Low-Quality Problems

Problem Description

You are given a table Problems with columns problem_id, likes, and dislikes. The problem_id is the primary key column representing the ID of each LeetCode problem, while likes and dislikes represent the number of likes and dislikes for each problem, respectively.

Write an SQL query to report the IDs of the low-quality problems. A LeetCode problem is considered low-quality if the like percentage (likes / (likes + dislikes)) is strictly less than 60%.

Return the result table ordered by problem_id in ascending order.

Examples

Example 1

Input

Problems table:
+------------+-------+----------+
| problem_id | likes | dislikes |
+------------+-------+----------+
| 6          | 1290  | 425      |
| 11         | 2677  | 8659     |
| 1          | 4446  | 2760     |
| 7          | 8569  | 6086     |
| 13         | 2050  | 4164     |
| 10         | 9002  | 7446     |
+------------+-------+----------+

Output:*

+------------+
| problem_id |
+------------+
| 7          |
| 10         |
| 11         |
| 13         |
+------------+

Explanation:
The like percentages are as follows:
- Problem 1: (4446 / (4446 + 2760)) * 100 = 61.69858%
- Problem 6: (1290 / (1290 + 425)) * 100 = 75.21866%
- Problem 7: (8569 / (8569 + 6086)) * 100 = 58.47151%
- Problem 10: (9002 / (9002 + 7446)) * 100 = 54.73006%
- Problem 11: (2677 / (2677 + 8659)) * 100 = 23.61503%
- Problem 13: (2050 / (2050 + 4164)) * 100 = 32.99002%

Problems 7, 10, 11, and 13 are low-quality problems because their like percentages are less than 60%.

Approach

To solve this problem, we need to:

1. Calculate the like percentage for each problem using the formula (likes / (likes + dislikes)) * 100.
2. Select the problem_id where the calculated like percentage is less than 60%.
3. Order the results by problem_id in ascending order.

SQL Query

SELECT problem_id
FROM Problems
WHERE likes * 100 / (likes + dislikes) < 60
ORDER BY problem_id;