Union‑Find Explained: Solving the 'Number of Provinces' Problem
Solve Number of Provinces with union‑find in TypeScript, comparing DFS, connected components, path compression, union by rank, and matrix scanning.
Articles
Data Structures
Data structures are the shapes we choose to organise information so the surrounding code can work with it efficiently. Tries, heaps, stacks, queues, linked lists, trees, hash maps, caches, and disjoint sets all solve different access and update problems, which is why they overlap so naturally with both Algorithms and LeetCode. This category is for the posts where the structure itself is a big part of the lesson, not just a background detail in the final solution.
Below you will find a subset of articles from my blog specifically about Data Structures. This is an area I have worked with for many years, and it has been a regular subject in my writing. There are twelve articles collected together for you below.
Union‑Find Explained: Solving the 'Number of Provinces' Problem. 
LeetCode: The 'Kth Smallest Element in a BST' Problem. LeetCode: The 'Kth Smallest Element in a BST' Problem
How to solve Kth Smallest Element in a BST by leaning on in‑order traversal instead of extra sorting the tree already makes unnecessary in interviews.
LeetCode: Finding the Diameter of a Binary Tree. LeetCode: Finding the Diameter of a Binary Tree
The diameter of a binary tree is the longest path between any two nodes. I'll explain clearly how we can solve this problem using recursion in JavaScript.
LeetCode: Solving the 'Merge Two Sorted Lists' Problem. LeetCode: Solving the 'Merge Two Sorted Lists' Problem
The 'Merge Two Sorted Lists' problem on LeetCode involves combining two sorted linked lists into one. Here, I explore a clear solution with TypeScript examples.
Monotonic Stack: Solving the 'Daily Temperatures' Problem. Monotonic Stack: Solving the 'Daily Temperatures' Problem
Solve Daily Temperatures with a monotonic stack in TypeScript, storing indices to find the next warmer day without repeated scanning and common mistakes.
Implementing a Trie in TypeScript: Solving 'Implement Trie (Prefix Tree)'. Implementing a Trie in TypeScript: Solving 'Implement Trie (Prefix Tree)'
Implement a Trie prefix tree in TypeScript with Map‑based nodes, insert, search, startsWith, shared prefixes, complexity, and alternative child storage.
Solving the LeetCode 'Binary Tree Zigzag Level Order Traversal' Problem. 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.
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.
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.
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.
Add Two Numbers in TypeScript: A LeetCode Linked List Solution. Add Two Numbers in TypeScript: A LeetCode Linked List Solution
Explore LeetCode's 'Add Two Numbers' problem: adding numbers represented as linked lists. Dive into the challenge, TypeScript solution, and its significance.