feat(content): hidden test cases

backend/data/questions/missing-number.yaml

@@ -26,6 +26,12 @@ test_cases:
       expected: 0
     - input: { nums: [0, 1, 2, 3, 5] }
       expected: 4
+    - input: { nums: [2, 0, 1, 4, 5, 6, 7] }
+      expected: 3
+    - input: { nums: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] }
+      expected: 10
+    - input: { nums: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] }
+      expected: 0
 
 description: |
   Given an array `nums` containing `n` distinct numbers in the range `[0, n]`, return *the only number in the range that is missing from the array*.