Collections in Java: interview exercises

Collections in Java: 6 test-checked interview exercises (Remove duplicates, keep the order), each beside a worked example, with tests as you go. Free.

1. Remove duplicates, keep the order
2. Group words by length
3. Balanced brackets
4. The k largest numbers
5. An LRU cache
6. Merge two count maps

Each exercise pairs a worked example with a twin problem to solve in a real editor; the tests run the moment you do. Progress is saved in your browser, and in your account if you sign in.

More Java topics

• Strings
• Streams & lambdas
• Records, classes & interfaces
• Generics & Optional
• Exceptions & validation
• Algorithms & recursion
• Modern Java

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