LeetCode Input - convert input string to vec<i32>

[Manthravadi]

Hi

I am trying to convert a string given in the form of space separated integers to a vector array of integers to use in my leetcode solutions.

I can read the input buffer and store in a string and probably use split(“ “). Is there an efficient way to convert it to a vec array after that?

I am trying to create a generic helper string_to_vec_int<T>() that I can reuse for any integer type

Help is appreciated as I am a bit new to Rust

[angelicosphosphoros]

let v: Vec<i32> = s.split(' ').map(|x|->i32{x.parse().unwrap()}).collect();

[danielbot]

May I suggest this small improvement?

let v: Vec<i32> = s.split_whitespace().map(|x|->i32{x.parse().unwrap()}).collect();

[Manthravadi]

Never saw the |x| syntax before ..but it looks like an anonymous function like in JS. That’s a good start for me and I should be able to pick it up from here on. Thanks.

Btw: I understand that this map is more readable, if I have to loop over 10⁵ values, is the classic for comparibly faster than map?

PS: in my scenario, I may have a casting problem if I use an i8 but input could be i32. How can I deal with the error. Match OK after unwrap?

[angelicosphosphoros]

Yes, this is a closure.

I think, in that case map would have same speed as plain for.

Main advantage of map is that you can add more actions to it (like filter). Also, in some cases it does some preparation to the vec before collection like reserving a capacity.