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 545 / 564 1200
Tree coloring 2 466 / 472 1200
Maximum sum path 386 / 436 1300
Path with length k 359 / 370 1300
Subgraph 310 / 320 1300
Beautiful tree 270 / 278 1500
Company 211 / 218 1700
Zero tree 175 / 192 1700
Selfie 109 / 124 1800