Every lesson rewritten around interactive widgets
Lessons open on a concrete problem and teach with widgets you can change: push and pop a stack, flip bits, move two pointers.
What changed
All 41 lessons on the Learn map use this format. Each one builds the idea in short sections and walks through a worked trace before you try it yourself.
Every lesson ends with common mistakes, where the idea shows up in problems, questions to check your understanding and the runnable exercise.
After the rewrite, we opened each lesson in a browser and fixed wrong claims, broken widgets and layouts that didn’t fit on phones. Geometry with integer points is still a short read.
Try it
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