problem 1 and problem 2 added

[Tejas274]

No description provided.

[super30admin]

1. Correctness:

   • For problem1-1194-tournament-winners.sql, the solution correctly calculates the total score for each player, joins with the players table, and selects the top player in each group based on score and player_id. This appears to solve the problem correctly.
   • For problem2-1159-market-analysis2.sql, the solution correctly identifies the second item sold by each seller and checks if it matches their favorite brand. The CASE statement handles all possible scenarios including when a seller hasn't sold any items or only one item.

2. Time Complexity:

   • For problem1: O(N) for the initial union, O(N) for the aggregation, and O(N log N) for the ranking operation where N is the number of matches.
   • For problem2: O(N) for the initial ranking, O(N) for the join with Items, and O(N) for the final join with Users where N is the number of orders.

3. Space Complexity:

   • For both problems, the space complexity is O(N) as we're creating intermediate tables that scale with the input size.

4. Code Quality:

   • The code is well-structured with clear CTEs (Common Table Expressions) that make the logic easy to follow.
   • Variable names are descriptive (e.g., player_id_score, total_score_player).
   • The indentation and formatting are consistent.
   • One minor issue: in problem2, the column alias "2nd_item_fav_brand" should be quoted or renamed to avoid starting with a number (e.g., "second_item_fav_brand").

5. Efficiency:

   • Both solutions are efficient given their approach.
   • For problem1, an alternative could be to use FIRST_VALUE() instead of ROW_NUMBER() to avoid the final filtering step.
   • For problem2, the solution could potentially be optimized by combining some of the CTEs, though the current separation makes the logic clearer.