10215

I checked the board, however, judges have just delete some tricky inputs.

http://online-judge.uva.es/board/viewtopic.php?t=12778

Why everybody got wa? I think if judges only delete inputs, programs which got accept first time should be accepted. So there must be some brandnew inputs.

Help! I need somebody, not just anybody but have got accept this time.

Here is my code.

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cut after got ac

Thanks in advance

[Jan]

Add eps before printing anything. I used 1e-7. Hope it helps.

[DIR EN GREY]

Add eps before printing anything. I used 1e-7. Hope it helps.

Thanks Jan!! I got accept immediately, but I can't understand that why I must use eps before printing? How eps works? I always use cout, setiosflags() and setprecision() when round off is required, and they works fine without EPS...

What input is crtical?? When I should use EPS??

thanks in advance

[Jan]

Imagine that the output is 1.05, but due to floating point calculation, your output became 1.049999999999. Now if you print only one digit after the decimal point your output is 1.0 but the real output is actually 1.1.
Thats why almost all problems that have floating point output are judged with a special judge program (marked by a yellow flag). But some problems dont have the special judge, for those problems its better to add eps before printing any floating point number. And eps should be as small as possible. Using 1e-7 to 1e-11 is sufficient.

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double a;
a=0.15;
printf("%.1lf\n",a);

The output will show .1, which is obviously not correct. But if you add eps before printing 'a', you will see .2, which is the correct output.

[DIR EN GREY]

Thanks Jan!! I understand this issue now. I didn't know purpose of the yellow mark.

Allow me to again thank you

[fpavetic]

i got this problem accepted by storing intermediate calculations in long double, and printing the result as double after many failed submissions.

[abhiramn]

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CODE ACCEPTED!!!

Please tell me why this if giving WA
@Mr. Jan
max+=0.0000001 is that what you meant when you said add eps??? If not, please tell me what you meant. Thanks a lot.[[/b]

[WingletE]

I got a lot of WA and finally got AC at once after changing COUT to printf...

[willima]

I really didn't undertand why your code print 3 numbers as output for some inputs. My WA code printed the following for the last 3 cases of the first post:

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1666.500 0.000 4999.500
0.250 0.000 0.500 4999.500
0.250 0.000 0.500 4999.500

If the minimum volume is 0 and the volume is (L-2x)(M-2x)x, I got:
- L - 2x = 0;
- M - 2x = 0;
- x = 0.

Where is my mistake?

Thanks,

Willian.

[fR0D]

here's my code....it seems right but gives WA...also suggest me how to use eps???

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CODE Deleted after AC