24+5670
mediumGrind 75

Add Two Numbers

This one has lots of possibilities, and it's really testing whether you can explore them systematically. Interviewers love it because it reveals your structured exploration and your edge-case discipline. The gotcha is duplicates and dead ends—good pruning and ordering rules make this manageable.

Linked ListBacktrackingMath & Geometry
👩‍🏫
👨‍💼

Meet Allison & Tim

Your AI coaches

Practice coding interviews out loud with real-time voice coaching. Your code actually runs.

Free · No sign up · Early access

Desktop required to run this problem

StrongYes runs real code + tests in a desktop editor. Mobile is view-only for now, so you can’t start this here. Sorry about that — email yourself a link and pick it up on your computer.

1Add Two Numbersmedium
2Part 2
3Part 3

Start Part 1 to unlock your next challenge

Based onLeetCode

Desktop required

Sorry — mobile can’t run the editor + tests yet. Email yourself a link to continue on desktop.