Is Find Candidates for Data Scientist Position easy or hard?

Find Candidates for Data Scientist Position is classified as an Easy database problem. It mainly tests understanding of SQL filtering, grouping, and aggregation rather than complex algorithms.

Find Candidates for Data Scientist Position Python/Java solution

This problem is a SQL database problem rather than an algorithm implemented in Python or Java. The solution is written as a SQL query using filtering, GROUP BY, and HAVING to verify that each candidate has the required skills.

How to solve Find Candidates for Data Scientist Position in O(n)?

Filter the table to only the required skills using a WHERE clause, then group rows by candidate_id. Use HAVING COUNT(DISTINCT skill) = 3 to ensure the candidate possesses all required skills. This approach processes each row once and aggregates results efficiently.

What is the best approach for Find Candidates for Data Scientist Position?

The best approach uses conditional filtering with GROUP BY aggregation. Filter rows to the required skills (Python, Tableau, PostgreSQL), group by candidate_id, and ensure COUNT(DISTINCT skill) equals 3. This scans the table once and efficiently verifies that each candidate has all required skills.

Is Find Candidates for Data Scientist Position asked at Google/Amazon/Meta?

Database filtering and aggregation problems like this commonly appear in SQL interview rounds at companies such as Amazon, Meta, and data-focused roles at Google. The pattern of validating multiple required attributes using GROUP BY and HAVING is frequently tested.

What data structure is used in Find Candidates for Data Scientist Position?

The solution relies on relational database operations rather than traditional data structures. SQL grouping and aggregation functions such as GROUP BY and COUNT(DISTINCT) act like a hash-based grouping mechanism internally within the database engine.

What is the time complexity of Find Candidates for Data Scientist Position?

The optimal SQL solution runs in O(n) time where n is the number of rows in the Candidates table. The database performs a single scan with filtering and aggregation using GROUP BY. Space complexity is O(1) aside from the query result.

3051. Find Candidates for Data Scientist Position - Practice Online

Table: Candidates

+--------------+---------+ 
| Column Name  | Type    | 
+--------------+---------+ 
| candidate_id | int     | 
| skill        | varchar |
+--------------+---------+
(candidate_id, skill) is the primary key (columns with unique values) for this table.
Each row includes candidate_id and skill.

Write a query to find the candidates best suited for a Data Scientist position. The candidate must be proficient in Python, Tableau, and PostgreSQL.

Return the result table ordered by candidate_id in ascending order.

The result format is in the following example.

Example 1:

Input: 
Candidates table:
+---------------+--------------+
| candidate_id  | skill        | 
+---------------+--------------+
| 123           | Python       |
| 234           | R            | 
| 123           | Tableau      | 
| 123           | PostgreSQL   | 
| 234           | PowerBI      | 
| 234           | SQL Server   | 
| 147           | Python       | 
| 147           | Tableau      | 
| 147           | Java         |
| 147           | PostgreSQL   |
| 256           | Tableau      |
| 102           | DataAnalysis |
+---------------+--------------+
Output: 
+--------------+
| candidate_id |  
+--------------+
| 123          |  
| 147          | 
+--------------+
Explanation: 
- Candidates 123 and 147 possess the necessary skills in Python, Tableau, and PostgreSQL for the data scientist position.
- Candidates 234 and 102 do not possess any of the required skills for this position.
- Candidate 256 has proficiency in Tableau but is missing skills in Python and PostgreSQL.
The output table is sorted by candidate_id in ascending order.