---
id: tree-euler
title: "Euler Tour on Tree"
author: ?
prerequisites:
- Silver - Depth First Search
- Gold - Static Range Queries
description: Subtree updates and queries and another way to compute lowest common ancestors.
- [CSES: Subtree Queries](https://cses.fi/problemset/task/1137)
## Tutorial
- CPH 18.2
- [cp-algorithms - LCA with Sparse Table](https://cp-algorithms.com/graph/lca.html)
## Problems
- [CSES: Path Queries](https://cses.fi/problemset/task/1138)
- USACO
- [Gold - Milk Visits](http://www.usaco.org/index.php?page=viewproblem2&cpid=970)
- [Plat - Promotion Counting](http://www.usaco.org/index.php?page=viewproblem2&cpid=696)
- [Plat - Snow-Cow](http://www.usaco.org/index.php?page=viewproblem2&cpid=973)
