I have the same pen as you / yours 选择哪个呢?

I have the same pen as you / yours 选择哪个呢?
I have the same pen as you / yours
关于这个句子后面用 as you ,as yours
我在网上搜索 了解到两种说法
1 I have the same pen as you
说是 as you (have) 省略了 have ,而且是 主语,I 和 后面的 人物,做对比
用 as you
2 I have the same pen as yours
两个人都有一样的钢笔,比较的对象是 钢笔.前后的词对应,所以后面用 as yours ( your pen )
有知道准确说法的 朋友么.