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 659 / 681 1200
Tree coloring 2 565 / 572 1200
Maximum sum path 468 / 520 1300
Path with length k 429 / 440 1300
Subgraph 377 / 387 1300
Beautiful tree 324 / 333 1500
Company 262 / 270 1700
Zero tree 213 / 232 1700
Selfie 139 / 154 1800