URL

https://leetcode.com/problems/group-anagrams/description/?envType=daily-question&envId=2024-02-06

Code

https://github.com/syohex/dotnet-study/blob/master/fsharp/leetcode/challenge/202402/group_anagrams/main.fsx

let groupAnagrams (strs: string list) : string list list =
    let rec groupAnagrams' strs acc =
        match strs with
        | [] -> acc |> Map.values |> Seq.toList
        | h :: t ->
            let freq =
                h
                |> Seq.fold
                    (fun acc c ->
                        match Map.tryFind c acc with
                        | Some(v) -> Map.add c (v + 1) acc
                        | None -> Map.add c 1 acc)
                    Map.empty

            match Map.tryFind freq acc with
            | Some(v) -> groupAnagrams' t (Map.add freq (h :: v) acc)
            | None -> groupAnagrams' t (Map.add freq [ h ] acc)

    groupAnagrams' strs Map.empty