in reply to Combinatorics problem. (Updated with more info.)

You may want to try Algorithm::Combinatorics or Math::Combinatorics CPAN modules (or some other CPAN modules on the subject).

Or are you looking for a way to do it yourself in Perl?

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Re^2: Combinatorics problem.
by BrowserUk (Patriarch) on Dec 11, 2015 at 07:58 UTC
    You may want to try Algorithm::Combinatorics

    I use Algorithm::Combinatorics all the time, but you have to work out which generator, or combination of generators to use for each particular problem, and this one is eluding me.

    Also, I suspect that the sequence I need is a subset of one of the classical sequences (combs/perms/variations/partitions), and I would then need to filter the generated sequence, which can be grossly inefficient; so it may be better to program an algorithm that generates the sequence directly?

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[reply]

      You are looking for Composition_(combinatorics) and need to filter on the number of parts (after taking away 1 postcard for each pidgeon hole as suggested below). I have not found any code on CPAN for this. The bad news is that there are exponentially many compositions for a given number of postcards.

[reply]

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