<h2 id="heading-url">URL</h2>
<p><a target="_blank" href="https://leetcode.com/problems/number-of-longest-increasing-subsequence/description/">Number of Longest Increasing Subsequence - 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/0673/main.fsx">https://github.com/syohex/dotnet-study/tree/master/fsharp/leetcode/problems/0673/main.fsx</a></p>
<pre><code class="lang-plaintext">let findNumberOfLIS (nums: int list) : int =
    let nums' = List.toArray nums
    let len = Array.length nums'

    let dpLen = Array.init len (fun _ -&gt; 1)
    let dpCount = Array.init len (fun _ -&gt; 1)

    for i in 0 .. (len - 1) do
        for j in 0 .. (i - 1) do
            if nums'.[j] &lt; nums'.[i] then
                if dpLen.[j] + 1 &gt; dpLen.[i] then
                    dpLen.[i] &lt;- dpLen.[j] + 1
                    dpCount.[i] &lt;- 0

                if dpLen.[j] + 1 = dpLen.[i] then
                    dpCount.[i] &lt;- dpCount.[i] + dpCount.[j]

    let maxLen = Array.max dpLen

    dpLen
    |&gt; Array.indexed
    |&gt; Array.fold (fun acc (i, len) -&gt; if len = maxLen then acc + dpCount.[i] else acc) 0
</code></pre>


## URL

[Number of Longest Increasing Subsequence - LeetCode](https://leetcode.com/problems/number-of-longest-increasing-subsequence/description/)

## Code

[https://github.com/syohex/dotnet-study/tree/master/fsharp/leetcode/problems/0673/main.fsx](https://github.com/syohex/dotnet-study/tree/master/fsharp/leetcode/problems/0673/main.fsx)

```plaintext
let findNumberOfLIS (nums: int list) : int =
    let nums' = List.toArray nums
    let len = Array.length nums'

    let dpLen = Array.init len (fun _ -> 1)
    let dpCount = Array.init len (fun _ -> 1)

    for i in 0 .. (len - 1) do
        for j in 0 .. (i - 1) do
            if nums'.[j] < nums'.[i] then
                if dpLen.[j] + 1 > dpLen.[i] then
                    dpLen.[i] <- dpLen.[j] + 1
                    dpCount.[i] <- 0

                if dpLen.[j] + 1 = dpLen.[i] then
                    dpCount.[i] <- dpCount.[i] + dpCount.[j]

    let maxLen = Array.max dpLen

    dpLen
    |> Array.indexed
    |> Array.fold (fun acc (i, len) -> if len = maxLen then acc + dpCount.[i] else acc) 0
```

LeetCode 673. Number of Longest Increasing Subsequence in F#

URL

Code