1. Removed the Boost dependency by adopting a newer cut-pursuit version from the authors (resulting in a 5–15× speed improvement).
2. Fixed an issue with the nearest neighbor search caused by an incorrect 2D array order input to the knn_cpp query function.
3. Enabled customization of the number of threads for knn-cpp, yielding a slight speed improvement.
4. Optimized array calculations through enhanced use of STL algorithms.