feat(content): more test cases

backend/data/questions/group-anagrams.yaml

@@ -10,6 +10,24 @@ categories:
 patterns:
   - hashing
 
+function_signature: "def group_anagrams(strs: list[str]) -> list[list[str]]:"
+
+test_cases:
+  visible:
+    - input: { strs: ["eat", "tea", "tan", "ate", "nat", "bat"] }
+      expected: [["eat", "tea", "ate"], ["tan", "nat"], ["bat"]]
+    - input: { strs: [""] }
+      expected: [[""]]
+    - input: { strs: ["a"] }
+      expected: [["a"]]
+  hidden:
+    - input: { strs: ["abc", "bca", "cab", "xyz", "zyx"] }
+      expected: [["abc", "bca", "cab"], ["xyz", "zyx"]]
+    - input: { strs: ["", ""] }
+      expected: [["", ""]]
+    - input: { strs: ["listen", "silent", "enlist"] }
+      expected: [["listen", "silent", "enlist"]]
+
 description: |
   Given an array of strings `strs`, group the **anagrams** together. You can return the answer in **any order**.