Thirty Days to Hard
Learn C++ and LeetCode-hard problem solving at the same time. Each day is a prerequisite refresher, three C++ lessons, one pattern playbook with the pattern worked from scratch, a four-question quiz, and three timed checkpoints — about two hours.
Already have progress in the standalone version? Import it.
- Refresher, then pattern
Every day opens with the structure it stands on — what it actually is, what each operation costs, and the one property the day's pattern exploits.
- Derived, not announced
Each pattern is worked on one concrete problem: a brute force, the waste in it named out loud, and the step that removes it. The reference card comes after.
- Recognition, not recall
Every playbook is a list of what you see on the page and what it tells you to reach for — plus the judgement call the pattern turns on.
- Timed, and honest
Miss a checkpoint and it queues for you to re-solve from scratch. Attempting counts; only reading the solution does not.