LeetCode Binary Tree Level Order Traversal
LeetCode 102 in detail — the queue-with-size BFS pattern, why DFS still works, and how this template extends to zigzag and right-side view.
·5 min read · #dsa#leetcode#trees
#trees
9 posts.
LeetCode Kth Smallest Element in a BST
LeetCode 230 in detail — the inorder traversal trick, the iterative early-exit version, and the follow-up that haunts FAANG interviews.
·4 min read · #dsa#leetcode#trees
LeetCode Lowest Common Ancestor of a BST
LeetCode 235 walked through end to end — why BST ordering collapses LCA into a one-line traversal, and the iterative version that needs zero extra space.
·5 min read · #dsa#leetcode#trees
LeetCode Path Sum: DFS With a Running Total
LeetCode 112 in detail — the DFS-with-decrement trick, why the leaf condition is the whole problem, and the variants that build on it.
·5 min read · #dsa#leetcode#trees
LeetCode Serialize and Deserialize Binary Tree
LeetCode 297 fully unpacked — the preorder-with-nulls encoding, the iterator-driven decoder, and why level-order is a worse choice than it looks.
·5 min read · #dsa#leetcode#trees
LeetCode Validate Binary Search Tree
LeetCode 98 in full — the seductive wrong answer, the correct min/max bounds approach, and how to defend it in an interview.
·5 min read · #dsa#leetcode#trees
Binary Trees in DSA: Introduction
A practical introduction to binary trees — the TreeNode class, terminology (full, complete, perfect, balanced), height vs depth, BSTs, and the small calculations you need to reason about tree problems.
·9 min read · #dsa#trees#beginners
Binary Trees: 8 Practice Problems with Solutions
Eight classic binary tree interview problems with examples, approach notes, and clean Python solutions — max depth, same tree, invert, symmetric, path sum, LCA, validate BST, and serialize/deserialize.
·9 min read · #dsa#trees#practice
Binary Tree Traversals: Inorder, Preorder, Postorder, Level-Order
A practical guide to the four canonical binary tree traversals — recursive and iterative versions, when to use each, and the patterns that make them click.
·7 min read · #dsa#trees#intermediate