---
categories: Graph theory
---

## Problems
- [Kingdom and its Cities](http://codeforces.com/problemset/problem/613/D) [^1]
- [Railway](https://open.kattis.com/problems/railway2)

## External links
- [CompressTree.h](https://github.com/kth-competitive-programming/kactl/blob/master/content/graph/CompressTree.h) in KACTL

[^1]: <http://codeforces.com/blog/entry/22832>