In the worst situation creating four iterators but using only the first & last yields

Question from a noob – would this (at scale, for instance) use more memory by creating two separate iterators, or would the compiler optimise this somehow?

thrice in my benchmark. it operates inplace

Thanks

https://github.com/Codewars/codewars.com/wiki/Language-Rust

You can use libraries? How?

As far as rust is concerned, mut a is not a change of signature.

Is this solution really twice faster than approach with iterators?

fixed

It's nice to see a solution that only uses iterator functions. Good job.

Rust translation kumited .

You don't have flatten, but you can easily replace it with flat_map:

let a = [vec![1, 3, 5], vec![7, 9]];
// let flat = a.iter().flatten().collect::<Vec<_>>();
let flat = a.iter().flat_map(|x| x).collect::<Vec<_>>();
println!("{:?}", flat);

Fixed

Yes, Rust.

It would be nice to mention in which language, Rust is it?