use warnings;
use strict;

my @arr = (29,24,0,24,24,12,0,10,29,10,19,17,15,13,1,12,12,24,31);


sub del_duplicate 
{
    my @sorted = sort{$a <=> $b} @_;
    my @unique;
    
    my $current;
    my $next;
    
    foreach my $index (0..@sorted-2) 
    {      
        $current = $sorted[$index];
        $next    = $sorted[++$index];
        if ($current != $next) 
        {
            push @unique, $current;
        }
    }
    
    # this is a "fix-it" statement after the loop
    # in order to get the last element of @sorted
    
    push @unique, $next;  # add the last value
    
    print "@unique\n";
}

del_duplicate(@arr); #0 1 10 12 13 15 17 19 24 29 31