Clean up HW1 code.

HW1.fedorind.hs

@@ -10,7 +10,7 @@ data Tree
 
 -- | An example binary tree, which will be used in tests.
 t1 :: Tree
-t1 = Node 1 (Node 2 (Node 3 (Leaf 4) (Leaf 5))
+t1 = Node 1 (Node 2 (Node 3 (Leaf 4) (Lea 5))
                     (Leaf 6))
             (Node 7 (Leaf 8) (Leaf 9))
 
@@ -62,7 +62,7 @@ treeFold f a (Node i l r) = f i $ treeFold f (treeFold f a r) l
 --   1
 --
 leftmost :: Tree -> Int
-leftmost = treeFoldr1 const
+leftmost = treeFoldr1 (\a _ -> a)
 
 -- | The integer at the right-most node of a binary tree.
 --
@@ -79,7 +79,7 @@ leftmost = treeFoldr1 const
 --   9
 --
 rightmost :: Tree -> Int
-rightmost = treeFoldl1 const
+rightmost = treeFoldl1 (\a _ -> a)
 
 -- | Get the maximum integer from a binary tree.
 --