<h2 id="heading-url">URL</h2>
<p><a href="https://leetcode.com/problems/replace-elements-in-an-array/" class="autolinkedURL autolinkedURL-url" target="_blank">leetcode.com/problems/replace-elements-in-a..</a></p>
<h2 id="heading-code">Code</h2>
<p><a href="https://github.com/syohex/dotnet-study/blob/master/fsharp/leetcode/problems/2295/main.fsx" class="autolinkedURL autolinkedURL-url" target="_blank">github.com/syohex/dotnet-study/blob/master/..</a></p>
<pre><code class="lang-fsharp">let arrayChange (nums: int list) (operations: (int * int) list) : int list =
    let rec arrayChange' (nums: int []) operations pos =
        match operations with
        | [] -&gt; nums |&gt; Array.toList
        | (v1, v2) :: rest -&gt;
            match Map.tryFind v1 pos with
            | None -&gt; failwith "never reach here"
            | Some (p) -&gt;
                nums.[p] &lt;- v2
                let pos' = pos |&gt; Map.remove v1 |&gt; Map.add v2 p
                arrayChange' nums rest pos'

    let pos =
        nums
        |&gt; List.mapi (fun i n -&gt; i, n)
        |&gt; List.fold (fun acc (i, n) -&gt; Map.add n i acc) Map.empty

    arrayChange' (nums |&gt; List.toArray) operations pos
</code></pre>


## URL

https://leetcode.com/problems/replace-elements-in-an-array/

## Code

https://github.com/syohex/dotnet-study/blob/master/fsharp/leetcode/problems/2295/main.fsx

```fsharp
let arrayChange (nums: int list) (operations: (int * int) list) : int list =
    let rec arrayChange' (nums: int []) operations pos =
        match operations with
        | [] -> nums |> Array.toList
        | (v1, v2) :: rest ->
            match Map.tryFind v1 pos with
            | None -> failwith "never reach here"
            | Some (p) ->
                nums.[p] <- v2
                let pos' = pos |> Map.remove v1 |> Map.add v2 p
                arrayChange' nums rest pos'

    let pos =
        nums
        |> List.mapi (fun i n -> i, n)
        |> List.fold (fun acc (i, n) -> Map.add n i acc) Map.empty

    arrayChange' (nums |> List.toArray) operations pos
```

LeetCode 2295. Replace Elements in an Array in F#

URL

Code