Last updated on October 9th, 2024 at 10:00 pm

This Leetcode problem Exchange Seats LeetCode Solution is done in SQL.

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Exchange Seats LeetCode Solution

Problem Statement

id is the primary key (unique value) column for this table. Each row of this table indicates the name and the ID of a student. id is a continuous increment.

Write a solution to swap the seat id of every two consecutive students. If the number of students is odd, the id of the last student is not swapped.

Return the result table ordered by id in ascending order.

The result format is in the following example.

Example 1:
Input:

Output:

Explanation: Note that if the number of students is odd, there is no need to change the last one’s seat.

1. Exchange Seats LeetCode Solution MySQL

select 
  if(
    mod(id, 2) = 0, 
    id - 1, 
    if(
      id < (
        select 
          max(id) 
        from 
          seat
      ), 
      id + 1, 
      id
    )
  ) as id, 
  student 
from 
  seat 
order by 
  id;