feat(content): more test cases

backend/data/questions/trapping-rain-water.yaml

@@ -11,6 +11,24 @@ patterns:
   - two-pointers
   - monotonic-stack
 
+function_signature: "def trap(height: list[int]) -> int:"
+
+test_cases:
+  visible:
+    - input: { height: [0, 1, 0, 2, 1, 0, 1, 3, 2, 1, 2, 1] }
+      expected: 6
+    - input: { height: [4, 2, 0, 3, 2, 5] }
+      expected: 9
+  hidden:
+    - input: { height: [0, 0, 0] }
+      expected: 0
+    - input: { height: [3, 0, 3] }
+      expected: 3
+    - input: { height: [1, 2, 3, 4, 5] }
+      expected: 0
+    - input: { height: [5, 4, 1, 2] }
+      expected: 1
+
 description: |
   Given `n` non-negative integers representing an elevation map where the width of each bar is `1`, compute how much water it can trap after raining.