College of Computer Science Sichuan University Chengdu 610041 China;
Chengdu Jincheng College Chengdu 611731 China;
College of Computer Science Sichuan University Chengdu 610041 China;
Editorial Department of Journal of Sichuan University(Engineering Science Edition) Chengdu 610065 China;
College of Computer Science Sichuan University Chengdu 610041 China;
Chengdu Wuhou Experimental Middle School Chengdu 611043 China;