Completed Mock-SQL-3

[alokusw2]

No description provided.

[super30admin]

1. Correctness:

   • For Problem 1 (Market-Analysis-II), the solution does not correctly address the problem requirements. It only selects users who have sold items and joined in 2019, but doesn't identify the second item sold or check if it matches their favorite brand. The problem requires more complex logic involving ordering by date and checking the second item's brand.
   • For Problem 2 (Tournament Winners), the solution is incomplete and incorrect. It only finds players who won the most matches overall, not per group, and doesn't handle ties as specified (lowest player_id should win in case of tie).

2. Time Complexity:

   • Problem 1: The current query has O(n) complexity for the subquery, but the overall solution is incomplete.
   • Problem 2: The query has O(n^2) complexity due to the subquery in HAVING clause, but it's solving the wrong problem.

3. Space Complexity:

   • Both solutions have O(n) space complexity for storing intermediate results, which is acceptable but irrelevant since the solutions are incorrect.

4. Code Quality:

   • The queries are syntactically correct but lack proper indentation and formatting.
   • Missing comments to explain the logic.
   • Problem statements are included in the file, which is good for documentation.

5. Efficiency:

   • Both solutions need significant improvement to address the actual problem requirements.
   • For Problem 1, need to join tables and use window functions to identify second items.
   • For Problem 2, need to group by group_id and calculate total points per player per group.