      "* You can short circuit if the lengths of each string are not equal, although len() in Python is generally O(1) unlike other languages like C where getting the length of a string is O(n)\n",
      "\n",
      "Complexity:\n",
      "* Time: O(n)\n",
      "* Space: Additional O(m), where m is the number of unique characters in the hash map"
     ]
    },
    {
     "cell_type": "markdown",
     "metadata": {},
 
</s> remove     "* Space: Additional O(l + m) is created by the sorting algorithm, where l is the length of one string and m is the length of the other"
 </s> add     "* Space: O(n)" </s> remove     "Anagrams contain the same strings but in different orders.  This approach could be slow for large strings due to sorting.\n",
 </s> add     "Permutations contain the same strings but in different orders.  This approach could be slow for large strings due to sorting.\n",
    "* Space: O(n)"
      "* You can short circuit if the lengths of each string are not equal, although len() in Python is generally O(1) unlike other languages like C where getting the length of a string is O(n)\n",
      "\n",
      "Complexity:\n",
      "* Time: O(n)\n",
    "* Space: O(n)"
     ]
    },
    {
     "cell_type": "markdown",
     "metadata": {},
keep keep keep keep replace keep keep keep keep keep
 Tweaked permutations challenge algorithm discussion. 
arrays_strings/permutation/permutation_solution.ipynb