Add edge case to handle negative rod length in RodCutting algorithm

[Chiefpatwal]

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Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 66.88%. Comparing base (69a1424) to head (7478547).

Additional details and impacted files

@@            Coverage Diff            @@
##             master    #5904   +/-   ##
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  Coverage     66.88%   66.88%           
- Complexity     4516     4517    +1     
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  Files           613      613           
  Lines         16994    16996    +2     
  Branches       3281     3282    +1     
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+ Hits          11366    11368    +2     
  Misses         5181     5181           
  Partials        447      447           

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[Chiefpatwal]

I’ve made some updates to the RodCutting algorithm to handle an edge case where the length of the rod is negative. Previously, the code didn’t account for this situation, which could lead to unexpected behavior.

Now, I’ve added an IllegalArgumentException to ensure that if a negative rod length is passed, it throws a clear error message, preventing any further calculations. This change should enhance the robustness of the algorithm.

Additionally, I've implemented a test case for this scenario, and it’s working correctly to validate the expected behavior.