Question

我有一个归纳类型树，定义如下：

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我希望有一个函数将这个树作为输入，在这个树中找到一个min值，将它加倍（让我们将结果称为a），然后再生另一个相同类型的树，它的所有叶子都被a。替换。

我有几个功能可以帮助我做到这一点：

type 'a tree1 = Leaf of 'a
           |Branch of 'a tree1 * 'a tree1

我的结果不是我的预期。

let rec findmin (mytree: int tree1) : int  = match mytree with
|Leaf a -> a
|Branch(Leaf x, Leaf y) -> min x y
|Branch(left, right) -> min (findmin left) (findmin right)  

let rec repdoublemin (mytree: int tree1) : int tree1 = match mytree with
|Leaf a -> Leaf (2*a)
|Branch(Leaf x, Leaf y) -> let result = 2 * findmin (Branch(Leaf x, Leaf y)) 
 in Branch (Leaf result, Leaf result)
|Branch(left,right) -> Branch(repdoublemin left, repdoublemin right)

我应该得到：

repdoublemin Branch (Leaf 5, Branch (Leaf 3, Leaf 10));;
- : int tree1 = Branch (Leaf 10, Branch (Leaf 6, Leaf 6))

Answer 1

我的建议是写一个辅助函数

replace_all_values : 'a -> 'b tree1 -> 'a tree1

归纳型树Ocaml中的双最小值

1 个答案: