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Diffstat (limited to '54a-60/57.hs')
-rw-r--r-- | 54a-60/57.hs | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/54a-60/57.hs b/54a-60/57.hs new file mode 100644 index 0000000..efe8588 --- /dev/null +++ b/54a-60/57.hs @@ -0,0 +1,23 @@ +import Data.List (foldl') + +data Tree a = Empty | Branch a (Tree a) (Tree a) deriving (Show, Eq) + +symmetric :: (Eq a) => Tree a -> Bool +mirror :: (Eq a) => Tree a -> Tree a -> Bool + +mirror Empty Empty = True +mirror (Branch _ a b) (Branch _ l r) = mirror a r && mirror b l +mirror _ _ = False + +symmetric Empty = True +symmetric (Branch _ l r) = mirror l r + +construct :: [Int] -> Tree Int +addNode :: Tree Int -> Int -> Tree Int + +addNode Empty n = Branch n Empty Empty -- create node +addNode (Branch x l r) n + | n <= x = Branch x (addNode l n) r + | otherwise = Branch x l (addNode r n) + +construct l = foldl' (\acc n -> addNode acc n) Empty l |