项目内容：
大学的每个专业都要进行排课。假设任何专业都有固定的学习年限，每学年含两学期，每个专业开设的课程都是确定的，而且课程在开设时间的安排必须满足先修关系。每门课程有哪些先修课程是确定的。每门课恰好占一个学期，假定每天上午与下午各有5节课。是在这样的前提下设计一个教学计划编制程序。

项目功能要求：
1输入数据包括：个学期所开的课程数（必须使每学期所开的课程数之和与课程总数相等），课程编号，课程名称，周学时数，指定开课学期，先决条件。如指定开课学期为0，表示有电脑自行指定开课学期。
2如输入数据不合理，比如每学期所开的课程数值和与课程总数不相等，应显示适当的提示信息。
3用文本文件存储输入数据，并且读入计算机。
4用文本文件存储产生的各学期的课表。(Project content:

Every major in the university has to arrange courses. Assuming that any major has a fixed number of years of study, each academic year contains two semesters, and the courses offered by each major are determined, and the arrangement of the course opening time must meet the prerequisite relationship. Which prerequisite courses are determined for each course. Each course takes up exactly one semester. Suppose there are five classes in the morning and five in the afternoon. Is in such a premise to design a teaching plan programming.)