]> On Wed, Oct 08, 2003 at 04:48:09PM +0200, Pierre Weis wrote: > Hi Michal, > > [...] > > Key points of my implementation: > [...] > > 3. It doesn't use Scanf. For such linear task as this Scanf takes 10 or > > more times to parse input then actual computations. > [...] > > -- > > : Michal Moskal :: http://www.kernel.pl/~malekith : GCS {C,UL}++++$ a? !tv > > : When in doubt, use brute force. -- Ken Thompson : {E-,w}-- {b++,e}>+++ h > > I'm sorry to report that I was so puzzled by your number 3) key point, > that I tested your code and a ``purely scanf'' version to see this > ``10 or more times to parse'' behaviour; I didn't notice any runtime > difference between the two (native code compiled) versions. Am I > missing something ? Hm, with your version it's only 3 times slower: -rw-r--r-- 1 malekith users 1909887 Oct 8 18:02 /shm/d2 ./statsf < /shm/d2 > /dev/null 0.31s user 0.01s system 103% cpu 0.308 total ./stats < /shm/d2 > /dev/null 0.10s user 0.00s system 155% cpu 0.064 total However, your code is not correct: > Could you please try to use the following version of your read > function, and report the runtime difference between your hand written > code ? > > (BTW, I compiled the 2 programs using ocamlopt -unsafe -inline 9) > > let read () = > try > Scanf.bscanf Scanf.Scanning.stdib " %c" (function > | 'D' -> > Scanf.bscanf Scanf.Scanning.stdib " %d %d %s" ----------------------------------------------------^^ It should be [^\n], as filenames can contain spaces. In this case: ./statsf < /shm/d2 > /dev/null 1.56s user 0.04s system 96% cpu 1.654 total Well, it's 15 times slower. All tests were run on athlon 1.56GHz, under pld-linux, ocaml 3.07, ocamlopt -unsafe -inline 9. -- : Michal Moskal :: http://www.kernel.pl/~malekith : GCS {C,UL}++++$ a? !tv : When in doubt, use brute force. -- Ken Thompson : {E-,w}-- {b++,e}>+++ h ------------------- To unsubscribe, mail caml-list-request@inria.fr Archives: http://caml.inria.fr Bug reports: http://caml.inria.fr/bin/caml-bugs FAQ: http://caml.inria.fr/FAQ/ Beginner's list: http://groups.yahoo.com/group/ocaml_beginners