LeetCode - 601. Human Traffic of Stadium

Posted 2020-10-06 码上哈希

X city built a new stadium, each day many people visit it and the stats are saved as these columns: id, date, people

Please write a query to display the records which have 3 or more consecutive rows and the amount of people more than 100(inclusive).

For example, the table stadium:

+------+------------+-----------+
| id   | date       | people    |
+------+------------+-----------+
| 1    | 2017-01-01 | 10        |
| 2    | 2017-01-02 | 109       |
| 3    | 2017-01-03 | 150       |
| 4    | 2017-01-04 | 99        |
| 5    | 2017-01-05 | 145       |
| 6    | 2017-01-06 | 1455      |
| 7    | 2017-01-07 | 199       |
| 8    | 2017-01-08 | 188       |
+------+------------+-----------+

For the sample data above, the output is:

+------+------------+-----------+
| id   | date       | people    |
+------+------------+-----------+
| 5    | 2017-01-05 | 145       |
| 6    | 2017-01-06 | 1455      |
| 7    | 2017-01-07 | 199       |
| 8    | 2017-01-08 | 188       |
+------+------------+-----------+

# Write your mysql query statement below
SELECT
    DISTINCT t1.*
FROM
    stadium t1,
    stadium t2,
    stadium t3
WHERE
    t1.people >= 100
AND t2.people >= 100
AND t3.people >= 100
AND (
    (
        t1.id - t2.id = 1
        AND t1.id - t3.id = 2
        AND t2.id - t3.id = 1
    )
    OR (
        t2.id - t1.id = 1
        AND t2.id - t3.id = 2
        AND t1.id - t3.id = 1
    )
    OR (
        t3.id - t2.id = 1
        AND t2.id - t1.id = 1
        AND t3.id - t1.id = 2
    )
)
ORDER BY
    t1.id