Solving LCA of Binary Tree using Recursion.

Problem

Find lowest common ancestor.

Pattern

This problem demonstrates the Recursion pattern.

Approach

Return node if found in subtree.

Solution 

  // Solution for LCA of Binary Tree
// Pattern: Recursion
// O(n) time

Complexity

O(n) time

Best Practices

  • Identify the pattern before coding — pattern recognition saves time
  • Handle edge cases: empty input, single element, duplicates
  • Use descriptive variable names even in timed interviews
  • Test with the provided examples plus one custom case