feat(content): function signatures + test cases

backend/data/questions/binary-tree-right-side-view.yaml

@@ -10,6 +10,30 @@ patterns:
   - dfs
   - tree-traversal
 
+function_signature: "def right_side_view(root: TreeNode) -> list[int]:"
+
+test_cases:
+  visible:
+    - input: { root: [1, 2, 3, null, 5, null, 4] }
+      expected: [1, 3, 4]
+    - input: { root: [1, 2, 3, 4, null, null, null, 5] }
+      expected: [1, 3, 4, 5]
+    - input: { root: [1, null, 3] }
+      expected: [1, 3]
+  hidden:
+    - input: { root: [] }
+      expected: []
+    - input: { root: [1] }
+      expected: [1]
+    - input: { root: [1, 2, null] }
+      expected: [1, 2]
+    - input: { root: [1, 2, 3, 4, 5, 6, 7] }
+      expected: [1, 3, 7]
+    - input: { root: [1, 2, null, 3, null, 4, null, 5] }
+      expected: [1, 2, 3, 4, 5]
+    - input: { root: [0, -1, 100] }
+      expected: [0, 100]
+
 description: |
   Given the `root` of a binary tree, imagine yourself standing on the **right side** of it, return *the values of the nodes you can see ordered from top to bottom*.