Subj : Re: efficient way of processing m combinations of n numbers in p sets
To   : comp.programming
From : W. D. Allen Sr.
Date : Wed Aug 17 2005 12:10 pm

The answer to your problem is in any college textbook on combinations and 
permutations.

end

"Mike" <mykyp@pearcey2001.freeserve.co.uk> wrote in message 
news:1124188190.499826.88190@g44g2000cwa.googlegroups.com...
> Hi,
>
>
> I am trying to process all combinations of 6 sets of numbers (using
> VB).  The
> minimum number in each set will be 2 and the maximum number is
> definable but will be the same for all 6 sets.  The increment in each
> set is also definable and is also the same for each set.
>
>
> As an example, if I set the Maxnumber as 4 and the increment as 1, I
> would end up with the following possibilities:
>
>
> 2,2,2,2,2,2
> 3,2,2,2,2,2
> 2,3,2,2,2,2
> 3,3,2,2,2,2
> 2,2,3,2,2,2
> 3,2,3,2,2,2
> 2,3,3,2,2,2
> 3,3,3,2,2,2
> ...
> ...
> 4,4,4,4,4,4 etc
> After each of the combinations is found I wish to perform a
> calculation.
>
>
> The way I am running it at the moment is 6 nested for loops as in the
> following:
>
>
> Stp = 1  'increment between numbers in each set
> Maxnumber = 4   'largest number in each set.
>
>
> For i = 2 To Maxnumber Step Stp
> For j = 2 To Maxnumber Step Stp
> For k = 2 To Maxnumber Step Stp
> For l = 2 To Maxnumber Step Stp
> For m = 2 To Maxnumber Step Stp
> For n = 2 To Maxnumber Step Stp
>
>
>    '     perform calc on i,j,k,l,m and n
>
>
> next n
> next m
> next l
> next k
> next j
> next i
>
>
> The problem I have is that as soon the maximum number is set too high
> or the increment is too low, the number of calculations increases
> exponentially and the pc freezes.  Ideally I am looking to perform
> these types of calculations in under 2 seconds.  The ideal ranges would
>
> be from 2 to 50 in each set with an increment of 0.1, so 2, 2.1,
> 2.2....up to 50.
>
>
> I would be really grateful if someone could offer some advice on how to
>
> perform these calculations in a more efficient manner.  For example,
> would placing all possibilities into an array first and then performing
>
> calculations at the end offer any improvements?
>
>
> My final question is would it be possible to vary the number of for
> loops involved e.g. in the above example, if I only had 3 sets of
> numbers I would only need 3 for loops to work through all of the
> possibilities.
>
>
> Many thanks in advance,
>
>
> Mike
>

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