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.
Articles
TypeScript, page 2 of 3
TypeScript is a typed superset of JavaScript designed to make larger codebases easier to reason about and safer to change. Most of the articles here focus on clearer data models and more honest component boundaries, using types to support the work rather than turning the type system into the subject for its own sake.
Prefix Sums and Hash Maps: Solving 'Subarray Sum Equals K'. 
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.
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.
Horizontal & Vertical Scanning: The Longest Common Prefix Problem. Horizontal & Vertical Scanning: The Longest Common Prefix Problem
Compare horizontal and vertical scanning for Longest Common Prefix in TypeScript, including complexity, edge cases and when each method is clearer.
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 ListRemove the nth node from a linked list in TypeScript. Compare the two‑pass and pointer‑gap approaches, their edge cases, types and linear‑time complexity.
Finding the Median of Two Sorted Arrays with JavaScript. Finding the Median of Two Sorted Arrays with JavaScript
Find the median of two sorted arrays in JavaScript, from a simple merge approach to edge cases and the logarithmic approach interviewers often expect.
Understanding the Composition API in Vue 3. Understanding the Composition API in Vue 3
The Vue 3 Composition API explained with practical TypeScript examples, refs, composables, reactivity, and when the pattern genuinely helps larger components.
Validating Parentheses Input Using TypeScript. Validating Parentheses Input Using TypeScript
Validate mixed parentheses and brackets in TypeScript with a stack, check nesting order, and see why separate counters and two pointers are not enough.
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.
Understanding and Solving Regular Expression Matching. Understanding and Solving Regular Expression Matching
Solve regular expression matching with recursive and dynamic‑programming context, covering dot and star behaviour, edge cases and TypeScript.
LeetCode Container with Most Water: The Two‑Pointer Solution. LeetCode Container with Most Water: The Two‑Pointer Solution
Solve Container With Most Water in TypeScript using the two‑pointer pattern, with pointer movement, complexity, edge cases, and testable logic explained.
The Longest Palindromic Substring in JavaScript. The Longest Palindromic Substring in JavaScript
Explore the 'Longest Palindromic Substring' problem: its relevance in web development and four JavaScript (ES6 & TypeScript) solutions for efficiency.
Using JavaScript and the Two‑Pointer Technique to Solve 4Sum. Using JavaScript and the Two‑Pointer Technique to Solve 4Sum
Master the 4Sum problem in JavaScript: Explore the two‑pointer technique, solve with ES6/TypeScript, and test using Cypress. Elevate your coding skills.
3Sum Closest in JavaScript: Sorting and Two Pointers. 3Sum Closest in JavaScript: Sorting and Two Pointers
Solve 3Sum Closest in JavaScript with sorting and two pointers, reducing brute‑force work whilst finding the nearest total efficiently in TypeScript.
Add Two Numbers in TypeScript: A LeetCode Linked List Solution. Add Two Numbers in TypeScript: A LeetCode Linked List Solution
Solve LeetCode Add Two Numbers in TypeScript with linked‑list traversal, carry handling, edge cases, and a clear implementation you can test and extend.