LeetCode 512: Game Play Analysis II

Explanation:

To solve this problem, we need to write an SQL query to find the average number of sessions per user in a game. We can achieve this by grouping the data by user_id and calculating the average of the number of sessions for each user.

Algorithm:

1. Use the GROUP BY clause to group the data by user_id.
2. Use the AVG() function to calculate the average of the number of sessions for each user.

Time Complexity:

The time complexity of the SQL query is O(N), where N is the number of rows in the input table.

Space Complexity:

The space complexity of the SQL query is O(1) as we are not using any extra space that grows with the input size.

:

SQL:

// SQL query can be executed directly using JDBC or any ORM framework
// No additional Java code is needed for this problem