fix(MiniMaxAlgorithm): correct power-of-2 validation and log2 handling + add unit tests

[Harsh-dubey-git]

Description

This PR fixes a bug in MiniMaxAlgorithm.java related to incorrect validation of power-of-2 array lengths in the setScores() method and improves edge case handling in the log2() method. Additionally, it adds a comprehensive JUnit 5 test suite to verify correctness and prevent future regressions.

Changes Made

1. setScores()

   • Added validation for null and empty arrays.
   • Correctly checks that the array length is a power of 2 using (length & (length - 1)) == 0.
   • Throws IllegalArgumentException for invalid inputs.

2. log2()

   • Handles invalid inputs (0 or negative numbers) safely.
   • Recursively calculates log2 for valid power-of-2 integers.
   • Optionally throws exceptions for non-power-of-2 numbers (ensures robustness).

3. Unit Tests

   • MiniMaxAlgorithmTest.java includes tests for:
     • Valid and invalid setScores() inputs.
     • Edge cases and invalid inputs for log2().
     • Correct miniMax() computation for deterministic score arrays.
   • Uses reflection to test private log2() method.
   • Ensures proper array lengths, heights, and exception handling.

4. Other Improvements

   • Tests verify the algorithm behaves correctly for maximizer and minimizer scenarios.
   • Helps prevent regressions for future contributors.