A few years ago I solved 200 LeetCode problems and still froze on Mediums I hadn't seen. The breakthrough wasn't another hundred problems. It was a different loop. A problem asks for the longest substring with at most K distinct characters. You've solved sliding window before. Maximum sum subarray of size K, done. Longest substring without repeating characters, done. This third one stalls you. Twe
I am a first-year CS student and I recently made a decision that most people around me think is unnecessary — I am building a relational database storage engine from scratch in raw C++, with zero STL dependency. No std::vector. No std::string. No iostream. Nothing. The Problem With How I Was Learning For a long time I was writing code that worked but I had no idea why it worked. I used abstraction