Your intuition to use Algorithm::Combinatorics is correct, but your choice of functions within that module was incorrect. The correct function exists, and is documented in the POD: variations_with_repetition.

use Algorithm::Combinatorics qw(variations_with_repetition);

my @data = (1,2);
my $at_a_time = 3;

my $variations_iterator = variations_with_repetition(\@data, $at_a_tim
+e);

while (my $variant = $variations_iterator->next) {
    print "@$variant\n";
}

[download]

This produces:

1 1 1
1 1 2
1 2 1
1 2 2
2 1 1
2 1 2
2 2 1
2 2 2

[download]

You were so close!

In the future, please post the sample code. In this case I would have used it to verify that you were using the module correctly, aside from using the incorrect function.

Also, a lesson from high school math, and from the POD: There are n^k variations with repetition. So in your case the input set size is 2, and you're taking 3 at a time. 2**3=8. So we can validate that we got the correct number of variations by checking that we got 8, and that there are no repeats.


Dave

In reply to Re: Combinations with variable length by davido
in thread Combinations with variable length by TryingTheBest

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