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 268 / 272 1300
Distance query 236 / 242 1400
Robot on tree 193 / 211 1400
Heaviest edge 187 / 191 1500
Equal path 142 / 149 1500
Triplet 116 / 120 1500
Path update 144 / 148 1600
Second best minimum spanning tree 61 / 114 1700
Oggy and the cockroaches 8 / 11 1800