reverse ucfirst lc reverse "ACta"
Try not to hurt our brains with hard to read regexes :)
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Not neccessarily the best way to do it, but it is pretty simple:
scalar reverse ucfirst lc reverse 'ACta';
note: scalar is only neccessary if you use this in a list context, such as print, but I left it in, just in case.
Just Another Perl Alchemist
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yet another way, which should be quickier than the double reverse:
my $string = "ACta";
$string = lc(substr($string, 0, length($string)-1))
. uc(substr($string, -1, 1));
cheers,
Aldo
King of Laziness, Wizard of Impatience, Lord of Hubris
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Well, I get it to almost the same speed as the double reverse,
but only after some modification:
#!/usr/bin/perl
use strict;
use warnings;
use Benchmark qw /cmpthese/;
chomp (our @strings = <DATA>);
our (@a, @b, @c, @d);
cmpthese -1 => {
juerd => '@a = map {scalar reverse ucfirst lc reverse} @strings',
davido => '@b = map {my $t = $_; $t =~ s/^(.*)(.)$/\L$1\U$2/; $t}
+@strings',
dada1 => '@c = map {lc (substr ($_, 0, length ($string) - 1)) .
uc (substr ($_, -1, 1))} @strings',
dada2 => '@d = map {lc (substr ($_, 0, -1)) .
uc (substr ($_, -1, 1))} @strings',
};
die 1 unless "@a" eq "@b";
die 2 unless "@a" eq "@c";
die 3 unless "@a" eq "@d";
__DATA__
ACta
abcdefghijklmnopqrstuvwxyz
abcdefghijklmnopqrstuvwxyz abcdefghijklmnopqrstuvwxyz abcdefghijklmnop
+qrstuvwxyz
I have a question!
yet another way, which should be quickier than the double reverse:
Rate davido dada1 dada2 juerd
davido 21081/s -- -68% -70% -70%
dada1 65511/s 211% -- -6% -7%
dada2 69592/s 230% 6% -- -1%
juerd 70275/s 233% 7% 1% --
Abigail | [reply] [Watch: Dir/Any] [d/l] |
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no I didn't, it was just a guess :-) and in fact, it seems the double reverse solution is faster for small strings, while the substr solution wins in the long run. anyway, here you get full benchmark:
use strict;
use List::Util qw(shuffle);
use Benchmark qw(:all);
my $string = "ACta";
print "*** ", length($string), " characters\n";
cmpthese(1_000_000, {
uclast_substr => sub { uclast_substr($string) },
uclast_2reverse => sub { uclast_2reverse($string) },
});
$string = join ("", shuffle( 'A'..'Z', 'a'..'z' ));
print "*** ", length($string), " characters\n";
cmpthese(1_000_000, {
uclast_substr => sub { uclast_substr($string) },
uclast_2reverse => sub { uclast_2reverse($string) },
});
$string .= join ("", shuffle( 'A'..'Z', 'a'..'z' ));
$string .= join ("", shuffle( 'A'..'Z', 'a'..'z' ));
$string .= join ("", shuffle( 'A'..'Z', 'a'..'z' ));
print "*** ", length($string), " characters\n";
cmpthese(1_000_000, {
uclast_substr => sub { uclast_substr($string) },
uclast_2reverse => sub { uclast_2reverse($string) },
});
$string .= join ("", shuffle( 'A'..'Z', 'a'..'z' ));
$string .= join ("", shuffle( 'A'..'Z', 'a'..'z' ));
$string .= join ("", shuffle( 'A'..'Z', 'a'..'z' ));
$string .= join ("", shuffle( 'A'..'Z', 'a'..'z' ));
$string .= join ("", shuffle( 'A'..'Z', 'a'..'z' ));
$string .= join ("", shuffle( 'A'..'Z', 'a'..'z' ));
$string .= join ("", shuffle( 'A'..'Z', 'a'..'z' ));
$string .= join ("", shuffle( 'A'..'Z', 'a'..'z' ));
$string .= join ("", shuffle( 'A'..'Z', 'a'..'z' ));
print "*** ", length($string), " characters\n";
cmpthese(1_000_000, {
uclast_substr => sub { uclast_substr($string) },
uclast_2reverse => sub { uclast_2reverse($string) },
});
sub uclast_substr {
my($string) = @_;
$string = lc(substr($string, 0, length($string)-1))
. uc(substr($string, -1, 1));
return $string;
}
sub uclast_2reverse {
my($string) = @_;
$string = reverse ucfirst lc reverse $string;
return $string;
}
and here the result:
*** 4 characters
Rate uclast_substr uclast_2reverse
uclast_substr 566572/s -- -15%
uclast_2reverse 666223/s 18% --
*** 52 characters
Rate uclast_substr uclast_2reverse
uclast_substr 470588/s -- -6%
uclast_2reverse 500000/s 6% --
*** 208 characters
Rate uclast_2reverse uclast_substr
uclast_2reverse 249938/s -- -9%
uclast_substr 273523/s 9% --
*** 676 characters
Rate uclast_2reverse uclast_substr
uclast_2reverse 102239/s -- -19%
uclast_substr 126231/s 23% --
cheers,
Aldo
King of Laziness, Wizard of Impatience, Lord of Hubris
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use Benchmark;
my $tests = [qw(these are a few test to try
andaverylongteststring
acoupleoftimesover
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
+xxxxxxxxxxxxxxxxxxxxxxxxxx
zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz
+zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz
zzzzzzzzzzzzzzzzzzzzzzzzzzzzz)];
timethese (100000, {
NoOpLoop =>
sub {
for my $test (@$tests) {
# NO Op Loop
}
},
regex1 =>
sub {
for my $test (@$tests) {
$test=~s/^(.*)(.)$/\L$1\U$2/;
}
},
substr =>
sub {
for my $test (@$tests) {
$test= lc(substr($test, 0, length($test)-1))
. uc(substr($test, -1, 1));
}
},
reverse=>
sub {
for my $test (@$tests) {
$test=reverse ucfirst lc reverse $test;
}
}
});
and the winner is :-
Benchmark: timing 100000 iterations of NoOpLoop, regex1, reverse, subs
+tr...
NoOpLoop: 2 wallclock secs ( 1.86 usr + 0.00 sys = 1.86 CPU)
@ 53763.44/s (n=100000)
regex1: 82 wallclock secs (30.31 usr + 0.01 sys = 30.32 CPU)
@ 3298.15/s (n=100000)
reverse: 8 wallclock secs ( 7.40 usr + 0.00 sys = 7.40 CPU)
@ 13513.51/s (n=100000)
substr: 8 wallclock secs ( 8.51 usr + 0.01 sys = 8.52 CPU)
@ 11737.09/s (n=100000)
Interesting: double reverse seamed the best but as always test on real data!!
Hope it helps
UnderMine
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As requested, the regexp approach.
my $string = "ACta";
$string =~ s/^(.*)(.)$/\L$1\U$2/;
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What is the best (easiest) way do this?
If perchance by "best (easiest)" you meant "with the least typing" :-), you could do this:
$_='ACta';
$_.=uc chop($_=lc);
print;
...but I imagine I'm far too late...
dave | [reply] [Watch: Dir/Any] [d/l] |
Yours looks pretty fine to me, almost excellent. I'd make it:
s/(\w*)(\w)/\L$1\U$2/
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($s = lc $s) =~ s[(.)\b][$1&'?']ge
Examine what is said, not who speaks.
"Efficiency is intelligent laziness." -David Dunham
"Think for yourself!" - Abigail
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