On Dec 14, 8:18 pm, Roy Smith <r...@panix.com> wrote: > Steven D'Aprano <st...@remove-this-cybersource.com.au> wrote: > > All the positive thinking in the world won't help you: > > > * make a four-sided triangle; > > > * split a magnet into two individual poles; > > These two are fundamentally different problems. > > The first is impossible by definition. The definition of triangle is, "a > three-sided polygon". Asking for a "four-sided triangle" is akin to asking > for "a value of three which is equal to four". > > The second is only "impossible" because it contradicts our understanding > (based on observation) of how the physical universe works. Our > understanding could simply be wrong. We've certainly been wrong before, > and we will undoubtedly be proven wrong again in the future. When it comes > to things like electromagnetic theory, it doesn't take too many steps to > get us to the fuzzy edge of quantum physics where we know there are huge > questions yet to be answered.
I agree. Most of his examples were tautologies. The magnet one was the exception. Then, to beat the O( n lg n ) limit, just break an assumption. > > * or design a comparison sort which does fewer than O(n*log n) two-way > > comparisons in the worst case, or fewer than O(n) comparisons in the best > > case. Make a three-way comparison, make a non-comparison sort, or make non- random inputs. -- http://mail.python.org/mailman/listinfo/python-list
