High-Enrollment Classes Report

Easy

You are given a Courses table where each row represents one enrollment record. Columns: student: student identifier or name class: class identifier or name The pair (student, class) is unique, so a student cannot be duplicated within the same class. Task: Return every class that has at least 5 enrolled students. Output requirements: Return exactly one column named class. Row order is not important. Supported submission environments: SQL (SQLite 3.27.2) Pandas (Python)

Example 1

Input

Courses:
| student | class    |
|---------|----------|
| A       | Math     |
| B       | English  |
| C       | Math     |
| D       | Biology  |
| E       | Math     |
| F       | Computer |
| G       | Math     |
| H       | Math     |
| I       | Math     |

Output

[
  {"class":"Math"}
]

Explanation

Math has 6 students, so it is included. Other classes have fewer than 5 enrollments.

Example 2

Input

Courses:
| student | class    |
|---------|----------|
| S1      | Data101  |
| S2      | Data101  |
| S3      | Data101  |
| S4      | Data101  |
| S5      | Data101  |
| S6      | Networks |
| S7      | Networks |
| S8      | Networks |

Output

[
  {"class":"Data101"}
]

Explanation

Data101 meets the threshold exactly with 5 enrollments. Networks has only 3.

Example 3

Input

Courses:
| student | class    |
|---------|----------|
| U1      | Physics  |
| U2      | Physics  |
| U3      | History  |
| U4      | Art      |

Output

[]

Explanation

No class reaches 5 enrollments.

Constraints

1 <= number of rows in Courses <= 50000
(student, class) is unique
student and class are non-empty strings
Use SQLite 3.27.2 semantics for SQL submissions
For Pandas submissions, return exactly one column named class