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 320 / 324 1300
Distance query 282 / 290 1400
Robot on tree 232 / 252 1400
Heaviest edge 215 / 221 1500
Equal path 167 / 176 1500
Triplet 142 / 146 1500
Path update 170 / 174 1600
Second best minimum spanning tree 79 / 135 1700
Oggy and the cockroaches 17 / 27 1800