Maybe not over efficient, at least on memory, but:

#!/usr/bin/perl use strict; use warnings; my $cards = 5; my $holes = 3; my @arrangements = arrange(0, $cards, $holes); print "@$_\n" for @arrangements; sub arrange { my ($usedHoles, $remainingCount, $totalHoles) = @_; my @arrangements; return [$remainingCount] if ++$usedHoles == $totalHoles; for my $thisCount (1 .. $remainingCount - ($totalHoles - $usedHole +s)) { my @subArrangements = arrange($usedHoles, $remainingCount - $thisCount, $totalHo +les); push @arrangements, map {[$thisCount, @$_]} @subArrangements; } return @arrangements; }

Prints:

1 1 3 1 2 2 1 3 1 2 1 2 2 2 1 3 1 1

Update: avoiding most of the memory usage:

#!/usr/bin/perl use strict; use warnings; my $cards = 5; my $holes = 3; arrange(0, $cards, $holes, ''); sub arrange { my ($usedHoles, $remainingCount, $totalHoles, $prefix) = @_; if (++$usedHoles == $totalHoles) { print "$prefix $remainingCount\n"; return; } for my $thisCount (1 .. $remainingCount - ($totalHoles - $usedHole +s)) { arrange($usedHoles, $remainingCount - $thisCount, $totalHoles, + "$prefix $thisCount"); } }
Premature optimization is the root of all job security

In reply to Re: Combinatorics problem. by GrandFather
in thread Combinatorics problem. (Updated with more info.) by BrowserUk

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