Re: how to refer the index of an array to another array of the same length

[CountZero]

With a regular expression and only one loop.

use Modern::Perl;
use Regexp::Assemble;

# load the arrays
my @cg = ( 1, 5, 12, 3 );
my @gl = map { int( rand 20 ) + 1 } ( 1 .. 100 );
my @csta = map { chr( $_ + 64 ) } @gl;
say "@gl\n@csta";    # for debug purposes only

# assemble the regex
my $ra = Regexp::Assemble->new;
$ra->add(@cg)->anchor_word(1)->re;
say $ra->as_string;    # for debug purposes only

# find the matches
for my $idx ( keys @gl ) {
    say "$idx: $gl[$idx] : $csta[$idx]" if ( $gl[$idx] =~ m/$ra/ );
}

Sample output:

3: 5 : E
13: 1 : A
15: 3 : C
19: 3 : C
26: 1 : A
35: 5 : E
39: 5 : E
42: 5 : E
44: 5 : E
53: 5 : E
73: 1 : A
75: 1 : A
81: 12 : L
83: 5 : E