一个startup店面跪了，追问hr要feedback。hr很友好，不一会儿就发来了：
Your interviewer thought you were smart and had great instincts, but wanted
to see cleaner code as you worked through the problem. He also felt you
sometimes had the tendency to over think working through the solution. Try
to keep both your code and your thought process as simple as your can.
想请版上的前辈分析分析，有什么提高的地方。
1） cleaner code是不是就是bug free，还是说一些代码的注释，编程风格习惯不够
professional呢
2） over think working through the solution是个什么意思呢？
