Low-Quality Problems

Problem

Table: Problems

+-------------+------+
| Column Name | Type |
+-------------+------+
| problem_id  | int  |
| likes       | int  |
| dislikes    | int  |
+-------------+------+
problem_id is the primary key column for this table.
Each row of this table indicates the number of likes and dislikes for a Leetcode problem.

Find the IDs of the low-quality problems. A LeetCode problem is low-quality if the like percentage of the problem (number of likes divided by the total number of votes) is strictly less than 60%.

Return the result table ordered by problem_id in ascending order.

The result format is in the following example.

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%.

Solution

Method 1 - Using Division

Code

Sql

SELECT problem_id
FROM Problems
WHERE (likes / (likes + dislikes)) < .6
ORDER BY problem_id;