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Databases / SQL DifficultyMedium SQL
This question asks for the 5th highest salary from the "Employees" table. The example input is a table with id, name, and salary columns, and the example output is a table with a salary column.
About this solution: The solution above is optimal because it uses the LIMIT clause to limit the number of rows returned by the query.
Feb 02
Python / Data Structures DifficultyMedium Python
Given a list of integers, this function will return a dictionary with the integers as keys and the number of times the integer appears in the list as values.
About this solution: This solution is complete and solves the problem. The approach is straightforward and easy to follow.
Jan 31
Databases / SQL DifficultyHard SQL
This technical problem deals with finding common records between two SQL tables. An example is given, along with the expected output.
About this solution: The candidate's solution is correct and uses an inner join, which is the most efficient way to find common records between two tables.
Jan 31
Python / Asynchronous DifficultyMedium Python
Given a list of numbers, this Python program finds the first unique element in the list. For example, given the input [1, 2, 3, 4, 5, 1, 2 , 3, 4], the output would be 5.
About this solution: The candidate's solution is correct and demonstrates a level of completeness. The candidate's approach is also correct, as it uses a dictionary to store the number of times each element appears in the list. This approach is optimal because it only iterates through the list once and then iterates through the dictionary once. Therefore, the time complexity is O(n) where n is the size of the list.
Jan 31
Databases / SQL DifficultyHard SQL
To find the id and value of the row with the highest value in a table with two columns, id and value, write a query that will return the id and the value of the row with the highest value.
About this solution: The solution above is optimal because it uses the ORDER BY and LIMIT clauses to sort the table by value in descending order and then return the first row.
Jan 31
Python / Asynchronous DifficultyMedium Python
This Python program finds the sum of the even-numbered elements in a list. For example, given the input list [1, 2, 3, 4, 5], the program would output 6.
About this solution: The candidate's solution is complete and solves the problem. The candidate's approach is efficient, using the modulo operator to check if a number is even.
Jan 31
Databases / SQL DifficultyHard SQL
This technical problem asks the reader to write a SQL query to find the top 10 customers by total spend. The table of customer data is provided as an example, and the expected output is also provided.
About this solution: The candidate's solution is correct and demonstrates a good understanding of SQL. The solution is optimal, using the ORDER BY and LIMIT clauses to sort the table by total_spend in descending order and then limit the results to the top 10 customers.
Jan 31
Python / Asynchronous DifficultyMedium Python
This problem is about returning a list of odd numbers from a given list of integers. For example, given the input list [1, 2, 3, 4, 5], the output would be [1, 3, 5].
About this solution: This solution is correct and demonstrates a good understanding of list comprehensions.
Jan 30