LeetCode 1903. Largest Odd Number in String in F#

URL

Largest Odd Number in String - LeetCode

Code

https://github.com/syohex/dotnet-study/tree/master/fsharp/leetcode/problems/1903/main.fsx

open System

let largestOddNumber (num: string) : string =
    let rec largestOddNumber' (cs: char list) =
        match cs with
        | [] -> ""
        | h :: t ->
            let n = int h - int '0'

            if n % 2 = 1 then
                cs |> List.rev |> String.Concat
            else
                largestOddNumber' t

    largestOddNumber' (num |> Seq.rev |> Seq.toList)