Maybe I'm missing something, but... 
for(@in){
   $hash{$_}++;
}
foreach my $key (keys %hash){
   print "$key is lonely\n" if ($hash{$key} == 1);
   print "$key has friends\n" if ($hash{$key} != 1);
}

[download]

thor

Update: changed %hash{$_}++ to $hash{$_}++ to make it correct.

In reply to Re: Get All Duplicated Elements in an Array (Once, without shifting) by thor
in thread Get All Duplicated Elements in an Array (Once, without shifting) by George_Sherston

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