Finished all but the bfs part

binary_search_tree/tree.py

@@ -1,5 +1,5 @@
 class TreeNode:
-    def __init__(self, key, val = None):
+    def __init__(self, key, val=None):
         if val == None:
             val = key
 
@@ -14,35 +14,108 @@ class Tree:
     def __init__(self):
         self.root = None
 
-    # Time Complexity: 
-    # Space Complexity: 
-    def add(self, key, value = None):
-        pass
+    def add_helper(self, current_node, key, value):
+        if current_node == None:
+            return TreeNode(key, value)
+        if current_node.key > key:
+            current_node.left = self.add_helper(current_node.left, key, value)
+        else:
+            current_node.right = self.add_helper(current_node.right, key, value)
+        return current_node
 
-    # Time Complexity: 
-    # Space Complexity: 
+    # Time Complexity: O(log n)
+    # Space Complexity: O(log n)
+    def add(self, key, value=None):
+        if self.root == None:
+            self.root = TreeNode(key, value)
+        else:
+            self.add_helper(self.root, key, value)
+
+    # Time Complexity: O(log n)
+    # Space Complexity: O(1)
     def find(self, key):
-        pass
+        current = self.root
+        while current:
+            if current.key == key:
+                return current.value
+            elif key < current.key:
+                current = current.left
+            else:
+                current = current.right
+        return None
+
+    def inorder_helper(self, root, elements):
+        if root == None:
+            return
 
-    # Time Complexity: 
-    # Space Complexity: 
+        self.inorder_helper(root.left, elements)
+        elements.append({"key": root.key, "value": root.value})
+        self.inorder_helper(root.right, elements)
+        return
+
+    # Time Complexity: O(n)
+    # Space Complexity: O(n)
     def inorder(self):
-        pass
+        if self.root == None:
+            return []
+
+        elements = []
+        self.inorder_helper(self.root, elements)
 
-    # Time Complexity: 
-    # Space Complexity:     
+        return elements
+
+    def preorder_helper(self, root, elements):
+        if root == None:
+            return
+
+        elements.append({"key": root.key, "value": root.value})
+        self.preorder_helper(root.left, elements)
+        self.preorder_helper(root.right, elements)
+        return elements
+
+    # Time Complexity: O(n)
+    # Space Complexity: O(n)   
     def preorder(self):
-        pass
+        if self.root == None:
+            return []
+
+        elements = []
+        self.preorder_helper(self.root, elements)
+        return elements
 
-    # Time Complexity: 
-    # Space Complexity:     
+    def postorder_helper(self, root, elements):
+        if root == None:
+            return
+
+        self.postorder_helper(root.left, elements)
+        self.postorder_helper(root.right, elements)
+        elements.append({"key": root.key, "value": root.value})
+
+    # Time Complexity: O(n)
+    # Space Complexity: O(n)  
     def postorder(self):
-        pass
+        if self.root == None:
+            return []
+        elements = []
+        self.postorder_helper(self.root, elements)
+        return elements
+
+    def height_helper(self, node):
+        if not node:
+            return 0
+
+        left = self.height_helper(node.left)
+        right = self.height_helper(node.right)
 
-    # Time Complexity: 
-    # Space Complexity:     
+        return max(left, right) + 1
+
+    # Time Complexity: O(n)
+    # Space Complexity: O(log n)  
     def height(self):
-        pass
+        if self.root == None:
+            return 0
+
+        return self.height_helper(self.root)
 
 
 #   # Optional Method
@@ -51,8 +124,6 @@ def height(self):
     def bfs(self):
         pass
 
-
-
 
 #   # Useful for printing
     def to_s(self):