Module Lowest common ancestor (LCA)

Lowest common ancestor (LCA)

**Frequency: 8/10** In many cases where a problem involves querying a path on a tree, there is a high likelihood that the Lowest Common Ancestor (LCA) will be a crucial element in the solution. There are also a lot of problems involving LCA in the next module, Euler tour.

Resources

- [CP Algorithms: Lowest Common Ancestor - Binary Lifting](https://cp-algorithms.com/graph/lca_binary_lifting.html)

Problems

LCA 445 / 451 1300
Distance query 403 / 413 1400
Robot on tree 332 / 355 1400
Heaviest edge 320 / 326 1500
Equal path 247 / 260 1500
Triplet 216 / 219 1500
Path update 243 / 249 1600
Second best minimum spanning tree 118 / 196 1700
Oggy and the cockroaches 36 / 59 1800