How to use this workbench
- Expand a puzzle and run the snippet in JShell or your IDE (every class is self-contained
Main). - Write the exact console output on paper — include line breaks.
- Tap Reveal output, then I got it right to track progress (saved in your browser).
- Use the four pack lessons when you want a smaller slice before an interview.
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Still to come · 1 section
- All 38 puzzles
Test yourself
Answer these before moving on — recall is what makes it stick.