improve zig-zag-pattern

[r4lly99]

• Simplified the logic by using row-by-row traversal with direct index calculations for efficiency
• Added Javadoc documentation for clarity.

• 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 code is formatted with clang-format -i --style=file path/to/your/file.java

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 73.76%. Comparing base (1e6ed97) to head (b648bf7).

Additional details and impacted files

@@             Coverage Diff              @@
##             master    #6128      +/-   ##
============================================
- Coverage     73.78%   73.76%   -0.03%     
  Complexity     5119     5119              
============================================
  Files           658      658              
  Lines         17632    17616      -16     
  Branches       3391     3390       -1     
============================================
- Hits          13010    12994      -16     
+ Misses         4118     4117       -1     
- Partials        504      505       +1     

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[siriak]

Looks good, thanks!