<h2 id="heading-url">URL</h2>
<p><a href="https://leetcode.com/problems/roman-to-integer/" class="autolinkedURL autolinkedURL-url" target="_blank">leetcode.com/problems/roman-to-integer</a></p>
<h2 id="heading-code">Code</h2>
<p><a href="https://github.com/syohex/dotnet-study/blob/master/fsharp/leetcode/problems/0013/main.fsx" class="autolinkedURL autolinkedURL-url" target="_blank">github.com/syohex/dotnet-study/blob/master/..</a></p>
<pre><code class="lang-fsharp">let romanToInt (s: string) : int =
    let getValue c prev =
        match c with
        | 'M' -&gt; if prev = 'C' then 800 else 1000
        | 'D' -&gt; if prev = 'C' then 300 else 500
        | 'C' -&gt; if prev = 'X' then 80 else 100
        | 'L' -&gt; if prev = 'X' then 30 else 50
        | 'X' -&gt; if prev = 'I' then 8 else 10
        | 'V' -&gt; if prev = 'I' then 3 else 5
        | 'I' -&gt; 1
        | _ -&gt; failwith "never reach here"

    let rec romanToInt' cs prev acc =
        match cs with
        | [] -&gt; acc
        | c :: rest -&gt; romanToInt' rest c (acc + (getValue c prev))

    romanToInt' (s |&gt; Seq.toList) ' ' 0
</code></pre>


## URL

https://leetcode.com/problems/roman-to-integer/

## Code

https://github.com/syohex/dotnet-study/blob/master/fsharp/leetcode/problems/0013/main.fsx

```fsharp
let romanToInt (s: string) : int =
    let getValue c prev =
        match c with
        | 'M' -> if prev = 'C' then 800 else 1000
        | 'D' -> if prev = 'C' then 300 else 500
        | 'C' -> if prev = 'X' then 80 else 100
        | 'L' -> if prev = 'X' then 30 else 50
        | 'X' -> if prev = 'I' then 8 else 10
        | 'V' -> if prev = 'I' then 3 else 5
        | 'I' -> 1
        | _ -> failwith "never reach here"

    let rec romanToInt' cs prev acc =
        match cs with
        | [] -> acc
        | c :: rest -> romanToInt' rest c (acc + (getValue c prev))

    romanToInt' (s |> Seq.toList) ' ' 0
```

LeetCode 13. Roman to Integer in F#

URL

Code