[LeetCode]#180. Consecutive Numbers

Environment: MySQL

Write a SQL query to find all numbers that appear at least three times consecutively.

+----+-----+
| Id | Num |
+----+-----+
| 1  |  1  |
| 2  |  1  |
| 3  |  1  |
| 4  |  2  |
| 5  |  1  |
| 6  |  2  |
| 7  |  2  |
+----+-----+

For example, given the above Logs table, 1 is the only number that appears consecutively for at least three times.

+-----------------+
| ConsecutiveNums |
+-----------------+
| 1               |
+-----------------+

Solution:

# Write your MySQL query statement below
SELECT DISTINCT
    l1.Num AS ConsecutiveNums
FROM
    Logs l1,
    Logs l2,
    Logs l3
WHERE
    l1.Id = l2.Id - 1
    AND l2.Id = l3.Id - 1
    AND l1.Num = l2.Num
    AND l2.Num = l3.Num
;

Submitted result:

Reference:

https://leetcode.com/problems/consecutive-numbers/solution/