If you're going to roll your own shuffle, there's no reason you need to work on an array:
sub rand2 {
my $foo = shift;
for (my $i = length($foo); --$i; ) {
my $j = int rand ($i+1);
(substr($foo, $i, 1), substr($foo, $j, 1)) = (substr($foo, $j,
+ 1), substr($foo, $i, 1))
}
return $foo;
}
But then, there's no strong argument for shuffling in-place, either:
sub rand3 {
my $foo = shift;
my $bar = '';
while (length $foo) {
$bar .= substr($foo, rand(length $foo), 1, '');
}
return $bar;
}
Benchmark results:
Rate rand1 rand2 rand3
rand1 2928/s -- -27% -78%
rand2 4008/s 37% -- -70%
rand3 13282/s 354% 231% --
Update: Benchmarked BrowserUK's shuffleword; it was about half as fast as rand3.
Caution: Contents may have been coded under pressure.
Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
Read Where should I post X? if you're not absolutely sure you're posting in the right place.
Please read these before you post! —
Posts may use any of the Perl Monks Approved HTML tags:
- a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
|
For: |
|
Use: |
| & | | & |
| < | | < |
| > | | > |
| [ | | [ |
| ] | | ] |
Link using PerlMonks shortcuts! What shortcuts can I use for linking?
See Writeup Formatting Tips and other pages linked from there for more info.