      "\n",
      "\n",
      "def permutations_alt(str1, str2):\n",
      "    if len(str1) != len(str2):\n",
      "        return False\n",
      "    unique_counts1 = defaultdict(int)\n",
      "    unique_counts2 = defaultdict(int)\n",
 
</s>
    "    if str1 is None or str2 is None:\n",
    "        return False\n",
      "\n",
      "\n",
      "def permutations_alt(str1, str2):\n",
    "    if str1 is None or str2 is None:\n",
    "        return False\n",
      "    if len(str1) != len(str2):\n",
      "        return False\n",
      "    unique_counts1 = defaultdict(int)\n",
      "    unique_counts2 = defaultdict(int)\n",
keep keep add keep keep keep keep
 Polish permutation challenge and solution
arrays_strings/permutation/permutation_solution.ipynb