Complete SQL2

[Aniruddh-2512]

No description provided.

[super30admin]

1. DepartmentTopThreeSalaries.sql:

   • Correctness: The solution correctly uses DENSE_RANK() to find the top 3 salaries in each department, which is the standard approach for this problem.
   • Time Complexity: O(n log n) due to the sorting required for the window function.
   • Space Complexity: O(n) for storing the intermediate result.
   • Code Quality: Well-structured and readable. The use of a CTE makes the query clear.
   • Efficiency: No obvious optimizations needed.

2. ExchangeSeat.sql:

   • Correctness: The solution correctly swaps adjacent students using a clever bit manipulation approach (^1 to toggle between odd and even).
   • Time Complexity: O(n) for the join operation.
   • Space Complexity: O(n) for the temporary result.
   • Code Quality: The query is concise but could benefit from a comment explaining the bit manipulation logic.
   • Efficiency: The solution is efficient, though the bit manipulation might be less readable than a CASE statement for some.

3. RankScore.sql:

   • Correctness: The solution correctly calculates ranks using a correlated subquery, which is a valid approach.
   • Time Complexity: O(n²) due to the correlated subquery, which is less efficient than window functions.
   • Space Complexity: O(n) for the result.
   • Code Quality: The query is simple but could be improved by using DENSE_RANK() for better performance and readability.
   • Efficiency: Using a window function would be more efficient (O(n log n)).

4. TreeNode.sql:

   • Correctness: The solution correctly identifies root, inner, and leaf nodes using nested IF statements.
   • Time Complexity: O(n) for the main query plus O(n) for the subquery.
   • Space Complexity: O(n) for the result.
   • Code Quality: The nested IFs are correct but could be made more readable with a CASE statement.
   • Efficiency: The solution is efficient, though the subquery could be optimized further.

General Observations:

• The solutions demonstrate good understanding of SQL concepts.
• Window functions are used appropriately where applicable.
• Some queries could benefit from comments explaining complex logic.
• The RankScore.sql solution could be optimized by using window functions instead of correlated subqueries.