stephanieshong / interview-exercises

An ad hoc repository for developing and administering questions related to software engineering and data analysis.

Interview exercises

A repository for developing and administering exercises related to software engineering and data analysis.

Instructions here are only loosely described and how you solve the problem is open-ended. This is in done to test your current abilities, and/or ability to search online, find, and implement solutions.

Rules

1. Pick a problem and follow the steps.
2. You'll be given an amount of time to complete the exercise. Complete it by that time.
3. You can search online as much as you want.
4. You can use any language or library.

Steps

1. Fork this repository.
2. Write out and commit code that solves the problem.
3. Describe what you did, either/both (a) comments throughout your code, (b) a summary. If (b), you can write it in the pull request, or as a block of text somewhere in your code.
4. Make a pull request with your solution.

If you can solve the problem, but are having issues with Git/GitHub, you can zip your code and submit your solution via email to [email protected].

Available problems

There's only one problem available to work on right now.

1. Common values

This exercise is in 1_common_values/:

• input/: Contains input files.
• solution.py: A placeholder file is here for you. If you're using Python, you can start editing this file. If you're using another language, you can delete this file and replace it with a file type corresponding to a language of your choice. If you want to split up your code into multiple modular files, that is fine too.

The input/ directory has two files, a.csv and b.csv. Both files have only 1 column, id. The idea here is that there are 2 different datasets, a and b, and values in the id column represent identifiers for entities in those datasets.

Mostly, the members of each dataset are different. Howeer, they do have some common members. Additionally, some members are listed multiple times within a dataset. For example, in b.csv, member with ID 264731 appears twice.

Your goal is to produce a table of results that show all of the IDs that exist in either set, and show how many times they appear in each set.

Bonus kudos points if the id column is sorted (either ascending or descending is fine).

id	a	b
264731	1	2

You can either (a) output this table as a CSV file and commit it, or (b) simply have your script print out the table to the console when it runs. If (b), you can print it out using whatever formatting you like, so long as it's readable.