1. School of Mathematics and Computational Science, Xiangtan University, Xiangtan, Hunan 411105, China
2. Feidong Shengquan Middle School, Feidong, Anhui 231600, China
3. Center for Applied Mathematics of Guangxi, Guangxi Colleges and Universities Key Laboratory of Complex System Optimization and Big Data Processing, Yulin Normal University, Yulin, Guangxi 537000, China