my @hashes = \( 
  my %countries,
  my %states,
  my %cities,
);

for ( grep !/HEADING/, @locations )
{
  my @v = split /,/;
  $hashes[$_]{$v[$_]}++ for 0 .. $#v;
}

my @countries = sort keys %countries;
my @states    = sort keys %states;
my @cities    = sort keys %cities;