In Perl, how can I iterate over the Cartesian product of multiple sets?

Question

Given x number of arrays, each with a possibly different number of elements, how can I iterate through all combinations where I select one item from each array?

Answer 1

There's one method I thought of first that uses a couple for loops and no recursion.

1. find total number of permutations
2. loop from 0 to total_permutations-1
3. observe that, by taking the loop index modulus the number of elements in an array, you can get every permutations

Example:

Given A[3], B[2], C[3],

for (index = 0..totalpermutations) {
    print A[index % 3];
    print B[(index / 3) % 2];
    print C[(index / 6) % 3];
}

where of course a for loop can be substituted to loop over [A B C ...], and a small part can be memoized. Of course, recursion is neater, but this might be useful for languages in which recursion is severely limited by stack size.