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 255 / 259 1300
Distance query 225 / 231 1400
Robot on tree 180 / 198 1400
Heaviest edge 173 / 178 1500
Equal path 132 / 138 1500
Triplet 110 / 113 1500
Path update 133 / 137 1600
Second best minimum spanning tree 57 / 104 1700