[hardikkaurani]

• I have read CONTRIBUTING.md.
• This pull request is all my own work -- I have not plagiarized it.
• All filenames are in PascalCase.
• All functions and variable names follow Java naming conventions.
• All new algorithms have a URL in their comments that points to Wikipedia or other similar explanations.
• All new algorithms include a corresponding test class that validates their functionality.
• All new code is formatted with clang-format -i --style=file path/to/your/file.java

Description

This pull request adds null safety, empty matrix handling, and marks RowColumnWiseSorted2dArrayBinarySearch final:

1. Null and Empty Input Validation: Added guards against matrix == null, empty 2D array (matrix.length == 0), empty first row (matrix[0].length == 0), and target == null, returning {-1, -1} safely.
2. Jagged/Null Row Safety: Inside the pointer iteration loop, verified that each row is non-null and that colPointer < matrix[rowPointer].length before reading elements to prevent NullPointerException and ArrayIndexOutOfBoundsException.
3. Class Modifier: Marked public final class RowColumnWiseSorted2dArrayBinarySearch.
4. Expanded Tests: Added unit tests covering null matrix, empty 2D array, matrix with empty first row, null target, matrix containing a null row, and verifying the find() interface method.

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[hardikkaurani]

Hi @DenizAltunkapan,

Could you please review this pull request when you have a moment?

Summary of Changes

• Null and Empty Input Handling: Added null and empty boundary checks in RowColumnWiseSorted2dArrayBinarySearch.search() to safely return {-1, -1} for null or empty inputs.
• Ragged Array Safety: Added guards against null or shorter rows during pointer traversal in search() to prevent invalid index access.
• Class Visibility: Declared RowColumnWiseSorted2dArrayBinarySearch as public final.
• Test Coverage: Added unit tests covering null inputs, empty matrices, jagged arrays, and interface validation.

Test Results

• RowColumnWiseSorted2dArrayBinarySearchTest: 25 passed, 0 failed, 0 skipped (BUILD SUCCESS).
• Formatted the changes using clang-format in accordance with project conventions.

Thank you for your time and consideration!

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 82.28%. Comparing base (8b49bc5) to head (a3fa5fc).
⚠️ Report is 6 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff              @@
##             master    #7725      +/-   ##
============================================
+ Coverage     82.23%   82.28%   +0.05%     
- Complexity     8402     8418      +16     
============================================
  Files           843      843              
  Lines         26140    26148       +8     
  Branches       5100     5103       +3     
============================================
+ Hits          21495    21516      +21     
+ Misses         3853     3840      -13     
  Partials        792      792              

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[Copilot]

🟡 Changes recommended

The search skips valid elements in shorter rows, causing existing targets to be reported as absent; it needs corrected handling and a regression test.

1 open issue

• Search shorter rows when the current column is out of bounds · New

_{Review effort: Balanced}

[DenizAltunkapan]

@hardikkaurani please check this

The null and empty input handling is a useful improvement. However, we found a correctness issue with the newly added support for jagged arrays.

Consider the following example:

Integer[][] matrix = {
    {1, 4, 7},
    {5}
};

Searching for 5 returns {-1, -1} instead of {1, 0} because the new bounds check skips the second row entirely when colPointer exceeds its length.

The current staircase search algorithm assumes a rectangular matrix with rows and columns sorted in ascending order. Supporting jagged arrays requires additional consideration to preserve correctness.

I would suggest keeping this PR focused on null and empty input validation for rectangular matrices, rather than introducing partial support for jagged arrays.

Please also add a regression test for the case above if jagged arrays are intended to be supported.

Thanks!

[hardikkaurani]

Agreed just making some changes !

[hardikkaurani]

Updated as suggested! Removed the partial jagged array checks to keep the implementation strictly focused on null and empty input validation for rectangular matrices, and replaced the jagged test with a null-first-row boundary test ({null}).

[hardikkaurani]

Hi @DenizAltunkapan,

I have updated the PR following your feedback:

• Removed the partial jagged array checks from the search loop so the algorithm stays strictly focused on rectangular row- and column-wise sorted matrices.
• Retained the null and empty input guards (matrix == null, matrix.length == 0, matrix[0] == null, matrix[0].length == 0, and arget == null).
• Replaced the null-row test case with a boundary test for a null-first-row matrix ({null}).
• Ran tests and formatted files with clang-format. All 25 tests pass cleanly.

Please let me know if everything looks good or if any further adjustments are needed. Thank you!