<h2 id="heading-url">URL</h2>
<p><a target="_blank" href="https://leetcode.com/problems/minimum-absolute-difference-in-bst/description/">Minimum Absolute Difference in BST - LeetCode</a></p>
<h2 id="heading-code">Code</h2>
<p><a target="_blank" href="https://github.com/syohex/dotnet-study/tree/master/fsharp/leetcode/problems/0530/main.fsx">https://github.com/syohex/dotnet-study/tree/master/fsharp/leetcode/problems/0530/main.fsx</a></p>
<pre><code class="lang-plaintext">open System

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

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

    collectValues root []
    |&gt; List.sort
    |&gt; List.windowed 2
    |&gt; List.fold
        (fun acc w -&gt;
            match w with
            | n1 :: n2 :: [] -&gt; Math.Min(acc, Math.Abs(n1 - n2))
            | _ -&gt; failwith "never reach here")
        Int32.MaxValue
</code></pre>


## URL

[Minimum Absolute Difference in BST - LeetCode](https://leetcode.com/problems/minimum-absolute-difference-in-bst/description/)

## Code

[https://github.com/syohex/dotnet-study/tree/master/fsharp/leetcode/problems/0530/main.fsx](https://github.com/syohex/dotnet-study/tree/master/fsharp/leetcode/problems/0530/main.fsx)

```plaintext
open System

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

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

    collectValues root []
    |> List.sort
    |> List.windowed 2
    |> List.fold
        (fun acc w ->
            match w with
            | n1 :: n2 :: [] -> Math.Min(acc, Math.Abs(n1 - n2))
            | _ -> failwith "never reach here")
        Int32.MaxValue
```

LeetCode 530. Minimum Absolute Difference in BST in F#

URL

Code