Core Java – Arrays

A small collection of Core Java array practice problems and example solutions. This repo contains beginner-friendly implementations grouped by approach (two-pointers, brute-force, 2D array exercises, sliding window, etc.).

What you'll find

• Practice problems implemented in plain Java (.java files).
• Example categories:
  • Two pointers
  • Brute-force approaches
  • Sliding window
  • 2D array exercises (matrix addition, transpose, multiplication)

Repository structure (important folders)

• Arrays/ — core array examples and exercises
  • 2D_Array/ — matrix and 2D-array problems
  • Brute_Force_Approach/ — straightforward solutions
  • Sliding_Window/ — sliding-window examples
  • Two pointers/ — two-pointer technique problems

Examples include: SortArray.java, RotateArray.java, PrimeArray.java, MaxSumSubarray.java, MatrixMultiplication.java, and more.

Quick: compile & run a file

Open a terminal (PowerShell) in the repository root or the specific folder and run:

# compile
javac Arrays\SortArray.java

# run (use the class name without .java)
java Arrays.SortArray

If a file is inside a package or the package statement is used, adjust the commands accordingly or compile from the project root respecting the package path.

Contributing

• Feel free to open issues for bugs or suggested problems.
• Pull requests are welcome. Keep solutions simple and add comments where helpful.
• If adding multiple new exercises, include a brief README in the folder describing the new content.

License & Notes

This repository is intended for learning and practice. If you reuse code in other projects, please attribute or fork as appropriate.

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Happy coding! 🧑‍💻