     "source": [
      "## Constraints\n",
      "\n",
      "* Is a naiive solution sufficient?\n",
      "    * Yes"
     ]
    },
    {
     "cell_type": "markdown",
     "metadata": {},
 
</s> remove     "    left = data[0:mid]\n",
 </s> add     "    left = data[:mid]\n", </s> remove    "version": "3.4.3"
 </s> add    "version": "3.5.0" </s> remove    "version": "3.4.3"
 </s> add    "version": "3.5.0"
    "    * Yes\n",
    "* Are duplicates allowed?\n",
     "source": [
      "## Constraints\n",
      "\n",
      "* Is a naiive solution sufficient?\n",
    "    * Yes\n",
    "* Are duplicates allowed?\n",
      "    * Yes"
     ]
    },
    {
     "cell_type": "markdown",
     "metadata": {},
keep keep keep add keep keep keep keep keep keep
 Polish merge sort challenge and solution

Update constraints and code. 
sorting_searching/merge_sort/merge_sort_solution.ipynb