Module DP on tree

DP on tree

**Frequency: 6/10** DP, but on tree.

Resources

- [USACO: DP on trees](https://usaco.guide/gold/dp-trees?lang=cpp)

Problems

Tree coloring 547 / 567 1200
Tree coloring 2 468 / 474 1200
Maximum sum path 387 / 437 1300
Path with length k 360 / 371 1300
Subgraph 310 / 320 1300
Beautiful tree 270 / 278 1500
Company 211 / 218 1700
Zero tree 175 / 192 1700
Selfie 109 / 124 1800