feat(content): function signatures + test cases

backend/data/questions/copy-list-with-random-pointer.yaml

@@ -9,6 +9,30 @@ categories:
 patterns:
   - linkedlist-reversal
 
+function_signature: "def copy_random_list(head: Node | None) -> Node | None:"
+
+test_cases:
+  visible:
+    - input: { head: [[7, null], [13, 0], [11, 4], [10, 2], [1, 0]] }
+      expected: [[7, null], [13, 0], [11, 4], [10, 2], [1, 0]]
+    - input: { head: [[1, 1], [2, 1]] }
+      expected: [[1, 1], [2, 1]]
+    - input: { head: [[3, null], [3, 0], [3, null]] }
+      expected: [[3, null], [3, 0], [3, null]]
+  hidden:
+    - input: { head: [] }
+      expected: []
+    - input: { head: [[1, null]] }
+      expected: [[1, null]]
+    - input: { head: [[5, 0]] }
+      expected: [[5, 0]]
+    - input: { head: [[1, 1], [2, 0]] }
+      expected: [[1, 1], [2, 0]]
+    - input: { head: [[1, null], [2, null], [3, null], [4, null], [5, null]] }
+      expected: [[1, null], [2, null], [3, null], [4, null], [5, null]]
+    - input: { head: [[-1, 0], [0, 1], [1, 0]] }
+      expected: [[-1, 0], [0, 1], [1, 0]]
+
 description: |
   A linked list of length `n` is given such that each node contains an additional random pointer, which could point to any node in the list, or `null`.