feat: group-anagrams

Author: dusunax

group-anagrams/dusunax.py

@@ -0,0 +1,26 @@
+'''
+# 49. Group Anagrams
+
+use **hash map** to solve the problem.
+
+## Time and Space Complexity
+```
+TC: O(N * K * Log(K))
+SC: O(N * K)
+```
+
+## TC is O(N * K * Log(K)):
+- iterating through the list of strings and sorting each string. = O(N * K * Log(K))
+
+## SC is O(N * K):
+- using a hash map to store the sorted strings. = O(N * K)
+'''
+class Solution:
+    def groupAnagrams(self, strs: List[str]) -> List[List[str]]:
+        result = defaultdict(list)
+        
+        for str in strs: # TC: O(N)
+            sorted_key = ''.join(sorted(str)) # sorting 👉 TC: O(K * Log(K))
+            result[sorted_key].append(str) # TC: O(1) on average
+        
+        return list(result.values())