MATLAB Central Newsreader - Can an empty solution be better than optimal?

Can an empty solution be better than optimal?

Dmitry — Thu, 05 Nov 2009 02:43:02 -0500

Hello,

In certain "pathological" problems it might be better not to provide a result, but to return empty matrix. For example:
[1 1;
1 3]

Solution is obviously [3]. But the score will be 15. Whereas if no solution is provided, score is 12.

Is this something the program should take care of?

- Dmitry

Re: Can an empty solution be better than optimal?

the cyclist — Thu, 05 Nov 2009 04:49:01 -0500

"Dmitry " <dmitry_vasilyev@yahoo.com> wrote in message <hcte3m$afn$1@fred.mathworks.com>...
> Hello,
>
> In certain "pathological" problems it might be better not to provide a result, but to return empty matrix. For example:
> [1 1;
> 1 3]
>
> Solution is obviously [3]. But the score will be 15. Whereas if no solution is provided, score is 12.
>
> Is this something the program should take care of?
>
> - Dmitry

In certain "pathological" posts, it might be better not to provide an answer, but rather to try to better understand the question.

What do you mean that the "solution" to

> [1 1; 1 3]

is obviously [3]? That's just an array. It has no "solution." It is also by no means clear what you mean by "score".

the cyclist

Re: Can an empty solution be better than optimal?

Darren Rowland — Thu, 05 Nov 2009 05:14:03 -0500

@ cyclist: I'm pretty sure that this is regarding the current contest.

You might like to evaluate a number of different strategies (including the 'do nothing' strategy) and choose the one which gives the lowest score.

The only real limit on how many different strategies you might try is that the program must conclude in under 3 minutes.

Hth
Darren

Re: Can an empty solution be better than optimal?

Steven Lord — Thu, 05 Nov 2009 15:01:40 -0500

"Darren Rowland" <darrenjremovethisrowland@hotmail.com> wrote in message
news:hctmur$dot$1@fred.mathworks.com...
>@ cyclist: I'm pretty sure that this is regarding the current contest.

I'd like to suggest that if you have questions about the contest, please
either post in the main contest thread:

http://www.mathworks.com/matlabcentral/newsreader/view_thread/264764

and/or tag your thread with the 'contest' tag, and/or include the words
'contest' or 'Fall 2009 contest' somewhere in your post, like the subject.

> You might like to evaluate a number of different strategies (including the
> 'do nothing' strategy) and choose the one which gives the lowest score.

Dmitry,

The "Other Considerations" heading in the Scoring section of the rules
states that returning the empty set is a legitimate answer.

http://www.mathworks.com/contest/flooding/rules.html

Whether it's a _good_ answer or not is for you and your code to decide :)

--
Steve Lord
slord@mathworks.com
comp.soft-sys.matlab (CSSM) FAQ: http://matlabwiki.mathworks.com/MATLAB_FAQ