8 lines
247 B
Haskell
8 lines
247 B
Haskell
data Tree a = Empty | Branch a (Tree a) (Tree a)
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deriving (Show, Eq)
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countLeaves :: Tree a -> Int
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countLeaves Empty = 0
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countLeaves (Branch _ Empty Empty) = 1
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countLeaves (Branch _ branch1 branch2) =
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countLeaves branch1 + countLeaves branch2
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