# Re: [algorithms-and-data-structures] Algorithms Meetup Problem #4

 From: Andy P. Sent on: Saturday, July 31, 2010 6:17 PM
```Hi,

Andy

On Sat, Jul 31, 2010 at 3:34 PM, Kervin <[address removed]> wrote:
> I'm not sure it's a complete solution but I've got a solution for problem 4 ( C# ) but I'm not being allowed to commit.
>
> Do I need to get special commit access?
>
> Best regards,
> Kervin
>
>
>
>
> -----Original Message-----
> Sent: Saturday, July 31,[masked]:52 AM
> Subject: [algorithms-and-data­-structures] Algorithms Meetup Problem #4
>
> Hi,
>
> I would like to express my gratitude and thanks to YangXikun,
> Deepankar, MichaelMellinger, SamSandberg, fjania, and dawgmatix for
> solving and uploading code to our Github repository. We have solutions
> in Java, Python, PHP, Lisp, and pseudo code. Great job! We need C,
> C++, Scala, Ruby, Ocaml, and Haskell.
>
> expand community.
>
> I would like to encourage everyone to start using our Meetup's email
> list and forums to share problems and ask questions.
>
> to our Github repository
>
> http://github.com...­
>
> Thanks,
> Andy
>
> --------------------­--------------------­--------------------­--------------------­--------------------­----------
>
> Problem Statement
>
> You may remember an old computer game called "The Incredible Machine".
> It was a game where you could simulate simple processes like balls
> falling, lasers shooting, or cats pursuing mice. Moreover, you were
> able to perform these observations with different values for
> gravitational acceleration.
>
> Imagine a system with some unknown acceleration of gravity. There are
> N balls, each fixed initially at some height above the ground. You are
> given a int[] height, where the i-th element is the height of the i-th
> ball above the ground. At time 0, the first ball is set loose and it
> starts falling. When it reaches the ground, the second ball is
> instantly set loose, and so on. This continues until the last ball
> reaches the ground at time T.
>
> Return the acceleration of gravity in this system. Neglect air
> resistance and any other resisting factors. The distance d travelled
> by an object falling for time t with no initial velocity in a system
> with gravitational acceleration g and no resisting factors is equal to
> d = 0.5 * g * t^2.
>
> Definition
>
> Class: ?IncredibleMachineEa­sy
> Method: gravitationalAcceler­ation
> Parameters: ? ? int[], int
> Returns: ? ? ? ?double
> Method signature: ? ? ? double gravitationalAcceler­ation(int[] height, int T)
> (be sure your method is public)
>
>
> Notes
> - ? ? ? The returned value must have an absolute or relative error less than 1e-9.
>
> Constraints
> - ? ? ? height will contain between 1 and 50 elements, inclusive.
> - ? ? ? Each element of height will be between 1 and 100, inclusive.
> - ? ? ? T will be between 1 and 100, inclusive.
>
> Examples
>
> 0)
>
>
> {16,23,85,3,35,72,96­,88,2,14,63}
>
> 30
>
>
> That's an acceleration of gravity that might be somewhere on Earth's surface.
>
> 1)
>
>
> {6,6,6,6,6,6,6,6,6,6­,6,6,6,6,6,6,6,5}
>
> 12
>
>
> And this is likely on Jupiter.
>
> 2)
>
>
> {8,8}
>
> 3
>
>
> That's a light one.
>
> 3)
>
>
> {3,1,3,1,3}
>
> 12
>
>
> You could nearly fly under such conditions.
>
>
>
> --
> http://www.meetup...­
> This message was sent by Andy Pliszka (andy+[address removed]) from Algorithms and Data Structures.
> Meetup, PO Box 4668 #37895 New York, New York[masked] | [address removed]
>
>
>
>
> --
> http://www.meetup...­
> This message was sent by Kervin ([address removed]) from Algorithms and Data Structures.
> Meetup, PO Box 4668 #37895 New York, New York[masked] | [address removed]
>
```

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