+61 +62 +63

1 files changed, 14 insertions, 0 deletions

diff --git a/H62.hs b/H62.hs
new file mode 100644
index 0000000..b835b20
--- /dev/null
+++ b/H62.hs
@@ -0,0 +1,14 @@
+import Tree
+-- import Tree4
+
+leaves Empty = []
+leaves (Branch x Empty Empty) = [x]
+leaves (Branch x t1 t2) = leaves t1 ++ leaves t2
+
+internals Empty = []
+internals (Branch x Empty Empty) = []
+internals (Branch x t1 t2) = [x] : internals t1 ++ internals t2
+
+atLevel Empty _ = []
+atLevel (Branch x _ _) 1 = [x]
+atLevel (Branch _ t1 t2) n = atLevel t1 (n-1) ++ atLevel t2 (n-1)