Sounds like the guy you're working for may have an XY problem, too... (Does that mean you have an X^2Y^2 problem? Or would it be an X^2 + 2XY + Y^2 problem?)

If you already have the means to generate all the permutations of a list, then I suspect that generating all permutations of each source list and then interleaving each pair of those would be much faster, much simpler, and much less memory-intensive than generating all permutations of the combined source lists and filtering out those which aren't interleaved.

In reply to Re^3: interleaved lists check by dsheroh
in thread interleaved lists check by Anonymous Monk

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