[AccessD] miracle required apparently

[Steve Schapel]

Hi Paul

Very interesting to hear of your experience, and your innovative 
approach to solving the problem.  And congratulations on your "win" over 
the colleague!  :-)

Regards
Steve

On 18/10/2023 12:10:06 pm, "Paul Wolstenholme" 
<Paul.W at industrialcontrol.co.nz> wrote:

>There is a similar problem at
>https://www.rd.com/article/einsteins-riddle-solve-it/
>
>I had a colleague who wrote code (probably in C or a derivative) that took
>about a day to execute in 1999 and gave an answer.
>I wrote an Access 95 query that took about a second to reveal the possible
>variations that are encompassed in the ambiguities of the problem statement.
>
>My technique was first to form a table of all the permutations (in this
>case of 5 things, meaning 120 entries).
>Next I formed a query for each thing that could lie in any of those
>permutations.
>Finally I formed a query that started as the cross product of each of those
>queries but was linked according to the rules of the problem.
>(After that I showed the final query's results in a form).
>
>I expect my former colleague is still plotting his revenge.
>
>Paul Wolstenholme
>
>On Wed, 18 Oct 2023 at 08:14, Paul Hartland via AccessD <
>accessd at databaseadvisors.com> wrote:
>
>>  I don't have much time until the weekend for knocking up a quick test, but
>>  think that scenario is pretty doable with 4 lots of times, 4 lots of
>>  classes, upto 8 participants and not being the same time or class zone more
>>  than once
>>
>>  Paul
>>
>>  On Tue, 17 Oct 2023, 02:22 Steve Schapel, <
>>steve at datamanagementsolutions.biz>
>>  wrote:
>>
>>  > Hi all
>>  >
>>  > I'm trying to do something that I initially thought would be reasonably
>>  > easy.  But alas, so far success has eluded me.  Any insights accepted
>>  > with much gratitude!
>>  >
>>  > The goal:  Assign a number of Participants to a number of Activities
>>  > over a number of Sessions.
>>  >
>>  > Very simple example:
>>  >      4 Sessions
>>  >      4 Activities
>>  >      8 Participants (therefore 2 per Activity)
>>  >
>>  > To illustrate:
>>  > Let's say the sessions are 9am, 10am, 11am, 12pm.
>>  > Let's sat the activities are chess, tai chi, bowls, diving
>>  > Let's say the participants are A, B, C, D, E, F, G, H
>>  >
>>  > The stipulation is that each participant should do each activity one
>>  > time.
>>  >
>>  > By trial and error brute force, I know that there is at least one
>>  > solution, namely:
>>  >
>>  >                       chess       tai chi       bowls        diving
>>  >    9am           A & E        C & F        D & G        B & H
>>  > 10am           C & G       A & H       B & E         D & F
>>  > 11am           D & H      B & G        A & F         C & E
>>  > 12pm           B & F       D & E        C & H        A & G
>>  >
>>  > HOWEVER, I have tried multiple angles of looping through nested (and
>>  > sometimes randomised) recordsets based on the core data elements
>>  > (sessions, activities, and participants), to write the assignments to
>>  > the available slots in a schedule table, and to my shock (and horror) we
>>  > always reach the point in the procedure where it gets stuck, due to
>>  > trying to assign a participant to two activities in the same session,
>>  > but with no valid alternative slot available.
>>  >
>>  > There is no problem if the model calls for the super simple option of
>>  > only one participant for each activity.  But otherwise, no dice, so far.
>>  >
>>  > There MUST be a way to make this work?  Surely?
>>  >
>>  > Thanks a lot.
>>  >
>>  > Regards
>>  > Steve
>>  > --
>>
>>
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