feat(content): function signatures + test cases

backend/data/questions/card-flipping-game.yaml

@@ -9,6 +9,26 @@ categories:
 patterns:
   - greedy
 
+function_signature: "def flipgame(fronts: list[int], backs: list[int]) -> int:"
+
+test_cases:
+  visible:
+    - input: { fronts: [1, 2, 4, 4, 7], backs: [1, 3, 4, 1, 3] }
+      expected: 2
+    - input: { fronts: [1], backs: [1] }
+      expected: 0
+  hidden:
+    - input: { fronts: [1, 2], backs: [2, 1] }
+      expected: 1
+    - input: { fronts: [2, 2], backs: [2, 2] }
+      expected: 0
+    - input: { fronts: [1, 1], backs: [1, 2] }
+      expected: 2
+    - input: { fronts: [5, 3, 7], backs: [5, 3, 8] }
+      expected: 7
+    - input: { fronts: [1, 2, 3], backs: [4, 5, 6] }
+      expected: 1
+
 description: |
   You are given two **0-indexed** integer arrays `fronts` and `backs` of length `n`, where the i<sup>th</sup> card has the positive integer `fronts[i]` printed on the front and `backs[i]` printed on the back. Initially, each card is placed on a table such that the front number is facing up and the other is facing down.