How about losing the duplicates while sorting? Here is the quicksort implementation from Rosetta Code: 

sub quick_sort {
    my @a = @_;
    return @a if @a < 2;
    my $p = pop @a;
    quick_sort(grep $_ < $p, @a), $p, quick_sort(grep $_ >= $p, @a);
}
 
my @a = (4, 65, 2, -31, 0, 99, 83, 782, 1);
@a = quick_sort @a;
print "@a\n";

[download]

(This is for sorting numbers.) If you now replace >= with > so you get 

quick_sort(grep $_ < $p, @a), $p, quick_sort(grep $_ > $p, @a);

[download]

you will get a sorted array without duplicates.

In reply to Re: Create unique array --the hard way! by hdb
in thread Create unique array --the hard way! by Anonymous Monk

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.