      "## Constraints\n",
      "\n",
      "* Is a naiive solution sufficient (ie not in-place)?\n",
      "    * Yes"
     ]
    },
    {
     "cell_type": "markdown",
 
</s> remove     "    return left + [pivot_value] + right"
 </s> add     "    return left + equal + right" </s> remove     "    for i in range(0, len(data)):\n",
    "        if i == pivot_index:\n",
    "            continue\n",
    "        if data[i] < pivot_value:\n",
 </s> add     "    for i in range(len(data)):\n",
    "        if data[i] == pivot_value:\n",
    "            equal.append(data[i])\n",
    "        elif data[i] < pivot_value:\n", </s> remove    "version": "3.4.3"
 </s> add    "version": "3.5.0"
    "    * Yes\n",
    "* Are duplicates allowed?\n",
      "## Constraints\n",
      "\n",
      "* Is a naiive solution sufficient (ie not in-place)?\n",
    "    * Yes\n",
    "* Are duplicates allowed?\n",
      "    * Yes"
     ]
    },
    {
     "cell_type": "markdown",
keep keep add keep keep keep keep keep
 Polish quicksort challenge and solution

Update constraints and code. 
sorting_searching/quick_sort/quick_sort_solution.ipynb