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 431 / 451 1200
Tree coloring 2 366 / 369 1200
Maximum sum path 309 / 349 1300
Path with length k 297 / 305 1300
Subgraph 243 / 254 1300
Beautiful tree 215 / 221 1500
Company 169 / 177 1700
Zero tree 142 / 158 1700
Selfie 76 / 90 1800