On Dec 11, 2007, at 9:53 PM, ciwei2103 wrote:
Give a disk sequence know that is incrementing with base 16, such
as ,
0001
0003
0004
0008
0009
000A
000B
000F
0010
0011
how do I extract the a subset that is have at least 4 consecutives,
such as "0008 0009 000A 000B"
Sorry, the previous code missed an edge case, I think this one is
correct:
use strict;
use warnings;
use constant AT_LEAST_THESE_MANY => 4;
my @disks = qw(
0001
0003
0004
0008
0009
000A
000B
000F
0010
0011
);
my @codes = map hex, @disks;
my $start;
my $nsucc = 0;
for (my $i = 0; $i < $#codes; ++$i) {
my $diff = $codes[$i+1] - $codes[$i];
++$nsucc if $diff == 1;
if ($nsucc + 1 >= AT_LEAST_THESE_MANY && ($diff != 1 || $i + 1 ==
$#codes)) {
$start = $i - $nsucc;
++$start if $diff == 1;
last;
} elsif ($diff != 1) {
$nsucc = 0;
}
}
print "@disks[$start..($start+$nsucc)]\n" if $start;
-- fxn
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