Class Design Problems

Candidates often describe Chewy screens as focused on object-oriented programming. You get a class to build with a few methods and some rules, and it has to run. Senior candidates have built these in one-hour rounds, and a Java screen opened with a class that had to stay safe across threads.

Each problem runs as a list of method calls against your class, so a bad call has to leave the object exactly as it was.

The warehouse and parking lot classes in OO Design & Debugging use the same template. State lives on one object, and each method checks its inputs before it changes that state. Every class below adds one idea on top of that, from a heap merge to a lock.

ChewyPremium lesson · Coding round

The 3 Chewy problems are below.

1. 1A Premium questionCoding · Medium
2. 2A Premium questionCoding · Medium
3. 3A Premium questionCoding · Easy

Each with hints, the follow-up and a tested solution.

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