Is Highest Grade For Each Student easy or hard?

The problem is rated Medium because it combines grouping logic with a tie-breaking rule. Basic SQL users can compute the maximum grade, but correctly handling ties and returning the smallest course_id requires stronger understanding of window functions or multi-step aggregation.

Highest Grade For Each Student Python/Java solution

Because this is a database problem, the solution is written in SQL rather than Python or Java. In coding interviews or backend systems, the query would run inside application code written in Python, Java, or another language using a database driver.

How to solve Highest Grade For Each Student in O(n)?

Use a grouped subquery to compute each student's maximum grade: SELECT student_id, MAX(grade). Then filter the original table to keep rows matching that grade and select the smallest course_id with MIN(course_id). This avoids per-partition sorting and behaves roughly like O(n) aggregation in many database engines.

What is the best approach for Highest Grade For Each Student?

The most practical solution uses the RANK() window function. Partition rows by student_id and order by grade descending and course_id ascending. Selecting rows with rank = 1 returns the highest grade per student while automatically resolving ties by choosing the smallest course_id. This approach runs in about O(n log n) time due to sorting within partitions.

Is Highest Grade For Each Student asked at Google/Amazon/Meta?

SQL aggregation and window function problems like this frequently appear in database interviews at companies such as Amazon, Meta, and Google. Variations often ask for the top record per group, highest salary per department, or best score per user.

What data structure is used in Highest Grade For Each Student?

This problem relies on relational database operations rather than traditional data structures. The key concepts are SQL grouping, aggregation functions like MAX(), and window functions such as RANK() or ROW_NUMBER(). Internally the database may use sorting or hash-based grouping.

What is the time complexity of Highest Grade For Each Student?

The window function solution typically runs in O(n log n) time because the database sorts rows within each student partition. The subquery aggregation approach is closer to O(n) since it performs a grouping operation to compute MAX(grade) and then filters rows. Actual performance depends on indexes and the database query planner.

Description Solution Video 14:10

1112. Highest Grade For Each Student

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Table: Enrollments

+---------------+---------+
| Column Name   | Type    |
+---------------+---------+
| student_id    | int     |
| course_id     | int     |
| grade         | int     |
+---------------+---------+
(student_id, course_id) is the primary key (combination of columns with unique values) of this table.
grade is never NULL.

Write a solution to find the highest grade with its corresponding course for each student. In case of a tie, you should find the course with the smallest course_id.

Return the result table ordered by student_id in ascending order.

The result format is in the following example.

Example 1:

Input: 
Enrollments table:
+------------+-------------------+
| student_id | course_id | grade |
+------------+-----------+-------+
| 2          | 2         | 95    |
| 2          | 3         | 95    |
| 1          | 1         | 90    |
| 1          | 2         | 99    |
| 3          | 1         | 80    |
| 3          | 2         | 75    |
| 3          | 3         | 82    |
+------------+-----------+-------+
Output: 
+------------+-------------------+
| student_id | course_id | grade |
+------------+-----------+-------+
| 1          | 2         | 99    |
| 2          | 2         | 95    |
| 3          | 3         | 82    |
+------------+-----------+-------+