Short Live-Coding Problems

Not every SpaceX round is a long build. Phone screens and one-hour technicals often start with a problem you already know, then push on the follow-up. A sorted list turns into a shuffled one, or ten strings become a million.

Five short problems are worked below, across binary search, bit tricks, hashing, linear algebra and linked lists. Two of them look trivial until you check the overflow or the scale.

Some of these rounds run in a shared doc with no compiler. Say what every variable means before you write the loop, and trace a tiny case by hand. Follow-ups push on scale and memory, and one asked what changes when the inputs hold a million items. Write each solution on paper first, then run it, so you get used to finding bugs without a compiler.

SpaceXPremium lesson · Coding round

The 5 SpaceX problems are below.

1. 1A Premium questionCoding · Easy
2. 2A Premium questionCoding · Easy
3. 3A Premium questionCoding · Easy

+ 2 more in this lesson

Each with hints, the follow-up and a tested solution.

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