作者机构:[1]School of Computer and Information Technology, Beijing Jiaotong University, Beijing 100044, China, [2]Department of Mathematics, Hong Kong Baptist University, Hong Kong, China
相关基金:Acknowledgments. The authors would like to thank Jianfeng Cai for providing the codes of [10,11]. The authors also thank the anonymous reviewers for their extremely useful suggestions for improving the quality of the paper. This work is partially supported by NSFC 11271049, NSFC. 61033013, RGC 211710, RGC 211911, RGC 201812 and the FRGs of Hong Kong Baptist University.