use strict;
use warnings;

my %result;
my %seq = (key => 'asdfasdfasdf');
my @string = 'asdf';

foreach my $string (@string) {
    chomp $string;
    foreach my $key (keys %seq) {
        $result{$string} =()= ($seq{$key} =~ /$string/ig); 
    }

    foreach my $s (keys %result) {
        print "$s => $result{$s}\n";
    }
}