module Lab09a where

data Color = Red | Green Float | Blue

data IntTree = ILeaf Int | INode IntTree IntTree

instance Show IntTree where
  show (ILeaf x) = "<Leaf " ++ show x ++ "/>"
  show (INode left right) = "<Node>" ++ show left ++ show right ++ "</Node>"

data Tree a = Leaf a | Node (Tree a) (Tree a)

instance (Show a) => Show (Tree a) where
  show (Leaf x) = "<Leaf " ++ show x ++ "/>"
  show (Node left right) = "<Node>" ++ show left ++ show right ++ "</Node>"

tree :: Tree Char
tree = Node (Node (Leaf 'a') (Node (Leaf 'b') (Leaf 'c'))) (Leaf 'd')

addParanthesis :: Show a => a -> [Char]
addParanthesis x = "(" ++ show x ++ ")"

treeDepth :: Tree a -> Int
treeDepth (Leaf _) = 1
treeDepth (Node l r) = 1 + max (treeDepth l) (treeDepth r)

labelTree :: Tree a -> Tree (a, Int)
labelTree t = fst (go 0 t)
  where
    go :: Int -> Tree a -> (Tree (a, Int), Int)
    go n (Leaf x) = (Leaf (x, n), n + 1)
    go n (Node l r) = let (newLeft, n') = go n l
                          (newRight, n'') = go n' r
                          a = 5
                          in (Node newLeft newRight, n'')