# [ANN] Ruby Challenge for Beginners #3 - Short Circuit

Discussion in 'Ruby' started by Satish Talim, Oct 30, 2009.

1. ### Satish TalimGuest

[Note: parts of this message were removed to make it a legal post.]

Ruby beginners: The third installment of the Ruby Programming Challenge for
Newbies (Short Circuit) is now live. The problem has been set by Gautam
Rege. Entry is free and registration is optional. You stand a chance to win
a prize. Hurry. Only 20 days per challenge -
http://rubylearning.com/blog/2009/10/30/rpcfn-short-circuit-3/

Satish Talim
RubyLearning.org

Satish Talim, Oct 30, 2009

2. ### Paul SmithGuest

On Fri, Oct 30, 2009 at 10:52 AM, Satish Talim <> wrote:
> Ruby beginners: The third installment of the Ruby Programming Challenge for
> Newbies (Short Circuit) is now live. The problem has been set by Gautam
> Rege. Entry is free and registration is optional. You stand a chance to win
> a prize. Hurry. Only 20 days per challenge -
> http://rubylearning.com/blog/2009/10/30/rpcfn-short-circuit-3/

I totally read that as "Entry fee is optional"

The problem statement might be flawed by trying to frame it in an
electrical context. The author uses the phrase "Electricity always
follows the path of least resistance" but I understood that current
could flow down multiple routes in proportion inverse to the
resistances, i.e. that if one path had a 10% higher resistance, it
would receive 10% less current, not that all current would flow
through the less resistive(?) path.

Feel free to correct my knowledge of physics and electrical engineering though.

I think the problem is just looking for a simple shortest path
algorithm Dijkstra or something.

--
Paul Smith

Paul Smith, Oct 30, 2009

3. ### Yossef MendelssohnGuest

Re: Ruby Challenge for Beginners #3 - Short Circuit

On Oct 30, 6:04=A0am, Paul Smith <> wrote:
> The problem statement might be flawed by trying to frame it in an
> electrical context. =A0The author uses the phrase "Electricity always
> follows the path of least resistance" but I understood that current
> could flow down multiple routes in proportion inverse to the
> resistances, i.e. that if one path had a 10% higher resistance, it
> would receive 10% less current, not that all current would flow
> through the less resistive(?) path.
>
> Feel free to correct my knowledge of physics and electrical engineering t=

hough.
>
> I think the problem is just looking for a simple shortest path
> algorithm =A0Dijkstra or something.

I think the challenge also suffers from a disconnect between the
apparently intended goal and the stated goal. To solve the problem,
you need to go through the effort of finding the shortest path; rather
than return this path as the solution, you need to indicate which
segments are *not* part of the path.

--
-yossef

Yossef Mendelssohn, Oct 30, 2009
4. ### Martin DeMelloGuest

Re: Ruby Challenge for Beginners #3 - Short Circuit

On Fri, Oct 30, 2009 at 9:00 PM, Yossef Mendelssohn <> wrote:
>
> I think the challenge also suffers from a disconnect between the
> apparently intended goal and the stated goal. To solve the problem,
> you need to go through the effort of finding the shortest path; rather
> than return this path as the solution, you need to indicate which
> segments are *not* part of the path.

that's actually a pretty good test of your datastructure.

martin

Martin DeMello, Oct 30, 2009