<h2 id="heading-url">URL</h2>
<p><a target="_blank" href="https://leetcode.com/problems/powx-n/description/">Pow(x, n) - 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/0050/main.fsx">https://github.com/syohex/dotnet-study/tree/master/fsharp/leetcode/problems/0050/main.fsx</a></p>
<pre><code class="lang-plaintext">let myPow (x: double) (n: int) : double =
    let rec myPow' x (n: int64) : double =
        match n with
        | 0L -&gt; 1
        | 1L -&gt; x
        | n when n &lt; 0L -&gt; 1.0 / myPow' x (-1L * n)
        | n when n % 2L = 1L -&gt;
            let tmp = myPow' x ((n - 1L) / 2L)
            tmp * tmp * x
        | _ -&gt;
            let tmp = myPow' x (n / 2L)
            tmp * tmp

    myPow' x (int64 n)
</code></pre>


## URL

[Pow(x, n) - LeetCode](https://leetcode.com/problems/powx-n/description/)

## Code

[https://github.com/syohex/dotnet-study/tree/master/fsharp/leetcode/problems/0050/main.fsx](https://github.com/syohex/dotnet-study/tree/master/fsharp/leetcode/problems/0050/main.fsx)

```plaintext
let myPow (x: double) (n: int) : double =
    let rec myPow' x (n: int64) : double =
        match n with
        | 0L -> 1
        | 1L -> x
        | n when n < 0L -> 1.0 / myPow' x (-1L * n)
        | n when n % 2L = 1L ->
            let tmp = myPow' x ((n - 1L) / 2L)
            tmp * tmp * x
        | _ ->
            let tmp = myPow' x (n / 2L)
            tmp * tmp

    myPow' x (int64 n)
```

LeetCode 50. Pow(x, n) in F#

URL

Code