Rock: Libby Gerber

binary_search_tree/tree.py

@@ -1,59 +1,114 @@
 class TreeNode:
-    def __init__(self, key, val = None):
+    def __init__(self, key, val=None):
         if val == None:
             val = key
 
         self.key = key
         self.value = val
         self.left = None
         self.right = None
-
-
 
 class Tree:
     def __init__(self):
         self.root = None
-
-    # Time Complexity: 
-    # Space Complexity: 
+    # Time Complexity: O(log n)
+    # Space Complexity: O(1)
+    def add_helper(self, current, key, value):
+        if current is None:
+            return TreeNode(key, value)
+        if current.key >= key:
+            current.left = self.add_helper(current.left, key, value)
+        else:
+            current.right = self.add_helper(current.right, key, value)
+        return current
+
     def add(self, key, value = None):
-        pass
+        if self.root == None:
+            self.root = TreeNode(key, value)
+        else:
+            self.add_helper(self.root, key, value)
 
-    # Time Complexity: 
-    # Space Complexity: 
+    # 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 current.key > key:
+                current = current.left
+            else:
+                current= current.right
+
+    # Time Complexity: O(n)
+    # Space Complexity: O(1)
 
-    # Time Complexity: 
-    # Space Complexity: 
+    def inorder_helper(self, current, values_list):
+        if not current: 
+            return values_list
+        object = {"key": current.key, "value": current.value}
+
+        self.inorder_helper(current.left, values_list)
+        values_list.append(object)
+        self.inorder_helper(current.right, values_list)
+
+        return values_list
+
     def inorder(self):
-        pass
+        values_list = []
+        return self.inorder_helper(self.root, values_list)
+
+    # Time Complexity: O(n)
+    # Space Complexity: O(1)  
+
+    def preorder_helper(self, current_node, values_list):
+        if not current_node:
+            return values_list
+        object = {"key": current_node.key, "value": current_node.value}
+
+        values_list.append(object)
+        self.preorder_helper(current_node.left, values_list)
+        self.preorder_helper(current_node.right, values_list)
+        return values_list
 
-    # Time Complexity: 
-    # Space Complexity:     
     def preorder(self):
-        pass
+        values_list = []
+        return self.preorder_helper(self.root, values_list)
+
+    # Time Complexity: O(n)
+    # Space Complexity: O(1)
+    def postorder_helper(self, current_node, values_list):
+        if not current_node:
+            return values_list
+        object = {"key": current_node.key, "value": current_node.value}
+
+        self.postorder_helper(current_node.left, values_list)
+        self.postorder_helper(current_node.right, values_list)
+        values_list.append(object)
+        return values_list
 
-    # Time Complexity: 
-    # Space Complexity:     
     def postorder(self):
-        pass
+        values_list = []
+        return self.postorder_helper(self.root, values_list)
+
 
-    # Time Complexity: 
-    # Space Complexity:     
-    def height(self):
-        pass
+    # Time Complexity: O(n)
+    # Space Complexity: O(n)
+    def height_helper(self, current_node):
+        if not current_node:
+            return 0
 
+        return max(self.height_helper(current_node.left), self.height_helper(current_node.right)) + 1
+    def height(self):
+        return self.height_helper(self.root)
+
 
 #   # Optional Method
 #   # Time Complexity: 
 #   # Space Complexity: 
     def bfs(self):
         pass
 
-
-
-
 #   # Useful for printing
     def to_s(self):
-        return f"{self.inorder()}"
+        return f"{self.inorder()}"