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 579 / 598 1200
Tree coloring 2 497 / 503 1200
Maximum sum path 409 / 459 1300
Path with length k 380 / 390 1300
Subgraph 329 / 340 1300
Beautiful tree 286 / 294 1500
Company 225 / 232 1700
Zero tree 190 / 207 1700
Selfie 118 / 133 1800