动态规划分类学习

https://www.bilibili.com/video/BV1ub411Q7sB/?vd_source=8eb26e2d2f7eefc64ebaafb06c72ab46

https://leetcode.cn/discuss/post/3581838/fen-xiang-gun-ti-dan-dong-tai-gui-hua-ru-007o/

1. 爬楼梯

https://leetcode.com/problems/climbing-stairs/

https://leetcode.com/problems/min-cost-climbing-stairs/

https://leetcode.com/problems/climbing-stairs-ii/