Rather than reading all your data into an array and then subsequently processing it, I'd suggest just reading it from the file and processing it line-by-line:

open my $fh, '<', 'sample.data' or die $!;
while (<$fh>) {
    # chomp
    # split
    # assign to hash
}
close $fh;
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Note I've suggested chomp - this will remove newlines which are probably might end up in your hash values after recoding. You haven't shown an example of your input so that's a guess.

Update: The paragraph about chomp was badly phrased - I've reworded it.