Every possible combination

How can I obtain every possible combination for a dynamic sized set? can it be done without recursion or methods? I've been trying to figure ou开发者_JAVA技巧t how to do it with just loops for the past hours and can't seem to come up with a solution.

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Quite a few methods can be found on the appropriate wikipedia page.

(note: this answer is overly generic because the OP doesn't go into any deep about what he needs)