chore: add some operations

src/main.py

@@ -3,9 +3,12 @@
 from strings import *
 from tree import *
 
-def main():
-
-  t = build_tree((1, (2, (3, None, None), None), (4, None, None)))
+def trees():
+  t = build_tree((1, 
+    (2, 
+      (3, None, None),
+      None),
+    (4, None, None)))
 
   print(t)
 
@@ -14,6 +17,64 @@ def main():
   assert t.left.left.val == 3
   assert t.right.val == 4
 
+  assert sum_tree(t) == 10
+  assert sum_tree(t, 1) == 6
+
+  t = build_tree((1, 
+    (2, 
+      (3, None, None), 
+      None),
+    (4, 
+      (5, None, None),
+      None)))
+
+  print(t)
+
+  assert sum_tree(t, 2) == 8
+
+  t = build_tree((1, (2, (3, None, None), None), (4, None, None)))
+
+  print(t)
+
+  assert sum_tree(t, 2) == 3
+
+  t = build_tree((1, 
+    (2, 
+      (3, 
+        None, 
+        (4, None, None)
+      ),
+      None), 
+      (5, None, None)))
+
+  print(t)
+
+  assert sum_tree(t, 3) == 4
+
+  assert tree_height(build_tree((1, None, None))) == 0
+  assert tree_height(build_tree((1, 
+    (2, 
+      None,
+      (3, None, None)), 
+    None))) == 2
+  assert tree_height(build_tree(
+      (1, 
+        (2, None, 
+          (3, None, None)), 
+        (4, None, 
+          (5, None, 
+            (6, 
+              (7, None, None), 
+              None))))
+      )) == 4
+    
+  assert number_of_nodes(build_tree((0, None, None))) == 1
+  assert number_of_nodes(build_tree((0, (1, None, None), None))) == 2
+  assert number_of_nodes(build_tree((0, (1, None, None), (2, None, None)))) == 3
+  assert number_of_nodes(build_tree((0, (1, (3, None, None), None), (2, None, None)))) == 4
+
+def main():
+
   pass
 
 if __name__ == "__main__":

src/tree.py

@@ -11,7 +11,7 @@ class Tree:
   def __print_leaf(self, leaf):
     if leaf:
       return f"{leaf}"
-    return "<empty>"
+    return "_"
 
   def is_leaf(self):
     return self.left == None and self.right == None
@@ -32,3 +32,37 @@ def build_tree(args):
     raise RuntimeError("Nodes must be tuples")
 
   return Tree(value, build_tree(right), build_tree(left))
+
+def sum_tree(t, deep_level=None):
+  if t == None:
+    return 0
+
+  if deep_level == None:
+    left_val = 0 if t.left == None else sum_tree(t.left)
+    right_val = 0 if t.right == None else sum_tree(t.right)
+    return t.val + left_val + right_val
+
+  if deep_level == 0:
+    return t.val
+
+  left_val = sum_tree(t.left, deep_level - 1)
+  right_val = sum_tree(t.right, deep_level - 1)
+  return left_val + right_val
+
+def tree_height(t):
+  if t == None:
+    return 0
+
+  if t.left == None and t.right == None:
+    return 0
+
+  return 1 + max(tree_height(t.left), tree_height(t.right))
+
+def number_of_nodes(t):
+  if t == None:
+    return 0
+  
+  if t.left == None and t.right == None:
+    return 1
+
+  return 1 + number_of_nodes(t.left) + number_of_nodes(t.right)