mock3.sql

[nagaraja993]

No description provided.

[super30admin]

The student's solution demonstrates a good understanding of SQL concepts and problem-solving approach. Here's a detailed evaluation:

1. Correctness: The solution appears logically correct. It:

   • Uses a CTE to combine both players' scores from each match
   • Joins with the Players table to get group information
   • Calculates total points per player
   • Uses RANK() to find the top player in each group
   • Handles ties by selecting the player with the smallest ID

2. Time Complexity: The solution should be efficient with:

   • O(M) for the CTE (where M is number of matches)
   • O(M + P) for the join (where P is number of players)
   • O(P log P) for the ranking operation per group

3. Space Complexity: The CTE creates temporary storage for all match scores, which is O(M). The intermediate results for grouping and ranking also require additional space.

4. Code Quality:
   Strengths:

   • Clear logical flow with CTE and subqueries
   • Proper use of window functions
   • Good handling of tie-breakers
     Areas for improvement:
   • The alias names ('random', 'random2') are not descriptive
   • Could add comments explaining each step
   • The LEFT JOIN could be an INNER JOIN since all players in matches should exist in Players table

5. Efficiency:

   • The solution is already quite efficient
   • Could potentially optimize by filtering out players with no matches early
   • Might consider using SUM() directly in the window function to avoid one subquery