I received a call from a recruiter for a screening round. They asked about my experience and tested my data structure and algorithm knowledge with some basic questions, such as "What is a hash table?"

In the second round, there was a programming interview on HackerRank CodePair with three engineers from Amsterdam.

I was given the following question to solve in 30 minutes.

Based on customer research, we know that our guests get confused when searching for accommodation and find multiple hotels with the same name in the same city.

To avoid this, we want to create a tool to identify "confusing" cities: cities with at least 3 hotels with the same name.

Given a list of tuples (hotel_id, hotel_name, city), return a list of all "confusing" cities.

Input: [ {hotel_1234, "Sheraton", "Amsterdam"}, {hotel_1000, "Sheraton", "Buenos Aires"}, {hotel_1001, "Hilton", "Amsterdam"}, {hotel_1002, "Royal Palace", "Bogota"}, {hotel_1003, "Hilton", "Amsterdam"}, {hotel_1004, "Sheraton", "Buenos Aires"}, {hotel_1005, "Sheraton", "Buenos Aires"} ]

Output: [ "Buenos Aires" ]