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 314 / 331 1200
Tree coloring 2 265 / 267 1200
Maximum sum path 219 / 254 1300
Path with length k 210 / 218 1300
Subgraph 171 / 182 1300
Beautiful tree 150 / 154 1500
Company 112 / 120 1700
Zero tree 97 / 110 1700
Selfie 37 / 50 1800