Solution: Lowest Common Ancestor of a Binary Tree III

Explore how to determine the lowest common ancestor of two nodes in a binary tree by applying the two-pointers technique on nodes with parent pointers. Understand the step-by-step method where two pointers traverse upward until they meet, ensuring an efficient and constant space solution. This lesson guides you through the algorithm, its implementation, and analysis of time and space complexity.

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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:

$-10^4 \leq$ ...