[LeetCode] 178. Rank Scores

Posted on | In

Problem

Write a SQL query to rank scores. If there is a tie between two scores, both should have the same ranking. Note that after a tie, the next ranking number should be the next consecutive integer value. In other words, there should be no “holes” between ranks.

1
2
3
4
5
6
7
8
9
10
+----+-------+
| Id | Score |
+----+-------+
| 1  | 3.50  |
| 2  | 3.65  |
| 3  | 4.00  |
| 4  | 3.85  |
| 5  | 4.00  |
| 6  | 3.65  |
+----+-------+

For example, given the above Scores table, your query should generate the following report (order by highest score):

1
2
3
4
5
6
7
8
9
10
+-------+------+
| Score | Rank |
+-------+------+
| 4.00  | 1    |
| 4.00  | 1    |
| 3.85  | 2    |
| 3.65  | 3    |
| 3.65  | 3    |
| 3.50  | 4    |
+-------+------+

Explanation

  1. For each score, we find out how many scores is greater than or equal to that score as the number of rank.

Solution

1
2
3
4
5
6
7
8
# Write your MySQL query statement below
SELECT s.Score, (
        SELECT COUNT(DISTINCT Score)
        FROM Scores
        WHERE Score >= s.Score
        ) AS Rank
FROM Scores s
ORDER BY s.Score DESC;