feat(content): function signatures + test cases

backend/data/questions/alternating-digit-sum.yaml

@@ -8,6 +8,28 @@ categories:
 patterns:
   - greedy
 
+function_signature: "def alternate_digit_sum(n: int) -> int:"
+
+test_cases:
+  visible:
+    - input: { n: 521 }
+      expected: 4
+    - input: { n: 111 }
+      expected: 1
+    - input: { n: 886996 }
+      expected: 0
+  hidden:
+    - input: { n: 1 }
+      expected: 1
+    - input: { n: 10 }
+      expected: 1
+    - input: { n: 99 }
+      expected: 0
+    - input: { n: 12345 }
+      expected: 3
+    - input: { n: 54321 }
+      expected: 3
+
 description: |
   You are given a positive integer `n`. Each digit of `n` has a sign according to the following rules: