In this section, I'll show you how to find the Lowest Common Ancestor (LCA) of two nodes in a tree. The LCA is the deepest node that is an ancestor of both nodes you are looking at.
This concept appears everywhere: version control systems use it to find merge points, file systems use it to find common directories, and competitive programming problems use it constantly. You will learn three approaches: a simple recursive solution, binary lifting for faster queries, and Euler tour with RMQ for the fastest method.
By the end, you will handle LCA queries in O() time after preprocessing.
