<h2 id="heading-url">URL</h2>
<p><a target="_blank" href="https://leetcode.com/problems/non-decreasing-subsequences/description/">https://leetcode.com/problems/non-decreasing-subsequences/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/0491/main.fsx">https://github.com/syohex/dotnet-study/blob/master/fsharp/leetcode/problems/0491/main.fsx</a></p>
<pre><code class="lang-plaintext">let findSubSequences (nums: int list) : int list list =
    let isNotEmpty = List.isEmpty &gt;&gt; not

    let rec findSubSequences' nums acc ret =
        match nums with
        | [] -&gt;
            if isNotEmpty acc &amp;&amp; List.tail acc |&gt; isNotEmpty then
                Set.add (acc |&gt; List.rev) ret
            else
                ret
        | h :: t -&gt;
            let ret' = findSubSequences' t acc ret

            match acc with
            | [] -&gt; findSubSequences' t (h :: acc) ret'
            | prev :: _ -&gt;
                if prev &lt;= h then
                    findSubSequences' t (h :: acc) ret'
                else
                    ret'

    findSubSequences' nums [] Set.empty |&gt; Seq.toList
</code></pre>


## URL

[https://leetcode.com/problems/non-decreasing-subsequences/description/](https://leetcode.com/problems/non-decreasing-subsequences/description/)

## Code

[https://github.com/syohex/dotnet-study/blob/master/fsharp/leetcode/problems/0491/main.fsx](https://github.com/syohex/dotnet-study/blob/master/fsharp/leetcode/problems/0491/main.fsx)

```plaintext
let findSubSequences (nums: int list) : int list list =
    let isNotEmpty = List.isEmpty >> not

    let rec findSubSequences' nums acc ret =
        match nums with
        | [] ->
            if isNotEmpty acc && List.tail acc |> isNotEmpty then
                Set.add (acc |> List.rev) ret
            else
                ret
        | h :: t ->
            let ret' = findSubSequences' t acc ret

            match acc with
            | [] -> findSubSequences' t (h :: acc) ret'
            | prev :: _ ->
                if prev <= h then
                    findSubSequences' t (h :: acc) ret'
                else
                    ret'

    findSubSequences' nums [] Set.empty |> Seq.toList
```

LeetCode 491. Non-decreasing Subsequences in F#

URL

Code