feat(content): more test cases

backend/data/questions/combination-sum.yaml

@@ -9,6 +9,24 @@ categories:
 patterns:
   - backtracking
 
+function_signature: "def combination_sum(candidates: list[int], target: int) -> list[list[int]]:"
+
+test_cases:
+  visible:
+    - input: { candidates: [2, 3, 6, 7], target: 7 }
+      expected: [[2, 2, 3], [7]]
+    - input: { candidates: [2, 3, 5], target: 8 }
+      expected: [[2, 2, 2, 2], [2, 3, 3], [3, 5]]
+    - input: { candidates: [2], target: 1 }
+      expected: []
+  hidden:
+    - input: { candidates: [1], target: 1 }
+      expected: [[1]]
+    - input: { candidates: [1], target: 2 }
+      expected: [[1, 1]]
+    - input: { candidates: [2, 3, 5], target: 5 }
+      expected: [[2, 3], [5]]
+
 description: |
   Given an array of **distinct** integers `candidates` and a target integer `target`, return *a list of all **unique combinations** of* `candidates` *where the chosen numbers sum to* `target`. You may return the combinations in **any order**.