为什么下面代码没让输入Y/N，进入死循环
            while (1)
            {
                puts("请输入学生的学号：");
                scanf_s("%d",& stu.iNum);
                puts("请输入学生的姓名:");
                scanf_s("%s",,sizeof());
                puts("请输入语文成绩：");
                scanf_s("%f", &stu.China);
                puts("请输入数学成绩：");
                scanf_s("%f", &stu.Math);
                puts("请输入英语成绩：");
                scanf_s("%lf", &stu.English);
                AddInf(stu);
                fflush(stdin);
                puts("是否继续输入(Y/N)");
                char c;
                scanf_s("%c", &c,sizeof(char));
                if (c == 'y')
                    continue;
                else
                    break;
            }

怎么加啊，能不能贴个图。谢谢。