Siemens Gamesa Renewable Power Private Limited Jr. Data Scientist Interview Questions and Answers

Implement a data structure to select a user in a database based on username in the fastest way possible.

• Use a hash table to store usernames as keys and corresponding user data as values.

• Hash function should be efficient and avoid collisions.

• Lookup time will be O(1) using hash table.

An SQL query to select all users with the same birthday.

• Use the SELECT statement to retrieve the required data.

• Group the data by the birthday column.

• Filter the groups with more than one user to find users with the same birthday.