return right - left + 1;
GBDT (tree-boosting algorithm): 1.1x-1.5x faster fit/predict than the treeboost Rust crate2, 24-42x faster fit/1-5x faster predict than Python’s xgboost，详情可参考im钱包官方下载
优点： 更平滑、更稳定，效果普遍优于 ReLU。，更多细节参见爱思助手下载最新版本
elements in the channel, you’ll see that you didn’t reduce the number