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 308 / 325 1200
Tree coloring 2 259 / 261 1200
Maximum sum path 216 / 250 1300
Path with length k 207 / 216 1300
Subgraph 168 / 180 1300
Beautiful tree 147 / 151 1500
Company 110 / 118 1700
Zero tree 95 / 108 1700
Selfie 35 / 46 1800