@arr = 1..10;
randomize(\@arr);

print "@arr";

sub randomize {
    my ($p, $size, $swap, $key);
    $p = $_[0];

    $size = $#$p;
    for (0..($size-1)) {
        $swap = int rand($size - $_ + 1) + $_;
        $key = $p->[$_];
        $p->[$_] = $p->[$swap];
        $p->[$swap] = $key;
    }
}