Terry Reedy: > Don't waste your time with problem sites that judge raw-clock time over > (and before) accuracy, thereby greatly favoring low-level languages and > hack tricks over clear high-level code.
I usually don't like to solve the kind of problems shown by those sites because those problems are too much artificial (and often too much difficult). But sometimes I have written some solutions. But those sites never judge "raw" running time over accuracy: in most or all such sites the programs are tested with tons of possible inputs, and if even one output is a bit wrong, the program is totally refused. This is a hard rule that encourages programmers to take a very good care of program correctness. Some sites add a little more "noise" in the inputs, simulating a bit more real-world inputs, while most of those online contests give clean inputs (the input bounds are well specified in the problem statement). >From what I've seen from some of the best solutions submitted to those sites (some sites allow people to see the source of the contest entries), the programs usually don't (need to) use "hack tricks" as you say (even if probably some program uses them). Using hacks is often unsafe so people usually prefer safer ways to code, because just a little bug may fully compromise the score of the program. I agree that the timing scores in such sites often encourage low level languages, like C (and sometimes C++, that's a multilevel language), but on the other hand such languages exist, C is used in many real- world places, so designing sites where people compete with such languages is legit. C allows people to understand better what's going on inside the computer, this is valuable and positive. Bashing low- level languages is silly. Even CPython is written in C. A good programmer has to know both higher and lower level languages. And in real-life sometimes you need performance. This thread shows that a normal Python program is not up to those timings for the enormous input problem (even if there are ways to write a Python program to solve this problem). People at Google are trying to create a 5 times faster Python (Unladen Swallow project) because they use lot of real-world Python code and they think Python is slow. I've found plenty of situations where CPython code is not fast enough for my purposes. Bye, bearophile -- http://mail.python.org/mailman/listinfo/python-list
