eigen_svec_t eigen_feature_mapper::convertc(const common::sfv_t& src) const {
  eigen_svec_t ret(d_);
  for (common::sfv_t::const_iterator it = src.begin(); it != src.end(); ++it) {
    insertc(*it, ret);
  }
  return ret;
}
void managementc()//课程管理主函数
{
    struct couse * incouse;
    int i,num1;
    printf("\t\t\t课程管理\n");
    printf("1.新增课程\n");
    printf("2.删除课程\n");
    printf("3.返回主菜单\n");
    printf("请选择(1~3):\n");
    scanf("%d",&i);
    switch(i)
    {
        case(1):
        {
            incouse=(struct couse *)malloc(sizeof(struct couse));
            printf("课程编号\t课程名称\t学分\t课程人数上限\n");
            scanf("%d%s%d%d",&incouse->num1,incouse->name1,&incouse->score,&incouse->Melepeo);
            incouse->nelepeo=0;
            insertc(incouse);
            break;
        }
        case(2):
        {
            printf("请输入要删除课程的编号:\n");
            scanf("%d",&num1);
            delc(num1);
            break;
        }
        case(3):break;
    }
}