Search⌘ K
AI Features
Home
Courses
Grokking the Coding Interview Patterns in C++

Solution: Lowest Common Ancestor of a Binary Tree III

Explore how to find the lowest common ancestor of two nodes in a binary tree using a two-pointer approach. Understand how pointers traverse parent links to identify the common ancestor without needing the tree root, optimizing for time and space.

We'll cover the following...

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. ...