@article{ahierarchicaloptimizerforrecommendation,
  title = {A Hierarchical Optimizer for Recommendation System Based on Shortest Path Algorithm},
  author = {Jiacheng Dai and Zhifeng Jia and Xiaofeng Gao and Guihai Chen},
  year = {2019},
  eprint = {1911.08994},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/1911.08994v1},
}