Read yelp2018 dataset done! u_num: 31668, i_num: 38048
Load a pre-trained model
 UL AUC before unlearning: 0.5026
ACC AUC before unlearning: 0.8844
NDCG@20 before unlearning: 0.0278
Start phantom user assignment k-means!
Finish phantom user assignment k-means!
