方便的管理学生的空闲时间，制作一个空闲时间表，程序设计了自动保存功能，录入学生的课表，生成空闲时间表，用链表储存数据-Facilitate the management of student free time, make a free schedule, the program is designed auto-save feature, enter the student curriculum, generate free time schedule, with chain store da