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tianyicui · Dec 2, 2010 · 07e7747 · 07e7747
1 parent db46b7d
commit 07e7747
Showing 1 changed file with 8 additions and 0 deletions.
diff --git a/BinaryTrees.hs b/BinaryTrees.hs
@@ -92,3 +92,11 @@ hbalTreeNodes n =
 countLeaves Empty                  = 0
 countLeaves (Branch _ Empty Empty) = 1
 countLeaves (Branch _ l     r    ) = countLeaves l + countLeaves r
+
+leaves Empty = []
+leaves (Branch x Empty Empty) = [x]
+leaves (Branch _ left  right) = leaves left ++ leaves right
+
+internals Empty = []
+internals (Branch _ Empty Empty) = []
+internals (Branch x left  right) = x : (internals left ++ internals right)