A bit of golfing. :-)

use strict;
use warnings;

my @rec = (
    'N(8) -- H(15) .. O(9)',
    'N(8) -- H(15) .. N(8)',
    'N(8) -- H(16) .. O(9)',
);

my %count;
for (@rec) {
    /(H\(\d+\))/ && do { push @{$count{$1}}, $_ }
}

for (keys %count) {
    if ($#{$count{$_}}) {
        print "$_\n" for @{$count{$_}}
    }
}

__END__

# another go...

$,="\n";
for (keys %count) {
    print @{$count{$_}} if $#{$count{$_}}
}

[download]


In reply to Re: Re: duplicate lines in array by Roger
in thread duplicate lines in array by harry34

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