> For the above example, it's worth sorting lists_of_sets by the > length of the sets, and doing the short ones first.
Thanks. I thought so - I'm doing just that using a simple Decorate- Sort-Undecorate idiom. > How big are the sets? If they're small, but you have a lot of > them, you may be better off with a bit-set representation, then > using AND operations for intersection. If they're huge (tens of millions > of entries), you might be better off doing sorts and merges on the > sets. I have either 2 or 3 sets (never more) which can be arbitrarily large. Most of them are small (between 0 and few elements - say less that 5). A few will be megamonstrous ( > 100,000 items) > When you ask questions like this, it's helpful to give some > background. We don't know whether this is a homework assignment, or > some massive application that's slow and you need to fix it, even > if it requires heavy implementation effort. > Its definitely not a homework assignment - its part of a commercial database query engine. Heavy implementation effort is no problem. Prateek -- http://mail.python.org/mailman/listinfo/python-list
