Lloyd is not the fastest algorithm for k-means for very long time. I am curious how e-means compares with more advanced algorithms such as BBD-tree based implementation. SMILE has a k-means implementation with both BBD-tree and llyod algorithm. BBD-tree approach is often 10x faster. Wonder if e-means is better than BBD-tree.

See https://www.aihalo.dev/api/java/smile/clustering/KMeans and https://www.aihalo.dev/api/java/smile/clustering/BBDTree

Maybe we combine the ideas of e-means and BBD-tree?