feat(content): function signatures + test cases

backend/data/questions/add-to-array-form-of-integer.yaml

@@ -9,6 +9,28 @@ categories:
 patterns:
   - two-pointers
 
+function_signature: "def add_to_array_form(num: list[int], k: int) -> list[int]:"
+
+test_cases:
+  visible:
+    - input: { num: [1, 2, 0, 0], k: 34 }
+      expected: [1, 2, 3, 4]
+    - input: { num: [2, 7, 4], k: 181 }
+      expected: [4, 5, 5]
+    - input: { num: [2, 1, 5], k: 806 }
+      expected: [1, 0, 2, 1]
+  hidden:
+    - input: { num: [0], k: 1 }
+      expected: [1]
+    - input: { num: [9, 9, 9], k: 1 }
+      expected: [1, 0, 0, 0]
+    - input: { num: [1], k: 99 }
+      expected: [1, 0, 0]
+    - input: { num: [0], k: 10000 }
+      expected: [1, 0, 0, 0, 0]
+    - input: { num: [5, 5, 5], k: 555 }
+      expected: [1, 1, 1, 0]
+
 description: |
   The **array-form** of an integer `num` is an array representing its digits in left to right order.