LeetCode 938. Range Sum of BST in F#

URL https://leetcode.com/problems/range-sum-of-bst/description/ Code https://github.com/syohex/dotnet-study/blob/master/fsharp/leetcode/problems/0938/main.fsx type Tree = | Leaf | Node of int * Tree * Tree let rangeSumBST (root: Tree) (low: ...