---
slug: /plat/trees
title: "Platinum - Trees"
author: Benjamin Qi
# Platinum - Trees
## Tree Diameter
### Tutorial
- CPH 14.2
### Problems
- [USACO Plat Newbarns](http://www.usaco.org/index.php?page=viewproblem2&cpid=817)
- Copy of [Brain Network "Hard"](https://codeforces.com/contest/690/problem/C3)
## Lowest Common Ancestor
- CPH 18
- [cp-algorithms: Lowest Common Ancestor](https://cp-algorithms.com/)
- [USACO Plat Max Flow](http://www.usaco.org/index.php?page=viewproblem2&cpid=576)
- [USACO Gold Milk Visits](http://www.usaco.org/index.php?page=viewproblem2&cpid=970)
- [USACO Gold Cow Land](http://www.usaco.org/index.php?page=viewproblem2&cpid=921)
- LCA + BIT
- [USACO Plat Promote](http://www.usaco.org/index.php?page=viewproblem2&cpid=696)
- Subtree + BIT
- [USACO Plat Disrupt](http://www.usaco.org/index.php?page=viewproblem2&cpid=842)
- HLD is possible, but just do binary jumps
- [USACO Plat Tree Boxes](http://www.usaco.org/index.php?page=viewproblem2&cpid=948)
- interactive!!
- [USACO Plat Gathering](http://www.usaco.org/index.php?page=viewproblem2&cpid=866)
- [USACO Plat Exercise](http://www.usaco.org/index.php?page=viewproblem2&cpid=901)
- tricky
## Centroid Decomposition
- [USACO Plat - At Large](http://www.usaco.org/index.php?page=viewproblem2&cpid=793)
- very tricky
- [DMOJ Bob Equilibrium](https://dmoj.ca/problem/dmopc19c7p6)
## Heavy-Light Decomposition
