http://qs1969.pair.com?node_id=213121


in reply to Re: Re: Re: Re: Re: Efficient run determination.
in thread Efficient run determination.

The cost of the startup thing is only included once, and even without it it makes no difference, the timing is the same, the startup cost is miniscule in comparison to the cost of the rest of the process.

If you don't agree with me, feel free to run your own benchmarks, my program is included at the end of this message. Your algorithm, while interesting, is one of the slowest.

Iterations: 100
Length: 1920
PhiRatE 1:  0.236097s  Perl/C
PhiRatE 3:  0.234754s  Perl/C
Dingus 1:   0.541398s  Perl
PhiRatE 2:  0.543576s  Perl
Dingus 2:   0.580746s  Perl + RE
TommyW 1:   0.897865s  Perl + RE
Enlil 2:    0.964746s  Perl + RE
Robartes 1: 1.021243s  Perl
Rasta 1:    2.015298s  Perl + RE
BrowserUk:  2.764815s  Perl + RE

Code for my benchmarking is here. Feel free to fiddle around to your liking.

use Data::Dumper; use Time::HiRes qw( usleep ualarm gettimeofday tv_interval ); use re 'eval'; $stn = "aaaaaaammm38fdkkkkkkkk3,,,,,,,,,,sad909999999994lkllllllllllll +lz,,,,,,,,,dd888888882jk2kkd8d888d8djkjkjkjkkk3kk4k5kkkk65"; $iterations = 500; for (1..4) { $stn.=$stn; } print "Iterations: $iterations\n";~ print "Length: ".length($stn)."\n"; # Enlil 2 $t0 = [gettimeofday]; for (1..$iterations) { @res = enlil_2($stn); } print "Enlil 2: ".tv_interval( $t0 )."\n"; # Dingus 1 $t0 = [gettimeofday]; for (1..$iterations) { @res = dingus_1($stn); } print "Dingus 1: ".tv_interval( $t0 )."\n"; # Rasta 1 $t0 = [gettimeofday]; for (1..$iterations) { @res = rasta_1($stn); } print "Rasta 1: ".tv_interval( $t0 )."\n"; # TommyW 1 $t0 = [gettimeofday]; for (1..$iterations) { @res = tommyw_1($stn); } print "TommyW 1: ".tv_interval( $t0 )."\n"; # Robartes 1 $t0 = [gettimeofday]; for (1..$iterations) { @res = robartes_1($stn); } print "Robartes 1: ".tv_interval( $t0 )."\n"; # PhiRatE 1 $t0 = [gettimeofday]; for (1..$iterations) { @res = p_process($stn); } print "PhiRatE 1: ".tv_interval( $t0 )."\n"; # BrowserUk $t0 = [gettimeofday]; #! Set up big regex. 1-time hit. my $re ='(?:(.)(??{"$+*"}))?' x 500; $re = qr/$re/o; for (1..$iterations) { @res = browseruk($stn); } print "BrowserUk: ".tv_interval( $t0 )."\n"; # Dingus 2 $t0 = [gettimeofday]; for (1..$iterations) { @res = dingus_2($stn); } print "Dingus 2: ".tv_interval( $t0 )."\n"; # PhiRatE 2 $t0 = [gettimeofday]; for (1..$iterations) { @res = phirate_2($stn); } print "PhiRatE 2: ".tv_interval( $t0 )."\n"; # PhiRatE 3 $t0 = [gettimeofday]; for (1..$iterations) { @res = p_process_2($stn); } print "PhiRatE 3: ".tv_interval( $t0 )."\n"; sub browseruk { $_ = shift; my @c = m/$re/; #! THIS LINE DOES ALL THE WORK. #! This truncates the list to exclude null matches returned from r +egex. $#c = $#- -1; return \@c; } sub enlil_2 { my $string = shift; my @bah; while ($string =~ /((.)\2*)/g) { push (@bah, [$2,$-[1],$+[1] - $-[1]]); } return \@bah; } sub dingus_1 { my $string = shift; my (@res, $c, $p, $i); $p = 0; $c = substr($string,$p,1); for ($i=1; $i<length($string); $i++) { next if ($c eq substr($string,$i,1)); push (@res, [$c,$p,($i-$p)]); $c = substr($string,$i,1); $p = $i; } push (@res, [$c,$p,($i-$p)]); return \@res; } sub dingus_2 { my $string = shift; my (@res, $i); $i = 0; while ($string =~ /(.)\1*/g) { push (@res, [$1, $i, pos($string)-$i]); $i = pos($string); } return \@res; } sub rasta_1 { my $string = shift; my ($pp, $l, @res); $l = length($string); $pp = 0; while ($pp < $l) { $c = substr $string, $pp, 1; if ($string =~ /\G\Q$c\E+/gc) { push @res,[$c,$pp,pos($string) - $pp]; $pp = pos($string); } } return \@res; } sub tommyw_1 { my $string = shift; my $pos=0; my @triples=(); my @reps=$string=~/((.)\2*)/g; while (@reps) { my $hits=shift @reps; my $char=shift @reps; push @triples, [$char, $pos, length $hits]; $pos+=length $hits; } return \@triples; } sub robartes_1 { my $string = shift; my @res; my @listedstring= split//,$string; my $prev=shift @listedstring; my $currstart=my $index=0; for (@listedstring) { if ($_ eq $prev) { $index++; } else { push @res, [$prev, $currstart, $index-$currstart+1]; $currstart=++$index; $prev=$_; } } push @res, [$prev, $currstart, $index-$currstart+1]; return \@res; } sub phirate_2 { $_ = shift; my @res; my $count=0; my ($prev, $next); my $i=0; $prev = $next = chop($_); while ($next || $prev) { if ($prev eq $next) { $count++; } else { push @res,[$prev, $i=$count, $count]; $prev = $next; $count = 1; } $i++; $next = chop; } return \@res; } use Inline C => <<'END_OF_C_CODE'; void p_process(char *s) { char prev = 0; long count = 0; long pos = 0; long i=0; AV *array; Inline_Stack_Vars; Inline_Stack_Reset; while((*s != 0) || (prev != 0)) { if (count==0) { pos = i; prev = *s; count = 1; } else if (prev == *s) { count++; } else { array = newAV(); av_push(array,newSVpvn(&prev,1)); av_push(array,newSViv(pos)); av_push(array,newSViv(count)); Inline_Stack_Push(newRV_inc(array)); pos=i; prev = *s; count=1; } i++; s++; } Inline_Stack_Done; } void p_process_2(char *s) { char prev = 0; long count = 0; long i=0; AV *array; Inline_Stack_Vars; Inline_Stack_Reset; prev = *s; while((*s != 0) || (prev != 0)) { if (prev == *s) { count++; } else { array = newAV(); av_push(array,newSVpvn(&prev,1)); av_push(array,newSViv(i-count)); av_push(array,newSViv(count)); Inline_Stack_Push(newRV_inc(array)); prev = *s; count=1; } i++; s++; } Inline_Stack_Done; } END_OF_C_CODE