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 281 / 285 1300
Distance query 250 / 256 1400
Robot on tree 205 / 224 1400
Heaviest edge 194 / 198 1500
Equal path 150 / 157 1500
Triplet 122 / 127 1500
Path update 150 / 154 1600
Second best minimum spanning tree 69 / 123 1700
Oggy and the cockroaches 13 / 21 1800