## 109 - SCUD Busters

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Pokemonster
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Location: Germany

### Problem 109 - SCUD Busters

Maybe someone can give me this information
The wall, eg. the polygon surrounding all the houses, should it be
convex ?

Guru
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Joined: Wed Dec 19, 2001 2:00 am
Location: Germany
Yes, it is obvious that it should be convex.

bjacoke001
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Joined: Fri Jul 26, 2002 6:42 pm

### 109

What are we supposed to do in the case of a shot on the perimeter of the kingdom? I'm getting WA and I can't find a bug anywhere in my code unless the shot is on one of the edges or vertices, which really complicates things. Thanks.

Brian

..
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Joined: Thu Oct 18, 2001 2:00 am
Location: Hong Kong
Each SCUD missile (anitary leansing niversal estroyer) that lands within the walls of a kingdom destroys that kingdom's power plant (without loss of life).

Missile on bound doesn't destroy the power~~

Good luck~~

vivid
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Joined: Tue Jul 16, 2002 6:31 pm

### Are there any tricky inputs in 109 - SCUD Busters ?

WA again & again, but my programm passes all my tests

seolv
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Joined: Wed Oct 24, 2001 2:00 am

### 109 - SCUD Busters

hi~

I am trying to solve this problem but I keep receiving WA.

I really don't know why my solution doesn't work.

In the problem description,

Each SCUD missile (anitary leansing niversal estroyer) that lands within the walls of a kingdom destroys that kingdom's power plant (without loss of life).

when missile launched at one of the points that compose of Convexhull,

the kingdom is not destroyed.. right? If the missile fired at the position of

power plant that is also a point composing of Convexhull, is the kingdom

destroyed?

my test input file and output are below. plz answer me.

12
3 3
4 6
4 11
4 8
10 6
5 7
6 6
6 3
7 9
10 4
10 9
1 7
5
20 20
20 40
40 20
40 40
30 30
3
10 10
21 10
21 13
10
100 101
200 195
143 199
111 200
107 154
132 102
101 223
110 155
118 107
102 148
-1
3 3
20 40
150 150

output
6961.00

12
3 3
4 6
4 11
4 8
10 6
5 7
6 6
6 3
7 9
10 4
10 9
1 7
5
20 20
20 40
40 20
40 40
30 30
3
10 10
21 10
21 13
10
100 101
200 195
143 199
111 200
107 154
132 102
101 223
110 155
118 107
102 148
-1
6 6
20 40
110 195

output
0.00

vivid
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Posts: 6
Joined: Tue Jul 16, 2002 6:31 pm
As i understand kingdom's wall surrounds power plant.
It seems to me you don't include in kingdom. (The square of the last poligon must be greater than yours).

seolv
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Posts: 11
Joined: Wed Oct 24, 2001 2:00 am
I found judge is wrong especially checking part of whether a point is in the convexhull or not.

I got accepted with a source code which outputs what it must not print

Additionally, the judge of problem 361(Cops and Robbers) is also wrong.

Ivan Golubev
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Posts: 167
Joined: Fri Oct 19, 2001 2:00 am
Location: Saint Petersburg, Russia
Judge is OK for problems 109 and 361. If you have some examples of incorrect datas then post them here.

seolv
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Posts: 11
Joined: Wed Oct 24, 2001 2:00 am
Try to input several positions of missiles launched on the lines composing convexhull.

vivid
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Joined: Tue Jul 16, 2002 6:31 pm
But do i need to include power plant into the kindom?

cyfra
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Posts: 144
Joined: Thu Nov 22, 2001 2:00 am
Location: Gdynia, Poland

### Hi!

Hi!

I am also trying to solve this problem...

I don't know what's wrong...

If SCUD hits the wall than is it counter as it hit the convex polygon or not ??

Could anyone who got AC tell me what is is output for this input:
4
0 0
1 1
1 0
0 1
4
10 10
20 10
20 20
10 20
-1
1 1
15 10
And could anyone give the right answers for seolv's inputs..

seolv
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Posts: 11
Joined: Wed Oct 24, 2001 2:00 am
100.00 printed by accepted solution

zbogi
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Joined: Thu Aug 29, 2002 11:00 pm
Location: Bulgaria

### a hint

I also got AC, but my solution prints 0.00 on the last test posted.
So I think that it is counted to be hitten if the position is inside the walls,
not on a site.
Tsvetan Bogdanov.
from Brain Explorer - Sofia University - FMI 2
e-mail: zbogi@yahoo.com

cyfra
Experienced poster
Posts: 144
Joined: Thu Nov 22, 2001 2:00 am
Location: Gdynia, Poland

### Hi!

Hi!

After a few tries I also got AC....

I think that there are no test cases with points inside walls...

And that's good

Thanks to all and Good Luck