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
Dart Records & Patterns Deep Dive — Destructuring, Sealed Classes & Exhaustive Matching Dart 3.0 shipped Records, Patterns, and Sealed Classes together. Used well, they eliminate entire categories of runtime errors and make state management dramatically more expressive. // Before: untyped Map Map<String, dynamic> getUserInfo() => {'name': 'Alice', 'age': 30}; // Dart 3: typed Record (String nam