<h2 id="heading-url">URL</h2>
<a target="_blank" href="https://leetcode.com/problems/count-number-of-homogenous-substrings/description/?envType=daily-question&amp;envId=2023-11-09">Count Number of Homogenous Substrings - LeetCode</a>
<h2 id="heading-code">Code</h2>
<a target="_blank" href="https://github.com/syohex/dotnet-study/tree/master/fsharp/leetcode/problems/1759/main.fsx">https://github.com/syohex/dotnet-study/tree/master/fsharp/leetcode/problems/1759/main.fsx</a>
<pre><code class="lang-fsharp">let countHomogenous (s: string) : int =
 let modulo = 1_000_000_007

 let rec countHomonogenous' cs prev count acc =
 match cs with
 | [] -&gt; acc
 | h :: t -&gt;
 if h = prev then
 let count' = count + 1
 countHomonogenous' t h count' ((acc + count') % modulo)
 else
 countHomonogenous' t h 1 ((acc + 1) % modulo)

 let cs = Seq.toList s
 countHomonogenous' (List.tail cs) (List.head cs) 1 1
</code></pre>

## URL

[Count Number of Homogenous Substrings - LeetCode](https://leetcode.com/problems/count-number-of-homogenous-substrings/description/?envType=daily-question&envId=2023-11-09)

## Code

[https://github.com/syohex/dotnet-study/tree/master/fsharp/leetcode/problems/1759/main.fsx](https://github.com/syohex/dotnet-study/tree/master/fsharp/leetcode/problems/1759/main.fsx)

```fsharp
let countHomogenous (s: string) : int =
    let modulo = 1_000_000_007

    let rec countHomonogenous' cs prev count acc =
        match cs with
        | [] -> acc
        | h :: t ->
            if h = prev then
                let count' = count + 1
                countHomonogenous' t h count' ((acc + count') % modulo)
            else
                countHomonogenous' t h 1 ((acc + 1) % modulo)

    let cs = Seq.toList s
    countHomonogenous' (List.tail cs) (List.head cs) 1 1
```

LeetCode 1759. Count Number of Homogenous Substrings in F#

URL

Code