Fixed Python2 vs Python3 division compatibility.

sorting_searching/quick_sort/quick_sort_solution.ipynb

@@ -34,7 +34,6 @@
    "source": [
     "## Constraints\n",
     "\n",
-
     "* Is a naiive solution sufficient (ie not in-place)?\n",
     "    * Yes"
    ]
@@ -88,12 +87,14 @@
    },
    "outputs": [],
    "source": [
+    "from __future__ import division\n",
+    "\n",
     "def quick_sort(data):\n",
     "    if len(data) < 2:\n",
     "        return data\n",
     "    left = []\n",
     "    right = []\n",
-    "    pivot_index = len(data) / 2\n",
+    "    pivot_index = int(len(data) / 2)\n",
     "    pivot_value = data[pivot_index]\n",
     "    \n",
     "    # Build the left and right partitions\n",