#  $ perl a.pl 1 1 1 1 1 3 4 4 4 4 4
#  len: 5 nums: 4 1
#  $ perl a.pl 1 1 1 1 1 3 4 4 4 4
#  len: 5 nums: 1

sub f {
    my ($x, @xs) = @_;
    if (not @xs) {
        (1, $x, 0, ());
    } else {
        my ($hl, $h, $yl, @ys) = f(@xs);
        if ($h eq $x) {
            if ($hl + 1 > $yl) {
                ($hl + 1, $h, 0, ());
            } else {
                ($hl + 1, $h, $yl, @ys);
            }
        } else {
            if ($hl == $yl) {
                (1, $x, $yl, @ys, $h);
            } elsif ($hl > $yl){
                (1, $x, $hl, $h);
            } else {
                (1, $x, $yl, @ys);
            }
        }
    }
}

my ($foo, $bar, $len, @nums) = f(undef, @ARGV);
print "len: $len nums: @nums\n";