A study partner who listens while you code — and talks back.
You know how to solve it. You fall apart explaining it.
Practice explaining code out loud with a coach who talks back — so studying stops feeling like homework and you stop blanking in real interviews.
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# Two Sum
# Find two numbers that add to target
# return their indices
# hash map for linear time
# Arrays & Hashing
Fin
Coach
That hashmap idea is right — you said 'check all the combos,' and that's the part an interviewer pokes. Say that part again, tightened.
As I scan, the map stores each value's index so I can check whether the target complement has already appeared.
See it in action
One explanation. One correction. One better take.
Coco catches the one part you rushed and has you say it again, out loud — so it's yours before the interview, not something you're hoping to remember.
Coco
Coach · Two Sum
Coco
Two Sum — just talk me through your plan first, like you'd say it to a friend.
You
I'd check every pair, then use a hash map for one pass.
Coco
The hash map is the right instinct. The one part to tighten: what does the map hold, and when do you check it? Say just that part again.
You
As I scan, the map stores each value's index. I check for the complement before I store the current one.
Coco
That's it — clear, and in order. That's the version that'll come out the same way when it counts.
Guest reps stay on this device. A free account carries future reps and Coco's notes across devices.
Do the first rep before you decide. Hear one thing to tighten. Say it again better.
Start with Two Sum. Text works without an account; voice needs a free one today.