Code should be written for readability, not typing speed.

This is not production quality code that is running on some important business. It's competitive programming.

Speed is the goal here.

I don't think code shortening is ever used for interview questions?

But if you're in a competitive environment that requires speed, why would you write for readability?

Because you’ll end up debugging the code an hour later when it fails on an edge case?

The really good competitors won't make that sort of mistake...

Because you probably have to re-read some, if not most, of the code while working through a solution.