Meet Allison & Tim
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Practice coding interviews out loud with real-time voice coaching. Your code actually runs.
Letter Combinations of a Phone Number
This one is about exploring choices without getting lost—choose, recurse, undo, repeat. Interviewers love it because it reveals your structured exploration and your edge-case discipline. If you can explain your pruning, this stops feeling like brute force.
Meet Allison & Tim
Your AI coaches
Practice coding interviews out loud with real-time voice coaching. Your code actually runs.
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.
Desktop required
Sorry — mobile can’t run the editor + tests yet. Email yourself a link to continue on desktop.