<h2 id="heading-url">URL</h2>
<p><a href="https://leetcode.com/problems/non-decreasing-array/" class="autolinkedURL autolinkedURL-url" target="_blank">leetcode.com/problems/non-decreasing-array</a></p>
<h2 id="heading-code">Code</h2>
<p><a href="https://github.com/syohex/dotnet-study/blob/master/fsharp/leetcode/problems/0665/main.fsx" class="autolinkedURL autolinkedURL-url" target="_blank">github.com/syohex/dotnet-study/blob/master/..</a></p>
<pre><code class="lang-fsharp">let checkPossibility (nums: int list) : bool =
    let rec checkPossibility' nums prev2 prev1 count =
        if count &gt;= 2 then
            false
        else
            match nums with
            | [] -&gt; true
            | h :: t -&gt;
                if h &gt;= prev1 then
                    checkPossibility' t prev1 h count
                else if prev2 &gt; h then
                    checkPossibility' t prev1 prev1 (count + 1)
                else
                    checkPossibility' t h h (count + 1)

    match nums with
    | []
    | _ :: []
    | _ :: _ :: [] -&gt; true
    | h1 :: h2 :: rest -&gt;
        if h1 &gt; h2 then
            checkPossibility' rest h2 h2 1
        else
            checkPossibility' rest h1 h2 0
</code></pre>


## URL

https://leetcode.com/problems/non-decreasing-array/

## Code

https://github.com/syohex/dotnet-study/blob/master/fsharp/leetcode/problems/0665/main.fsx

```fsharp
let checkPossibility (nums: int list) : bool =
    let rec checkPossibility' nums prev2 prev1 count =
        if count >= 2 then
            false
        else
            match nums with
            | [] -> true
            | h :: t ->
                if h >= prev1 then
                    checkPossibility' t prev1 h count
                else if prev2 > h then
                    checkPossibility' t prev1 prev1 (count + 1)
                else
                    checkPossibility' t h h (count + 1)

    match nums with
    | []
    | _ :: []
    | _ :: _ :: [] -> true
    | h1 :: h2 :: rest ->
        if h1 > h2 then
            checkPossibility' rest h2 h2 1
        else
            checkPossibility' rest h1 h2 0
```

LeetCode 665. Non-decreasing Array in F#

URL

Code