how to find duplicate array values in perl [duplicate]

Question

Possible Duplicate:
What's the most efficient way to check for duplicates in an array of data using Perl?

How to find duplicate values in array?

This is my array:

@arr - ("one","two","one","three","two");

Output will be:

one
two

Code:

while (<RFH>) {
    chomp;
    @arr = split(/\|/,$_);
    push(@arr1,$arr[4]."\n");
}

Answer 1

One pass solution:

my %seen = ();
@dup = map { 1==$seen{$_}++ ? $_ : () } @list;