sub printElement(\%$)
{
   my %hash1 = %{($_[0])};
   my $key = $_[1];
   print $key." ".$hash1{$key}."\n";

...

   &printElement(\%hash, $key);
[download]

You are copying the entire hash inside the subroutine so you may as well just do it like this:

sub printElement
{
   my ( $key, %hash1 ) = @_;
   print "$key $hash1{$key}\n";

...

   printElement( $key, %hash );
[download]

Of course, using a reference means that you don't have to copy the hash:

sub printElement
{
   my ( $hash1, $key ) = @_;
   print "$key $hash1->{$key}\n";

...

   printElement( \%hash, $key );
[download]

Also, if you use the prototype (\%$) then the first argument in the call to the subroutine has to be a hash and not a reference to a hash or you will get this error message:

Type of arg 1 to main::printElement must be hash (not reference constructor) at -e line 10