Added TODO to include more optimal solutions to maximizing xor challenge.

online_judges/maximizing_xor/maximizing_xor_solution.ipynb

@@ -60,8 +60,11 @@
     "* return max\n",
     "\n",
     "Complexity:\n",
-    "* Time: O(n^2)\n",
-    "* Space: O(1)"
+    "* Time: O(n^2) - See note below\n",
+    "* Space: O(1)\n",
+    "\n",
+    "Note:\n",
+    "* TODO: Add more optimal solutions such as those discussed [here](https://www.hackerrank.com/challenges/maximizing-xor/editorial)."
    ]
   },
   {