<h2 id="heading-url">URL</h2>
<p><a target="_blank" href="https://leetcode.com/problems/word-pattern/description/">https://leetcode.com/problems/word-pattern/description/</a></p>
<h2 id="heading-code">Code</h2>
<p><a target="_blank" href="https://github.com/syohex/dotnet-study/blob/master/fsharp/leetcode/problems/0290/main.fsx">https://github.com/syohex/dotnet-study/blob/master/fsharp/leetcode/problems/0290/main.fsx</a></p>
<pre><code class="lang-plaintext">let wordPattern (pattern: string) (s: string) : bool =
    let rec wordPattern' pattern words m registered =
        match pattern, words with
        | [], [] -&gt; true
        | p1 :: t1, word :: t2 -&gt;
            match Map.tryFind p1 m with
            | Some (v) -&gt;
                if word &lt;&gt; v then
                    false
                else
                    wordPattern' t1 t2 m registered
            | None -&gt;
                if Set.contains word registered then
                    false
                else
                    wordPattern' t1 t2 (Map.add p1 word m) (Set.add word registered)
        | _, _ -&gt; failwith "never reach here"

    let words = s.Split ' '

    if pattern.Length &lt;&gt; words.Length then
        false
    else
        wordPattern' (pattern |&gt; Seq.toList) (words |&gt; Array.toList) Map.empty Set.empty
</code></pre>


## URL

[https://leetcode.com/problems/word-pattern/description/](https://leetcode.com/problems/word-pattern/description/)

## Code

[https://github.com/syohex/dotnet-study/blob/master/fsharp/leetcode/problems/0290/main.fsx](https://github.com/syohex/dotnet-study/blob/master/fsharp/leetcode/problems/0290/main.fsx)

```plaintext
let wordPattern (pattern: string) (s: string) : bool =
    let rec wordPattern' pattern words m registered =
        match pattern, words with
        | [], [] -> true
        | p1 :: t1, word :: t2 ->
            match Map.tryFind p1 m with
            | Some (v) ->
                if word <> v then
                    false
                else
                    wordPattern' t1 t2 m registered
            | None ->
                if Set.contains word registered then
                    false
                else
                    wordPattern' t1 t2 (Map.add p1 word m) (Set.add word registered)
        | _, _ -> failwith "never reach here"

    let words = s.Split ' '

    if pattern.Length <> words.Length then
        false
    else
        wordPattern' (pattern |> Seq.toList) (words |> Array.toList) Map.empty Set.empty
```

290. Word Pattern in F#

URL

Code