oof

i'm deceased

You should think for yourself, not in my place.

This code doesn't follow typical styling, which would have the line broken into a couple new lines and helps dramatically with readability. I think some believe one-liners look cooler.

I understand that xs.len() is said to be >=3 and Rust has some underflow protection.
Yet still xs.len() - 1 is a buggy programing practice I don't that makes me nervous.

How did you solve problem?

Really clean.

I've finally read that I had to round results, but test cases for C++ showing me:

ExampleTests
Expected: [ 4.2, -35.8, -2.8, 23.2, 11.2 ]
Actual: [ 4.2, -35.8, -2.8, 23.2, 11.2 ]
were really misleading.
They were literaly telling me that x is not the answer because the answer is x.

One could tinker with TC_COUNT and RANGE constants in “Test Cases” section.
Interesting configurations include:

• TC_COUNT = 0, RANGE = 0..=1000 which would enforce 0 randomness and covering literally all cases that abide by specification.

_ is NOT unreachable. It can be reached due to misuse of the provided function.
This match arm should panic with clear message targeting API user who misused the function.