Solution: Lowest Common Ancestor of a Binary Tree

Explore how to determine the lowest common ancestor of two nodes in a binary tree by applying a depth-first search recursion. Learn to track node presence through left, right, and current node checks to identify the ancestor efficiently. Understand the method's time and space complexity to solve binary tree ancestor problems confidently.

We'll cover the following...

Statement
Solution

Statement

Given the root node of a binary tree with $n$ nodes, your task is to find the lowest common ancestor of two of its nodes, p and q.

Note: The lowest common ancestor of two nodes, p and q, is defined as the lowest node in the binary tree that has both p and q as descendants.

A node can also be a descendant of itself. For example, if q is a descendant of p, and we know that p is a descendant of itself, then p will be the lowest common ancestor of p and q.

Constraints:

$2 \leq n \leq 500$

...