Recursion scales very, very poorly. Given that thenetfreaker has reported that several hundred bits are involved, any of the recursive solutions in this thread will surely run out of memory before producing a single result (for that size of problem). The iterators, however, immediately produce the first result and never use much memory at all.

Update: I think only the immediately above solution tries to return all of the answers in one big list (as I'm used to recursive solutions doing). So some other solutions (both recursive and not) just require a call-back be used (or the code to process each item be in-lined), which is inconvenient compared to using an interator but not a "show stopper."

- tye        

In reply to Re^5: One Zero variants_without_repetition (reversion from recursion) by tye
in thread One Zero variants_without_repetition by thenetfreaker

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