<h2 id="heading-url">URL</h2>
<p><a target="_blank" href="https://leetcode.com/problems/evaluate-reverse-polish-notation/description/">https://leetcode.com/problems/evaluate-reverse-polish-notation/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/0150/main.fsx">https://github.com/syohex/dotnet-study/blob/master/fsharp/leetcode/problems/0150/main.fsx</a></p>
<pre><code class="lang-plaintext">let evalRPN (tokens: string list) : int =
    let rec evalRPN' tokens stack =
        match tokens with
        | [] -&gt; stack |&gt; List.head |&gt; int
        | h :: t -&gt;
            match h with
            | "+" -&gt;
                let n =
                    (List.head stack)
                    + (stack |&gt; List.tail |&gt; List.head)

                evalRPN' t (n :: (stack |&gt; List.skip 2))
            | "-" -&gt;
                let n =
                    (stack |&gt; List.tail |&gt; List.head)
                    - (List.head stack)

                evalRPN' t (n :: (stack |&gt; List.skip 2))
            | "*" -&gt;
                let n =
                    (stack |&gt; List.tail |&gt; List.head)
                    * (List.head stack)

                evalRPN' t (n :: (stack |&gt; List.skip 2))
            | "/" -&gt;
                let n =
                    (stack |&gt; List.tail |&gt; List.head)
                    / (List.head stack)

                evalRPN' t (n :: (stack |&gt; List.skip 2))
            | _ -&gt; evalRPN' t ((h |&gt; int64) :: stack)

    evalRPN' tokens []
</code></pre>


## URL

[https://leetcode.com/problems/evaluate-reverse-polish-notation/description/](https://leetcode.com/problems/evaluate-reverse-polish-notation/description/)

## Code

[https://github.com/syohex/dotnet-study/blob/master/fsharp/leetcode/problems/0150/main.fsx](https://github.com/syohex/dotnet-study/blob/master/fsharp/leetcode/problems/0150/main.fsx)

```plaintext
let evalRPN (tokens: string list) : int =
    let rec evalRPN' tokens stack =
        match tokens with
        | [] -> stack |> List.head |> int
        | h :: t ->
            match h with
            | "+" ->
                let n =
                    (List.head stack)
                    + (stack |> List.tail |> List.head)

                evalRPN' t (n :: (stack |> List.skip 2))
            | "-" ->
                let n =
                    (stack |> List.tail |> List.head)
                    - (List.head stack)

                evalRPN' t (n :: (stack |> List.skip 2))
            | "*" ->
                let n =
                    (stack |> List.tail |> List.head)
                    * (List.head stack)

                evalRPN' t (n :: (stack |> List.skip 2))
            | "/" ->
                let n =
                    (stack |> List.tail |> List.head)
                    / (List.head stack)

                evalRPN' t (n :: (stack |> List.skip 2))
            | _ -> evalRPN' t ((h |> int64) :: stack)

    evalRPN' tokens []
```

LeetCode 150. Evaluate Reverse Polish Notation in F#

URL

Code