Last week I posted about a new website I'm starting: http://vplanetcoding.com.
I added a dynamic programming video tutorial for 855B - Marvolo Gaunt's Ring. I explained the idea of dynamic programming and how to use dynamic programming to solve the problem. I accidentally filmed a very short part of the video vertically (sorry!) but most of the video is filmed horizontally.
Here is the solution: https://www.vplanetcoding.com/course-2-standard-algorithms-and-data-structures#2.
In addition, I am in the process of adding a bunch of Codeforces and USACO problems sorted by topic and difficulty. I have added several problems at every level for several topics.