php-general Digest 3 Oct 2013 12:47:41 -0000 Issue 8386
Topics (messages 322235 through 322240):
Re: Algorithm Help
322235 by: Stuart Dallas
322236 by: Serge Fonville
322237 by: Floyd Resler
322238 by: Marc Guay
322239 by: Tamara Temple
322240 by: Floyd Resler
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--- Begin Message ---
On 1 Oct 2013, at 19:51, Floyd Resler <fres...@adex-intl.com> wrote:
> Here's my task: A group of kids is going to be staying with different host
> families throughout the next 8 months. The number of kids staying with a
> host family can range from 2 to 10. When deciding which kids should stay
> together at a host family, the idea is for the system to put together kids
> who have stayed with each other the least on past weekends. So, if a host
> family can keep 5 kids, then the group of 5 kids who have stayed together the
> least will be chosen.
>
> I can't think of an easy, quick way to accomplish this. I've tried various
> approaches that have resulted in a lot of coding and being very slow. My
> idea was to give each group of kids a score and the lowest score is the group
> that is selected. However, this approach wound of iterating through several
> arrays several times which was really slow. Does anyone have any ideas on
> this puzzle?
Sounds like a job for a directed graph data structure. I wish I had time to
knock up a solution but I don't right now. This article should help you get
started:
http://www.codediesel.com/algorithms/building-a-graph-data-structure-in-php/
-Stuart
--
Stuart Dallas
3ft9 Ltd
http://3ft9.com/
--- End Message ---
--- Begin Message ---
It also depends on the amount of kids, families and stays.
If the numbers are low, by hand may be a lot easier and faster
Kind regards/met vriendelijke groet,
Serge Fonville
http://www.sergefonville.nl
2013/10/2 Tamara Temple <tamouse.li...@gmail.com>
>
> On Oct 1, 2013, at 1:51 PM, Floyd Resler <fres...@adex-intl.com> wrote:
>
> > Here's my task: A group of kids is going to be staying with different
> host families throughout the next 8 months. The number of kids staying
> with a host family can range from 2 to 10. When deciding which kids should
> stay together at a host family, the idea is for the system to put together
> kids who have stayed with each other the least on past weekends. So, if a
> host family can keep 5 kids, then the group of 5 kids who have stayed
> together the least will be chosen.
> >
> > I can't think of an easy, quick way to accomplish this. I've tried
> various approaches that have resulted in a lot of coding and being very
> slow. My idea was to give each group of kids a score and the lowest score
> is the group that is selected. However, this approach wound of iterating
> through several arrays several times which was really slow. Does anyone
> have any ideas on this puzzle?
> >
> > Thanks!
> > Floyd
> >
> >
> > --
> > PHP General Mailing List (http://www.php.net/)
> > To unsubscribe, visit: http://www.php.net/unsub.php
> >
>
> While definitely a tempting coding exercise, I just want to say that if
> this is urgent in any way, shuffling cards with the kids' names on them by
> hand might just be faster and less frustrating :)
>
> OTOH, if this is something you're going to have to figure out week after
> week, then a software solution might be handy.
>
> This is also not an *easy* problem to solve; there isn't a simple approach
> to optimizing this sort of thing because you're building a net between all
> the various kids based on past stays, in addition to the constraints of
> host family capacity. Thus your previous code attempts might in fact be
> the end result.
>
> Obviously, structuring the data is the key here.
>
> I'm thinking of 3 primary models: Kids, Hosts, and Stays.
>
> Kids and Hosts seem pretty obvious. Stays is the interesing model, and
> needs to have joining tables with Kids and Hosts.
>
> A Stay will have one Host, and have many Kids and a date.
>
> The algorithm then needs to make the graph where it can pull out the
> number of times any particular kid has stayed with another, looking
> something like this:
>
> Amy:
> Ben: 10
> Jill: 3
> Carlos: 7
> Chen: 2
> Ben:
> Amy: 10
> Jill: 5
> Carlos: 8
> Chen: 3
> Jill:
> … and so on
>
> Then you be able to pull through that graph and find the smallest number
> of stays for each kid.
>
> Not simple, but I hope this helps.
>
>
>
> --
> PHP General Mailing List (http://www.php.net/)
> To unsubscribe, visit: http://www.php.net/unsub.php
>
>
--- End Message ---
--- Begin Message ---
On Oct 2, 2013, at 9:51 AM, Tamara Temple <tamouse.li...@gmail.com> wrote:
>
> On Oct 1, 2013, at 1:51 PM, Floyd Resler <fres...@adex-intl.com> wrote:
>
>> Here's my task: A group of kids is going to be staying with different host
>> families throughout the next 8 months. The number of kids staying with a
>> host family can range from 2 to 10. When deciding which kids should stay
>> together at a host family, the idea is for the system to put together kids
>> who have stayed with each other the least on past weekends. So, if a host
>> family can keep 5 kids, then the group of 5 kids who have stayed together
>> the least will be chosen.
>>
>> I can't think of an easy, quick way to accomplish this. I've tried various
>> approaches that have resulted in a lot of coding and being very slow. My
>> idea was to give each group of kids a score and the lowest score is the
>> group that is selected. However, this approach wound of iterating through
>> several arrays several times which was really slow. Does anyone have any
>> ideas on this puzzle?
>>
>> Thanks!
>> Floyd
>>
>>
>> --
>> PHP General Mailing List (http://www.php.net/)
>> To unsubscribe, visit: http://www.php.net/unsub.php
>>
>
> While definitely a tempting coding exercise, I just want to say that if this
> is urgent in any way, shuffling cards with the kids' names on them by hand
> might just be faster and less frustrating :)
>
> OTOH, if this is something you're going to have to figure out week after
> week, then a software solution might be handy.
>
> This is also not an *easy* problem to solve; there isn't a simple approach to
> optimizing this sort of thing because you're building a net between all the
> various kids based on past stays, in addition to the constraints of host
> family capacity. Thus your previous code attempts might in fact be the end
> result.
>
> Obviously, structuring the data is the key here.
>
> I'm thinking of 3 primary models: Kids, Hosts, and Stays.
>
> Kids and Hosts seem pretty obvious. Stays is the interesing model, and needs
> to have joining tables with Kids and Hosts.
>
> A Stay will have one Host, and have many Kids and a date.
>
> The algorithm then needs to make the graph where it can pull out the number
> of times any particular kid has stayed with another, looking something like
> this:
>
> Amy:
> Ben: 10
> Jill: 3
> Carlos: 7
> Chen: 2
> Ben:
> Amy: 10
> Jill: 5
> Carlos: 8
> Chen: 3
> Jill:
> … and so on
>
> Then you be able to pull through that graph and find the smallest number of
> stays for each kid.
>
> Not simple, but I hope this helps.
>
>
That's the only approach I could think of. I may have to tell the director it
may be a bit slow but at least she won't have to do it by hand!
Thanks!
Floyd
--- End Message ---
--- Begin Message ---
If you have the technology handy, it could also just be easier to wipe
the children's memories after each stay.
Marc
--- End Message ---
--- Begin Message ---
On Oct 2, 2013, at 9:05 AM, Marc Guay <marc.g...@gmail.com> wrote:
> If you have the technology handy, it could also just be easier to wipe
> the children's memories after each stay.
>
> Marc
>
> --
> PHP General Mailing List (http://www.php.net/)
> To unsubscribe, visit: http://www.php.net/unsub.php
>
Well played! (.. eying the black suit…. "What's that funny stick you're hol….")
--- End Message ---
--- Begin Message ---
On Oct 2, 2013, at 6:23 PM, Tamara Temple <tamouse.li...@gmail.com> wrote:
>
> On Oct 2, 2013, at 9:05 AM, Marc Guay <marc.g...@gmail.com> wrote:
>
>> If you have the technology handy, it could also just be easier to wipe
>> the children's memories after each stay.
>>
>> Marc
>>
>> --
>> PHP General Mailing List (http://www.php.net/)
>> To unsubscribe, visit: http://www.php.net/unsub.php
>>
>
> Well played! (.. eying the black suit…. "What's that funny stick you're
> hol….")
>
>
>
I love it! Our director loved it too! Too funny!
Thanks!
Floyd
--- End Message ---
