diff --git a/binary_search_trees/array_to_bst.py b/binary_search_trees/array_to_bst.py
index f69cc42..145cfae 100644
--- a/binary_search_trees/array_to_bst.py
+++ b/binary_search_trees/array_to_bst.py
@@ -4,10 +4,20 @@ def __init__(self, value, left = None, right = None):
         self.left = left
         self.right = right
 
-
 def arr_to_bst(arr):
     """ Given a sorted array, write a function to create a 
         Balanced Binary Search Tree using the elements in the array.
         Return the root of the Binary Search Tree.
+
+        Time Complexity = O(logn)
+        Space Complexity = O(n)
     """
-    pass
\ No newline at end of file
+
+    if not arr: 
+        return None
+
+    mid = (len(arr)) // 2
+    root = TreeNode(arr[mid])
+    root.left = arr_to_bst(arr[:mid])
+    root.right = arr_to_bst(arr[mid+1:])
+    return root