Create binary search tree

exercises/binary-search-tree/bst.py

@@ -0,0 +1,61 @@
+# A binary search tree implementation
+
+
+class Node:
+
+    def __init__(self, data=0, left=None, right=None):
+        # initialize node data
+        self.left = None
+        self.right = None
+        self.data = data
+
+
+class BST:
+    def __init__(self):
+        # initialize the root node
+        self.root = None
+
+    def add_node(self, data):
+        # Returns a new node initialized with data
+        return Node(data)
+
+    def insert(self, root, data):
+
+        if root is None:    # Tree is empty
+            return self.add_node(data)
+        else:
+            # Modifying the tree
+            if data <= root.data:
+                root.left = self.insert(root.left, data)
+            else:
+                root.right = self.insert(root.right, data)
+            return root
+
+    def search(self, root, target):
+
+        if root is None:
+            return 0
+        else:
+            if target == root.data:
+                return 1
+            else:
+                if target < root.data:
+                    return self.search(root.left, target)
+                else:
+                    return self.search(root.right, target)
+
+    def min_value(self, root):
+        while root.left is not None:
+            root = root.left
+        return root.data
+
+    def max_value(self, root):
+        while root.right is not None:
+            root = root.right
+        return root.data
+
+    def size(self, root):
+        if root is None:
+            return 0
+        else:
+            return self.size(root.left) + self.size(root.right) + 1