feat(content): function signatures + test cases

backend/data/questions/adding-two-negabinary-numbers.yaml

@@ -9,6 +9,26 @@ categories:
 patterns:
   - two-pointers
 
+function_signature: "def add_negabinary(arr1: list[int], arr2: list[int]) -> list[int]:"
+
+test_cases:
+  visible:
+    - input: { arr1: [1, 1, 1, 1, 1], arr2: [1, 0, 1] }
+      expected: [1, 0, 0, 0, 0]
+    - input: { arr1: [0], arr2: [0] }
+      expected: [0]
+    - input: { arr1: [0], arr2: [1] }
+      expected: [1]
+  hidden:
+    - input: { arr1: [1], arr2: [1] }
+      expected: [1, 1, 0]
+    - input: { arr1: [1, 0], arr2: [1, 0] }
+      expected: [1, 1, 0, 0]
+    - input: { arr1: [1, 1], arr2: [1, 1] }
+      expected: [0]
+    - input: { arr1: [1, 0, 1], arr2: [1, 0, 1] }
+      expected: [1, 1, 1, 1, 0]
+
 description: |
   Given two numbers `arr1` and `arr2` in base **-2** (negabinary), return the result of adding them together.