void *insert()//插入课程信息
{
SUB *ptr,*subj;
int size=sizeof(SUB);
char ch,ch1;
while(ch!='0')
{
subj=(SUB *)malloc(size);
ptr=subj;
printf("输入要插入的课程信息:\n");
printf("\n\t\t请输入课程编号:");scanf("%d",&subj->num);
printf("\n\t\t请输入课程名称:");scanf("%s",&subj->name);
printf("\n\t\t请输入课程性质:");scanf("%s",&subj->kind);
printf("\n\t\t请输入总学时:");scanf("%d",&subj->stime);
printf("\n\t\t请输入授课学时:");scanf("%d",&subj->ttime);
printf("\n\t\t请输入实验或上机学时:");scanf("%d",&subj->etime);
printf("\n\t\t请输入学分:");scanf("%d",&subj->score);
printf("\n\t\t请输入开课学期:");scanf("%d",&subj->term);
myInsert(subj);
printf("\n添加完毕,新信息存入文件中\n");
printf("\n继续插入请按回车\n");
printf("\n结束添加课程按 0: [ ]\b\b");
ch1=getchar();
ch=getchar();
}
return head;
}
int size=sizeof(SUB); subj=(SUB *)malloc(size); 能帮忙解释一下这两句的作用吗