LeetCode 3201. Find the Maximum Length of Valid Subsequence I in F#

URL https://leetcode.com/problems/find-the-maximum-length-of-valid-subsequence-i/description/?envType=daily-question&envId=2025-07-16 Code https://github.com/syohex/dotnet-study/blob/master/fsharp/leetcode/challenge/202507/find_the_maximum_length_of_...