nth-highest-salary.sql

# Time:  O(n^2)
# Space: O(n)

CREATE FUNCTION getNthHighestSalary(N INT) RETURNS INT
BEGIN
  RETURN (
     # Write your MySQL query statement below.
     SELECT MAX(Salary) /*This is the outer query part */
            FROM Employee Emp1
            WHERE (N-1) = ( /* Subquery starts here */
                 SELECT COUNT(DISTINCT(Emp2.Salary))
                        FROM Employee Emp2
                        WHERE Emp2.Salary > Emp1.Salary)
  );
END