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Posted: **Fri Jul 05, 2002 8:37 pm**

by **Picard**

are you sure it's not just a compile error because of redefining M_PI (if you include math.h).

this is a good solution and it's very much a spoiler

Posted: **Sat Jul 06, 2002 3:00 am**

by **Joe Smith**

Picard wrote:are you sure it's not just a compile error because of redefining M_PI (if you include math.h).

this is a good solution and it's very much a spoiler

This is strange -- I get AC now.

The only thing I remember changing from my most recent WA was I factored out a M_PI... but maybe that did it. Or maybe there was some bad data they changed. (I hate floating point.)

The reason I redefined M_PI (it's only a warning, not a compile error) is because I seem to remember that it wasn't defined in math.h on UVA. I may be wrong on that, but I know hypot isn't defined.

### 10320 cow trouble

Posted: **Tue Sep 10, 2002 7:45 am**

by **Subeen**

my code gets WA.

but i think the problem is simple and easy to solve. i find the area of 3/4 of the circle using the formula pi*R*R, and rest of the area using similar formula.

someone plz find what wrong with my code or the approach is wrong

[c]

#include <stdio.h>

#include <math.h>

#define pi 2*acos(0)

void main()

{

double l, w, R, area, area1, area2, area3;

while(3==scanf("%lf%lf%lf", &l, &w, &R))

{

area2 = area3 = 0;

area1 = 3 * pi * R * R / 4;

if(R >= l)

area2 = pi * (R - l) * (R - l) / 4;

if(R >= w)

area3 = pi * (R - w) * (R - w) / 4;

area = area1 + area2 + area3;

printf("%0.10lf\n", area);

}

}

[/c]

thanx...

Posted: **Tue Sep 10, 2002 8:16 am**

by **Dominik Michniewski**

Are yot sure that

is similar to

I think (maybe wrong) that 0.10 prints in some systems something like 0001.00000000 - maybe it's your problem ?

I don't try to solve this question yet and I can't say any word about your algorithm

Best greetings

### Moo!

Posted: **Tue Sep 10, 2002 1:38 pm**

by **Yarin**

Your solution only works when R<=l+w. This is the easy case, it gets a lot more complicated when R >l+w. Sadly the sample input doesn't have such an input case...

Try the input

7 3 9

9 5 2

18 2 7

The correct answer should be

222.2676802415

9.4247779608

135.0884841044

Posted: **Wed Sep 11, 2002 7:31 am**

by **Subeen**

Yarin, I don't understand what do u mean by

Your solution only works when R<=l+w. This is the easy case, it gets a lot more complicated when R >l+w.

after some modification ( area2 = area3 = 0) my program gives the same output as your's.

but still getting WA...

Posted: **Wed Sep 11, 2002 11:37 am**

by **Yarin**

I'm terribly sorry, I had the parameters the wrong way. The input should be

3 9 7

5 2 9

2 7 18

and the correct answer

128.0199006338

238.3325404965

992.2996351671

which your program does not output.

### how is that?

Posted: **Wed Mar 05, 2003 12:18 am**

by **choyon_buet**

Thanks to yarin cause i could realize my mistake with my calculation from the sample I/O given by u.And i got this problem accepted at last

.

but i am so astonished to see that my output doesn't match with yours completely.it differs in the 9th and10th points after the decimal.

suppose for the

input : 5 2 9

my code gives the output: 238.3325404991

so here the last two digits are 91 when ur output is 65.

but both of us got accepted.

CAN U TELL ME HOW IS THAT POSSIBLE?

Posted: **Mon Mar 10, 2003 9:44 pm**

by **saiqbal**

its possible bcoz its an special judge problem.

an special corrector program is written for this problem to ignore small precision error.

### 10320(Needed formula)

Posted: **Tue Dec 18, 2007 10:03 pm**

by **hridoy**

Can anyone plz tell me How can I evaluate the formula when R>(l+w)??

Posted: **Wed Dec 19, 2007 8:07 am**

by **CMG**

im not exactly sure myself at the moment, but from observation I found a good approximation for when R>(l+w):

A = (pi*3*R^2)/4 + (pi*(R - l)^2)/4 + (pi*(R - w)^2)/4 - (pi*(R - l - w)^2)/4

= pi*(R^2 - l*w/2)

which gives 238.76104 for the 5 2 9 case above.

If I come up with anything better Ill post it.

### Re: 10320 - Cow Trouble! Help Please!!

Posted: **Mon Nov 17, 2008 9:21 pm**

by **Sh0rty**

PLs can somebody help me?I have problem like others when R > W+L.I still don`t know resolution for this case.It`s very important for me - Thank you very much.

### Re: 10320 - Cow Trouble! Help Please!!

Posted: **Sun Apr 17, 2011 10:35 pm**

by **DD**

The most tricky case happens when R > l + w. You need to solve some equations first to get the final answer.

Sh0rty wrote:PLs can somebody help me?I have problem like others when R > W+L.I still don`t know resolution for this case.It`s very important for me - Thank you very much.