LeetCode in Kotlin

180. Consecutive Numbers

Medium

SQL Schema

Table: Logs

+-------------+---------+
| Column Name | Type    |
+-------------+---------+
| id          | int     |
| num         | varchar |
+-------------+---------+
id is the primary key for this table. 

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

Return the result table in any order.

The query result format is in the following example.

Example 1:

Input:

Logs table:
+----+-----+
| id | num |
+----+-----+
| 1  | 1   |
| 2  | 1   |
| 3  | 1   |
| 4  | 2   |
| 5  | 1   |
| 6  | 2   |
| 7  | 2   |
+----+-----+

Output:

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

Explanation: 1 is the only number that appears consecutively for at least three times.

Solution

# Write your MySQL query statement below
select distinct num as ConsecutiveNums from
(select num, lag(num,1) over(order by id) as l1, lag(num,2) over(order by id) as l2
from Logs) con_thr
where num = l1 and num = l2