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