13 lines
325 B
Plaintext
13 lines
325 B
Plaintext
|
(* Binary tree with leaves carrying an integer. *)
|
|||
|
|
type tree = Leaf of int | Node of tree * tree
|
|||
|
|
|
|||
|
|
let rec exists_leaf test tree =
|
|||
|
|
match tree with
|
|||
|
|
| Leaf v -> test v
|
|||
|
|
| Node (left, right) ->
|
|||
|
|
exists_leaf test left
|
|||
|
|
|| exists_leaf test right
|
|||
|
|
|
|||
|
|
let has_even_leaf tree =
|
|||
|
|
exists_leaf (fun n -> n mod 2 = 0) tree
|