<h2 id="heading-url">URL</h2>
<p><a href="https://leetcode.com/problems/kth-smallest-element-in-a-bst/" class="autolinkedURL autolinkedURL-url" target="_blank">leetcode.com/problems/kth-smallest-element-..</a></p>
<h2 id="heading-code">Code</h2>
<p><a href="https://github.com/syohex/dotnet-study/blob/master/fsharp/leetcode/problems/0230/main.fsx" class="autolinkedURL autolinkedURL-url" target="_blank">github.com/syohex/dotnet-study/blob/master/..</a></p>
<pre><code class="lang-fsharp">type Tree =
    | Leaf
    | Node of int * Tree * Tree

let kthSmallest (root: Tree) (k: int) : int =
    let rec kthSmallest' node acc =
        match node with
        | Leaf -&gt; acc
        | Node (v, left, right) -&gt;
            let acc' = kthSmallest' left acc
            kthSmallest' right  (v :: acc')

    kthSmallest' root []
    |&gt; List.rev
    |&gt; List.item (k - 1)
</code></pre>


## URL

https://leetcode.com/problems/kth-smallest-element-in-a-bst/

## Code

https://github.com/syohex/dotnet-study/blob/master/fsharp/leetcode/problems/0230/main.fsx

```fsharp
type Tree =
    | Leaf
    | Node of int * Tree * Tree

let kthSmallest (root: Tree) (k: int) : int =
    let rec kthSmallest' node acc =
        match node with
        | Leaf -> acc
        | Node (v, left, right) ->
            let acc' = kthSmallest' left acc
            kthSmallest' right  (v :: acc')

    kthSmallest' root []
    |> List.rev
    |> List.item (k - 1)
```

LeetCode 230. Kth Smallest Element in a BST in F#

URL

Code