feat(content): function signatures + test cases

backend/data/questions/bulls-and-cows.yaml

@@ -9,6 +9,30 @@ categories:
 patterns:
   - two-pointers
 
+function_signature: "def get_hint(secret: str, guess: str) -> str:"
+
+test_cases:
+  visible:
+    - input: { secret: "1807", guess: "7810" }
+      expected: "1A3B"
+    - input: { secret: "1123", guess: "0111" }
+      expected: "1A1B"
+  hidden:
+    - input: { secret: "1", guess: "0" }
+      expected: "0A0B"
+    - input: { secret: "1", guess: "1" }
+      expected: "1A0B"
+    - input: { secret: "1111", guess: "1111" }
+      expected: "4A0B"
+    - input: { secret: "1234", guess: "4321" }
+      expected: "0A4B"
+    - input: { secret: "1122", guess: "2211" }
+      expected: "0A4B"
+    - input: { secret: "0000", guess: "1111" }
+      expected: "0A0B"
+    - input: { secret: "1234", guess: "0000" }
+      expected: "0A0B"
+
 description: |
   You are playing the **Bulls and Cows** game with your friend.