How to use this
For each card: say your approach and its Big-O out loud before revealing. Then mark "Knew it" or "Revise again". The goal is instant pattern recognition, not memorizing code.
Stuck on 'how would I even start?'
That's a trained skill, not a talent. Read How to Think (the Interview Cheat Code) first — it gives you the clue → pattern decoder table and walks you through the questions to ask yourself on real problems. Then come back and drill.