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 453 / 472 1200
Tree coloring 2 383 / 386 1200
Maximum sum path 323 / 363 1300
Path with length k 305 / 314 1300
Subgraph 253 / 264 1300
Beautiful tree 223 / 230 1500
Company 177 / 185 1700
Zero tree 144 / 161 1700
Selfie 81 / 95 1800