技术第一轮：
- b/w C++ 和Java 的区别。 Java字节码如何与平台无关?
- https://www.geeksforgeeks.org/design-a-stack-that-supports-getmin-in-o1-time-and-o1-extra-space/
- https://www.geeksforgeeks.org/rotate-matrix-90-degree-without-using-extra-space-set-2/
技术第 2 轮：
- https://leetcode.com/problems/course-schedule-ii/