How to Approach a System Design Interview: URL Shortener Example
A repeatable framework for system design interviews, applied to designing a URL shortener with simple capacity estimates.
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A 30-Day Coding Interview Study Plan That Actually Works
A realistic four-week plan for coding interview preparation, with daily habits, topic order and how to review your mistakes.
Dynamic Programming for Beginners: Climbing Stairs and Coin Change
A gentle introduction to dynamic programming: recursion, memoization and tabulation on two classic interview problems.
Tree Traversals in Python: DFS, BFS and Grid Problems
Understand inorder DFS, level-order BFS and how the same ideas solve Number of Islands on a grid.
Binary Search: A Reliable Template and the Mistakes to Avoid
A simple binary search template, a lower-bound variant and the search-on-answer trick, with the off-by-one mistakes that cause most bugs.
Sliding Window Pattern Explained with Python Examples
Learn the fixed and variable sliding window techniques with two worked problems and a template you can reuse.
Two Sum: From Brute Force to Hash Map
Solve LeetCode Two Sum step by step, from the obvious O(n squared) loop to a one-pass hash map solution in…