// 原因：先处理右侧元素，把结果存在栈里，供左侧元素直接使用
Backpressure: good in theory, broken in practice
，更多细节参见91视频
Hartwig adds: "My grandpa started the business in a small building, and my dad was able to expand and grow it, so it'll be interesting to see where me and my brothers are able to take it next. It should be a fun journey."，这一点在heLLoword翻译官方下载中也有详细论述
siftDown(arr, n, i);，这一点在爱思助手下载最新版本中也有详细论述
If you could go back in your business journey and change one process or approach, what would it be, and how do you wish you’d done it differently?