<h2 id="heading-url">URL</h2>
<a target="_blank" href="https://leetcode.com/problems/first-unique-character-in-a-string/description/?envType=daily-question&amp;envId=2024-02-05">https://leetcode.com/problems/first-unique-character-in-a-string/description/?envType=daily-question&amp;envId=2024-02-05</a>
<h2 id="heading-code">Code</h2>
<a target="_blank" href="https://github.com/syohex/dotnet-study/blob/master/fsharp/leetcode/challenge/202402/first_unique_character_in_a_string/main.fsx">https://github.com/syohex/dotnet-study/blob/master/fsharp/leetcode/challenge/202402/first_unique_character_in_a_string/main.fsx</a>
<pre><code class="lang-fsharp">let firstUniqueChar (s: string) : int =
 let m =
 s
 |&gt; Seq.indexed
 |&gt; Seq.fold
 (fun acc (i, c) -&gt;
 match Map.tryFind c acc with
 | None -&gt; Map.add c i acc
 | Some(v) -&gt; Map.add c -1 acc)
 Map.empty
 |&gt; Map.values
 |&gt; Seq.filter (fun n -&gt; n &gt;= 0)

 if Seq.isEmpty m then -1 else Seq.min m
</code></pre>

## URL

[https://leetcode.com/problems/first-unique-character-in-a-string/description/?envType=daily-question&envId=2024-02-05](https://leetcode.com/problems/first-unique-character-in-a-string/description/?envType=daily-question&envId=2024-02-05)

## Code

[https://github.com/syohex/dotnet-study/blob/master/fsharp/leetcode/challenge/202402/first\_unique\_character\_in\_a\_string/main.fsx](https://github.com/syohex/dotnet-study/blob/master/fsharp/leetcode/challenge/202402/first_unique_character_in_a_string/main.fsx)

```fsharp
let firstUniqueChar (s: string) : int =
    let m =
        s
        |> Seq.indexed
        |> Seq.fold
            (fun acc (i, c) ->
                match Map.tryFind c acc with
                | None -> Map.add c i acc
                | Some(v) -> Map.add c -1 acc)
            Map.empty
        |> Map.values
        |> Seq.filter (fun n -> n >= 0)

    if Seq.isEmpty m then -1 else Seq.min m
```

LeetCode 387. First Unique Character in a String in F#

URL

Code