Solution: Lowest Common Ancestor of a Binary Tree III

Learn to find the lowest common ancestor of two nodes in a binary tree when only parent pointers are available. This lesson teaches a two-pointer technique that efficiently traverses up the tree, ensuring both pointers meet at the common ancestor, regardless of node depths. You will understand the step-by-step process, the algorithm's time and space complexity, and how to implement this approach in your coding interviews.

We'll cover the following...

Statement
Solution
- Time complexity
- Space complexity

Statement

You are given two nodes, p and q. The task is to return their lowest common ancestor (LCA). Both nodes have a reference to their parent node. The tree’s root is not provided; you must use the parent pointers to find the nodes’ common ancestor.

Note: The lowest common ancestor of two nodes, p and q, is the lowest node in the binary tree, with both p and q as descendants.
In a tree, a descendant of a node is any node reachable by following edges downward from that node, including the node itself.

Constraints:

$-10^4 \leq$ ...