Rename bst_is_balanced.py to bt_is_balanced.py

trees/bt_is_balanced.py

@@ -0,0 +1,21 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+# author: bt3gl
+
+
+def height(root):
+  
+    if root is None:
+      return -1
+      
+    return 1 + max(height(root.left), height(root.right))
+
+
+def is_balanced(root):
+  
+    if root is None:
+      return True
+
+    return abs(height(root.left) - height(root.right)) < 2 and \
+            is_balanced(root.left) and is_balanced(root.right)
+