fix hash_table variable type

Author: sbk1014

group-anagrams/bhyun-kim.py

@@ -29,15 +29,18 @@
 
 class Solution:
     def groupAnagrams(self, strs: List[str]) -> List[List[str]]:
-        hash_table = []
-        counters = []
+        
+        hash_table = dict()
+        output = []
+
         for s in strs:
-            count_s = "".join(sorted(s))
+            count_s = ''.join(sorted(s))
             if count_s in hash_table:
-                idx = hash_table.index(count_s)
-                counters[idx].append(s)
+                idx = hash_table[count_s]
+                output[idx].append(s)
             else:
-                hash_table.append(count_s)
-                counters.append([s])
+                hash_table[count_s] = len(output)
+                output.append([s])
+                 
+        return output
 
-        return counters