sub naive (@) {
    for (reverse 1..$#_) {
        my $r=int rand($_+1);
        @_[$_,$r]=@_[$r,$_];
    }
}

##</code><code>##

sub bzr (@) {
    my @a = 0..$#_;
    my $i = @_;
    my $n;
    map +($_[$a[$n=rand($i--)]], $a[$n]=$a[$i])[0], @_;
}

##</code><code>##

        my $x = $l[$r];
        $l[$r] = $l[$_];
        $l[$_] = $x;

##</code><code>##

sub naive2 (@) {
    my @l=@_;
    my @l2;
    for (reverse 0..$#l) {
        my $r=int rand($_+1);
        push @l2, $l[$r];
        $l[$r] = $l[$_];
    }
    @l2;
}