LeetCode - 1633. Percentage of Users Attended a Contest (MySQL)

Easy, SQL - 계산

RunTime : 1257 ms

문제

Write a solution to find the percentage of the users registered in each contest rounded to two decimals.

Return the result table ordered by percentage in descending order. In case of a tie, order it by contest_id in ascending order.

The result format is in the following example.

풀이

• 해당 값을 선택한 인원 수/전체 인원 수를 계산해야 했던 문제
• 프로그래머스 Lv3 ~ Lv4 되지 않을까 싶다.

SELECT contest_id,
ROUND(COUNT(DISTINCT user_id) / (SELECT COUNT(*) FROM Users) * 100 ,2) as percentage
FROM Register
GROUP BY 1
ORDER BY 2 desc, 1