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 551 / 571 1200
Tree coloring 2 471 / 477 1200
Maximum sum path 389 / 439 1300
Path with length k 361 / 371 1300
Subgraph 312 / 322 1300
Beautiful tree 273 / 281 1500
Company 212 / 219 1700
Zero tree 176 / 193 1700
Selfie 110 / 125 1800