feat(content): function signatures + test cases

backend/data/questions/bulb-switcher.yaml

@@ -8,6 +8,30 @@ categories:
 patterns:
   - greedy
 
+function_signature: "def bulb_switch(n: int) -> int:"
+
+test_cases:
+  visible:
+    - input: { n: 3 }
+      expected: 1
+    - input: { n: 0 }
+      expected: 0
+    - input: { n: 1 }
+      expected: 1
+  hidden:
+    - input: { n: 4 }
+      expected: 2
+    - input: { n: 9 }
+      expected: 3
+    - input: { n: 16 }
+      expected: 4
+    - input: { n: 25 }
+      expected: 5
+    - input: { n: 100 }
+      expected: 10
+    - input: { n: 99999999 }
+      expected: 9999
+
 description: |
   There are `n` bulbs that are initially off. You first turn on all the bulbs, then you turn off every second bulb.