Core Idea - Multiple Approaches Exist

There are several ways to solve LCA. One approach converts the tree into an array using an Euler tour, then reduces LCA to a Range Minimum Query. I'll cover that technique later in this section.

For a single LCA query on a moderate tree, a simpler recursive approach works well. You recurse through both subtrees and combine results. If you find one target on each side, the current node is the LCA. This runs in $O(n)$ time and $O(h)$ space, and you can implement it in a few lines of code.