Solving the LeetCode 'Binary Tree Zigzag Level Order Traversal' Problem
Solve Binary Tree Zigzag Level Order Traversal with breadth‑first search, level sizing, alternating output order, and TypeScript implementation details.
Articles
LeetCode, page 2 of 3
LeetCode is a platform intended for preparing for technical coding interviews and improving coding skills. It presents hundreds of complex (and some less‑complex) problems, and invites users to submit solutions using the programming language of choice. Naturally, where I discuss solutions here, it will almost always be in a front‑end language like JavaScript or TypeScript...
Below you will find a subset of articles from my blog specifically about LeetCode. This is an area I have worked with for many years, and it has been a regular subject in my writing. There are fifty‑one articles collected together for you below.
Solving the LeetCode 'Binary Tree Zigzag Level Order Traversal' Problem. 
Breadth‑First Search: Solving Binary Tree Level Order Traversal. Breadth‑First Search: Solving Binary Tree Level Order Traversal
Solve Binary Tree Level Order Traversal with breadth‑first search in TypeScript, using a queue, level sizing, edge cases, and cleaner iteration well.
Prefix Sums and Hash Maps: Solving 'Subarray Sum Equals K'. Prefix Sums and Hash Maps: Solving 'Subarray Sum Equals K'
Solve Subarray Sum Equals K with prefix sums and a hash map in TypeScript, including negative numbers, count storage, and why sliding window fails.
Understanding the Backtracking Approach: Solving the 'Word Search' Problem. Understanding the Backtracking Approach: Solving the 'Word Search' Problem
Solve Word Search with backtracking in JavaScript, covering recursive path exploration, visited state, pruning, restoration, and grid trade‑offs.
Fast and Slow Pointers: Solving the 'Linked List Cycle' Problem. Fast and Slow Pointers: Solving the 'Linked List Cycle' Problem
Solve Linked List Cycle with fast and slow pointers in TypeScript, comparing visited‑node storage with Floyd's cycle detection and common mistakes.
Single Number in TypeScript with Bit Manipulation. Single Number in TypeScript with Bit Manipulation
Solve Single Number in TypeScript with XOR bit manipulation, comparing hash maps, constant extra space, duplicate cancellation, and why the trick works.
Grid Traversal: Solving the 'Number of Islands' Problem. Grid Traversal: Solving the 'Number of Islands' Problem
How to solve Number of Islands with grid traversal, treating the matrix like a graph, marking visited land safely, and reasoning about DFS in TypeScript.
Sliding Window Fundamentals: Solving 'Longest Substring Without Repeating Characters'. Sliding Window Fundamentals: Solving 'Longest Substring Without Repeating Characters'
How to solve Longest Substring Without Repeating Characters with sliding window basics, comparing Set and last‑seen‑index approaches in TypeScript.
LeetCode: The 'Trapping Rain Water' Problem with Two‑Pointer Approach. LeetCode: The 'Trapping Rain Water' Problem with Two‑Pointer Approach
How to solve Trapping Rain Water with the two‑pointer approach, and the simple invariant that makes the O(n) solution click under interview pressure.
Horizontal & Vertical Scanning: The Longest Common Prefix Problem. Horizontal & Vertical Scanning: The Longest Common Prefix Problem
Unravel the art of finding the Longest Common Prefix in strings using TypeScript. Dive deep into Horizontal & Vertical Scanning methods with code insights.
Intervals in Practice: Solving the 'Merge Intervals' Problem. Intervals in Practice: Solving the 'Merge Intervals' Problem
Solve Merge Intervals in TypeScript by sorting ranges, merging overlaps, handling touching intervals, preserving inputs, and avoiding common mistakes.
Prefix and Suffix Products: Solving 'Product of Array Except Self'. Prefix and Suffix Products: Solving 'Product of Array Except Self'
How to solve Product of Array Except Self without division, using prefix and suffix products to keep the logic linear and interview‑safe in TypeScript.
LeetCode: Removing the nth Node from the End of a List. LeetCode: Removing the
nthNode from the End of a ListHow to remove the Nth node from the end of a linked list in TypeScript. Here we break down and explore a simple double‑pass and an efficient single‑pass method.
The Palindrome Number Problem: Strings vs. Maths in JavaScript. The Palindrome Number Problem: Strings vs. Maths in JavaScript
Distinguishing two approaches to detect palindrome numbers: the intuitive string method vs. the optimised mathematical technique, highlighting their merits.
Finding the Median of Two Sorted Arrays with JavaScript. Finding the Median of Two Sorted Arrays with JavaScript
Exploring the 'Find Median of Two Sorted Arrays' problem: Understand its significance in interviews, dive into a TypeScript solution, and test with Cypress.
Validating Parentheses Input Using TypeScript. Validating Parentheses Input Using TypeScript
Validate parentheses input in TypeScript with a stack, checking bracket order, matching pairs, real parser‑style use cases, and alternative approaches.
Solving the 'Letter Combinations of a Phone Number' Problem with TypeScript. Solving the 'Letter Combinations of a Phone Number' Problem with TypeScript
An exploration of solutions to the 'Letter Combinations of Phone Number' problem using front‑end and TypeScript: recursion, backtracking, and iteration.
LeetCode: Converting Roman Numerals to Integers. LeetCode: Converting Roman Numerals to Integers
Decode the mystique of Roman numerals! Discover their structure, learn their significance, and master the art of converting them back to integers in code.